diff options
Diffstat (limited to 'libexec/rtld-elf/rtld.c')
| -rw-r--r-- | libexec/rtld-elf/rtld.c | 6737 |
1 files changed, 6737 insertions, 0 deletions
diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c new file mode 100644 index 000000000000..d27af520c21d --- /dev/null +++ b/libexec/rtld-elf/rtld.c @@ -0,0 +1,6737 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. + * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. + * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. + * Copyright 2012 John Marino <draco@marino.st>. + * Copyright 2014-2017 The FreeBSD Foundation + * All rights reserved. + * + * Portions of this software were developed by Konstantin Belousov + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * Dynamic linker for ELF. + * + * John Polstra <jdp@polstra.com>. + */ + +#include <sys/param.h> +#include <sys/ktrace.h> +#include <sys/mman.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/sysctl.h> +#include <sys/uio.h> +#include <sys/utsname.h> + +#include <dlfcn.h> +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "debug.h" +#include "libmap.h" +#include "notes.h" +#include "rtld.h" +#include "rtld_libc.h" +#include "rtld_malloc.h" +#include "rtld_paths.h" +#include "rtld_printf.h" +#include "rtld_tls.h" +#include "rtld_utrace.h" + +/* Types. */ +typedef void (*func_ptr_type)(void); +typedef void *(*path_enum_proc)(const char *path, size_t len, void *arg); + +/* Variables that cannot be static: */ +extern struct r_debug r_debug; /* For GDB */ +extern int _thread_autoinit_dummy_decl; +extern void (*__cleanup)(void); + +struct dlerror_save { + int seen; + char *msg; +}; + +struct tcb_list_entry { + TAILQ_ENTRY(tcb_list_entry) next; +}; + +/* + * Function declarations. + */ +static bool allocate_tls_offset_common(size_t *offp, size_t tlssize, + size_t tlsalign, size_t tlspoffset); +static const char *basename(const char *); +static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, + const Elf_Dyn **, const Elf_Dyn **); +static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, + const Elf_Dyn *); +static bool digest_dynamic(Obj_Entry *, int); +static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); +static void distribute_static_tls(Objlist *); +static Obj_Entry *dlcheck(void *); +static int dlclose_locked(void *, RtldLockState *); +static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, + int lo_flags, int mode, RtldLockState *lockstate); +static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); +static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); +static bool donelist_check(DoneList *, const Obj_Entry *); +static void dump_auxv(Elf_Auxinfo **aux_info); +static void errmsg_restore(struct dlerror_save *); +static struct dlerror_save *errmsg_save(void); +static void *fill_search_info(const char *, size_t, void *); +static char *find_library(const char *, const Obj_Entry *, int *); +static const char *gethints(bool); +static void hold_object(Obj_Entry *); +static void unhold_object(Obj_Entry *); +static void init_dag(Obj_Entry *); +static void init_marker(Obj_Entry *); +static void init_pagesizes(Elf_Auxinfo **aux_info); +static void init_rtld(caddr_t, Elf_Auxinfo **); +static void initlist_add_neededs(Needed_Entry *, Objlist *, Objlist *); +static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *, + Objlist *); +static void initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, + Objlist *list); +static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); +static void linkmap_add(Obj_Entry *); +static void linkmap_delete(Obj_Entry *); +static void load_filtees(Obj_Entry *, int flags, RtldLockState *); +static void unload_filtees(Obj_Entry *, RtldLockState *); +static int load_needed_objects(Obj_Entry *, int); +static int load_preload_objects(const char *, bool); +static int load_kpreload(const void *addr); +static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); +static void map_stacks_exec(RtldLockState *); +static int obj_disable_relro(Obj_Entry *); +static int obj_enforce_relro(Obj_Entry *); +static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); +static void objlist_call_init(Objlist *, RtldLockState *); +static void objlist_clear(Objlist *); +static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); +static void objlist_init(Objlist *); +static void objlist_push_head(Objlist *, Obj_Entry *); +static void objlist_push_tail(Objlist *, Obj_Entry *); +static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); +static void objlist_remove(Objlist *, Obj_Entry *); +static int open_binary_fd(const char *argv0, bool search_in_path, + const char **binpath_res); +static int parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, + const char **argv0, bool *dir_ignore); +static int parse_integer(const char *); +static void *path_enumerate(const char *, path_enum_proc, const char *, void *); +static void print_usage(const char *argv0); +static void release_object(Obj_Entry *); +static int relocate_object_dag(Obj_Entry *root, bool bind_now, + Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); +static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, + int flags, RtldLockState *lockstate); +static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, + RtldLockState *); +static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); +static int rtld_dirname(const char *, char *); +static int rtld_dirname_abs(const char *, char *); +static void *rtld_dlopen(const char *name, int fd, int mode); +static void rtld_exit(void); +static void rtld_nop_exit(void); +static char *search_library_path(const char *, const char *, const char *, + int *); +static char *search_library_pathfds(const char *, const char *, int *); +static const void **get_program_var_addr(const char *, RtldLockState *); +static void set_program_var(const char *, const void *); +static int symlook_default(SymLook *, const Obj_Entry *refobj); +static int symlook_global(SymLook *, DoneList *); +static void symlook_init_from_req(SymLook *, const SymLook *); +static int symlook_list(SymLook *, const Objlist *, DoneList *); +static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); +static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); +static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); +static void *tls_get_addr_slow(struct tcb *, int, size_t, bool) __noinline; +static void trace_loaded_objects(Obj_Entry *, bool); +static void unlink_object(Obj_Entry *); +static void unload_object(Obj_Entry *, RtldLockState *lockstate); +static void unref_dag(Obj_Entry *); +static void ref_dag(Obj_Entry *); +static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, + bool); +static char *origin_subst(Obj_Entry *, const char *); +static bool obj_resolve_origin(Obj_Entry *obj); +static void preinit_main(void); +static int rtld_verify_versions(const Objlist *); +static int rtld_verify_object_versions(Obj_Entry *); +static void object_add_name(Obj_Entry *, const char *); +static int object_match_name(const Obj_Entry *, const char *); +static void ld_utrace_log(int, void *, void *, size_t, int, const char *); +static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, + struct dl_phdr_info *phdr_info); +static uint32_t gnu_hash(const char *); +static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, + const unsigned long); + +void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; +void _r_debug_postinit(struct link_map *) __noinline __exported; + +int __sys_openat(int, const char *, int, ...); + +/* + * Data declarations. + */ +struct r_debug r_debug __exported; /* for GDB; */ +static bool libmap_disable; /* Disable libmap */ +static bool ld_loadfltr; /* Immediate filters processing */ +static const char *libmap_override; /* Maps to use in addition to libmap.conf */ +static bool trust; /* False for setuid and setgid programs */ +static bool dangerous_ld_env; /* True if environment variables have been + used to affect the libraries loaded */ +bool ld_bind_not; /* Disable PLT update */ +static const char *ld_bind_now; /* Environment variable for immediate binding */ +static const char *ld_debug; /* Environment variable for debugging */ +static bool ld_dynamic_weak = true; /* True if non-weak definition overrides + weak definition */ +static const char *ld_library_path; /* Environment variable for search path */ +static const char + *ld_library_dirs; /* Environment variable for library descriptors */ +static const char *ld_preload; /* Environment variable for libraries to + load first */ +static const char *ld_preload_fds; /* Environment variable for libraries + represented by descriptors */ +static const char + *ld_elf_hints_path; /* Environment variable for alternative hints path */ +static const char *ld_tracing; /* Called from ldd to print libs */ +static const char *ld_utrace; /* Use utrace() to log events. */ +static struct obj_entry_q obj_list; /* Queue of all loaded objects */ +static Obj_Entry *obj_main; /* The main program shared object */ +static Obj_Entry obj_rtld; /* The dynamic linker shared object */ +static unsigned int obj_count; /* Number of objects in obj_list */ +static unsigned int obj_loads; /* Number of loads of objects (gen count) */ +size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ + RTLD_STATIC_TLS_EXTRA; + +static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ + STAILQ_HEAD_INITIALIZER(list_global); +static Objlist list_main = /* Objects loaded at program startup */ + STAILQ_HEAD_INITIALIZER(list_main); +static Objlist list_fini = /* Objects needing fini() calls */ + STAILQ_HEAD_INITIALIZER(list_fini); + +Elf_Sym sym_zero; /* For resolving undefined weak refs. */ + +#define GDB_STATE(s, m) \ + r_debug.r_state = s; \ + r_debug_state(&r_debug, m); + +extern Elf_Dyn _DYNAMIC; +#pragma weak _DYNAMIC + +int dlclose(void *) __exported; +char *dlerror(void) __exported; +void *dlopen(const char *, int) __exported; +void *fdlopen(int, int) __exported; +void *dlsym(void *, const char *) __exported; +dlfunc_t dlfunc(void *, const char *) __exported; +void *dlvsym(void *, const char *, const char *) __exported; +int dladdr(const void *, Dl_info *) __exported; +void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), + void (*)(void *), void (*)(void *), void (*)(void *)) __exported; +int dlinfo(void *, int, void *) __exported; +int _dl_iterate_phdr_locked(__dl_iterate_hdr_callback, void *) __exported; +int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; +int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; +int _rtld_get_stack_prot(void) __exported; +int _rtld_is_dlopened(void *) __exported; +void _rtld_error(const char *, ...) __exported; +const char *rtld_get_var(const char *name) __exported; +int rtld_set_var(const char *name, const char *val) __exported; + +/* Only here to fix -Wmissing-prototypes warnings */ +int __getosreldate(void); +func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); +Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); + +int npagesizes; +static int osreldate; +size_t *pagesizes; +size_t page_size; + +static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; +static int max_stack_flags; + +/* + * Global declarations normally provided by crt1. The dynamic linker is + * not built with crt1, so we have to provide them ourselves. + */ +char *__progname; +char **environ; + +/* + * Used to pass argc, argv to init functions. + */ +int main_argc; +char **main_argv; + +/* + * Globals to control TLS allocation. + */ +size_t tls_last_offset; /* Static TLS offset of last module */ +size_t tls_last_size; /* Static TLS size of last module */ +size_t tls_static_space; /* Static TLS space allocated */ +static size_t tls_static_max_align; +Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ +int tls_max_index = 1; /* Largest module index allocated */ + +static TAILQ_HEAD(, tcb_list_entry) tcb_list = + TAILQ_HEAD_INITIALIZER(tcb_list); +static size_t tcb_list_entry_offset; + +static bool ld_library_path_rpath = false; +bool ld_fast_sigblock = false; + +/* + * Globals for path names, and such + */ +const char *ld_elf_hints_default = _PATH_ELF_HINTS; +const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; +const char *ld_path_rtld = _PATH_RTLD; +const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; +const char *ld_env_prefix = LD_; + +static void (*rtld_exit_ptr)(void); + +/* + * Fill in a DoneList with an allocation large enough to hold all of + * the currently-loaded objects. Keep this as a macro since it calls + * alloca and we want that to occur within the scope of the caller. + */ +#define donelist_init(dlp) \ + ((dlp)->objs = alloca(obj_count * sizeof(dlp)->objs[0]), \ + assert((dlp)->objs != NULL), (dlp)->num_alloc = obj_count, \ + (dlp)->num_used = 0) + +#define LD_UTRACE(e, h, mb, ms, r, n) \ + do { \ + if (ld_utrace != NULL) \ + ld_utrace_log(e, h, mb, ms, r, n); \ + } while (0) + +static void +ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, + int refcnt, const char *name) +{ + struct utrace_rtld ut; + static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; + + memset(&ut, 0, sizeof(ut)); /* clear holes */ + memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); + ut.event = event; + ut.handle = handle; + ut.mapbase = mapbase; + ut.mapsize = mapsize; + ut.refcnt = refcnt; + if (name != NULL) + strlcpy(ut.name, name, sizeof(ut.name)); + utrace(&ut, sizeof(ut)); +} + +struct ld_env_var_desc { + const char *const n; + const char *val; + const bool unsecure : 1; + const bool can_update : 1; + const bool debug : 1; + bool owned : 1; +}; +#define LD_ENV_DESC(var, unsec, ...) \ + [LD_##var] = { .n = #var, .unsecure = unsec, __VA_ARGS__ } + +static struct ld_env_var_desc ld_env_vars[] = { + LD_ENV_DESC(BIND_NOW, false), + LD_ENV_DESC(PRELOAD, true), + LD_ENV_DESC(LIBMAP, true), + LD_ENV_DESC(LIBRARY_PATH, true, .can_update = true), + LD_ENV_DESC(LIBRARY_PATH_FDS, true, .can_update = true), + LD_ENV_DESC(LIBMAP_DISABLE, true), + LD_ENV_DESC(BIND_NOT, true), + LD_ENV_DESC(DEBUG, true, .can_update = true, .debug = true), + LD_ENV_DESC(ELF_HINTS_PATH, true), + LD_ENV_DESC(LOADFLTR, true), + LD_ENV_DESC(LIBRARY_PATH_RPATH, true, .can_update = true), + LD_ENV_DESC(PRELOAD_FDS, true), + LD_ENV_DESC(DYNAMIC_WEAK, true, .can_update = true), + LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), + LD_ENV_DESC(UTRACE, false, .can_update = true), + LD_ENV_DESC(DUMP_REL_PRE, false, .can_update = true), + LD_ENV_DESC(DUMP_REL_POST, false, .can_update = true), + LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), + LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), + LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), + LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), + LD_ENV_DESC(SHOW_AUXV, false), + LD_ENV_DESC(STATIC_TLS_EXTRA, false), + LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false), +}; + +const char * +ld_get_env_var(int idx) +{ + return (ld_env_vars[idx].val); +} + +static const char * +rtld_get_env_val(char **env, const char *name, size_t name_len) +{ + char **m, *n, *v; + + for (m = env; *m != NULL; m++) { + n = *m; + v = strchr(n, '='); + if (v == NULL) { + /* corrupt environment? */ + continue; + } + if (v - n == (ptrdiff_t)name_len && + strncmp(name, n, name_len) == 0) + return (v + 1); + } + return (NULL); +} + +static void +rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) +{ + struct ld_env_var_desc *lvd; + size_t prefix_len, nlen; + char **m, *n, *v; + int i; + + prefix_len = strlen(env_prefix); + for (m = env; *m != NULL; m++) { + n = *m; + if (strncmp(env_prefix, n, prefix_len) != 0) { + /* Not a rtld environment variable. */ + continue; + } + n += prefix_len; + v = strchr(n, '='); + if (v == NULL) { + /* corrupt environment? */ + continue; + } + for (i = 0; i < (int)nitems(ld_env_vars); i++) { + lvd = &ld_env_vars[i]; + if (lvd->val != NULL) { + /* Saw higher-priority variable name already. */ + continue; + } + nlen = strlen(lvd->n); + if (v - n == (ptrdiff_t)nlen && + strncmp(lvd->n, n, nlen) == 0) { + lvd->val = v + 1; + break; + } + } + } +} + +static void +rtld_init_env_vars(char **env) +{ + rtld_init_env_vars_for_prefix(env, ld_env_prefix); +} + +static void +set_ld_elf_hints_path(void) +{ + if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) + ld_elf_hints_path = ld_elf_hints_default; +} + +uintptr_t +rtld_round_page(uintptr_t x) +{ + return (roundup2(x, page_size)); +} + +uintptr_t +rtld_trunc_page(uintptr_t x) +{ + return (rounddown2(x, page_size)); +} + +/* + * Main entry point for dynamic linking. The first argument is the + * stack pointer. The stack is expected to be laid out as described + * in the SVR4 ABI specification, Intel 386 Processor Supplement. + * Specifically, the stack pointer points to a word containing + * ARGC. Following that in the stack is a null-terminated sequence + * of pointers to argument strings. Then comes a null-terminated + * sequence of pointers to environment strings. Finally, there is a + * sequence of "auxiliary vector" entries. + * + * The second argument points to a place to store the dynamic linker's + * exit procedure pointer and the third to a place to store the main + * program's object. + * + * The return value is the main program's entry point. + */ +func_ptr_type +_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) +{ + Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT], auxtmp; + Objlist_Entry *entry; + Obj_Entry *last_interposer, *obj, *preload_tail; + const Elf_Phdr *phdr; + Objlist initlist; + RtldLockState lockstate; + struct stat st; + Elf_Addr *argcp; + char **argv, **env, **envp, *kexecpath; + const char *argv0, *binpath, *library_path_rpath, *static_tls_extra; + struct ld_env_var_desc *lvd; + caddr_t imgentry; + char buf[MAXPATHLEN]; + int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; + size_t sz; +#ifdef __powerpc__ + int old_auxv_format = 1; +#endif + bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; + + /* + * On entry, the dynamic linker itself has not been relocated yet. + * Be very careful not to reference any global data until after + * init_rtld has returned. It is OK to reference file-scope statics + * and string constants, and to call static and global functions. + */ + + /* Find the auxiliary vector on the stack. */ + argcp = sp; + argc = *sp++; + argv = (char **)sp; + sp += argc + 1; /* Skip over arguments and NULL terminator */ + env = (char **)sp; + while (*sp++ != 0) /* Skip over environment, and NULL terminator */ + ; + aux = (Elf_Auxinfo *)sp; + + /* Digest the auxiliary vector. */ + for (i = 0; i < AT_COUNT; i++) + aux_info[i] = NULL; + for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { + if (auxp->a_type < AT_COUNT) + aux_info[auxp->a_type] = auxp; +#ifdef __powerpc__ + if (auxp->a_type == 23) /* AT_STACKPROT */ + old_auxv_format = 0; +#endif + } + +#ifdef __powerpc__ + if (old_auxv_format) { + /* Remap from old-style auxv numbers. */ + aux_info[23] = aux_info[21]; /* AT_STACKPROT */ + aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ + aux_info[19] = aux_info[17]; /* AT_NCPUS */ + aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ + aux_info[15] = aux_info[13]; /* AT_EXECPATH */ + aux_info[13] = NULL; /* AT_GID */ + + aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ + aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ + aux_info[16] = aux_info[14]; /* AT_CANARY */ + aux_info[14] = NULL; /* AT_EGID */ + } +#endif + + /* Initialize and relocate ourselves. */ + assert(aux_info[AT_BASE] != NULL); + init_rtld((caddr_t)aux_info[AT_BASE]->a_un.a_ptr, aux_info); + + dlerror_dflt_init(); + + __progname = obj_rtld.path; + argv0 = argv[0] != NULL ? argv[0] : "(null)"; + environ = env; + main_argc = argc; + main_argv = argv; + + if (aux_info[AT_BSDFLAGS] != NULL && + (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) + ld_fast_sigblock = true; + + trust = !issetugid(); + direct_exec = false; + + md_abi_variant_hook(aux_info); + rtld_init_env_vars(env); + + fd = -1; + if (aux_info[AT_EXECFD] != NULL) { + fd = aux_info[AT_EXECFD]->a_un.a_val; + } else { + assert(aux_info[AT_PHDR] != NULL); + phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; + if (phdr == obj_rtld.phdr) { + if (!trust) { + _rtld_error( + "Tainted process refusing to run binary %s", + argv0); + rtld_die(); + } + direct_exec = true; + + dbg("opening main program in direct exec mode"); + if (argc >= 2) { + rtld_argc = parse_args(argv, argc, + &search_in_path, &fd, &argv0, &dir_ignore); + explicit_fd = (fd != -1); + binpath = NULL; + if (!explicit_fd) + fd = open_binary_fd(argv0, + search_in_path, &binpath); + if (fstat(fd, &st) == -1) { + _rtld_error( + "Failed to fstat FD %d (%s): %s", + fd, + explicit_fd ? + "user-provided descriptor" : + argv0, + rtld_strerror(errno)); + rtld_die(); + } + + /* + * Rough emulation of the permission checks done + * by execve(2), only Unix DACs are checked, + * ACLs are ignored. Preserve the semantic of + * disabling owner to execute if owner x bit is + * cleared, even if others x bit is enabled. + * mmap(2) does not allow to mmap with PROT_EXEC + * if binary' file comes from noexec mount. We + * cannot set a text reference on the binary. + */ + dir_enable = false; + if (st.st_uid == geteuid()) { + if ((st.st_mode & S_IXUSR) != 0) + dir_enable = true; + } else if (st.st_gid == getegid()) { + if ((st.st_mode & S_IXGRP) != 0) + dir_enable = true; + } else if ((st.st_mode & S_IXOTH) != 0) { + dir_enable = true; + } + if (!dir_enable && !dir_ignore) { + _rtld_error( + "No execute permission for binary %s", + argv0); + rtld_die(); + } + + /* + * For direct exec mode, argv[0] is the + * interpreter name, we must remove it and shift + * arguments left before invoking binary main. + * Since stack layout places environment + * pointers and aux vectors right after the + * terminating NULL, we must shift environment + * and aux as well. + */ + main_argc = argc - rtld_argc; + for (i = 0; i <= main_argc; i++) + argv[i] = argv[i + rtld_argc]; + *argcp -= rtld_argc; + environ = env = envp = argv + main_argc + 1; + dbg("move env from %p to %p", envp + rtld_argc, + envp); + do { + *envp = *(envp + rtld_argc); + } while (*envp++ != NULL); + aux = auxp = (Elf_Auxinfo *)envp; + auxpf = (Elf_Auxinfo *)(envp + rtld_argc); + dbg("move aux from %p to %p", auxpf, aux); + /* + * XXXKIB insert place for AT_EXECPATH if not + * present + */ + for (;; auxp++, auxpf++) { + /* + * NB: Use a temporary since *auxpf and + * *auxp overlap if rtld_argc is 1 + */ + auxtmp = *auxpf; + *auxp = auxtmp; + if (auxp->a_type == AT_NULL) + break; + } + /* + * Since the auxiliary vector has moved, + * redigest it. + */ + for (i = 0; i < AT_COUNT; i++) + aux_info[i] = NULL; + for (auxp = aux; auxp->a_type != AT_NULL; + auxp++) { + if (auxp->a_type < AT_COUNT) + aux_info[auxp->a_type] = auxp; + } + + /* + * Point AT_EXECPATH auxv and aux_info to the + * binary path. + */ + if (binpath == NULL) { + aux_info[AT_EXECPATH] = NULL; + } else { + if (aux_info[AT_EXECPATH] == NULL) { + aux_info[AT_EXECPATH] = xmalloc( + sizeof(Elf_Auxinfo)); + aux_info[AT_EXECPATH]->a_type = + AT_EXECPATH; + } + aux_info[AT_EXECPATH]->a_un.a_ptr = + __DECONST(void *, binpath); + } + } else { + _rtld_error("No binary"); + rtld_die(); + } + } + } + + ld_bind_now = ld_get_env_var(LD_BIND_NOW); + + /* + * If the process is tainted, then we un-set the dangerous environment + * variables. The process will be marked as tainted until setuid(2) + * is called. If any child process calls setuid(2) we do not want any + * future processes to honor the potentially un-safe variables. + */ + if (!trust) { + for (i = 0; i < (int)nitems(ld_env_vars); i++) { + lvd = &ld_env_vars[i]; + if (lvd->unsecure) + lvd->val = NULL; + } + } + + ld_debug = ld_get_env_var(LD_DEBUG); + if (ld_bind_now == NULL) + ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; + ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; + libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; + libmap_override = ld_get_env_var(LD_LIBMAP); + ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); + ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); + ld_preload = ld_get_env_var(LD_PRELOAD); + ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); + ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); + ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; + library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); + if (library_path_rpath != NULL) { + if (library_path_rpath[0] == 'y' || + library_path_rpath[0] == 'Y' || + library_path_rpath[0] == '1') + ld_library_path_rpath = true; + else + ld_library_path_rpath = false; + } + static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); + if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { + sz = parse_integer(static_tls_extra); + if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) + ld_static_tls_extra = sz; + } + dangerous_ld_env = libmap_disable || libmap_override != NULL || + ld_library_path != NULL || ld_preload != NULL || + ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || + static_tls_extra != NULL; + ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); + ld_utrace = ld_get_env_var(LD_UTRACE); + + set_ld_elf_hints_path(); + if (ld_debug != NULL && *ld_debug != '\0') + debug = 1; + dbg("%s is initialized, base address = %p", __progname, + (caddr_t)aux_info[AT_BASE]->a_un.a_ptr); + dbg("RTLD dynamic = %p", obj_rtld.dynamic); + dbg("RTLD pltgot = %p", obj_rtld.pltgot); + + dbg("initializing thread locks"); + lockdflt_init(); + + /* + * Load the main program, or process its program header if it is + * already loaded. + */ + if (fd != -1) { /* Load the main program. */ + dbg("loading main program"); + obj_main = map_object(fd, argv0, NULL, true); + close(fd); + if (obj_main == NULL) + rtld_die(); + max_stack_flags = obj_main->stack_flags; + } else { /* Main program already loaded. */ + dbg("processing main program's program header"); + assert(aux_info[AT_PHDR] != NULL); + phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; + assert(aux_info[AT_PHNUM] != NULL); + phnum = aux_info[AT_PHNUM]->a_un.a_val; + assert(aux_info[AT_PHENT] != NULL); + assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); + assert(aux_info[AT_ENTRY] != NULL); + imgentry = (caddr_t)aux_info[AT_ENTRY]->a_un.a_ptr; + if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == + NULL) + rtld_die(); + } + + if (aux_info[AT_EXECPATH] != NULL && fd == -1) { + kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; + dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); + if (kexecpath[0] == '/') + obj_main->path = kexecpath; + else if (getcwd(buf, sizeof(buf)) == NULL || + strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || + strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) + obj_main->path = xstrdup(argv0); + else + obj_main->path = xstrdup(buf); + } else { + dbg("No AT_EXECPATH or direct exec"); + obj_main->path = xstrdup(argv0); + } + dbg("obj_main path %s", obj_main->path); + obj_main->mainprog = true; + + if (aux_info[AT_STACKPROT] != NULL && + aux_info[AT_STACKPROT]->a_un.a_val != 0) + stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; + +#ifndef COMPAT_libcompat + /* + * Get the actual dynamic linker pathname from the executable if + * possible. (It should always be possible.) That ensures that + * gdb will find the right dynamic linker even if a non-standard + * one is being used. + */ + if (obj_main->interp != NULL && + strcmp(obj_main->interp, obj_rtld.path) != 0) { + free(obj_rtld.path); + obj_rtld.path = xstrdup(obj_main->interp); + __progname = obj_rtld.path; + } +#endif + + if (!digest_dynamic(obj_main, 0)) + rtld_die(); + dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", + obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, + obj_main->dynsymcount); + + linkmap_add(obj_main); + linkmap_add(&obj_rtld); + LD_UTRACE(UTRACE_LOAD_OBJECT, obj_main, obj_main->mapbase, + obj_main->mapsize, 0, obj_main->path); + LD_UTRACE(UTRACE_LOAD_OBJECT, &obj_rtld, obj_rtld.mapbase, + obj_rtld.mapsize, 0, obj_rtld.path); + + /* Link the main program into the list of objects. */ + TAILQ_INSERT_HEAD(&obj_list, obj_main, next); + obj_count++; + obj_loads++; + + /* Initialize a fake symbol for resolving undefined weak references. */ + sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); + sym_zero.st_shndx = SHN_UNDEF; + sym_zero.st_value = -(uintptr_t)obj_main->relocbase; + + if (!libmap_disable) + libmap_disable = (bool)lm_init(libmap_override); + + if (aux_info[AT_KPRELOAD] != NULL && + aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { + dbg("loading kernel vdso"); + if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) + rtld_die(); + } + + dbg("loading LD_PRELOAD_FDS libraries"); + if (load_preload_objects(ld_preload_fds, true) == -1) + rtld_die(); + + dbg("loading LD_PRELOAD libraries"); + if (load_preload_objects(ld_preload, false) == -1) + rtld_die(); + preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); + + dbg("loading needed objects"); + if (load_needed_objects(obj_main, + ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) + rtld_die(); + + /* Make a list of all objects loaded at startup. */ + last_interposer = obj_main; + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker) + continue; + if (obj->z_interpose && obj != obj_main) { + objlist_put_after(&list_main, last_interposer, obj); + last_interposer = obj; + } else { + objlist_push_tail(&list_main, obj); + } + obj->refcount++; + } + + dbg("checking for required versions"); + if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) + rtld_die(); + + if (ld_get_env_var(LD_SHOW_AUXV) != NULL) + dump_auxv(aux_info); + + if (ld_tracing) { /* We're done */ + trace_loaded_objects(obj_main, true); + exit(0); + } + + if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { + dump_relocations(obj_main); + exit(0); + } + + /* + * Processing tls relocations requires having the tls offsets + * initialized. Prepare offsets before starting initial + * relocation processing. + */ + dbg("initializing initial thread local storage offsets"); + STAILQ_FOREACH(entry, &list_main, link) { + /* + * Allocate all the initial objects out of the static TLS + * block even if they didn't ask for it. + */ + allocate_tls_offset(entry->obj); + } + + if (!allocate_tls_offset_common(&tcb_list_entry_offset, + sizeof(struct tcb_list_entry), _Alignof(struct tcb_list_entry), + 0)) { + /* + * This should be impossible as the static block size is not + * yet fixed, but catch and diagnose it failing if that ever + * changes or somehow turns out to be false. + */ + _rtld_error("Could not allocate offset for tcb_list_entry"); + rtld_die(); + } + dbg("tcb_list_entry_offset %zu", tcb_list_entry_offset); + + if (relocate_objects(obj_main, + ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, + SYMLOOK_EARLY, NULL) == -1) + rtld_die(); + + dbg("doing copy relocations"); + if (do_copy_relocations(obj_main) == -1) + rtld_die(); + + if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { + dump_relocations(obj_main); + exit(0); + } + + ifunc_init(aux_info); + + /* + * Setup TLS for main thread. This must be done after the + * relocations are processed, since tls initialization section + * might be the subject for relocations. + */ + dbg("initializing initial thread local storage"); + allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); + + dbg("initializing key program variables"); + set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); + set_program_var("environ", env); + set_program_var("__elf_aux_vector", aux); + + /* Make a list of init functions to call. */ + objlist_init(&initlist); + initlist_for_loaded_obj(globallist_curr(TAILQ_FIRST(&obj_list)), + preload_tail, &initlist); + + r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ + + map_stacks_exec(NULL); + + if (!obj_main->crt_no_init) { + /* + * Make sure we don't call the main program's init and fini + * functions for binaries linked with old crt1 which calls + * _init itself. + */ + obj_main->init = obj_main->fini = (Elf_Addr)NULL; + obj_main->preinit_array = obj_main->init_array = + obj_main->fini_array = (Elf_Addr)NULL; + } + + if (direct_exec) { + /* Set osrel for direct-execed binary */ + mib[0] = CTL_KERN; + mib[1] = KERN_PROC; + mib[2] = KERN_PROC_OSREL; + mib[3] = getpid(); + osrel = obj_main->osrel; + sz = sizeof(old_osrel); + dbg("setting osrel to %d", osrel); + (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); + } + + wlock_acquire(rtld_bind_lock, &lockstate); + + dbg("resolving ifuncs"); + if (initlist_objects_ifunc(&initlist, + ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, + &lockstate) == -1) + rtld_die(); + + rtld_exit_ptr = rtld_exit; + if (obj_main->crt_no_init) + preinit_main(); + objlist_call_init(&initlist, &lockstate); + _r_debug_postinit(&obj_main->linkmap); + objlist_clear(&initlist); + dbg("loading filtees"); + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker) + continue; + if (ld_loadfltr || obj->z_loadfltr) + load_filtees(obj, 0, &lockstate); + } + + dbg("enforcing main obj relro"); + if (obj_enforce_relro(obj_main) == -1) + rtld_die(); + + lock_release(rtld_bind_lock, &lockstate); + + dbg("transferring control to program entry point = %p", + obj_main->entry); + + /* Return the exit procedure and the program entry point. */ + *exit_proc = rtld_exit_ptr; + *objp = obj_main; + return ((func_ptr_type)obj_main->entry); +} + +void * +rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) +{ + void *ptr; + Elf_Addr target; + + ptr = (void *)make_function_pointer(def, obj); + target = call_ifunc_resolver(ptr); + return ((void *)target); +} + +Elf_Addr +_rtld_bind(Obj_Entry *obj, Elf_Size reloff) +{ + const Elf_Rel *rel; + const Elf_Sym *def; + const Obj_Entry *defobj; + Elf_Addr *where; + Elf_Addr target; + RtldLockState lockstate; + +relock: + rlock_acquire(rtld_bind_lock, &lockstate); + if (sigsetjmp(lockstate.env, 0) != 0) + lock_upgrade(rtld_bind_lock, &lockstate); + if (obj->pltrel) + rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); + else + rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); + + where = (Elf_Addr *)(obj->relocbase + rel->r_offset); + def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, + NULL, &lockstate); + if (def == NULL) + rtld_die(); + if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { + if (lockstate_wlocked(&lockstate)) { + lock_release(rtld_bind_lock, &lockstate); + goto relock; + } + target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); + } else { + target = (Elf_Addr)(defobj->relocbase + def->st_value); + } + + dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, + obj->path == NULL ? NULL : basename(obj->path), (void *)target, + defobj->path == NULL ? NULL : basename(defobj->path)); + + /* + * Write the new contents for the jmpslot. Note that depending on + * architecture, the value which we need to return back to the + * lazy binding trampoline may or may not be the target + * address. The value returned from reloc_jmpslot() is the value + * that the trampoline needs. + */ + target = reloc_jmpslot(where, target, defobj, obj, rel); + lock_release(rtld_bind_lock, &lockstate); + return (target); +} + +/* + * Error reporting function. Use it like printf. If formats the message + * into a buffer, and sets things up so that the next call to dlerror() + * will return the message. + */ +void +_rtld_error(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, fmt, + ap); + va_end(ap); + *lockinfo.dlerror_seen() = 0; + dbg("rtld_error: %s", lockinfo.dlerror_loc()); + LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); +} + +/* + * Return a dynamically-allocated copy of the current error message, if any. + */ +static struct dlerror_save * +errmsg_save(void) +{ + struct dlerror_save *res; + + res = xmalloc(sizeof(*res)); + res->seen = *lockinfo.dlerror_seen(); + if (res->seen == 0) + res->msg = xstrdup(lockinfo.dlerror_loc()); + return (res); +} + +/* + * Restore the current error message from a copy which was previously saved + * by errmsg_save(). The copy is freed. + */ +static void +errmsg_restore(struct dlerror_save *saved_msg) +{ + if (saved_msg == NULL || saved_msg->seen == 1) { + *lockinfo.dlerror_seen() = 1; + } else { + *lockinfo.dlerror_seen() = 0; + strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, + lockinfo.dlerror_loc_sz); + free(saved_msg->msg); + } + free(saved_msg); +} + +static const char * +basename(const char *name) +{ + const char *p; + + p = strrchr(name, '/'); + return (p != NULL ? p + 1 : name); +} + +static struct utsname uts; + +static char * +origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, + bool may_free) +{ + char *p, *p1, *res, *resp; + int subst_len, kw_len, subst_count, old_len, new_len; + + kw_len = strlen(kw); + + /* + * First, count the number of the keyword occurrences, to + * preallocate the final string. + */ + for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { + p1 = strstr(p, kw); + if (p1 == NULL) + break; + } + + /* + * If the keyword is not found, just return. + * + * Return non-substituted string if resolution failed. We + * cannot do anything more reasonable, the failure mode of the + * caller is unresolved library anyway. + */ + if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) + return (may_free ? real : xstrdup(real)); + if (obj != NULL) + subst = obj->origin_path; + + /* + * There is indeed something to substitute. Calculate the + * length of the resulting string, and allocate it. + */ + subst_len = strlen(subst); + old_len = strlen(real); + new_len = old_len + (subst_len - kw_len) * subst_count; + res = xmalloc(new_len + 1); + + /* + * Now, execute the substitution loop. + */ + for (p = real, resp = res, *resp = '\0';;) { + p1 = strstr(p, kw); + if (p1 != NULL) { + /* Copy the prefix before keyword. */ + memcpy(resp, p, p1 - p); + resp += p1 - p; + /* Keyword replacement. */ + memcpy(resp, subst, subst_len); + resp += subst_len; + *resp = '\0'; + p = p1 + kw_len; + } else + break; + } + + /* Copy to the end of string and finish. */ + strcat(resp, p); + if (may_free) + free(real); + return (res); +} + +static const struct { + const char *kw; + bool pass_obj; + const char *subst; +} tokens[] = { + { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, + { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, + { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, + { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, + { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, + { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, + { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, + { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, + { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, + { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, +}; + +static char * +origin_subst(Obj_Entry *obj, const char *real) +{ + char *res; + int i; + + if (obj == NULL || !trust) + return (xstrdup(real)); + if (uts.sysname[0] == '\0') { + if (uname(&uts) != 0) { + _rtld_error("utsname failed: %d", errno); + return (NULL); + } + } + + /* __DECONST is safe here since without may_free real is unchanged */ + res = __DECONST(char *, real); + for (i = 0; i < (int)nitems(tokens); i++) { + res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, res, + tokens[i].kw, tokens[i].subst, i != 0); + } + return (res); +} + +void +rtld_die(void) +{ + const char *msg = dlerror(); + + if (msg == NULL) + msg = "Fatal error"; + rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); + rtld_fdputstr(STDERR_FILENO, msg); + rtld_fdputchar(STDERR_FILENO, '\n'); + _exit(1); +} + +/* + * Process a shared object's DYNAMIC section, and save the important + * information in its Obj_Entry structure. + */ +static void +digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, + const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) +{ + const Elf_Dyn *dynp; + Needed_Entry **needed_tail = &obj->needed; + Needed_Entry **needed_filtees_tail = &obj->needed_filtees; + Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; + const Elf_Hashelt *hashtab; + const Elf32_Word *hashval; + Elf32_Word bkt, nmaskwords; + int bloom_size32; + int plttype = DT_REL; + + *dyn_rpath = NULL; + *dyn_soname = NULL; + *dyn_runpath = NULL; + + obj->bind_now = false; + dynp = obj->dynamic; + if (dynp == NULL) + return; + for (; dynp->d_tag != DT_NULL; dynp++) { + switch (dynp->d_tag) { + case DT_REL: + obj->rel = (const Elf_Rel *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_RELSZ: + obj->relsize = dynp->d_un.d_val; + break; + + case DT_RELENT: + assert(dynp->d_un.d_val == sizeof(Elf_Rel)); + break; + + case DT_JMPREL: + obj->pltrel = (const Elf_Rel *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_PLTRELSZ: + obj->pltrelsize = dynp->d_un.d_val; + break; + + case DT_RELA: + obj->rela = (const Elf_Rela *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_RELASZ: + obj->relasize = dynp->d_un.d_val; + break; + + case DT_RELAENT: + assert(dynp->d_un.d_val == sizeof(Elf_Rela)); + break; + + case DT_RELR: + obj->relr = (const Elf_Relr *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_RELRSZ: + obj->relrsize = dynp->d_un.d_val; + break; + + case DT_RELRENT: + assert(dynp->d_un.d_val == sizeof(Elf_Relr)); + break; + + case DT_PLTREL: + plttype = dynp->d_un.d_val; + assert( + dynp->d_un.d_val == DT_REL || plttype == DT_RELA); + break; + + case DT_SYMTAB: + obj->symtab = (const Elf_Sym *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_SYMENT: + assert(dynp->d_un.d_val == sizeof(Elf_Sym)); + break; + + case DT_STRTAB: + obj->strtab = (const char *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_STRSZ: + obj->strsize = dynp->d_un.d_val; + break; + + case DT_VERNEED: + obj->verneed = (const Elf_Verneed *)(obj->relocbase + + dynp->d_un.d_val); + break; + + case DT_VERNEEDNUM: + obj->verneednum = dynp->d_un.d_val; + break; + + case DT_VERDEF: + obj->verdef = (const Elf_Verdef *)(obj->relocbase + + dynp->d_un.d_val); + break; + + case DT_VERDEFNUM: + obj->verdefnum = dynp->d_un.d_val; + break; + + case DT_VERSYM: + obj->versyms = (const Elf_Versym *)(obj->relocbase + + dynp->d_un.d_val); + break; + + case DT_HASH: { + hashtab = (const Elf_Hashelt *)(obj->relocbase + + dynp->d_un.d_ptr); + obj->nbuckets = hashtab[0]; + obj->nchains = hashtab[1]; + obj->buckets = hashtab + 2; + obj->chains = obj->buckets + obj->nbuckets; + obj->valid_hash_sysv = obj->nbuckets > 0 && + obj->nchains > 0 && obj->buckets != NULL; + } break; + + case DT_GNU_HASH: { + hashtab = (const Elf_Hashelt *)(obj->relocbase + + dynp->d_un.d_ptr); + obj->nbuckets_gnu = hashtab[0]; + obj->symndx_gnu = hashtab[1]; + nmaskwords = hashtab[2]; + bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; + obj->maskwords_bm_gnu = nmaskwords - 1; + obj->shift2_gnu = hashtab[3]; + obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); + obj->buckets_gnu = hashtab + 4 + bloom_size32; + obj->chain_zero_gnu = obj->buckets_gnu + + obj->nbuckets_gnu - obj->symndx_gnu; + /* Number of bitmask words is required to be power of 2 + */ + obj->valid_hash_gnu = powerof2(nmaskwords) && + obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; + } break; + + case DT_NEEDED: + if (!obj->rtld) { + Needed_Entry *nep = NEW(Needed_Entry); + nep->name = dynp->d_un.d_val; + nep->obj = NULL; + nep->next = NULL; + + *needed_tail = nep; + needed_tail = &nep->next; + } + break; + + case DT_FILTER: + if (!obj->rtld) { + Needed_Entry *nep = NEW(Needed_Entry); + nep->name = dynp->d_un.d_val; + nep->obj = NULL; + nep->next = NULL; + + *needed_filtees_tail = nep; + needed_filtees_tail = &nep->next; + + if (obj->linkmap.l_refname == NULL) + obj->linkmap.l_refname = + (char *)dynp->d_un.d_val; + } + break; + + case DT_AUXILIARY: + if (!obj->rtld) { + Needed_Entry *nep = NEW(Needed_Entry); + nep->name = dynp->d_un.d_val; + nep->obj = NULL; + nep->next = NULL; + + *needed_aux_filtees_tail = nep; + needed_aux_filtees_tail = &nep->next; + } + break; + + case DT_PLTGOT: + obj->pltgot = (Elf_Addr *)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_TEXTREL: + obj->textrel = true; + break; + + case DT_SYMBOLIC: + obj->symbolic = true; + break; + + case DT_RPATH: + /* + * We have to wait until later to process this, because + * we might not have gotten the address of the string + * table yet. + */ + *dyn_rpath = dynp; + break; + + case DT_SONAME: + *dyn_soname = dynp; + break; + + case DT_RUNPATH: + *dyn_runpath = dynp; + break; + + case DT_INIT: + obj->init = (Elf_Addr)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_PREINIT_ARRAY: + obj->preinit_array = (Elf_Addr)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_PREINIT_ARRAYSZ: + obj->preinit_array_num = dynp->d_un.d_val / + sizeof(Elf_Addr); + break; + + case DT_INIT_ARRAY: + obj->init_array = (Elf_Addr)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_INIT_ARRAYSZ: + obj->init_array_num = dynp->d_un.d_val / + sizeof(Elf_Addr); + break; + + case DT_FINI: + obj->fini = (Elf_Addr)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_FINI_ARRAY: + obj->fini_array = (Elf_Addr)(obj->relocbase + + dynp->d_un.d_ptr); + break; + + case DT_FINI_ARRAYSZ: + obj->fini_array_num = dynp->d_un.d_val / + sizeof(Elf_Addr); + break; + + case DT_DEBUG: + if (!early) + dbg("Filling in DT_DEBUG entry"); + (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = + (Elf_Addr)&r_debug; + break; + + case DT_FLAGS: + if (dynp->d_un.d_val & DF_ORIGIN) + obj->z_origin = true; + if (dynp->d_un.d_val & DF_SYMBOLIC) + obj->symbolic = true; + if (dynp->d_un.d_val & DF_TEXTREL) + obj->textrel = true; + if (dynp->d_un.d_val & DF_BIND_NOW) + obj->bind_now = true; + if (dynp->d_un.d_val & DF_STATIC_TLS) + obj->static_tls = true; + break; + + case DT_FLAGS_1: + if (dynp->d_un.d_val & DF_1_NOOPEN) + obj->z_noopen = true; + if (dynp->d_un.d_val & DF_1_ORIGIN) + obj->z_origin = true; + if (dynp->d_un.d_val & DF_1_GLOBAL) + obj->z_global = true; + if (dynp->d_un.d_val & DF_1_BIND_NOW) + obj->bind_now = true; + if (dynp->d_un.d_val & DF_1_NODELETE) + obj->z_nodelete = true; + if (dynp->d_un.d_val & DF_1_LOADFLTR) + obj->z_loadfltr = true; + if (dynp->d_un.d_val & DF_1_INTERPOSE) + obj->z_interpose = true; + if (dynp->d_un.d_val & DF_1_NODEFLIB) + obj->z_nodeflib = true; + if (dynp->d_un.d_val & DF_1_PIE) + obj->z_pie = true; + if (dynp->d_un.d_val & DF_1_INITFIRST) + obj->z_initfirst = true; + break; + + default: + if (arch_digest_dynamic(obj, dynp)) + break; + + if (!early) { + dbg("Ignoring d_tag %ld = %#lx", + (long)dynp->d_tag, (long)dynp->d_tag); + } + break; + } + } + + obj->traced = false; + + if (plttype == DT_RELA) { + obj->pltrela = (const Elf_Rela *)obj->pltrel; + obj->pltrel = NULL; + obj->pltrelasize = obj->pltrelsize; + obj->pltrelsize = 0; + } + + /* Determine size of dynsym table (equal to nchains of sysv hash) */ + if (obj->valid_hash_sysv) + obj->dynsymcount = obj->nchains; + else if (obj->valid_hash_gnu) { + obj->dynsymcount = 0; + for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { + if (obj->buckets_gnu[bkt] == 0) + continue; + hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; + do + obj->dynsymcount++; + while ((*hashval++ & 1u) == 0); + } + obj->dynsymcount += obj->symndx_gnu; + } + + if (obj->linkmap.l_refname != NULL) + obj->linkmap.l_refname = obj->strtab + + (unsigned long)obj->linkmap.l_refname; +} + +static bool +obj_resolve_origin(Obj_Entry *obj) +{ + if (obj->origin_path != NULL) + return (true); + obj->origin_path = xmalloc(PATH_MAX); + return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); +} + +static bool +digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, + const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) +{ + if (obj->z_origin && !obj_resolve_origin(obj)) + return (false); + + if (dyn_runpath != NULL) { + obj->runpath = (const char *)obj->strtab + + dyn_runpath->d_un.d_val; + obj->runpath = origin_subst(obj, obj->runpath); + } else if (dyn_rpath != NULL) { + obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; + obj->rpath = origin_subst(obj, obj->rpath); + } + if (dyn_soname != NULL) + object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); + return (true); +} + +static bool +digest_dynamic(Obj_Entry *obj, int early) +{ + const Elf_Dyn *dyn_rpath; + const Elf_Dyn *dyn_soname; + const Elf_Dyn *dyn_runpath; + + digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); + return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); +} + +/* + * Process a shared object's program header. This is used only for the + * main program, when the kernel has already loaded the main program + * into memory before calling the dynamic linker. It creates and + * returns an Obj_Entry structure. + */ +static Obj_Entry * +digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) +{ + Obj_Entry *obj; + const Elf_Phdr *phlimit = phdr + phnum; + const Elf_Phdr *ph; + Elf_Addr note_start, note_end; + int nsegs = 0; + + obj = obj_new(); + for (ph = phdr; ph < phlimit; ph++) { + if (ph->p_type != PT_PHDR) + continue; + + obj->phdr = phdr; + obj->phsize = ph->p_memsz; + obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; + break; + } + + obj->stack_flags = PF_X | PF_R | PF_W; + + for (ph = phdr; ph < phlimit; ph++) { + switch (ph->p_type) { + case PT_INTERP: + obj->interp = (const char *)(ph->p_vaddr + + obj->relocbase); + break; + + case PT_LOAD: + if (nsegs == 0) { /* First load segment */ + obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); + obj->mapbase = obj->vaddrbase + obj->relocbase; + } else { /* Last load segment */ + obj->mapsize = rtld_round_page( + ph->p_vaddr + ph->p_memsz) - + obj->vaddrbase; + } + nsegs++; + break; + + case PT_DYNAMIC: + obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + + obj->relocbase); + break; + + case PT_TLS: + obj->tlsindex = 1; + obj->tlssize = ph->p_memsz; + obj->tlsalign = ph->p_align; + obj->tlsinitsize = ph->p_filesz; + obj->tlsinit = (void *)(ph->p_vaddr + obj->relocbase); + obj->tlspoffset = ph->p_offset; + break; + + case PT_GNU_STACK: + obj->stack_flags = ph->p_flags; + break; + + case PT_NOTE: + note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; + note_end = note_start + ph->p_filesz; + digest_notes(obj, note_start, note_end); + break; + } + } + if (nsegs < 1) { + _rtld_error("%s: too few PT_LOAD segments", path); + return (NULL); + } + + obj->entry = entry; + return (obj); +} + +void +digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) +{ + const Elf_Note *note; + const char *note_name; + uintptr_t p; + + for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; + note = (const Elf_Note *)((const char *)(note + 1) + + roundup2(note->n_namesz, sizeof(Elf32_Addr)) + + roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { + if (arch_digest_note(obj, note)) + continue; + + if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || + note->n_descsz != sizeof(int32_t)) + continue; + if (note->n_type != NT_FREEBSD_ABI_TAG && + note->n_type != NT_FREEBSD_FEATURE_CTL && + note->n_type != NT_FREEBSD_NOINIT_TAG) + continue; + note_name = (const char *)(note + 1); + if (strncmp(NOTE_FREEBSD_VENDOR, note_name, + sizeof(NOTE_FREEBSD_VENDOR)) != 0) + continue; + switch (note->n_type) { + case NT_FREEBSD_ABI_TAG: + /* FreeBSD osrel note */ + p = (uintptr_t)(note + 1); + p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); + obj->osrel = *(const int32_t *)(p); + dbg("note osrel %d", obj->osrel); + break; + case NT_FREEBSD_FEATURE_CTL: + /* FreeBSD ABI feature control note */ + p = (uintptr_t)(note + 1); + p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); + obj->fctl0 = *(const uint32_t *)(p); + dbg("note fctl0 %#x", obj->fctl0); + break; + case NT_FREEBSD_NOINIT_TAG: + /* FreeBSD 'crt does not call init' note */ + obj->crt_no_init = true; + dbg("note crt_no_init"); + break; + } + } +} + +static Obj_Entry * +dlcheck(void *handle) +{ + Obj_Entry *obj; + + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj == (Obj_Entry *)handle) + break; + } + + if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { + _rtld_error("Invalid shared object handle %p", handle); + return (NULL); + } + return (obj); +} + +/* + * If the given object is already in the donelist, return true. Otherwise + * add the object to the list and return false. + */ +static bool +donelist_check(DoneList *dlp, const Obj_Entry *obj) +{ + unsigned int i; + + for (i = 0; i < dlp->num_used; i++) + if (dlp->objs[i] == obj) + return (true); + /* + * Our donelist allocation should always be sufficient. But if + * our threads locking isn't working properly, more shared objects + * could have been loaded since we allocated the list. That should + * never happen, but we'll handle it properly just in case it does. + */ + if (dlp->num_used < dlp->num_alloc) + dlp->objs[dlp->num_used++] = obj; + return (false); +} + +/* + * SysV hash function for symbol table lookup. It is a slightly optimized + * version of the hash specified by the System V ABI. + */ +Elf32_Word +elf_hash(const char *name) +{ + const unsigned char *p = (const unsigned char *)name; + Elf32_Word h = 0; + + while (*p != '\0') { + h = (h << 4) + *p++; + h ^= (h >> 24) & 0xf0; + } + return (h & 0x0fffffff); +} + +/* + * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits + * unsigned in case it's implemented with a wider type. + */ +static uint32_t +gnu_hash(const char *s) +{ + uint32_t h; + unsigned char c; + + h = 5381; + for (c = *s; c != '\0'; c = *++s) + h = h * 33 + c; + return (h & 0xffffffff); +} + +/* + * Find the library with the given name, and return its full pathname. + * The returned string is dynamically allocated. Generates an error + * message and returns NULL if the library cannot be found. + * + * If the second argument is non-NULL, then it refers to an already- + * loaded shared object, whose library search path will be searched. + * + * If a library is successfully located via LD_LIBRARY_PATH_FDS, its + * descriptor (which is close-on-exec) will be passed out via the third + * argument. + * + * The search order is: + * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) + * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) + * LD_LIBRARY_PATH + * DT_RUNPATH in the referencing file + * ldconfig hints (if -z nodefaultlib, filter out default library directories + * from list) + * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib + * + * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. + */ +static char * +find_library(const char *xname, const Obj_Entry *refobj, int *fdp) +{ + char *pathname, *refobj_path; + const char *name; + bool nodeflib, objgiven; + + objgiven = refobj != NULL; + + if (libmap_disable || !objgiven || + (name = lm_find(refobj->path, xname)) == NULL) + name = xname; + + if (strchr(name, '/') != NULL) { /* Hard coded pathname */ + if (name[0] != '/' && !trust) { + _rtld_error( + "Absolute pathname required for shared object \"%s\"", + name); + return (NULL); + } + return (origin_subst(__DECONST(Obj_Entry *, refobj), + __DECONST(char *, name))); + } + + dbg(" Searching for \"%s\"", name); + refobj_path = objgiven ? refobj->path : NULL; + + /* + * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall + * back to pre-conforming behaviour if user requested so with + * LD_LIBRARY_PATH_RPATH environment variable and ignore -z + * nodeflib. + */ + if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { + pathname = search_library_path(name, ld_library_path, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + if (refobj != NULL) { + pathname = search_library_path(name, refobj->rpath, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + } + pathname = search_library_pathfds(name, ld_library_dirs, fdp); + if (pathname != NULL) + return (pathname); + pathname = search_library_path(name, gethints(false), + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + pathname = search_library_path(name, ld_standard_library_path, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + } else { + nodeflib = objgiven ? refobj->z_nodeflib : false; + if (objgiven) { + pathname = search_library_path(name, refobj->rpath, + refobj->path, fdp); + if (pathname != NULL) + return (pathname); + } + if (objgiven && refobj->runpath == NULL && refobj != obj_main) { + pathname = search_library_path(name, obj_main->rpath, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + } + pathname = search_library_path(name, ld_library_path, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + if (objgiven) { + pathname = search_library_path(name, refobj->runpath, + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + } + pathname = search_library_pathfds(name, ld_library_dirs, fdp); + if (pathname != NULL) + return (pathname); + pathname = search_library_path(name, gethints(nodeflib), + refobj_path, fdp); + if (pathname != NULL) + return (pathname); + if (objgiven && !nodeflib) { + pathname = search_library_path(name, + ld_standard_library_path, refobj_path, fdp); + if (pathname != NULL) + return (pathname); + } + } + + if (objgiven && refobj->path != NULL) { + _rtld_error( + "Shared object \"%s\" not found, required by \"%s\"", + name, basename(refobj->path)); + } else { + _rtld_error("Shared object \"%s\" not found", name); + } + return (NULL); +} + +/* + * Given a symbol number in a referencing object, find the corresponding + * definition of the symbol. Returns a pointer to the symbol, or NULL if + * no definition was found. Returns a pointer to the Obj_Entry of the + * defining object via the reference parameter DEFOBJ_OUT. + */ +const Elf_Sym * +find_symdef(unsigned long symnum, const Obj_Entry *refobj, + const Obj_Entry **defobj_out, int flags, SymCache *cache, + RtldLockState *lockstate) +{ + const Elf_Sym *ref; + const Elf_Sym *def; + const Obj_Entry *defobj; + const Ver_Entry *ve; + SymLook req; + const char *name; + int res; + + /* + * If we have already found this symbol, get the information from + * the cache. + */ + if (symnum >= refobj->dynsymcount) + return (NULL); /* Bad object */ + if (cache != NULL && cache[symnum].sym != NULL) { + *defobj_out = cache[symnum].obj; + return (cache[symnum].sym); + } + + ref = refobj->symtab + symnum; + name = refobj->strtab + ref->st_name; + def = NULL; + defobj = NULL; + ve = NULL; + + /* + * We don't have to do a full scale lookup if the symbol is local. + * We know it will bind to the instance in this load module; to + * which we already have a pointer (ie ref). By not doing a lookup, + * we not only improve performance, but it also avoids unresolvable + * symbols when local symbols are not in the hash table. This has + * been seen with the ia64 toolchain. + */ + if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { + if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { + _rtld_error("%s: Bogus symbol table entry %lu", + refobj->path, symnum); + } + symlook_init(&req, name); + req.flags = flags; + ve = req.ventry = fetch_ventry(refobj, symnum); + req.lockstate = lockstate; + res = symlook_default(&req, refobj); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + } else { + def = ref; + defobj = refobj; + } + + /* + * If we found no definition and the reference is weak, treat the + * symbol as having the value zero. + */ + if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { + def = &sym_zero; + defobj = obj_main; + } + + if (def != NULL) { + *defobj_out = defobj; + /* + * Record the information in the cache to avoid subsequent + * lookups. + */ + if (cache != NULL) { + cache[symnum].sym = def; + cache[symnum].obj = defobj; + } + } else { + if (refobj != &obj_rtld) + _rtld_error("%s: Undefined symbol \"%s%s%s\"", + refobj->path, name, ve != NULL ? "@" : "", + ve != NULL ? ve->name : ""); + } + return (def); +} + +/* Convert between native byte order and forced little resp. big endian. */ +#define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) + +/* + * Return the search path from the ldconfig hints file, reading it if + * necessary. If nostdlib is true, then the default search paths are + * not added to result. + * + * Returns NULL if there are problems with the hints file, + * or if the search path there is empty. + */ +static const char * +gethints(bool nostdlib) +{ + static char *filtered_path; + static const char *hints; + static struct elfhints_hdr hdr; + struct fill_search_info_args sargs, hargs; + struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; + struct dl_serpath *SLPpath, *hintpath; + char *p; + struct stat hint_stat; + unsigned int SLPndx, hintndx, fndx, fcount; + int fd; + size_t flen; + uint32_t dl; + uint32_t magic; /* Magic number */ + uint32_t version; /* File version (1) */ + uint32_t strtab; /* Offset of string table in file */ + uint32_t dirlist; /* Offset of directory list in string table */ + uint32_t dirlistlen; /* strlen(dirlist) */ + bool is_le; /* Does the hints file use little endian */ + bool skip; + + /* First call, read the hints file */ + if (hints == NULL) { + /* Keep from trying again in case the hints file is bad. */ + hints = ""; + + if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == + -1) { + dbg("failed to open hints file \"%s\"", + ld_elf_hints_path); + return (NULL); + } + + /* + * Check of hdr.dirlistlen value against type limit + * intends to pacify static analyzers. Further + * paranoia leads to checks that dirlist is fully + * contained in the file range. + */ + if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { + dbg("failed to read %lu bytes from hints file \"%s\"", + (u_long)sizeof hdr, ld_elf_hints_path); +cleanup1: + close(fd); + hdr.dirlistlen = 0; + return (NULL); + } + dbg("host byte-order: %s-endian", + le32toh(1) == 1 ? "little" : "big"); + dbg("hints file byte-order: %s-endian", + hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); + is_le = /*htole32(1) == 1 || */ hdr.magic == + htole32(ELFHINTS_MAGIC); + magic = COND_SWAP(hdr.magic); + version = COND_SWAP(hdr.version); + strtab = COND_SWAP(hdr.strtab); + dirlist = COND_SWAP(hdr.dirlist); + dirlistlen = COND_SWAP(hdr.dirlistlen); + if (magic != ELFHINTS_MAGIC) { + dbg("invalid magic number %#08x (expected: %#08x)", + magic, ELFHINTS_MAGIC); + goto cleanup1; + } + if (version != 1) { + dbg("hints file version %d (expected: 1)", version); + goto cleanup1; + } + if (dirlistlen > UINT_MAX / 2) { + dbg("directory list is to long: %d > %d", dirlistlen, + UINT_MAX / 2); + goto cleanup1; + } + if (fstat(fd, &hint_stat) == -1) { + dbg("failed to find length of hints file \"%s\"", + ld_elf_hints_path); + goto cleanup1; + } + dl = strtab; + if (dl + dirlist < dl) { + dbg("invalid string table position %d", dl); + goto cleanup1; + } + dl += dirlist; + if (dl + dirlistlen < dl) { + dbg("invalid directory list offset %d", dirlist); + goto cleanup1; + } + dl += dirlistlen; + if (dl > hint_stat.st_size) { + dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", + ld_elf_hints_path, dl, + (uintmax_t)hint_stat.st_size); + goto cleanup1; + } + p = xmalloc(dirlistlen + 1); + if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != + (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { + free(p); + dbg( + "failed to read %d bytes starting at %d from hints file \"%s\"", + dirlistlen + 1, strtab + dirlist, + ld_elf_hints_path); + goto cleanup1; + } + hints = p; + close(fd); + } + + /* + * If caller agreed to receive list which includes the default + * paths, we are done. Otherwise, if we still did not + * calculated filtered result, do it now. + */ + if (!nostdlib) + return (hints[0] != '\0' ? hints : NULL); + if (filtered_path != NULL) + goto filt_ret; + + /* + * Obtain the list of all configured search paths, and the + * list of the default paths. + * + * First estimate the size of the results. + */ + smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); + smeta.dls_cnt = 0; + hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); + hmeta.dls_cnt = 0; + + sargs.request = RTLD_DI_SERINFOSIZE; + sargs.serinfo = &smeta; + hargs.request = RTLD_DI_SERINFOSIZE; + hargs.serinfo = &hmeta; + + path_enumerate(ld_standard_library_path, fill_search_info, NULL, + &sargs); + path_enumerate(hints, fill_search_info, NULL, &hargs); + + SLPinfo = xmalloc(smeta.dls_size); + hintinfo = xmalloc(hmeta.dls_size); + + /* + * Next fetch both sets of paths. + */ + sargs.request = RTLD_DI_SERINFO; + sargs.serinfo = SLPinfo; + sargs.serpath = &SLPinfo->dls_serpath[0]; + sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; + + hargs.request = RTLD_DI_SERINFO; + hargs.serinfo = hintinfo; + hargs.serpath = &hintinfo->dls_serpath[0]; + hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; + + path_enumerate(ld_standard_library_path, fill_search_info, NULL, + &sargs); + path_enumerate(hints, fill_search_info, NULL, &hargs); + + /* + * Now calculate the difference between two sets, by excluding + * standard paths from the full set. + */ + fndx = 0; + fcount = 0; + filtered_path = xmalloc(dirlistlen + 1); + hintpath = &hintinfo->dls_serpath[0]; + for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { + skip = false; + SLPpath = &SLPinfo->dls_serpath[0]; + /* + * Check each standard path against current. + */ + for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { + /* matched, skip the path */ + if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { + skip = true; + break; + } + } + if (skip) + continue; + /* + * Not matched against any standard path, add the path + * to result. Separate consequtive paths with ':'. + */ + if (fcount > 0) { + filtered_path[fndx] = ':'; + fndx++; + } + fcount++; + flen = strlen(hintpath->dls_name); + strncpy((filtered_path + fndx), hintpath->dls_name, flen); + fndx += flen; + } + filtered_path[fndx] = '\0'; + + free(SLPinfo); + free(hintinfo); + +filt_ret: + return (filtered_path[0] != '\0' ? filtered_path : NULL); +} + +static void +init_dag(Obj_Entry *root) +{ + const Needed_Entry *needed; + const Objlist_Entry *elm; + DoneList donelist; + + if (root->dag_inited) + return; + donelist_init(&donelist); + + /* Root object belongs to own DAG. */ + objlist_push_tail(&root->dldags, root); + objlist_push_tail(&root->dagmembers, root); + donelist_check(&donelist, root); + + /* + * Add dependencies of root object to DAG in breadth order + * by exploiting the fact that each new object get added + * to the tail of the dagmembers list. + */ + STAILQ_FOREACH(elm, &root->dagmembers, link) { + for (needed = elm->obj->needed; needed != NULL; + needed = needed->next) { + if (needed->obj == NULL || + donelist_check(&donelist, needed->obj)) + continue; + objlist_push_tail(&needed->obj->dldags, root); + objlist_push_tail(&root->dagmembers, needed->obj); + } + } + root->dag_inited = true; +} + +static void +init_marker(Obj_Entry *marker) +{ + bzero(marker, sizeof(*marker)); + marker->marker = true; +} + +Obj_Entry * +globallist_curr(const Obj_Entry *obj) +{ + for (;;) { + if (obj == NULL) + return (NULL); + if (!obj->marker) + return (__DECONST(Obj_Entry *, obj)); + obj = TAILQ_PREV(obj, obj_entry_q, next); + } +} + +Obj_Entry * +globallist_next(const Obj_Entry *obj) +{ + for (;;) { + obj = TAILQ_NEXT(obj, next); + if (obj == NULL) + return (NULL); + if (!obj->marker) + return (__DECONST(Obj_Entry *, obj)); + } +} + +/* Prevent the object from being unmapped while the bind lock is dropped. */ +static void +hold_object(Obj_Entry *obj) +{ + obj->holdcount++; +} + +static void +unhold_object(Obj_Entry *obj) +{ + assert(obj->holdcount > 0); + if (--obj->holdcount == 0 && obj->unholdfree) + release_object(obj); +} + +static void +process_z(Obj_Entry *root) +{ + const Objlist_Entry *elm; + Obj_Entry *obj; + + /* + * Walk over object DAG and process every dependent object + * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need + * to grow their own DAG. + * + * For DF_1_GLOBAL, DAG is required for symbol lookups in + * symlook_global() to work. + * + * For DF_1_NODELETE, the DAG should have its reference upped. + */ + STAILQ_FOREACH(elm, &root->dagmembers, link) { + obj = elm->obj; + if (obj == NULL) + continue; + if (obj->z_nodelete && !obj->ref_nodel) { + dbg("obj %s -z nodelete", obj->path); + init_dag(obj); + ref_dag(obj); + obj->ref_nodel = true; + } + if (obj->z_global && objlist_find(&list_global, obj) == NULL) { + dbg("obj %s -z global", obj->path); + objlist_push_tail(&list_global, obj); + init_dag(obj); + } + } +} + +static void +parse_rtld_phdr(Obj_Entry *obj) +{ + const Elf_Phdr *ph; + Elf_Addr note_start, note_end; + bool first_seg; + + first_seg = true; + obj->stack_flags = PF_X | PF_R | PF_W; + for (ph = obj->phdr; + (const char *)ph < (const char *)obj->phdr + obj->phsize; ph++) { + switch (ph->p_type) { + case PT_LOAD: + if (first_seg) { + obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); + first_seg = false; + } + obj->mapsize = rtld_round_page(ph->p_vaddr + + ph->p_memsz) - obj->vaddrbase; + break; + case PT_GNU_STACK: + obj->stack_flags = ph->p_flags; + break; + case PT_NOTE: + note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; + note_end = note_start + ph->p_filesz; + digest_notes(obj, note_start, note_end); + break; + } + } +} + +/* + * Initialize the dynamic linker. The argument is the address at which + * the dynamic linker has been mapped into memory. The primary task of + * this function is to relocate the dynamic linker. + */ +static void +init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) +{ + Obj_Entry objtmp; /* Temporary rtld object */ + const Elf_Ehdr *ehdr; + const Elf_Dyn *dyn_rpath; + const Elf_Dyn *dyn_soname; + const Elf_Dyn *dyn_runpath; + + /* + * Conjure up an Obj_Entry structure for the dynamic linker. + * + * The "path" member can't be initialized yet because string constants + * cannot yet be accessed. Below we will set it correctly. + */ + memset(&objtmp, 0, sizeof(objtmp)); + objtmp.path = NULL; + objtmp.rtld = true; + objtmp.mapbase = mapbase; +#ifdef PIC + objtmp.relocbase = mapbase; +#endif + + objtmp.dynamic = rtld_dynamic(&objtmp); + digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); + assert(objtmp.needed == NULL); + assert(!objtmp.textrel); + /* + * Temporarily put the dynamic linker entry into the object list, so + * that symbols can be found. + */ + relocate_objects(&objtmp, true, &objtmp, 0, NULL); + + ehdr = (Elf_Ehdr *)mapbase; + objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); + objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); + + /* Initialize the object list. */ + TAILQ_INIT(&obj_list); + + /* Now that non-local variables can be accesses, copy out obj_rtld. */ + memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); + + /* The page size is required by the dynamic memory allocator. */ + init_pagesizes(aux_info); + + if (aux_info[AT_OSRELDATE] != NULL) + osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; + + digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); + + /* Replace the path with a dynamically allocated copy. */ + obj_rtld.path = xstrdup(ld_path_rtld); + + parse_rtld_phdr(&obj_rtld); + if (obj_enforce_relro(&obj_rtld) == -1) + rtld_die(); + + r_debug.r_version = R_DEBUG_VERSION; + r_debug.r_brk = r_debug_state; + r_debug.r_state = RT_CONSISTENT; + r_debug.r_ldbase = obj_rtld.relocbase; +} + +/* + * Retrieve the array of supported page sizes. The kernel provides the page + * sizes in increasing order. + */ +static void +init_pagesizes(Elf_Auxinfo **aux_info) +{ + static size_t psa[MAXPAGESIZES]; + int mib[2]; + size_t len, size; + + if (aux_info[AT_PAGESIZES] != NULL && + aux_info[AT_PAGESIZESLEN] != NULL) { + size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; + pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; + } else { + len = 2; + if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) + size = sizeof(psa); + else { + /* As a fallback, retrieve the base page size. */ + size = sizeof(psa[0]); + if (aux_info[AT_PAGESZ] != NULL) { + psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; + goto psa_filled; + } else { + mib[0] = CTL_HW; + mib[1] = HW_PAGESIZE; + len = 2; + } + } + if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { + _rtld_error("sysctl for hw.pagesize(s) failed"); + rtld_die(); + } + psa_filled: + pagesizes = psa; + } + npagesizes = size / sizeof(pagesizes[0]); + /* Discard any invalid entries at the end of the array. */ + while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) + npagesizes--; + + page_size = pagesizes[0]; +} + +/* + * Add the init functions from a needed object list (and its recursive + * needed objects) to "list". This is not used directly; it is a helper + * function for initlist_add_objects(). The write lock must be held + * when this function is called. + */ +static void +initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) +{ + /* Recursively process the successor needed objects. */ + if (needed->next != NULL) + initlist_add_neededs(needed->next, list, iflist); + + /* Process the current needed object. */ + if (needed->obj != NULL) + initlist_add_objects(needed->obj, needed->obj, list, iflist); +} + +/* + * Scan all of the DAGs rooted in the range of objects from "obj" to + * "tail" and add their init functions to "list". This recurses over + * the DAGs and ensure the proper init ordering such that each object's + * needed libraries are initialized before the object itself. At the + * same time, this function adds the objects to the global finalization + * list "list_fini" in the opposite order. The write lock must be + * held when this function is called. + */ +static void +initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) +{ + Objlist iflist; /* initfirst objs and their needed */ + Objlist_Entry *tmp; + + objlist_init(&iflist); + initlist_add_objects(obj, tail, list, &iflist); + + STAILQ_FOREACH(tmp, &iflist, link) { + Obj_Entry *tobj = tmp->obj; + + if ((tobj->fini != (Elf_Addr)NULL || + tobj->fini_array != (Elf_Addr)NULL) && + !tobj->on_fini_list) { + objlist_push_tail(&list_fini, tobj); + tobj->on_fini_list = true; + } + } + + /* + * This might result in the same object appearing more + * than once on the init list. objlist_call_init() + * uses obj->init_scanned to avoid dup calls. + */ + STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); + STAILQ_FOREACH(tmp, &iflist, link) + objlist_push_head(list, tmp->obj); + + objlist_clear(&iflist); +} + +static void +initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, + Objlist *iflist) +{ + Obj_Entry *nobj; + + if (obj->init_done) + return; + + if (obj->z_initfirst || list == NULL) { + /* + * Ignore obj->init_scanned. The object might indeed + * already be on the init list, but due to being + * needed by an initfirst object, we must put it at + * the head of the init list. obj->init_done protects + * against double-initialization. + */ + if (obj->needed != NULL) + initlist_add_neededs(obj->needed, NULL, iflist); + if (obj->needed_filtees != NULL) + initlist_add_neededs(obj->needed_filtees, NULL, + iflist); + if (obj->needed_aux_filtees != NULL) + initlist_add_neededs(obj->needed_aux_filtees, + NULL, iflist); + objlist_push_tail(iflist, obj); + } else { + if (obj->init_scanned) + return; + obj->init_scanned = true; + + /* Recursively process the successor objects. */ + nobj = globallist_next(obj); + if (nobj != NULL && obj != tail) + initlist_add_objects(nobj, tail, list, iflist); + + /* Recursively process the needed objects. */ + if (obj->needed != NULL) + initlist_add_neededs(obj->needed, list, iflist); + if (obj->needed_filtees != NULL) + initlist_add_neededs(obj->needed_filtees, list, + iflist); + if (obj->needed_aux_filtees != NULL) + initlist_add_neededs(obj->needed_aux_filtees, list, + iflist); + + /* Add the object to the init list. */ + objlist_push_tail(list, obj); + + /* + * Add the object to the global fini list in the + * reverse order. + */ + if ((obj->fini != (Elf_Addr)NULL || + obj->fini_array != (Elf_Addr)NULL) && + !obj->on_fini_list) { + objlist_push_head(&list_fini, obj); + obj->on_fini_list = true; + } + } +} + +static void +free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) +{ + Needed_Entry *needed, *needed1; + + for (needed = n; needed != NULL; needed = needed->next) { + if (needed->obj != NULL) { + dlclose_locked(needed->obj, lockstate); + needed->obj = NULL; + } + } + for (needed = n; needed != NULL; needed = needed1) { + needed1 = needed->next; + free(needed); + } +} + +static void +unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) +{ + free_needed_filtees(obj->needed_filtees, lockstate); + obj->needed_filtees = NULL; + free_needed_filtees(obj->needed_aux_filtees, lockstate); + obj->needed_aux_filtees = NULL; + obj->filtees_loaded = false; +} + +static void +load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, + RtldLockState *lockstate) +{ + for (; needed != NULL; needed = needed->next) { + needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, + flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : + RTLD_LAZY) | RTLD_LOCAL, lockstate); + } +} + +static void +load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) +{ + if (obj->filtees_loaded || obj->filtees_loading) + return; + lock_restart_for_upgrade(lockstate); + obj->filtees_loading = true; + load_filtee1(obj, obj->needed_filtees, flags, lockstate); + load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); + obj->filtees_loaded = true; + obj->filtees_loading = false; +} + +static int +process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) +{ + Obj_Entry *obj1; + + for (; needed != NULL; needed = needed->next) { + obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, + obj, flags & ~RTLD_LO_NOLOAD); + if (obj1 == NULL && !ld_tracing && + (flags & RTLD_LO_FILTEES) == 0) + return (-1); + } + return (0); +} + +/* + * Given a shared object, traverse its list of needed objects, and load + * each of them. Returns 0 on success. Generates an error message and + * returns -1 on failure. + */ +static int +load_needed_objects(Obj_Entry *first, int flags) +{ + Obj_Entry *obj; + + for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { + if (obj->marker) + continue; + if (process_needed(obj, obj->needed, flags) == -1) + return (-1); + } + return (0); +} + +static int +load_preload_objects(const char *penv, bool isfd) +{ + Obj_Entry *obj; + const char *name; + size_t len; + char savech, *p, *psave; + int fd; + static const char delim[] = " \t:;"; + + if (penv == NULL) + return (0); + + p = psave = xstrdup(penv); + p += strspn(p, delim); + while (*p != '\0') { + len = strcspn(p, delim); + + savech = p[len]; + p[len] = '\0'; + if (isfd) { + name = NULL; + fd = parse_integer(p); + if (fd == -1) { + free(psave); + return (-1); + } + } else { + name = p; + fd = -1; + } + + obj = load_object(name, fd, NULL, 0); + if (obj == NULL) { + free(psave); + return (-1); /* XXX - cleanup */ + } + obj->z_interpose = true; + p[len] = savech; + p += len; + p += strspn(p, delim); + } + LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); + + free(psave); + return (0); +} + +static const char * +printable_path(const char *path) +{ + return (path == NULL ? "<unknown>" : path); +} + +/* + * Load a shared object into memory, if it is not already loaded. The + * object may be specified by name or by user-supplied file descriptor + * fd_u. In the later case, the fd_u descriptor is not closed, but its + * duplicate is. + * + * Returns a pointer to the Obj_Entry for the object. Returns NULL + * on failure. + */ +static Obj_Entry * +load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) +{ + Obj_Entry *obj; + int fd; + struct stat sb; + char *path; + + fd = -1; + if (name != NULL) { + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker || obj->doomed) + continue; + if (object_match_name(obj, name)) + return (obj); + } + + path = find_library(name, refobj, &fd); + if (path == NULL) + return (NULL); + } else + path = NULL; + + if (fd >= 0) { + /* + * search_library_pathfds() opens a fresh file descriptor for + * the library, so there is no need to dup(). + */ + } else if (fd_u == -1) { + /* + * If we didn't find a match by pathname, or the name is not + * supplied, open the file and check again by device and inode. + * This avoids false mismatches caused by multiple links or ".." + * in pathnames. + * + * To avoid a race, we open the file and use fstat() rather than + * using stat(). + */ + if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { + _rtld_error("Cannot open \"%s\"", path); + free(path); + return (NULL); + } + } else { + fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); + if (fd == -1) { + _rtld_error("Cannot dup fd"); + free(path); + return (NULL); + } + } + if (fstat(fd, &sb) == -1) { + _rtld_error("Cannot fstat \"%s\"", printable_path(path)); + close(fd); + free(path); + return (NULL); + } + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker || obj->doomed) + continue; + if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) + break; + } + if (obj != NULL) { + if (name != NULL) + object_add_name(obj, name); + free(path); + close(fd); + return (obj); + } + if (flags & RTLD_LO_NOLOAD) { + free(path); + close(fd); + return (NULL); + } + + /* First use of this object, so we must map it in */ + obj = do_load_object(fd, name, path, &sb, flags); + if (obj == NULL) + free(path); + close(fd); + + return (obj); +} + +static Obj_Entry * +do_load_object(int fd, const char *name, char *path, struct stat *sbp, + int flags) +{ + Obj_Entry *obj; + struct statfs fs; + + /* + * First, make sure that environment variables haven't been + * used to circumvent the noexec flag on a filesystem. + * We ignore fstatfs(2) failures, since fd might reference + * not a file, e.g. shmfd. + */ + if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && + (fs.f_flags & MNT_NOEXEC) != 0) { + _rtld_error("Cannot execute objects on %s", fs.f_mntonname); + return (NULL); + } + + dbg("loading \"%s\"", printable_path(path)); + obj = map_object(fd, printable_path(path), sbp, false); + if (obj == NULL) + return (NULL); + + /* + * If DT_SONAME is present in the object, digest_dynamic2 already + * added it to the object names. + */ + if (name != NULL) + object_add_name(obj, name); + obj->path = path; + if (!digest_dynamic(obj, 0)) + goto errp; + dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, + obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); + if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { + dbg("refusing to load PIE executable \"%s\"", obj->path); + _rtld_error("Cannot load PIE binary %s as DSO", obj->path); + goto errp; + } + if (obj->z_noopen && + (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { + dbg("refusing to load non-loadable \"%s\"", obj->path); + _rtld_error("Cannot dlopen non-loadable %s", obj->path); + goto errp; + } + + obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; + TAILQ_INSERT_TAIL(&obj_list, obj, next); + obj_count++; + obj_loads++; + linkmap_add(obj); /* for GDB & dlinfo() */ + max_stack_flags |= obj->stack_flags; + + dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, + obj->path); + if (obj->textrel) + dbg(" WARNING: %s has impure text", obj->path); + LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, + obj->path); + + return (obj); + +errp: + munmap(obj->mapbase, obj->mapsize); + obj_free(obj); + return (NULL); +} + +static int +load_kpreload(const void *addr) +{ + Obj_Entry *obj; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; + static const char kname[] = "[vdso]"; + + ehdr = addr; + if (!check_elf_headers(ehdr, "kpreload")) + return (-1); + obj = obj_new(); + phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); + obj->phdr = phdr; + obj->phsize = ehdr->e_phnum * sizeof(*phdr); + phlimit = phdr + ehdr->e_phnum; + seg0 = segn = NULL; + + for (; phdr < phlimit; phdr++) { + switch (phdr->p_type) { + case PT_DYNAMIC: + phdyn = phdr; + break; + case PT_GNU_STACK: + /* Absense of PT_GNU_STACK implies stack_flags == 0. */ + obj->stack_flags = phdr->p_flags; + break; + case PT_LOAD: + if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) + seg0 = phdr; + if (segn == NULL || + segn->p_vaddr + segn->p_memsz < + phdr->p_vaddr + phdr->p_memsz) + segn = phdr; + break; + } + } + + obj->mapbase = __DECONST(caddr_t, addr); + obj->mapsize = segn->p_vaddr + segn->p_memsz; + obj->vaddrbase = 0; + obj->relocbase = obj->mapbase; + + object_add_name(obj, kname); + obj->path = xstrdup(kname); + obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); + + if (!digest_dynamic(obj, 0)) { + obj_free(obj); + return (-1); + } + + /* + * We assume that kernel-preloaded object does not need + * relocation. It is currently written into read-only page, + * handling relocations would mean we need to allocate at + * least one additional page per AS. + */ + dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", + obj->path, obj->mapbase, obj->phdr, seg0, + obj->relocbase + seg0->p_vaddr, obj->dynamic); + + TAILQ_INSERT_TAIL(&obj_list, obj, next); + obj_count++; + obj_loads++; + linkmap_add(obj); /* for GDB & dlinfo() */ + max_stack_flags |= obj->stack_flags; + + LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, + obj->path); + return (0); +} + +Obj_Entry * +obj_from_addr(const void *addr) +{ + Obj_Entry *obj; + + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker) + continue; + if (addr < (void *)obj->mapbase) + continue; + if (addr < (void *)(obj->mapbase + obj->mapsize)) + return obj; + } + return (NULL); +} + +static void +preinit_main(void) +{ + Elf_Addr *preinit_addr; + int index; + + preinit_addr = (Elf_Addr *)obj_main->preinit_array; + if (preinit_addr == NULL) + return; + + for (index = 0; index < obj_main->preinit_array_num; index++) { + if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { + dbg("calling preinit function for %s at %p", + obj_main->path, (void *)preinit_addr[index]); + LD_UTRACE(UTRACE_INIT_CALL, obj_main, + (void *)preinit_addr[index], 0, 0, obj_main->path); + call_init_pointer(obj_main, preinit_addr[index]); + } + } +} + +/* + * Call the finalization functions for each of the objects in "list" + * belonging to the DAG of "root" and referenced once. If NULL "root" + * is specified, every finalization function will be called regardless + * of the reference count and the list elements won't be freed. All of + * the objects are expected to have non-NULL fini functions. + */ +static void +objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) +{ + Objlist_Entry *elm; + struct dlerror_save *saved_msg; + Elf_Addr *fini_addr; + int index; + + assert(root == NULL || root->refcount == 1); + + if (root != NULL) + root->doomed = true; + + /* + * Preserve the current error message since a fini function might + * call into the dynamic linker and overwrite it. + */ + saved_msg = errmsg_save(); + do { + STAILQ_FOREACH(elm, list, link) { + if (root != NULL && + (elm->obj->refcount != 1 || + objlist_find(&root->dagmembers, elm->obj) == + NULL)) + continue; + /* Remove object from fini list to prevent recursive + * invocation. */ + STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); + /* Ensure that new references cannot be acquired. */ + elm->obj->doomed = true; + + hold_object(elm->obj); + lock_release(rtld_bind_lock, lockstate); + /* + * It is legal to have both DT_FINI and DT_FINI_ARRAY + * defined. When this happens, DT_FINI_ARRAY is + * processed first. + */ + fini_addr = (Elf_Addr *)elm->obj->fini_array; + if (fini_addr != NULL && elm->obj->fini_array_num > 0) { + for (index = elm->obj->fini_array_num - 1; + index >= 0; index--) { + if (fini_addr[index] != 0 && + fini_addr[index] != 1) { + dbg("calling fini function for %s at %p", + elm->obj->path, + (void *)fini_addr[index]); + LD_UTRACE(UTRACE_FINI_CALL, + elm->obj, + (void *)fini_addr[index], 0, + 0, elm->obj->path); + call_initfini_pointer(elm->obj, + fini_addr[index]); + } + } + } + if (elm->obj->fini != (Elf_Addr)NULL) { + dbg("calling fini function for %s at %p", + elm->obj->path, (void *)elm->obj->fini); + LD_UTRACE(UTRACE_FINI_CALL, elm->obj, + (void *)elm->obj->fini, 0, 0, + elm->obj->path); + call_initfini_pointer(elm->obj, elm->obj->fini); + } + wlock_acquire(rtld_bind_lock, lockstate); + unhold_object(elm->obj); + /* No need to free anything if process is going down. */ + if (root != NULL) + free(elm); + /* + * We must restart the list traversal after every fini + * call because a dlclose() call from the fini function + * or from another thread might have modified the + * reference counts. + */ + break; + } + } while (elm != NULL); + errmsg_restore(saved_msg); +} + +/* + * Call the initialization functions for each of the objects in + * "list". All of the objects are expected to have non-NULL init + * functions. + */ +static void +objlist_call_init(Objlist *list, RtldLockState *lockstate) +{ + Objlist_Entry *elm; + Obj_Entry *obj; + struct dlerror_save *saved_msg; + Elf_Addr *init_addr; + void (*reg)(void (*)(void)); + int index; + + /* + * Clean init_scanned flag so that objects can be rechecked and + * possibly initialized earlier if any of vectors called below + * cause the change by using dlopen. + */ + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker) + continue; + obj->init_scanned = false; + } + + /* + * Preserve the current error message since an init function might + * call into the dynamic linker and overwrite it. + */ + saved_msg = errmsg_save(); + STAILQ_FOREACH(elm, list, link) { + if (elm->obj->init_done) /* Initialized early. */ + continue; + /* + * Race: other thread might try to use this object before + * current one completes the initialization. Not much can be + * done here without better locking. + */ + elm->obj->init_done = true; + hold_object(elm->obj); + reg = NULL; + if (elm->obj == obj_main && obj_main->crt_no_init) { + reg = (void (*)(void (*)(void))) + get_program_var_addr("__libc_atexit", lockstate); + } + lock_release(rtld_bind_lock, lockstate); + if (reg != NULL) { + reg(rtld_exit); + rtld_exit_ptr = rtld_nop_exit; + } + + /* + * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. + * When this happens, DT_INIT is processed first. + */ + if (elm->obj->init != (Elf_Addr)NULL) { + dbg("calling init function for %s at %p", + elm->obj->path, (void *)elm->obj->init); + LD_UTRACE(UTRACE_INIT_CALL, elm->obj, + (void *)elm->obj->init, 0, 0, elm->obj->path); + call_init_pointer(elm->obj, elm->obj->init); + } + init_addr = (Elf_Addr *)elm->obj->init_array; + if (init_addr != NULL) { + for (index = 0; index < elm->obj->init_array_num; + index++) { + if (init_addr[index] != 0 && + init_addr[index] != 1) { + dbg("calling init function for %s at %p", + elm->obj->path, + (void *)init_addr[index]); + LD_UTRACE(UTRACE_INIT_CALL, elm->obj, + (void *)init_addr[index], 0, 0, + elm->obj->path); + call_init_pointer(elm->obj, + init_addr[index]); + } + } + } + wlock_acquire(rtld_bind_lock, lockstate); + unhold_object(elm->obj); + } + errmsg_restore(saved_msg); +} + +static void +objlist_clear(Objlist *list) +{ + Objlist_Entry *elm; + + while (!STAILQ_EMPTY(list)) { + elm = STAILQ_FIRST(list); + STAILQ_REMOVE_HEAD(list, link); + free(elm); + } +} + +static Objlist_Entry * +objlist_find(Objlist *list, const Obj_Entry *obj) +{ + Objlist_Entry *elm; + + STAILQ_FOREACH(elm, list, link) + if (elm->obj == obj) + return elm; + return (NULL); +} + +static void +objlist_init(Objlist *list) +{ + STAILQ_INIT(list); +} + +static void +objlist_push_head(Objlist *list, Obj_Entry *obj) +{ + Objlist_Entry *elm; + + elm = NEW(Objlist_Entry); + elm->obj = obj; + STAILQ_INSERT_HEAD(list, elm, link); +} + +static void +objlist_push_tail(Objlist *list, Obj_Entry *obj) +{ + Objlist_Entry *elm; + + elm = NEW(Objlist_Entry); + elm->obj = obj; + STAILQ_INSERT_TAIL(list, elm, link); +} + +static void +objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) +{ + Objlist_Entry *elm, *listelm; + + STAILQ_FOREACH(listelm, list, link) { + if (listelm->obj == listobj) + break; + } + elm = NEW(Objlist_Entry); + elm->obj = obj; + if (listelm != NULL) + STAILQ_INSERT_AFTER(list, listelm, elm, link); + else + STAILQ_INSERT_TAIL(list, elm, link); +} + +static void +objlist_remove(Objlist *list, Obj_Entry *obj) +{ + Objlist_Entry *elm; + + if ((elm = objlist_find(list, obj)) != NULL) { + STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); + free(elm); + } +} + +/* + * Relocate dag rooted in the specified object. + * Returns 0 on success, or -1 on failure. + */ + +static int +relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, + int flags, RtldLockState *lockstate) +{ + Objlist_Entry *elm; + int error; + + error = 0; + STAILQ_FOREACH(elm, &root->dagmembers, link) { + error = relocate_object(elm->obj, bind_now, rtldobj, flags, + lockstate); + if (error == -1) + break; + } + return (error); +} + +/* + * Prepare for, or clean after, relocating an object marked with + * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only + * segments are remapped read-write. After relocations are done, the + * segment's permissions are returned back to the modes specified in + * the phdrs. If any relocation happened, or always for wired + * program, COW is triggered. + */ +static int +reloc_textrel_prot(Obj_Entry *obj, bool before) +{ + const Elf_Phdr *ph; + void *base; + size_t l, sz; + int prot; + + for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; l--, ph++) { + if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) + continue; + base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); + sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - + rtld_trunc_page(ph->p_vaddr); + prot = before ? (PROT_READ | PROT_WRITE) : + convert_prot(ph->p_flags); + if (mprotect(base, sz, prot) == -1) { + _rtld_error("%s: Cannot write-%sable text segment: %s", + obj->path, before ? "en" : "dis", + rtld_strerror(errno)); + return (-1); + } + } + return (0); +} + +/* Process RELR relative relocations. */ +static void +reloc_relr(Obj_Entry *obj) +{ + const Elf_Relr *relr, *relrlim; + Elf_Addr *where; + + relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); + for (relr = obj->relr; relr < relrlim; relr++) { + Elf_Relr entry = *relr; + + if ((entry & 1) == 0) { + where = (Elf_Addr *)(obj->relocbase + entry); + *where++ += (Elf_Addr)obj->relocbase; + } else { + for (long i = 0; (entry >>= 1) != 0; i++) + if ((entry & 1) != 0) + where[i] += (Elf_Addr)obj->relocbase; + where += CHAR_BIT * sizeof(Elf_Relr) - 1; + } + } +} + +/* + * Relocate single object. + * Returns 0 on success, or -1 on failure. + */ +static int +relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, + RtldLockState *lockstate) +{ + if (obj->relocated) + return (0); + obj->relocated = true; + if (obj != rtldobj) + dbg("relocating \"%s\"", obj->path); + + if (obj->symtab == NULL || obj->strtab == NULL || + !(obj->valid_hash_sysv || obj->valid_hash_gnu)) + dbg("object %s has no run-time symbol table", obj->path); + + /* There are relocations to the write-protected text segment. */ + if (obj->textrel && reloc_textrel_prot(obj, true) != 0) + return (-1); + + /* Process the non-PLT non-IFUNC relocations. */ + if (reloc_non_plt(obj, rtldobj, flags, lockstate)) + return (-1); + reloc_relr(obj); + + /* Re-protected the text segment. */ + if (obj->textrel && reloc_textrel_prot(obj, false) != 0) + return (-1); + + /* Set the special PLT or GOT entries. */ + init_pltgot(obj); + + /* Process the PLT relocations. */ + if (reloc_plt(obj, flags, lockstate) == -1) + return (-1); + /* Relocate the jump slots if we are doing immediate binding. */ + if ((obj->bind_now || bind_now) && + reloc_jmpslots(obj, flags, lockstate) == -1) + return (-1); + + if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) + return (-1); + + /* + * Set up the magic number and version in the Obj_Entry. These + * were checked in the crt1.o from the original ElfKit, so we + * set them for backward compatibility. + */ + obj->magic = RTLD_MAGIC; + obj->version = RTLD_VERSION; + + return (0); +} + +/* + * Relocate newly-loaded shared objects. The argument is a pointer to + * the Obj_Entry for the first such object. All objects from the first + * to the end of the list of objects are relocated. Returns 0 on success, + * or -1 on failure. + */ +static int +relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, + RtldLockState *lockstate) +{ + Obj_Entry *obj; + int error; + + for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { + if (obj->marker) + continue; + error = relocate_object(obj, bind_now, rtldobj, flags, + lockstate); + if (error == -1) + break; + } + return (error); +} + +/* + * The handling of R_MACHINE_IRELATIVE relocations and jumpslots + * referencing STT_GNU_IFUNC symbols is postponed till the other + * relocations are done. The indirect functions specified as + * ifunc are allowed to call other symbols, so we need to have + * objects relocated before asking for resolution from indirects. + * + * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, + * instead of the usual lazy handling of PLT slots. It is + * consistent with how GNU does it. + */ +static int +resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, + RtldLockState *lockstate) +{ + if (obj->ifuncs_resolved) + return (0); + obj->ifuncs_resolved = true; + if (!obj->irelative && !obj->irelative_nonplt && + !((obj->bind_now || bind_now) && obj->gnu_ifunc) && + !obj->non_plt_gnu_ifunc) + return (0); + if (obj_disable_relro(obj) == -1 || + (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || + (obj->irelative_nonplt && + reloc_iresolve_nonplt(obj, lockstate) == -1) || + ((obj->bind_now || bind_now) && obj->gnu_ifunc && + reloc_gnu_ifunc(obj, flags, lockstate) == -1) || + (obj->non_plt_gnu_ifunc && + reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, + lockstate) == -1) || + obj_enforce_relro(obj) == -1) + return (-1); + return (0); +} + +static int +initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, + RtldLockState *lockstate) +{ + Objlist_Entry *elm; + Obj_Entry *obj; + + STAILQ_FOREACH(elm, list, link) { + obj = elm->obj; + if (obj->marker) + continue; + if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) + return (-1); + } + return (0); +} + +/* + * Cleanup procedure. It will be called (by the atexit mechanism) just + * before the process exits. + */ +static void +rtld_exit(void) +{ + RtldLockState lockstate; + + wlock_acquire(rtld_bind_lock, &lockstate); + dbg("rtld_exit()"); + objlist_call_fini(&list_fini, NULL, &lockstate); + /* No need to remove the items from the list, since we are exiting. */ + if (!libmap_disable) + lm_fini(); + lock_release(rtld_bind_lock, &lockstate); +} + +static void +rtld_nop_exit(void) +{ +} + +/* + * Iterate over a search path, translate each element, and invoke the + * callback on the result. + */ +static void * +path_enumerate(const char *path, path_enum_proc callback, + const char *refobj_path, void *arg) +{ + const char *trans; + if (path == NULL) + return (NULL); + + path += strspn(path, ":;"); + while (*path != '\0') { + size_t len; + char *res; + + len = strcspn(path, ":;"); + trans = lm_findn(refobj_path, path, len); + if (trans) + res = callback(trans, strlen(trans), arg); + else + res = callback(path, len, arg); + + if (res != NULL) + return (res); + + path += len; + path += strspn(path, ":;"); + } + + return (NULL); +} + +struct try_library_args { + const char *name; + size_t namelen; + char *buffer; + size_t buflen; + int fd; +}; + +static void * +try_library_path(const char *dir, size_t dirlen, void *param) +{ + struct try_library_args *arg; + int fd; + + arg = param; + if (*dir == '/' || trust) { + char *pathname; + + if (dirlen + 1 + arg->namelen + 1 > arg->buflen) + return (NULL); + + pathname = arg->buffer; + strncpy(pathname, dir, dirlen); + pathname[dirlen] = '/'; + strcpy(pathname + dirlen + 1, arg->name); + + dbg(" Trying \"%s\"", pathname); + fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); + if (fd >= 0) { + dbg(" Opened \"%s\", fd %d", pathname, fd); + pathname = xmalloc(dirlen + 1 + arg->namelen + 1); + strcpy(pathname, arg->buffer); + arg->fd = fd; + return (pathname); + } else { + dbg(" Failed to open \"%s\": %s", pathname, + rtld_strerror(errno)); + } + } + return (NULL); +} + +static char * +search_library_path(const char *name, const char *path, const char *refobj_path, + int *fdp) +{ + char *p; + struct try_library_args arg; + + if (path == NULL) + return (NULL); + + arg.name = name; + arg.namelen = strlen(name); + arg.buffer = xmalloc(PATH_MAX); + arg.buflen = PATH_MAX; + arg.fd = -1; + + p = path_enumerate(path, try_library_path, refobj_path, &arg); + *fdp = arg.fd; + + free(arg.buffer); + + return (p); +} + +/* + * Finds the library with the given name using the directory descriptors + * listed in the LD_LIBRARY_PATH_FDS environment variable. + * + * Returns a freshly-opened close-on-exec file descriptor for the library, + * or -1 if the library cannot be found. + */ +static char * +search_library_pathfds(const char *name, const char *path, int *fdp) +{ + char *envcopy, *fdstr, *found, *last_token; + size_t len; + int dirfd, fd; + + dbg("%s('%s', '%s', fdp)", __func__, name, path); + + /* Don't load from user-specified libdirs into setuid binaries. */ + if (!trust) + return (NULL); + + /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ + if (path == NULL) + return (NULL); + + /* LD_LIBRARY_PATH_FDS only works with relative paths. */ + if (name[0] == '/') { + dbg("Absolute path (%s) passed to %s", name, __func__); + return (NULL); + } + + /* + * Use strtok_r() to walk the FD:FD:FD list. This requires a local + * copy of the path, as strtok_r rewrites separator tokens + * with '\0'. + */ + found = NULL; + envcopy = xstrdup(path); + for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; + fdstr = strtok_r(NULL, ":", &last_token)) { + dirfd = parse_integer(fdstr); + if (dirfd < 0) { + _rtld_error("failed to parse directory FD: '%s'", + fdstr); + break; + } + fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); + if (fd >= 0) { + *fdp = fd; + len = strlen(fdstr) + strlen(name) + 3; + found = xmalloc(len); + if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < + 0) { + _rtld_error("error generating '%d/%s'", dirfd, + name); + rtld_die(); + } + dbg("open('%s') => %d", found, fd); + break; + } + } + free(envcopy); + + return (found); +} + +int +dlclose(void *handle) +{ + RtldLockState lockstate; + int error; + + wlock_acquire(rtld_bind_lock, &lockstate); + error = dlclose_locked(handle, &lockstate); + lock_release(rtld_bind_lock, &lockstate); + return (error); +} + +static int +dlclose_locked(void *handle, RtldLockState *lockstate) +{ + Obj_Entry *root; + + root = dlcheck(handle); + if (root == NULL) + return (-1); + LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, + root->path); + + /* Unreference the object and its dependencies. */ + root->dl_refcount--; + + if (root->refcount == 1) { + /* + * The object will be no longer referenced, so we must unload + * it. First, call the fini functions. + */ + objlist_call_fini(&list_fini, root, lockstate); + + unref_dag(root); + + /* Finish cleaning up the newly-unreferenced objects. */ + GDB_STATE(RT_DELETE, &root->linkmap); + unload_object(root, lockstate); + GDB_STATE(RT_CONSISTENT, NULL); + } else + unref_dag(root); + + LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); + return (0); +} + +char * +dlerror(void) +{ + if (*(lockinfo.dlerror_seen()) != 0) + return (NULL); + *lockinfo.dlerror_seen() = 1; + return (lockinfo.dlerror_loc()); +} + +/* + * This function is deprecated and has no effect. + */ +void +dllockinit(void *context, void *(*_lock_create)(void *context)__unused, + void (*_rlock_acquire)(void *lock) __unused, + void (*_wlock_acquire)(void *lock) __unused, + void (*_lock_release)(void *lock) __unused, + void (*_lock_destroy)(void *lock) __unused, + void (*context_destroy)(void *context)) +{ + static void *cur_context; + static void (*cur_context_destroy)(void *); + + /* Just destroy the context from the previous call, if necessary. */ + if (cur_context_destroy != NULL) + cur_context_destroy(cur_context); + cur_context = context; + cur_context_destroy = context_destroy; +} + +void * +dlopen(const char *name, int mode) +{ + return (rtld_dlopen(name, -1, mode)); +} + +void * +fdlopen(int fd, int mode) +{ + return (rtld_dlopen(NULL, fd, mode)); +} + +static void * +rtld_dlopen(const char *name, int fd, int mode) +{ + RtldLockState lockstate; + int lo_flags; + + LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); + ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; + if (ld_tracing != NULL) { + rlock_acquire(rtld_bind_lock, &lockstate); + if (sigsetjmp(lockstate.env, 0) != 0) + lock_upgrade(rtld_bind_lock, &lockstate); + environ = __DECONST(char **, + *get_program_var_addr("environ", &lockstate)); + lock_release(rtld_bind_lock, &lockstate); + } + lo_flags = RTLD_LO_DLOPEN; + if (mode & RTLD_NODELETE) + lo_flags |= RTLD_LO_NODELETE; + if (mode & RTLD_NOLOAD) + lo_flags |= RTLD_LO_NOLOAD; + if (mode & RTLD_DEEPBIND) + lo_flags |= RTLD_LO_DEEPBIND; + if (ld_tracing != NULL) + lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; + + return (dlopen_object(name, fd, obj_main, lo_flags, + mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); +} + +static void +dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) +{ + obj->dl_refcount--; + unref_dag(obj); + if (obj->refcount == 0) + unload_object(obj, lockstate); +} + +static Obj_Entry * +dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, + int mode, RtldLockState *lockstate) +{ + Obj_Entry *obj; + Objlist initlist; + RtldLockState mlockstate; + int result; + + dbg( + "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", + name != NULL ? name : "<null>", fd, + refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); + objlist_init(&initlist); + + if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { + wlock_acquire(rtld_bind_lock, &mlockstate); + lockstate = &mlockstate; + } + GDB_STATE(RT_ADD, NULL); + + obj = NULL; + if (name == NULL && fd == -1) { + obj = obj_main; + obj->refcount++; + } else { + obj = load_object(name, fd, refobj, lo_flags); + } + + if (obj != NULL) { + obj->dl_refcount++; + if ((mode & RTLD_GLOBAL) != 0 && + objlist_find(&list_global, obj) == NULL) + objlist_push_tail(&list_global, obj); + + if (!obj->init_done) { + /* We loaded something new and have to init something. + */ + if ((lo_flags & RTLD_LO_DEEPBIND) != 0) + obj->deepbind = true; + result = 0; + if ((lo_flags & (RTLD_LO_EARLY | + RTLD_LO_IGNSTLS)) == 0 && + obj->static_tls && !allocate_tls_offset(obj)) { + _rtld_error( + "%s: No space available for static Thread Local Storage", + obj->path); + result = -1; + } + if (result != -1) + result = load_needed_objects(obj, + lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | + RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); + init_dag(obj); + ref_dag(obj); + if (result != -1) + result = rtld_verify_versions(&obj->dagmembers); + if (result != -1 && ld_tracing) + goto trace; + if (result == -1 || relocate_object_dag(obj, + (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, + (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, + lockstate) == -1) { + dlopen_cleanup(obj, lockstate); + obj = NULL; + } else if ((lo_flags & RTLD_LO_EARLY) != 0) { + /* + * Do not call the init functions for early + * loaded filtees. The image is still not + * initialized enough for them to work. + * + * Our object is found by the global object list + * and will be ordered among all init calls done + * right before transferring control to main. + */ + } else { + /* Make list of init functions to call. */ + initlist_for_loaded_obj(obj, obj, &initlist); + } + /* + * Process all no_delete or global objects here, given + * them own DAGs to prevent their dependencies from + * being unloaded. This has to be done after we have + * loaded all of the dependencies, so that we do not + * miss any. + */ + if (obj != NULL) + process_z(obj); + } else { + /* + * Bump the reference counts for objects on this DAG. If + * this is the first dlopen() call for the object that + * was already loaded as a dependency, initialize the + * dag starting at it. + */ + init_dag(obj); + ref_dag(obj); + + if ((lo_flags & RTLD_LO_TRACE) != 0) + goto trace; + } + if (obj != NULL && + ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && + !obj->ref_nodel) { + dbg("obj %s nodelete", obj->path); + ref_dag(obj); + obj->z_nodelete = obj->ref_nodel = true; + } + } + + LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, + name); + GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); + + if ((lo_flags & RTLD_LO_EARLY) == 0) { + map_stacks_exec(lockstate); + if (obj != NULL) + distribute_static_tls(&initlist); + } + + if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == + RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, + lockstate) == -1) { + objlist_clear(&initlist); + dlopen_cleanup(obj, lockstate); + if (lockstate == &mlockstate) + lock_release(rtld_bind_lock, lockstate); + return (NULL); + } + + if ((lo_flags & RTLD_LO_EARLY) == 0) { + /* Call the init functions. */ + objlist_call_init(&initlist, lockstate); + } + objlist_clear(&initlist); + if (lockstate == &mlockstate) + lock_release(rtld_bind_lock, lockstate); + return (obj); +trace: + trace_loaded_objects(obj, false); + if (lockstate == &mlockstate) + lock_release(rtld_bind_lock, lockstate); + exit(0); +} + +static void * +do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, + int flags) +{ + DoneList donelist; + const Obj_Entry *obj, *defobj; + const Elf_Sym *def; + SymLook req; + RtldLockState lockstate; + tls_index ti; + void *sym; + int res; + + def = NULL; + defobj = NULL; + symlook_init(&req, name); + req.ventry = ve; + req.flags = flags | SYMLOOK_IN_PLT; + req.lockstate = &lockstate; + + LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); + rlock_acquire(rtld_bind_lock, &lockstate); + if (sigsetjmp(lockstate.env, 0) != 0) + lock_upgrade(rtld_bind_lock, &lockstate); + if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || + handle == RTLD_SELF) { + if ((obj = obj_from_addr(retaddr)) == NULL) { + _rtld_error("Cannot determine caller's shared object"); + lock_release(rtld_bind_lock, &lockstate); + LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); + return (NULL); + } + if (handle == NULL) { /* Just the caller's shared object. */ + res = symlook_obj(&req, obj); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + } else if (handle == RTLD_NEXT || /* Objects after caller's */ + handle == RTLD_SELF) { /* ... caller included */ + if (handle == RTLD_NEXT) + obj = globallist_next(obj); + for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { + if (obj->marker) + continue; + res = symlook_obj(&req, obj); + if (res == 0) { + if (def == NULL || + (ld_dynamic_weak && + ELF_ST_BIND( + req.sym_out->st_info) != + STB_WEAK)) { + def = req.sym_out; + defobj = req.defobj_out; + if (!ld_dynamic_weak || + ELF_ST_BIND(def->st_info) != + STB_WEAK) + break; + } + } + } + /* + * Search the dynamic linker itself, and possibly + * resolve the symbol from there. This is how the + * application links to dynamic linker services such as + * dlopen. Note that we ignore ld_dynamic_weak == false + * case, always overriding weak symbols by rtld + * definitions. + */ + if (def == NULL || + ELF_ST_BIND(def->st_info) == STB_WEAK) { + res = symlook_obj(&req, &obj_rtld); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + } + } else { + assert(handle == RTLD_DEFAULT); + res = symlook_default(&req, obj); + if (res == 0) { + defobj = req.defobj_out; + def = req.sym_out; + } + } + } else { + if ((obj = dlcheck(handle)) == NULL) { + lock_release(rtld_bind_lock, &lockstate); + LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); + return (NULL); + } + + donelist_init(&donelist); + if (obj->mainprog) { + /* Handle obtained by dlopen(NULL, ...) implies global + * scope. */ + res = symlook_global(&req, &donelist); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + /* + * Search the dynamic linker itself, and possibly + * resolve the symbol from there. This is how the + * application links to dynamic linker services such as + * dlopen. + */ + if (def == NULL || + ELF_ST_BIND(def->st_info) == STB_WEAK) { + res = symlook_obj(&req, &obj_rtld); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + } + } else { + /* Search the whole DAG rooted at the given object. */ + res = symlook_list(&req, &obj->dagmembers, &donelist); + if (res == 0) { + def = req.sym_out; + defobj = req.defobj_out; + } + } + } + + if (def != NULL) { + lock_release(rtld_bind_lock, &lockstate); + + /* + * The value required by the caller is derived from the value + * of the symbol. this is simply the relocated value of the + * symbol. + */ + if (ELF_ST_TYPE(def->st_info) == STT_FUNC) + sym = make_function_pointer(def, defobj); + else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) + sym = rtld_resolve_ifunc(defobj, def); + else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { + ti.ti_module = defobj->tlsindex; + ti.ti_offset = def->st_value - TLS_DTV_OFFSET; + sym = __tls_get_addr(&ti); + } else + sym = defobj->relocbase + def->st_value; + LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); + return (sym); + } + + _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", + ve != NULL ? ve->name : ""); + lock_release(rtld_bind_lock, &lockstate); + LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); + return (NULL); +} + +void * +dlsym(void *handle, const char *name) +{ + return (do_dlsym(handle, name, __builtin_return_address(0), NULL, + SYMLOOK_DLSYM)); +} + +dlfunc_t +dlfunc(void *handle, const char *name) +{ + union { + void *d; + dlfunc_t f; + } rv; + + rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, + SYMLOOK_DLSYM); + return (rv.f); +} + +void * +dlvsym(void *handle, const char *name, const char *version) +{ + Ver_Entry ventry; + + ventry.name = version; + ventry.file = NULL; + ventry.hash = elf_hash(version); + ventry.flags = 0; + return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, + SYMLOOK_DLSYM)); +} + +int +_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) +{ + const Obj_Entry *obj; + RtldLockState lockstate; + + rlock_acquire(rtld_bind_lock, &lockstate); + obj = obj_from_addr(addr); + if (obj == NULL) { + _rtld_error("No shared object contains address"); + lock_release(rtld_bind_lock, &lockstate); + return (0); + } + rtld_fill_dl_phdr_info(obj, phdr_info); + lock_release(rtld_bind_lock, &lockstate); + return (1); +} + +int +dladdr(const void *addr, Dl_info *info) +{ + const Obj_Entry *obj; + const Elf_Sym *def; + void *symbol_addr; + unsigned long symoffset; + RtldLockState lockstate; + + rlock_acquire(rtld_bind_lock, &lockstate); + obj = obj_from_addr(addr); + if (obj == NULL) { + _rtld_error("No shared object contains address"); + lock_release(rtld_bind_lock, &lockstate); + return (0); + } + info->dli_fname = obj->path; + info->dli_fbase = obj->mapbase; + info->dli_saddr = (void *)0; + info->dli_sname = NULL; + + /* + * Walk the symbol list looking for the symbol whose address is + * closest to the address sent in. + */ + for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { + def = obj->symtab + symoffset; + + /* + * For skip the symbol if st_shndx is either SHN_UNDEF or + * SHN_COMMON. + */ + if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) + continue; + + /* + * If the symbol is greater than the specified address, or if it + * is further away from addr than the current nearest symbol, + * then reject it. + */ + symbol_addr = obj->relocbase + def->st_value; + if (symbol_addr > addr || symbol_addr < info->dli_saddr) + continue; + + /* Update our idea of the nearest symbol. */ + info->dli_sname = obj->strtab + def->st_name; + info->dli_saddr = symbol_addr; + + /* Exact match? */ + if (info->dli_saddr == addr) + break; + } + lock_release(rtld_bind_lock, &lockstate); + return (1); +} + +int +dlinfo(void *handle, int request, void *p) +{ + const Obj_Entry *obj; + RtldLockState lockstate; + int error; + + rlock_acquire(rtld_bind_lock, &lockstate); + + if (handle == NULL || handle == RTLD_SELF) { + void *retaddr; + + retaddr = __builtin_return_address(0); /* __GNUC__ only */ + if ((obj = obj_from_addr(retaddr)) == NULL) + _rtld_error("Cannot determine caller's shared object"); + } else + obj = dlcheck(handle); + + if (obj == NULL) { + lock_release(rtld_bind_lock, &lockstate); + return (-1); + } + + error = 0; + switch (request) { + case RTLD_DI_LINKMAP: + *((struct link_map const **)p) = &obj->linkmap; + break; + case RTLD_DI_ORIGIN: + error = rtld_dirname(obj->path, p); + break; + + case RTLD_DI_SERINFOSIZE: + case RTLD_DI_SERINFO: + error = do_search_info(obj, request, (struct dl_serinfo *)p); + break; + + default: + _rtld_error("Invalid request %d passed to dlinfo()", request); + error = -1; + } + + lock_release(rtld_bind_lock, &lockstate); + + return (error); +} + +static void +rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) +{ + phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; + phdr_info->dlpi_name = obj->path; + phdr_info->dlpi_phdr = obj->phdr; + phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); + phdr_info->dlpi_tls_modid = obj->tlsindex; + phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), + obj->tlsindex, 0, true); + phdr_info->dlpi_adds = obj_loads; + phdr_info->dlpi_subs = obj_loads - obj_count; +} + +/* + * It's completely UB to actually use this, so extreme caution is advised. It's + * probably not what you want. + */ +int +_dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) +{ + struct dl_phdr_info phdr_info; + Obj_Entry *obj; + int error; + + for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; + obj = globallist_next(obj)) { + rtld_fill_dl_phdr_info(obj, &phdr_info); + error = callback(&phdr_info, sizeof(phdr_info), param); + if (error != 0) + return (error); + } + + rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); + return (callback(&phdr_info, sizeof(phdr_info), param)); +} + +int +dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) +{ + struct dl_phdr_info phdr_info; + Obj_Entry *obj, marker; + RtldLockState bind_lockstate, phdr_lockstate; + int error; + + init_marker(&marker); + error = 0; + + wlock_acquire(rtld_phdr_lock, &phdr_lockstate); + wlock_acquire(rtld_bind_lock, &bind_lockstate); + for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { + TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); + rtld_fill_dl_phdr_info(obj, &phdr_info); + hold_object(obj); + lock_release(rtld_bind_lock, &bind_lockstate); + + error = callback(&phdr_info, sizeof phdr_info, param); + + wlock_acquire(rtld_bind_lock, &bind_lockstate); + unhold_object(obj); + obj = globallist_next(&marker); + TAILQ_REMOVE(&obj_list, &marker, next); + if (error != 0) { + lock_release(rtld_bind_lock, &bind_lockstate); + lock_release(rtld_phdr_lock, &phdr_lockstate); + return (error); + } + } + + if (error == 0) { + rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); + lock_release(rtld_bind_lock, &bind_lockstate); + error = callback(&phdr_info, sizeof(phdr_info), param); + } + lock_release(rtld_phdr_lock, &phdr_lockstate); + return (error); +} + +static void * +fill_search_info(const char *dir, size_t dirlen, void *param) +{ + struct fill_search_info_args *arg; + + arg = param; + + if (arg->request == RTLD_DI_SERINFOSIZE) { + arg->serinfo->dls_cnt++; + arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + + 1; + } else { + struct dl_serpath *s_entry; + + s_entry = arg->serpath; + s_entry->dls_name = arg->strspace; + s_entry->dls_flags = arg->flags; + + strncpy(arg->strspace, dir, dirlen); + arg->strspace[dirlen] = '\0'; + + arg->strspace += dirlen + 1; + arg->serpath++; + } + + return (NULL); +} + +static int +do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) +{ + struct dl_serinfo _info; + struct fill_search_info_args args; + + args.request = RTLD_DI_SERINFOSIZE; + args.serinfo = &_info; + + _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); + _info.dls_cnt = 0; + + path_enumerate(obj->rpath, fill_search_info, NULL, &args); + path_enumerate(ld_library_path, fill_search_info, NULL, &args); + path_enumerate(obj->runpath, fill_search_info, NULL, &args); + path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, + &args); + if (!obj->z_nodeflib) + path_enumerate(ld_standard_library_path, fill_search_info, NULL, + &args); + + if (request == RTLD_DI_SERINFOSIZE) { + info->dls_size = _info.dls_size; + info->dls_cnt = _info.dls_cnt; + return (0); + } + + if (info->dls_cnt != _info.dls_cnt || + info->dls_size != _info.dls_size) { + _rtld_error( + "Uninitialized Dl_serinfo struct passed to dlinfo()"); + return (-1); + } + + args.request = RTLD_DI_SERINFO; + args.serinfo = info; + args.serpath = &info->dls_serpath[0]; + args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; + + args.flags = LA_SER_RUNPATH; + if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) + return (-1); + + args.flags = LA_SER_LIBPATH; + if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != + NULL) + return (-1); + + args.flags = LA_SER_RUNPATH; + if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) + return (-1); + + args.flags = LA_SER_CONFIG; + if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, + &args) != NULL) + return (-1); + + args.flags = LA_SER_DEFAULT; + if (!obj->z_nodeflib && + path_enumerate(ld_standard_library_path, fill_search_info, NULL, + &args) != NULL) + return (-1); + return (0); +} + +static int +rtld_dirname(const char *path, char *bname) +{ + const char *endp; + + /* Empty or NULL string gets treated as "." */ + if (path == NULL || *path == '\0') { + bname[0] = '.'; + bname[1] = '\0'; + return (0); + } + + /* Strip trailing slashes */ + endp = path + strlen(path) - 1; + while (endp > path && *endp == '/') + endp--; + + /* Find the start of the dir */ + while (endp > path && *endp != '/') + endp--; + + /* Either the dir is "/" or there are no slashes */ + if (endp == path) { + bname[0] = *endp == '/' ? '/' : '.'; + bname[1] = '\0'; + return (0); + } else { + do { + endp--; + } while (endp > path && *endp == '/'); + } + + if (endp - path + 2 > PATH_MAX) { + _rtld_error("Filename is too long: %s", path); + return (-1); + } + + strncpy(bname, path, endp - path + 1); + bname[endp - path + 1] = '\0'; + return (0); +} + +static int +rtld_dirname_abs(const char *path, char *base) +{ + char *last; + + if (realpath(path, base) == NULL) { + _rtld_error("realpath \"%s\" failed (%s)", path, + rtld_strerror(errno)); + return (-1); + } + dbg("%s -> %s", path, base); + last = strrchr(base, '/'); + if (last == NULL) { + _rtld_error("non-abs result from realpath \"%s\"", path); + return (-1); + } + if (last != base) + *last = '\0'; + return (0); +} + +static void +linkmap_add(Obj_Entry *obj) +{ + struct link_map *l, *prev; + + l = &obj->linkmap; + l->l_name = obj->path; + l->l_base = obj->mapbase; + l->l_ld = obj->dynamic; + l->l_addr = obj->relocbase; + + if (r_debug.r_map == NULL) { + r_debug.r_map = l; + return; + } + + /* + * Scan to the end of the list, but not past the entry for the + * dynamic linker, which we want to keep at the very end. + */ + for (prev = r_debug.r_map; + prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; + prev = prev->l_next) + ; + + /* Link in the new entry. */ + l->l_prev = prev; + l->l_next = prev->l_next; + if (l->l_next != NULL) + l->l_next->l_prev = l; + prev->l_next = l; +} + +static void +linkmap_delete(Obj_Entry *obj) +{ + struct link_map *l; + + l = &obj->linkmap; + if (l->l_prev == NULL) { + if ((r_debug.r_map = l->l_next) != NULL) + l->l_next->l_prev = NULL; + return; + } + + if ((l->l_prev->l_next = l->l_next) != NULL) + l->l_next->l_prev = l->l_prev; +} + +/* + * Function for the debugger to set a breakpoint on to gain control. + * + * The two parameters allow the debugger to easily find and determine + * what the runtime loader is doing and to whom it is doing it. + * + * When the loadhook trap is hit (r_debug_state, set at program + * initialization), the arguments can be found on the stack: + * + * +8 struct link_map *m + * +4 struct r_debug *rd + * +0 RetAddr + */ +void +r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) +{ + /* + * The following is a hack to force the compiler to emit calls to + * this function, even when optimizing. If the function is empty, + * the compiler is not obliged to emit any code for calls to it, + * even when marked __noinline. However, gdb depends on those + * calls being made. + */ + __compiler_membar(); +} + +/* + * A function called after init routines have completed. This can be used to + * break before a program's entry routine is called, and can be used when + * main is not available in the symbol table. + */ +void +_r_debug_postinit(struct link_map *m __unused) +{ + /* See r_debug_state(). */ + __compiler_membar(); +} + +static void +release_object(Obj_Entry *obj) +{ + if (obj->holdcount > 0) { + obj->unholdfree = true; + return; + } + munmap(obj->mapbase, obj->mapsize); + linkmap_delete(obj); + obj_free(obj); +} + +/* + * Get address of the pointer variable in the main program. + * Prefer non-weak symbol over the weak one. + */ +static const void ** +get_program_var_addr(const char *name, RtldLockState *lockstate) +{ + SymLook req; + DoneList donelist; + + symlook_init(&req, name); + req.lockstate = lockstate; + donelist_init(&donelist); + if (symlook_global(&req, &donelist) != 0) + return (NULL); + if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) + return ((const void **)make_function_pointer(req.sym_out, + req.defobj_out)); + else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) + return ((const void **)rtld_resolve_ifunc(req.defobj_out, + req.sym_out)); + else + return ((const void **)(req.defobj_out->relocbase + + req.sym_out->st_value)); +} + +/* + * Set a pointer variable in the main program to the given value. This + * is used to set key variables such as "environ" before any of the + * init functions are called. + */ +static void +set_program_var(const char *name, const void *value) +{ + const void **addr; + + if ((addr = get_program_var_addr(name, NULL)) != NULL) { + dbg("\"%s\": *%p <-- %p", name, addr, value); + *addr = value; + } +} + +/* + * Search the global objects, including dependencies and main object, + * for the given symbol. + */ +static int +symlook_global(SymLook *req, DoneList *donelist) +{ + SymLook req1; + const Objlist_Entry *elm; + int res; + + symlook_init_from_req(&req1, req); + + /* Search all objects loaded at program start up. */ + if (req->defobj_out == NULL || (ld_dynamic_weak && + ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { + res = symlook_list(&req1, &list_main, donelist); + if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || + ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + assert(req->defobj_out != NULL); + } + } + + /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ + STAILQ_FOREACH(elm, &list_global, link) { + if (req->defobj_out != NULL && (!ld_dynamic_weak || + ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) + break; + res = symlook_list(&req1, &elm->obj->dagmembers, donelist); + if (res == 0 && (req->defobj_out == NULL || + ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + assert(req->defobj_out != NULL); + } + } + + return (req->sym_out != NULL ? 0 : ESRCH); +} + +/* + * Given a symbol name in a referencing object, find the corresponding + * definition of the symbol. Returns a pointer to the symbol, or NULL if + * no definition was found. Returns a pointer to the Obj_Entry of the + * defining object via the reference parameter DEFOBJ_OUT. + */ +static int +symlook_default(SymLook *req, const Obj_Entry *refobj) +{ + DoneList donelist; + const Objlist_Entry *elm; + SymLook req1; + int res; + + donelist_init(&donelist); + symlook_init_from_req(&req1, req); + + /* + * Look first in the referencing object if linked symbolically, + * and similarly handle protected symbols. + */ + res = symlook_obj(&req1, refobj); + if (res == 0 && (refobj->symbolic || + ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || + refobj->deepbind)) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + assert(req->defobj_out != NULL); + } + if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) + donelist_check(&donelist, refobj); + + if (!refobj->deepbind) + symlook_global(req, &donelist); + + /* Search all dlopened DAGs containing the referencing object. */ + STAILQ_FOREACH(elm, &refobj->dldags, link) { + if (req->sym_out != NULL && (!ld_dynamic_weak || + ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) + break; + res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); + if (res == 0 && (req->sym_out == NULL || + ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + assert(req->defobj_out != NULL); + } + } + + if (refobj->deepbind) + symlook_global(req, &donelist); + + /* + * Search the dynamic linker itself, and possibly resolve the + * symbol from there. This is how the application links to + * dynamic linker services such as dlopen. + */ + if (req->sym_out == NULL || + ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { + res = symlook_obj(&req1, &obj_rtld); + if (res == 0) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + assert(req->defobj_out != NULL); + } + } + + return (req->sym_out != NULL ? 0 : ESRCH); +} + +static int +symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) +{ + const Elf_Sym *def; + const Obj_Entry *defobj; + const Objlist_Entry *elm; + SymLook req1; + int res; + + def = NULL; + defobj = NULL; + STAILQ_FOREACH(elm, objlist, link) { + if (donelist_check(dlp, elm->obj)) + continue; + symlook_init_from_req(&req1, req); + if ((res = symlook_obj(&req1, elm->obj)) == 0) { + if (def == NULL || (ld_dynamic_weak && + ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { + def = req1.sym_out; + defobj = req1.defobj_out; + if (!ld_dynamic_weak || + ELF_ST_BIND(def->st_info) != STB_WEAK) + break; + } + } + } + if (def != NULL) { + req->sym_out = def; + req->defobj_out = defobj; + return (0); + } + return (ESRCH); +} + +/* + * Search the chain of DAGS cointed to by the given Needed_Entry + * for a symbol of the given name. Each DAG is scanned completely + * before advancing to the next one. Returns a pointer to the symbol, + * or NULL if no definition was found. + */ +static int +symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) +{ + const Elf_Sym *def; + const Needed_Entry *n; + const Obj_Entry *defobj; + SymLook req1; + int res; + + def = NULL; + defobj = NULL; + symlook_init_from_req(&req1, req); + for (n = needed; n != NULL; n = n->next) { + if (n->obj == NULL || (res = symlook_list(&req1, + &n->obj->dagmembers, dlp)) != 0) + continue; + if (def == NULL || (ld_dynamic_weak && + ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { + def = req1.sym_out; + defobj = req1.defobj_out; + if (!ld_dynamic_weak || + ELF_ST_BIND(def->st_info) != STB_WEAK) + break; + } + } + if (def != NULL) { + req->sym_out = def; + req->defobj_out = defobj; + return (0); + } + return (ESRCH); +} + +static int +symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, + Needed_Entry *needed) +{ + DoneList donelist; + int flags; + + flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; + load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); + donelist_init(&donelist); + symlook_init_from_req(req1, req); + return (symlook_needed(req1, needed, &donelist)); +} + +/* + * Search the symbol table of a single shared object for a symbol of + * the given name and version, if requested. Returns a pointer to the + * symbol, or NULL if no definition was found. If the object is + * filter, return filtered symbol from filtee. + * + * The symbol's hash value is passed in for efficiency reasons; that + * eliminates many recomputations of the hash value. + */ +int +symlook_obj(SymLook *req, const Obj_Entry *obj) +{ + SymLook req1; + int res, mres; + + /* + * If there is at least one valid hash at this point, we prefer to + * use the faster GNU version if available. + */ + if (obj->valid_hash_gnu) + mres = symlook_obj1_gnu(req, obj); + else if (obj->valid_hash_sysv) + mres = symlook_obj1_sysv(req, obj); + else + return (EINVAL); + + if (mres == 0) { + if (obj->needed_filtees != NULL) { + res = symlook_obj_load_filtees(req, &req1, obj, + obj->needed_filtees); + if (res == 0) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + } + return (res); + } + if (obj->needed_aux_filtees != NULL) { + res = symlook_obj_load_filtees(req, &req1, obj, + obj->needed_aux_filtees); + if (res == 0) { + req->sym_out = req1.sym_out; + req->defobj_out = req1.defobj_out; + return (res); + } + } + } + return (mres); +} + +/* Symbol match routine common to both hash functions */ +static bool +matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, + const unsigned long symnum) +{ + Elf_Versym verndx; + const Elf_Sym *symp; + const char *strp; + + symp = obj->symtab + symnum; + strp = obj->strtab + symp->st_name; + + switch (ELF_ST_TYPE(symp->st_info)) { + case STT_FUNC: + case STT_NOTYPE: + case STT_OBJECT: + case STT_COMMON: + case STT_GNU_IFUNC: + if (symp->st_value == 0) + return (false); + /* fallthrough */ + case STT_TLS: + if (symp->st_shndx != SHN_UNDEF) + break; + else if (((req->flags & SYMLOOK_IN_PLT) == 0) && + (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) + break; + /* fallthrough */ + default: + return (false); + } + if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) + return (false); + + if (req->ventry == NULL) { + if (obj->versyms != NULL) { + verndx = VER_NDX(obj->versyms[symnum]); + if (verndx > obj->vernum) { + _rtld_error( + "%s: symbol %s references wrong version %d", + obj->path, obj->strtab + symnum, verndx); + return (false); + } + /* + * If we are not called from dlsym (i.e. this + * is a normal relocation from unversioned + * binary), accept the symbol immediately if + * it happens to have first version after this + * shared object became versioned. Otherwise, + * if symbol is versioned and not hidden, + * remember it. If it is the only symbol with + * this name exported by the shared object, it + * will be returned as a match by the calling + * function. If symbol is global (verndx < 2) + * accept it unconditionally. + */ + if ((req->flags & SYMLOOK_DLSYM) == 0 && + verndx == VER_NDX_GIVEN) { + result->sym_out = symp; + return (true); + } else if (verndx >= VER_NDX_GIVEN) { + if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == + 0) { + if (result->vsymp == NULL) + result->vsymp = symp; + result->vcount++; + } + return (false); + } + } + result->sym_out = symp; + return (true); + } + if (obj->versyms == NULL) { + if (object_match_name(obj, req->ventry->name)) { + _rtld_error( + "%s: object %s should provide version %s for symbol %s", + obj_rtld.path, obj->path, req->ventry->name, + obj->strtab + symnum); + return (false); + } + } else { + verndx = VER_NDX(obj->versyms[symnum]); + if (verndx > obj->vernum) { + _rtld_error("%s: symbol %s references wrong version %d", + obj->path, obj->strtab + symnum, verndx); + return (false); + } + if (obj->vertab[verndx].hash != req->ventry->hash || + strcmp(obj->vertab[verndx].name, req->ventry->name)) { + /* + * Version does not match. Look if this is a + * global symbol and if it is not hidden. If + * global symbol (verndx < 2) is available, + * use it. Do not return symbol if we are + * called by dlvsym, because dlvsym looks for + * a specific version and default one is not + * what dlvsym wants. + */ + if ((req->flags & SYMLOOK_DLSYM) || + (verndx >= VER_NDX_GIVEN) || + (obj->versyms[symnum] & VER_NDX_HIDDEN)) + return (false); + } + } + result->sym_out = symp; + return (true); +} + +/* + * Search for symbol using SysV hash function. + * obj->buckets is known not to be NULL at this point; the test for this was + * performed with the obj->valid_hash_sysv assignment. + */ +static int +symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) +{ + unsigned long symnum; + Sym_Match_Result matchres; + + matchres.sym_out = NULL; + matchres.vsymp = NULL; + matchres.vcount = 0; + + for (symnum = obj->buckets[req->hash % obj->nbuckets]; + symnum != STN_UNDEF; symnum = obj->chains[symnum]) { + if (symnum >= obj->nchains) + return (ESRCH); /* Bad object */ + + if (matched_symbol(req, obj, &matchres, symnum)) { + req->sym_out = matchres.sym_out; + req->defobj_out = obj; + return (0); + } + } + if (matchres.vcount == 1) { + req->sym_out = matchres.vsymp; + req->defobj_out = obj; + return (0); + } + return (ESRCH); +} + +/* Search for symbol using GNU hash function */ +static int +symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) +{ + Elf_Addr bloom_word; + const Elf32_Word *hashval; + Elf32_Word bucket; + Sym_Match_Result matchres; + unsigned int h1, h2; + unsigned long symnum; + + matchres.sym_out = NULL; + matchres.vsymp = NULL; + matchres.vcount = 0; + + /* Pick right bitmask word from Bloom filter array */ + bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & + obj->maskwords_bm_gnu]; + + /* Calculate modulus word size of gnu hash and its derivative */ + h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); + h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); + + /* Filter out the "definitely not in set" queries */ + if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) + return (ESRCH); + + /* Locate hash chain and corresponding value element*/ + bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; + if (bucket == 0) + return (ESRCH); + hashval = &obj->chain_zero_gnu[bucket]; + do { + if (((*hashval ^ req->hash_gnu) >> 1) == 0) { + symnum = hashval - obj->chain_zero_gnu; + if (matched_symbol(req, obj, &matchres, symnum)) { + req->sym_out = matchres.sym_out; + req->defobj_out = obj; + return (0); + } + } + } while ((*hashval++ & 1) == 0); + if (matchres.vcount == 1) { + req->sym_out = matchres.vsymp; + req->defobj_out = obj; + return (0); + } + return (ESRCH); +} + +static void +trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) +{ + *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); + if (*main_local == NULL) + *main_local = ""; + + *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); + if (*fmt1 == NULL) + *fmt1 = "\t%o => %p (%x)\n"; + + *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); + if (*fmt2 == NULL) + *fmt2 = "\t%o (%x)\n"; +} + +static void +trace_print_obj(Obj_Entry *obj, const char *name, const char *path, + const char *main_local, const char *fmt1, const char *fmt2) +{ + const char *fmt; + int c; + + if (fmt1 == NULL) + fmt = fmt2; + else + /* XXX bogus */ + fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; + + while ((c = *fmt++) != '\0') { + switch (c) { + default: + rtld_putchar(c); + continue; + case '\\': + switch (c = *fmt) { + case '\0': + continue; + case 'n': + rtld_putchar('\n'); + break; + case 't': + rtld_putchar('\t'); + break; + } + break; + case '%': + switch (c = *fmt) { + case '\0': + continue; + case '%': + default: + rtld_putchar(c); + break; + case 'A': + rtld_putstr(main_local); + break; + case 'a': + rtld_putstr(obj_main->path); + break; + case 'o': + rtld_putstr(name); + break; + case 'p': + rtld_putstr(path); + break; + case 'x': + rtld_printf("%p", + obj != NULL ? obj->mapbase : NULL); + break; + } + break; + } + ++fmt; + } +} + +static void +trace_loaded_objects(Obj_Entry *obj, bool show_preload) +{ + const char *fmt1, *fmt2, *main_local; + const char *name, *path; + bool first_spurious, list_containers; + + trace_calc_fmts(&main_local, &fmt1, &fmt2); + list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; + + for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { + Needed_Entry *needed; + + if (obj->marker) + continue; + if (list_containers && obj->needed != NULL) + rtld_printf("%s:\n", obj->path); + for (needed = obj->needed; needed; needed = needed->next) { + if (needed->obj != NULL) { + if (needed->obj->traced && !list_containers) + continue; + needed->obj->traced = true; + path = needed->obj->path; + } else + path = "not found"; + + name = obj->strtab + needed->name; + trace_print_obj(needed->obj, name, path, main_local, + fmt1, fmt2); + } + } + + if (show_preload) { + if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) + fmt2 = "\t%p (%x)\n"; + first_spurious = true; + + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker || obj == obj_main || obj->traced) + continue; + + if (list_containers && first_spurious) { + rtld_printf("[preloaded]\n"); + first_spurious = false; + } + + Name_Entry *fname = STAILQ_FIRST(&obj->names); + name = fname == NULL ? "<unknown>" : fname->name; + trace_print_obj(obj, name, obj->path, main_local, NULL, + fmt2); + } + } +} + +/* + * Unload a dlopened object and its dependencies from memory and from + * our data structures. It is assumed that the DAG rooted in the + * object has already been unreferenced, and that the object has a + * reference count of 0. + */ +static void +unload_object(Obj_Entry *root, RtldLockState *lockstate) +{ + Obj_Entry marker, *obj, *next; + + assert(root->refcount == 0); + + /* + * Pass over the DAG removing unreferenced objects from + * appropriate lists. + */ + unlink_object(root); + + /* Unmap all objects that are no longer referenced. */ + for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { + next = TAILQ_NEXT(obj, next); + if (obj->marker || obj->refcount != 0) + continue; + LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, + 0, obj->path); + dbg("unloading \"%s\"", obj->path); + /* + * Unlink the object now to prevent new references from + * being acquired while the bind lock is dropped in + * recursive dlclose() invocations. + */ + TAILQ_REMOVE(&obj_list, obj, next); + obj_count--; + + if (obj->filtees_loaded) { + if (next != NULL) { + init_marker(&marker); + TAILQ_INSERT_BEFORE(next, &marker, next); + unload_filtees(obj, lockstate); + next = TAILQ_NEXT(&marker, next); + TAILQ_REMOVE(&obj_list, &marker, next); + } else + unload_filtees(obj, lockstate); + } + release_object(obj); + } +} + +static void +unlink_object(Obj_Entry *root) +{ + Objlist_Entry *elm; + + if (root->refcount == 0) { + /* Remove the object from the RTLD_GLOBAL list. */ + objlist_remove(&list_global, root); + + /* Remove the object from all objects' DAG lists. */ + STAILQ_FOREACH(elm, &root->dagmembers, link) { + objlist_remove(&elm->obj->dldags, root); + if (elm->obj != root) + unlink_object(elm->obj); + } + } +} + +static void +ref_dag(Obj_Entry *root) +{ + Objlist_Entry *elm; + + assert(root->dag_inited); + STAILQ_FOREACH(elm, &root->dagmembers, link) + elm->obj->refcount++; +} + +static void +unref_dag(Obj_Entry *root) +{ + Objlist_Entry *elm; + + assert(root->dag_inited); + STAILQ_FOREACH(elm, &root->dagmembers, link) + elm->obj->refcount--; +} + +/* + * Common code for MD __tls_get_addr(). + */ +static void * +tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) +{ + struct dtv *newdtv, *dtv; + RtldLockState lockstate; + int to_copy; + + dtv = tcb->tcb_dtv; + /* Check dtv generation in case new modules have arrived */ + if (dtv->dtv_gen != tls_dtv_generation) { + if (!locked) + wlock_acquire(rtld_bind_lock, &lockstate); + newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * + sizeof(struct dtv_slot)); + to_copy = dtv->dtv_size; + if (to_copy > tls_max_index) + to_copy = tls_max_index; + memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * + sizeof(struct dtv_slot)); + newdtv->dtv_gen = tls_dtv_generation; + newdtv->dtv_size = tls_max_index; + free(dtv); + if (!locked) + lock_release(rtld_bind_lock, &lockstate); + dtv = tcb->tcb_dtv = newdtv; + } + + /* Dynamically allocate module TLS if necessary */ + if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { + /* Signal safe, wlock will block out signals. */ + if (!locked) + wlock_acquire(rtld_bind_lock, &lockstate); + if (!dtv->dtv_slots[index - 1].dtvs_tls) + dtv->dtv_slots[index - 1].dtvs_tls = + allocate_module_tls(tcb, index); + if (!locked) + lock_release(rtld_bind_lock, &lockstate); + } + return (dtv->dtv_slots[index - 1].dtvs_tls + offset); +} + +void * +tls_get_addr_common(struct tcb *tcb, int index, size_t offset) +{ + struct dtv *dtv; + + dtv = tcb->tcb_dtv; + /* Check dtv generation in case new modules have arrived */ + if (__predict_true(dtv->dtv_gen == tls_dtv_generation && + dtv->dtv_slots[index - 1].dtvs_tls != 0)) + return (dtv->dtv_slots[index - 1].dtvs_tls + offset); + return (tls_get_addr_slow(tcb, index, offset, false)); +} + +static struct tcb * +tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) +{ +#ifdef TLS_VARIANT_I + return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); +#else + return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); +#endif +} + +static struct tcb_list_entry * +tcb_list_entry_from_tcb(struct tcb *tcb) +{ +#ifdef TLS_VARIANT_I + return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); +#else + return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); +#endif +} + +static void +tcb_list_insert(struct tcb *tcb) +{ + struct tcb_list_entry *tcbelm; + + tcbelm = tcb_list_entry_from_tcb(tcb); + TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); +} + +static void +tcb_list_remove(struct tcb *tcb) +{ + struct tcb_list_entry *tcbelm; + + tcbelm = tcb_list_entry_from_tcb(tcb); + TAILQ_REMOVE(&tcb_list, tcbelm, next); +} + +#ifdef TLS_VARIANT_I + +/* + * Return pointer to allocated TLS block + */ +static void * +get_tls_block_ptr(void *tcb, size_t tcbsize) +{ + size_t extra_size, post_size, pre_size, tls_block_size; + size_t tls_init_align; + + tls_init_align = MAX(obj_main->tlsalign, 1); + + /* Compute fragments sizes. */ + extra_size = tcbsize - TLS_TCB_SIZE; + post_size = calculate_tls_post_size(tls_init_align); + tls_block_size = tcbsize + post_size; + pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; + + return ((char *)tcb - pre_size - extra_size); +} + +/* + * Allocate Static TLS using the Variant I method. + * + * For details on the layout, see lib/libc/gen/tls.c. + * + * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as + * it is based on tls_last_offset, and TLS offsets here are really TCB + * offsets, whereas libc's tls_static_space is just the executable's static + * TLS segment. + * + * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to + * the end of the TCB. + */ +void * +allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) +{ + Obj_Entry *obj; + char *tls_block; + struct dtv *dtv; + struct tcb *tcb; + char *addr; + size_t i; + size_t extra_size, maxalign, post_size, pre_size, tls_block_size; + size_t tls_init_align, tls_init_offset; + + if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) + return (oldtcb); + + assert(tcbsize >= TLS_TCB_SIZE); + maxalign = MAX(tcbalign, tls_static_max_align); + tls_init_align = MAX(obj_main->tlsalign, 1); + + /* Compute fragments sizes. */ + extra_size = tcbsize - TLS_TCB_SIZE; + post_size = calculate_tls_post_size(tls_init_align); + tls_block_size = tcbsize + post_size; + pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; + tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - + post_size; + + /* Allocate whole TLS block */ + tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); + tcb = (struct tcb *)(tls_block + pre_size + extra_size); + + if (oldtcb != NULL) { + memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), + tls_static_space); + free(get_tls_block_ptr(oldtcb, tcbsize)); + + /* Adjust the DTV. */ + dtv = tcb->tcb_dtv; + for (i = 0; i < dtv->dtv_size; i++) { + if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= + (uintptr_t)oldtcb && + (uintptr_t)dtv->dtv_slots[i].dtvs_tls < + (uintptr_t)oldtcb + tls_static_space) { + dtv->dtv_slots[i].dtvs_tls = (char *)tcb + + (dtv->dtv_slots[i].dtvs_tls - + (char *)oldtcb); + } + } + } else { + dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * + sizeof(struct dtv_slot)); + tcb->tcb_dtv = dtv; + dtv->dtv_gen = tls_dtv_generation; + dtv->dtv_size = tls_max_index; + + for (obj = globallist_curr(objs); obj != NULL; + obj = globallist_next(obj)) { + if (obj->tlsoffset == 0) + continue; + tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); + addr = (char *)tcb + obj->tlsoffset; + if (tls_init_offset > 0) + memset(addr, 0, tls_init_offset); + if (obj->tlsinitsize > 0) { + memcpy(addr + tls_init_offset, obj->tlsinit, + obj->tlsinitsize); + } + if (obj->tlssize > obj->tlsinitsize) { + memset(addr + tls_init_offset + + obj->tlsinitsize, + 0, + obj->tlssize - obj->tlsinitsize - + tls_init_offset); + } + dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; + } + } + + tcb_list_insert(tcb); + return (tcb); +} + +void +free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) +{ + struct dtv *dtv; + uintptr_t tlsstart, tlsend; + size_t post_size; + size_t i, tls_init_align __unused; + + tcb_list_remove(tcb); + + assert(tcbsize >= TLS_TCB_SIZE); + tls_init_align = MAX(obj_main->tlsalign, 1); + + /* Compute fragments sizes. */ + post_size = calculate_tls_post_size(tls_init_align); + + tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; + tlsend = (uintptr_t)tcb + tls_static_space; + + dtv = ((struct tcb *)tcb)->tcb_dtv; + for (i = 0; i < dtv->dtv_size; i++) { + if (dtv->dtv_slots[i].dtvs_tls != NULL && + ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || + (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { + free(dtv->dtv_slots[i].dtvs_tls); + } + } + free(dtv); + free(get_tls_block_ptr(tcb, tcbsize)); +} + +#endif /* TLS_VARIANT_I */ + +#ifdef TLS_VARIANT_II + +/* + * Allocate Static TLS using the Variant II method. + */ +void * +allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) +{ + Obj_Entry *obj; + size_t size, ralign; + char *tls_block; + struct dtv *dtv, *olddtv; + struct tcb *tcb; + char *addr; + size_t i; + + ralign = tcbalign; + if (tls_static_max_align > ralign) + ralign = tls_static_max_align; + size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); + + assert(tcbsize >= 2 * sizeof(uintptr_t)); + tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); + dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * + sizeof(struct dtv_slot)); + + tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); + tcb->tcb_self = tcb; + tcb->tcb_dtv = dtv; + + dtv->dtv_gen = tls_dtv_generation; + dtv->dtv_size = tls_max_index; + + if (oldtcb != NULL) { + /* + * Copy the static TLS block over whole. + */ + memcpy((char *)tcb - tls_static_space, + (const char *)oldtcb - tls_static_space, + tls_static_space); + + /* + * If any dynamic TLS blocks have been created tls_get_addr(), + * move them over. + */ + olddtv = ((struct tcb *)oldtcb)->tcb_dtv; + for (i = 0; i < olddtv->dtv_size; i++) { + if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < + (uintptr_t)oldtcb - size || + (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > + (uintptr_t)oldtcb) { + dtv->dtv_slots[i].dtvs_tls = + olddtv->dtv_slots[i].dtvs_tls; + olddtv->dtv_slots[i].dtvs_tls = NULL; + } + } + + /* + * We assume that this block was the one we created with + * allocate_initial_tls(). + */ + free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); + } else { + for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { + if (obj->marker || obj->tlsoffset == 0) + continue; + addr = (char *)tcb - obj->tlsoffset; + memset(addr + obj->tlsinitsize, 0, obj->tlssize - + obj->tlsinitsize); + if (obj->tlsinit) { + memcpy(addr, obj->tlsinit, obj->tlsinitsize); + obj->static_tls_copied = true; + } + dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; + } + } + + tcb_list_insert(tcb); + return (tcb); +} + +void +free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) +{ + struct dtv *dtv; + size_t size, ralign; + size_t i; + uintptr_t tlsstart, tlsend; + + tcb_list_remove(tcb); + + /* + * Figure out the size of the initial TLS block so that we can + * find stuff which ___tls_get_addr() allocated dynamically. + */ + ralign = tcbalign; + if (tls_static_max_align > ralign) + ralign = tls_static_max_align; + size = roundup(tls_static_space, ralign); + + dtv = ((struct tcb *)tcb)->tcb_dtv; + tlsend = (uintptr_t)tcb; + tlsstart = tlsend - size; + for (i = 0; i < dtv->dtv_size; i++) { + if (dtv->dtv_slots[i].dtvs_tls != NULL && + ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || + (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { + free(dtv->dtv_slots[i].dtvs_tls); + } + } + + free((void *)tlsstart); + free(dtv); +} + +#endif /* TLS_VARIANT_II */ + +/* + * Allocate TLS block for module with given index. + */ +void * +allocate_module_tls(struct tcb *tcb, int index) +{ + Obj_Entry *obj; + char *p; + + TAILQ_FOREACH(obj, &obj_list, next) { + if (obj->marker) + continue; + if (obj->tlsindex == index) + break; + } + if (obj == NULL) { + _rtld_error("Can't find module with TLS index %d", index); + rtld_die(); + } + + if (obj->tls_static) { +#ifdef TLS_VARIANT_I + p = (char *)tcb + obj->tlsoffset; +#else + p = (char *)tcb - obj->tlsoffset; +#endif + return (p); + } + + obj->tls_dynamic = true; + + p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); + memcpy(p, obj->tlsinit, obj->tlsinitsize); + memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); + return (p); +} + +static bool +allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, + size_t tlspoffset __unused) +{ + size_t off; + + if (tls_last_offset == 0) + off = calculate_first_tls_offset(tlssize, tlsalign, + tlspoffset); + else + off = calculate_tls_offset(tls_last_offset, tls_last_size, + tlssize, tlsalign, tlspoffset); + + *offp = off; +#ifdef TLS_VARIANT_I + off += tlssize; +#endif + + /* + * If we have already fixed the size of the static TLS block, we + * must stay within that size. When allocating the static TLS, we + * leave a small amount of space spare to be used for dynamically + * loading modules which use static TLS. + */ + if (tls_static_space != 0) { + if (off > tls_static_space) + return (false); + } else if (tlsalign > tls_static_max_align) { + tls_static_max_align = tlsalign; + } + + tls_last_offset = off; + tls_last_size = tlssize; + + return (true); +} + +bool +allocate_tls_offset(Obj_Entry *obj) +{ + if (obj->tls_dynamic) + return (false); + + if (obj->tls_static) + return (true); + + if (obj->tlssize == 0) { + obj->tls_static = true; + return (true); + } + + if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, + obj->tlsalign, obj->tlspoffset)) + return (false); + + obj->tls_static = true; + + return (true); +} + +void +free_tls_offset(Obj_Entry *obj) +{ + /* + * If we were the last thing to allocate out of the static TLS + * block, we give our space back to the 'allocator'. This is a + * simplistic workaround to allow libGL.so.1 to be loaded and + * unloaded multiple times. + */ + size_t off = obj->tlsoffset; + +#ifdef TLS_VARIANT_I + off += obj->tlssize; +#endif + if (off == tls_last_offset) { + tls_last_offset -= obj->tlssize; + tls_last_size = 0; + } +} + +void * +_rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) +{ + void *ret; + RtldLockState lockstate; + + wlock_acquire(rtld_bind_lock, &lockstate); + ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, + tcbsize, tcbalign); + lock_release(rtld_bind_lock, &lockstate); + return (ret); +} + +void +_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) +{ + RtldLockState lockstate; + + wlock_acquire(rtld_bind_lock, &lockstate); + free_tls(tcb, tcbsize, tcbalign); + lock_release(rtld_bind_lock, &lockstate); +} + +static void +object_add_name(Obj_Entry *obj, const char *name) +{ + Name_Entry *entry; + size_t len; + + len = strlen(name); + entry = malloc(sizeof(Name_Entry) + len); + + if (entry != NULL) { + strcpy(entry->name, name); + STAILQ_INSERT_TAIL(&obj->names, entry, link); + } +} + +static int +object_match_name(const Obj_Entry *obj, const char *name) +{ + Name_Entry *entry; + + STAILQ_FOREACH(entry, &obj->names, link) { + if (strcmp(name, entry->name) == 0) + return (1); + } + return (0); +} + +static Obj_Entry * +locate_dependency(const Obj_Entry *obj, const char *name) +{ + const Objlist_Entry *entry; + const Needed_Entry *needed; + + STAILQ_FOREACH(entry, &list_main, link) { + if (object_match_name(entry->obj, name)) + return (entry->obj); + } + + for (needed = obj->needed; needed != NULL; needed = needed->next) { + if (strcmp(obj->strtab + needed->name, name) == 0 || + (needed->obj != NULL && object_match_name(needed->obj, + name))) { + /* + * If there is DT_NEEDED for the name we are looking + * for, we are all set. Note that object might not be + * found if dependency was not loaded yet, so the + * function can return NULL here. This is expected and + * handled properly by the caller. + */ + return (needed->obj); + } + } + _rtld_error("%s: Unexpected inconsistency: dependency %s not found", + obj->path, name); + rtld_die(); +} + +static int +check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, + const Elf_Vernaux *vna) +{ + const Elf_Verdef *vd; + const char *vername; + + vername = refobj->strtab + vna->vna_name; + vd = depobj->verdef; + if (vd == NULL) { + _rtld_error("%s: version %s required by %s not defined", + depobj->path, vername, refobj->path); + return (-1); + } + for (;;) { + if (vd->vd_version != VER_DEF_CURRENT) { + _rtld_error( + "%s: Unsupported version %d of Elf_Verdef entry", + depobj->path, vd->vd_version); + return (-1); + } + if (vna->vna_hash == vd->vd_hash) { + const Elf_Verdaux *aux = + (const Elf_Verdaux *)((const char *)vd + + vd->vd_aux); + if (strcmp(vername, depobj->strtab + aux->vda_name) == + 0) + return (0); + } + if (vd->vd_next == 0) + break; + vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); + } + if (vna->vna_flags & VER_FLG_WEAK) + return (0); + _rtld_error("%s: version %s required by %s not found", depobj->path, + vername, refobj->path); + return (-1); +} + +static int +rtld_verify_object_versions(Obj_Entry *obj) +{ + const Elf_Verneed *vn; + const Elf_Verdef *vd; + const Elf_Verdaux *vda; + const Elf_Vernaux *vna; + const Obj_Entry *depobj; + int maxvernum, vernum; + + if (obj->ver_checked) + return (0); + obj->ver_checked = true; + + maxvernum = 0; + /* + * Walk over defined and required version records and figure out + * max index used by any of them. Do very basic sanity checking + * while there. + */ + vn = obj->verneed; + while (vn != NULL) { + if (vn->vn_version != VER_NEED_CURRENT) { + _rtld_error( + "%s: Unsupported version %d of Elf_Verneed entry", + obj->path, vn->vn_version); + return (-1); + } + vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); + for (;;) { + vernum = VER_NEED_IDX(vna->vna_other); + if (vernum > maxvernum) + maxvernum = vernum; + if (vna->vna_next == 0) + break; + vna = (const Elf_Vernaux *)((const char *)vna + + vna->vna_next); + } + if (vn->vn_next == 0) + break; + vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); + } + + vd = obj->verdef; + while (vd != NULL) { + if (vd->vd_version != VER_DEF_CURRENT) { + _rtld_error( + "%s: Unsupported version %d of Elf_Verdef entry", + obj->path, vd->vd_version); + return (-1); + } + vernum = VER_DEF_IDX(vd->vd_ndx); + if (vernum > maxvernum) + maxvernum = vernum; + if (vd->vd_next == 0) + break; + vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); + } + + if (maxvernum == 0) + return (0); + + /* + * Store version information in array indexable by version index. + * Verify that object version requirements are satisfied along the + * way. + */ + obj->vernum = maxvernum + 1; + obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); + + vd = obj->verdef; + while (vd != NULL) { + if ((vd->vd_flags & VER_FLG_BASE) == 0) { + vernum = VER_DEF_IDX(vd->vd_ndx); + assert(vernum <= maxvernum); + vda = (const Elf_Verdaux *)((const char *)vd + + vd->vd_aux); + obj->vertab[vernum].hash = vd->vd_hash; + obj->vertab[vernum].name = obj->strtab + vda->vda_name; + obj->vertab[vernum].file = NULL; + obj->vertab[vernum].flags = 0; + } + if (vd->vd_next == 0) + break; + vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); + } + + vn = obj->verneed; + while (vn != NULL) { + depobj = locate_dependency(obj, obj->strtab + vn->vn_file); + if (depobj == NULL) + return (-1); + vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); + for (;;) { + if (check_object_provided_version(obj, depobj, vna)) + return (-1); + vernum = VER_NEED_IDX(vna->vna_other); + assert(vernum <= maxvernum); + obj->vertab[vernum].hash = vna->vna_hash; + obj->vertab[vernum].name = obj->strtab + vna->vna_name; + obj->vertab[vernum].file = obj->strtab + vn->vn_file; + obj->vertab[vernum].flags = (vna->vna_other & + VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; + if (vna->vna_next == 0) + break; + vna = (const Elf_Vernaux *)((const char *)vna + + vna->vna_next); + } + if (vn->vn_next == 0) + break; + vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); + } + return (0); +} + +static int +rtld_verify_versions(const Objlist *objlist) +{ + Objlist_Entry *entry; + int rc; + + rc = 0; + STAILQ_FOREACH(entry, objlist, link) { + /* + * Skip dummy objects or objects that have their version + * requirements already checked. + */ + if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) + continue; + if (rtld_verify_object_versions(entry->obj) == -1) { + rc = -1; + if (ld_tracing == NULL) + break; + } + } + if (rc == 0 || ld_tracing != NULL) + rc = rtld_verify_object_versions(&obj_rtld); + return (rc); +} + +const Ver_Entry * +fetch_ventry(const Obj_Entry *obj, unsigned long symnum) +{ + Elf_Versym vernum; + + if (obj->vertab) { + vernum = VER_NDX(obj->versyms[symnum]); + if (vernum >= obj->vernum) { + _rtld_error("%s: symbol %s has wrong verneed value %d", + obj->path, obj->strtab + symnum, vernum); + } else if (obj->vertab[vernum].hash != 0) { + return (&obj->vertab[vernum]); + } + } + return (NULL); +} + +int +_rtld_get_stack_prot(void) +{ + return (stack_prot); +} + +int +_rtld_is_dlopened(void *arg) +{ + Obj_Entry *obj; + RtldLockState lockstate; + int res; + + rlock_acquire(rtld_bind_lock, &lockstate); + obj = dlcheck(arg); + if (obj == NULL) + obj = obj_from_addr(arg); + if (obj == NULL) { + _rtld_error("No shared object contains address"); + lock_release(rtld_bind_lock, &lockstate); + return (-1); + } + res = obj->dlopened ? 1 : 0; + lock_release(rtld_bind_lock, &lockstate); + return (res); +} + +static int +obj_remap_relro(Obj_Entry *obj, int prot) +{ + const Elf_Phdr *ph; + caddr_t relro_page; + size_t relro_size; + + for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + + obj->phsize; ph++) { + if (ph->p_type != PT_GNU_RELRO) + continue; + relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); + relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - + rtld_trunc_page(ph->p_vaddr); + if (mprotect(relro_page, relro_size, prot) == -1) { + _rtld_error( + "%s: Cannot set relro protection to %#x: %s", + obj->path, prot, rtld_strerror(errno)); + return (-1); + } + break; + } + return (0); +} + +static int +obj_disable_relro(Obj_Entry *obj) +{ + return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); +} + +static int +obj_enforce_relro(Obj_Entry *obj) +{ + return (obj_remap_relro(obj, PROT_READ)); +} + +static void +map_stacks_exec(RtldLockState *lockstate) +{ + void (*thr_map_stacks_exec)(void); + + if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) + return; + thr_map_stacks_exec = (void (*)(void))( + uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", + lockstate); + if (thr_map_stacks_exec != NULL) { + stack_prot |= PROT_EXEC; + thr_map_stacks_exec(); + } +} + +static void +distribute_static_tls(Objlist *list) +{ + struct tcb_list_entry *tcbelm; + Objlist_Entry *objelm; + struct tcb *tcb; + Obj_Entry *obj; + char *tlsbase; + + STAILQ_FOREACH(objelm, list, link) { + obj = objelm->obj; + if (obj->marker || !obj->tls_static || obj->static_tls_copied) + continue; + TAILQ_FOREACH(tcbelm, &tcb_list, next) { + tcb = tcb_from_tcb_list_entry(tcbelm); +#ifdef TLS_VARIANT_I + tlsbase = (char *)tcb + obj->tlsoffset; +#else + tlsbase = (char *)tcb - obj->tlsoffset; +#endif + memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); + memset(tlsbase + obj->tlsinitsize, 0, + obj->tlssize - obj->tlsinitsize); + } + obj->static_tls_copied = true; + } +} + +void +symlook_init(SymLook *dst, const char *name) +{ + bzero(dst, sizeof(*dst)); + dst->name = name; + dst->hash = elf_hash(name); + dst->hash_gnu = gnu_hash(name); +} + +static void +symlook_init_from_req(SymLook *dst, const SymLook *src) +{ + dst->name = src->name; + dst->hash = src->hash; + dst->hash_gnu = src->hash_gnu; + dst->ventry = src->ventry; + dst->flags = src->flags; + dst->defobj_out = NULL; + dst->sym_out = NULL; + dst->lockstate = src->lockstate; +} + +static int +open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) +{ + char *binpath, *pathenv, *pe, *res1; + const char *res; + int fd; + + binpath = NULL; + res = NULL; + if (search_in_path && strchr(argv0, '/') == NULL) { + binpath = xmalloc(PATH_MAX); + pathenv = getenv("PATH"); + if (pathenv == NULL) { + _rtld_error("-p and no PATH environment variable"); + rtld_die(); + } + pathenv = strdup(pathenv); + if (pathenv == NULL) { + _rtld_error("Cannot allocate memory"); + rtld_die(); + } + fd = -1; + errno = ENOENT; + while ((pe = strsep(&pathenv, ":")) != NULL) { + if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) + continue; + if (binpath[0] != '\0' && + strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) + continue; + if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) + continue; + fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); + if (fd != -1 || errno != ENOENT) { + res = binpath; + break; + } + } + free(pathenv); + } else { + fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); + res = argv0; + } + + if (fd == -1) { + _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); + rtld_die(); + } + if (res != NULL && res[0] != '/') { + res1 = xmalloc(PATH_MAX); + if (realpath(res, res1) != NULL) { + if (res != argv0) + free(__DECONST(char *, res)); + res = res1; + } else { + free(res1); + } + } + *binpath_res = res; + return (fd); +} + +/* + * Parse a set of command-line arguments. + */ +static int +parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, + const char **argv0, bool *dir_ignore) +{ + const char *arg; + char machine[64]; + size_t sz; + int arglen, fd, i, j, mib[2]; + char opt; + bool seen_b, seen_f; + + dbg("Parsing command-line arguments"); + *use_pathp = false; + *fdp = -1; + *dir_ignore = false; + seen_b = seen_f = false; + + for (i = 1; i < argc; i++) { + arg = argv[i]; + dbg("argv[%d]: '%s'", i, arg); + + /* + * rtld arguments end with an explicit "--" or with the first + * non-prefixed argument. + */ + if (strcmp(arg, "--") == 0) { + i++; + break; + } + if (arg[0] != '-') + break; + + /* + * All other arguments are single-character options that can + * be combined, so we need to search through `arg` for them. + */ + arglen = strlen(arg); + for (j = 1; j < arglen; j++) { + opt = arg[j]; + if (opt == 'h') { + print_usage(argv[0]); + _exit(0); + } else if (opt == 'b') { + if (seen_f) { + _rtld_error("Both -b and -f specified"); + rtld_die(); + } + if (j != arglen - 1) { + _rtld_error("Invalid options: %s", arg); + rtld_die(); + } + i++; + *argv0 = argv[i]; + seen_b = true; + break; + } else if (opt == 'd') { + *dir_ignore = true; + } else if (opt == 'f') { + if (seen_b) { + _rtld_error("Both -b and -f specified"); + rtld_die(); + } + + /* + * -f XX can be used to specify a + * descriptor for the binary named at + * the command line (i.e., the later + * argument will specify the process + * name but the descriptor is what + * will actually be executed). + * + * -f must be the last option in the + * group, e.g., -abcf <fd>. + */ + if (j != arglen - 1) { + _rtld_error("Invalid options: %s", arg); + rtld_die(); + } + i++; + fd = parse_integer(argv[i]); + if (fd == -1) { + _rtld_error( + "Invalid file descriptor: '%s'", + argv[i]); + rtld_die(); + } + *fdp = fd; + seen_f = true; + break; + } else if (opt == 'o') { + struct ld_env_var_desc *l; + char *n, *v; + u_int ll; + + if (j != arglen - 1) { + _rtld_error("Invalid options: %s", arg); + rtld_die(); + } + i++; + n = argv[i]; + v = strchr(n, '='); + if (v == NULL) { + _rtld_error("No '=' in -o parameter"); + rtld_die(); + } + for (ll = 0; ll < nitems(ld_env_vars); ll++) { + l = &ld_env_vars[ll]; + if (v - n == (ptrdiff_t)strlen(l->n) && + strncmp(n, l->n, v - n) == 0) { + l->val = v + 1; + break; + } + } + if (ll == nitems(ld_env_vars)) { + _rtld_error("Unknown LD_ option %s", n); + rtld_die(); + } + } else if (opt == 'p') { + *use_pathp = true; + } else if (opt == 'u') { + u_int ll; + + for (ll = 0; ll < nitems(ld_env_vars); ll++) + ld_env_vars[ll].val = NULL; + } else if (opt == 'v') { + machine[0] = '\0'; + mib[0] = CTL_HW; + mib[1] = HW_MACHINE; + sz = sizeof(machine); + sysctl(mib, nitems(mib), machine, &sz, NULL, 0); + ld_elf_hints_path = ld_get_env_var( + LD_ELF_HINTS_PATH); + set_ld_elf_hints_path(); + rtld_printf( + "FreeBSD ld-elf.so.1 %s\n" + "FreeBSD_version %d\n" + "Default lib path %s\n" + "Hints lib path %s\n" + "Env prefix %s\n" + "Default hint file %s\n" + "Hint file %s\n" + "libmap file %s\n" + "Optional static TLS size %zd bytes\n", + machine, __FreeBSD_version, + ld_standard_library_path, gethints(false), + ld_env_prefix, ld_elf_hints_default, + ld_elf_hints_path, ld_path_libmap_conf, + ld_static_tls_extra); + _exit(0); + } else { + _rtld_error("Invalid argument: '%s'", arg); + print_usage(argv[0]); + rtld_die(); + } + } + } + + if (!seen_b) + *argv0 = argv[i]; + return (i); +} + +/* + * Parse a file descriptor number without pulling in more of libc (e.g. atoi). + */ +static int +parse_integer(const char *str) +{ + static const int RADIX = 10; /* XXXJA: possibly support hex? */ + const char *orig; + int n; + char c; + + orig = str; + n = 0; + for (c = *str; c != '\0'; c = *++str) { + if (c < '0' || c > '9') + return (-1); + + n *= RADIX; + n += c - '0'; + } + + /* Make sure we actually parsed something. */ + if (str == orig) + return (-1); + return (n); +} + +static void +print_usage(const char *argv0) +{ + rtld_printf( + "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" + "\n" + "Options:\n" + " -h Display this help message\n" + " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" + " -d Ignore lack of exec permissions for the binary\n" + " -f <FD> Execute <FD> instead of searching for <binary>\n" + " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" + " -p Search in PATH for named binary\n" + " -u Ignore LD_ environment variables\n" + " -v Display identification information\n" + " -- End of RTLD options\n" + " <binary> Name of process to execute\n" + " <args> Arguments to the executed process\n", + argv0); +} + +#define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } +static const struct auxfmt { + const char *name; + const char *fmt; +} auxfmts[] = { + AUXFMT(AT_NULL, NULL), + AUXFMT(AT_IGNORE, NULL), + AUXFMT(AT_EXECFD, "%ld"), + AUXFMT(AT_PHDR, "%p"), + AUXFMT(AT_PHENT, "%lu"), + AUXFMT(AT_PHNUM, "%lu"), + AUXFMT(AT_PAGESZ, "%lu"), + AUXFMT(AT_BASE, "%#lx"), + AUXFMT(AT_FLAGS, "%#lx"), + AUXFMT(AT_ENTRY, "%p"), + AUXFMT(AT_NOTELF, NULL), + AUXFMT(AT_UID, "%ld"), + AUXFMT(AT_EUID, "%ld"), + AUXFMT(AT_GID, "%ld"), + AUXFMT(AT_EGID, "%ld"), + AUXFMT(AT_EXECPATH, "%s"), + AUXFMT(AT_CANARY, "%p"), + AUXFMT(AT_CANARYLEN, "%lu"), + AUXFMT(AT_OSRELDATE, "%lu"), + AUXFMT(AT_NCPUS, "%lu"), + AUXFMT(AT_PAGESIZES, "%p"), + AUXFMT(AT_PAGESIZESLEN, "%lu"), + AUXFMT(AT_TIMEKEEP, "%p"), + AUXFMT(AT_STACKPROT, "%#lx"), + AUXFMT(AT_EHDRFLAGS, "%#lx"), + AUXFMT(AT_HWCAP, "%#lx"), + AUXFMT(AT_HWCAP2, "%#lx"), + AUXFMT(AT_BSDFLAGS, "%#lx"), + AUXFMT(AT_ARGC, "%lu"), + AUXFMT(AT_ARGV, "%p"), + AUXFMT(AT_ENVC, "%p"), + AUXFMT(AT_ENVV, "%p"), + AUXFMT(AT_PS_STRINGS, "%p"), + AUXFMT(AT_FXRNG, "%p"), + AUXFMT(AT_KPRELOAD, "%p"), + AUXFMT(AT_USRSTACKBASE, "%#lx"), + AUXFMT(AT_USRSTACKLIM, "%#lx"), + /* AT_CHERI_STATS */ + AUXFMT(AT_HWCAP3, "%#lx"), + AUXFMT(AT_HWCAP4, "%#lx"), + +}; + +static bool +is_ptr_fmt(const char *fmt) +{ + char last; + + last = fmt[strlen(fmt) - 1]; + return (last == 'p' || last == 's'); +} + +static void +dump_auxv(Elf_Auxinfo **aux_info) +{ + Elf_Auxinfo *auxp; + const struct auxfmt *fmt; + int i; + + for (i = 0; i < AT_COUNT; i++) { + auxp = aux_info[i]; + if (auxp == NULL) + continue; + fmt = &auxfmts[i]; + if (fmt->fmt == NULL) + continue; + rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); + if (is_ptr_fmt(fmt->fmt)) { + rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, + auxp->a_un.a_ptr); + } else { + rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, + auxp->a_un.a_val); + } + rtld_fdprintf(STDOUT_FILENO, "\n"); + } +} + +const char * +rtld_get_var(const char *name) +{ + const struct ld_env_var_desc *lvd; + u_int i; + + for (i = 0; i < nitems(ld_env_vars); i++) { + lvd = &ld_env_vars[i]; + if (strcmp(lvd->n, name) == 0) + return (lvd->val); + } + return (NULL); +} + +int +rtld_set_var(const char *name, const char *val) +{ + struct ld_env_var_desc *lvd; + u_int i; + + for (i = 0; i < nitems(ld_env_vars); i++) { + lvd = &ld_env_vars[i]; + if (strcmp(lvd->n, name) != 0) + continue; + if (!lvd->can_update || (lvd->unsecure && !trust)) + return (EPERM); + if (lvd->owned) + free(__DECONST(char *, lvd->val)); + if (val != NULL) + lvd->val = xstrdup(val); + else + lvd->val = NULL; + lvd->owned = true; + if (lvd->debug) + debug = lvd->val != NULL && *lvd->val != '\0'; + return (0); + } + return (ENOENT); +} + +/* + * Overrides for libc_pic-provided functions. + */ + +int +__getosreldate(void) +{ + size_t len; + int oid[2]; + int error, osrel; + + if (osreldate != 0) + return (osreldate); + + oid[0] = CTL_KERN; + oid[1] = KERN_OSRELDATE; + osrel = 0; + len = sizeof(osrel); + error = sysctl(oid, 2, &osrel, &len, NULL, 0); + if (error == 0 && osrel > 0 && len == sizeof(osrel)) + osreldate = osrel; + return (osreldate); +} +const char * +rtld_strerror(int errnum) +{ + if (errnum < 0 || errnum >= sys_nerr) + return ("Unknown error"); + return (sys_errlist[errnum]); +} + +char * +getenv(const char *name) +{ + return (__DECONST(char *, rtld_get_env_val(environ, name, + strlen(name)))); +} + +/* malloc */ +void * +malloc(size_t nbytes) +{ + return (__crt_malloc(nbytes)); +} + +void * +calloc(size_t num, size_t size) +{ + return (__crt_calloc(num, size)); +} + +void +free(void *cp) +{ + __crt_free(cp); +} + +void * +realloc(void *cp, size_t nbytes) +{ + return (__crt_realloc(cp, nbytes)); +} + +extern int _rtld_version__FreeBSD_version __exported; +int _rtld_version__FreeBSD_version = __FreeBSD_version; + +extern char _rtld_version_laddr_offset __exported; +char _rtld_version_laddr_offset; + +extern char _rtld_version_dlpi_tls_data __exported; +char _rtld_version_dlpi_tls_data; |