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Diffstat (limited to 'sys/compat/linux/linux_vdso.c')
-rw-r--r--sys/compat/linux/linux_vdso.c240
1 files changed, 240 insertions, 0 deletions
diff --git a/sys/compat/linux/linux_vdso.c b/sys/compat/linux/linux_vdso.c
new file mode 100644
index 000000000000..871a5daa5b84
--- /dev/null
+++ b/sys/compat/linux/linux_vdso.c
@@ -0,0 +1,240 @@
+/*-
+ * Copyright (c) 2013 Dmitry Chagin
+ * All rights reserved.
+ *
+ * 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
+ * in this position and unchanged.
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_compat.h"
+
+#define __ELF_WORD_SIZE 32
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/elf.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/rwlock.h>
+#include <sys/queue.h>
+#include <sys/sysent.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+#include <vm/vm_extern.h>
+#include <vm/vm_kern.h>
+#include <vm/vm_map.h>
+#include <vm/vm_object.h>
+#include <vm/vm_page.h>
+#include <vm/vm_pager.h>
+
+#include <compat/linux/linux_vdso.h>
+
+SLIST_HEAD(, linux_vdso_sym) __elfN(linux_vdso_syms) =
+ SLIST_HEAD_INITIALIZER(__elfN(linux_vdso_syms));
+
+static int __elfN(symtabindex);
+static int __elfN(symstrindex);
+
+static void
+__elfN(linux_vdso_lookup)(Elf_Ehdr *, struct linux_vdso_sym *);
+
+
+void
+__elfN(linux_vdso_sym_init)(struct linux_vdso_sym *s)
+{
+
+ SLIST_INSERT_HEAD(&__elfN(linux_vdso_syms), s, sym);
+}
+
+vm_object_t
+__elfN(linux_shared_page_init)(char **mapping)
+{
+ vm_page_t m;
+ vm_object_t obj;
+ vm_offset_t addr;
+
+ obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE,
+ VM_PROT_DEFAULT, 0, NULL);
+ VM_OBJECT_WLOCK(obj);
+ m = vm_page_grab(obj, 0, VM_ALLOC_NOBUSY | VM_ALLOC_ZERO);
+ m->valid = VM_PAGE_BITS_ALL;
+ VM_OBJECT_WUNLOCK(obj);
+ addr = kva_alloc(PAGE_SIZE);
+ pmap_qenter(addr, &m, 1);
+ *mapping = (char *)addr;
+ return (obj);
+}
+
+void
+__elfN(linux_shared_page_fini)(vm_object_t obj)
+{
+
+ vm_object_deallocate(obj);
+}
+
+void
+__elfN(linux_vdso_fixup)(struct sysentvec *sv)
+{
+ Elf_Ehdr *ehdr;
+ Elf_Shdr *shdr;
+ int i;
+
+ ehdr = (Elf_Ehdr *) sv->sv_sigcode;
+
+ if (!IS_ELF(*ehdr) ||
+ ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
+ ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
+ ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
+ ehdr->e_shoff == 0 ||
+ ehdr->e_shentsize != sizeof(Elf_Shdr))
+ panic("Linux invalid vdso header.\n");
+
+ if (ehdr->e_type != ET_DYN)
+ panic("Linux invalid vdso header.\n");
+
+ shdr = (Elf_Shdr *) ((caddr_t)ehdr + ehdr->e_shoff);
+
+ __elfN(symtabindex) = -1;
+ __elfN(symstrindex) = -1;
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (shdr[i].sh_size == 0)
+ continue;
+ if (shdr[i].sh_type == SHT_DYNSYM) {
+ __elfN(symtabindex) = i;
+ __elfN(symstrindex) = shdr[i].sh_link;
+ }
+ }
+
+ if (__elfN(symtabindex) == -1 || __elfN(symstrindex) == -1)
+ panic("Linux invalid vdso header.\n");
+
+ ehdr->e_ident[EI_OSABI] = ELFOSABI_LINUX;
+}
+
+void
+__elfN(linux_vdso_reloc)(struct sysentvec *sv, int vdso_adjust)
+{
+ struct linux_vdso_sym *lsym;
+ Elf_Ehdr *ehdr;
+ Elf_Phdr *phdr;
+ Elf_Shdr *shdr;
+ Elf_Dyn *dyn;
+ Elf_Sym *sym;
+ int i, symcnt;
+
+ ehdr = (Elf_Ehdr *) sv->sv_sigcode;
+
+ /* Adjust our so relative to the sigcode_base */
+ if (vdso_adjust != 0) {
+ ehdr->e_entry += vdso_adjust;
+ phdr = (Elf_Phdr *)((caddr_t)ehdr + ehdr->e_phoff);
+
+ /* phdrs */
+ for (i = 0; i < ehdr->e_phnum; i++) {
+ phdr[i].p_vaddr += vdso_adjust;
+ if (phdr[i].p_type != PT_DYNAMIC)
+ continue;
+ dyn = (Elf_Dyn *)((caddr_t)ehdr + phdr[i].p_offset);
+ for(; dyn->d_tag != DT_NULL; dyn++) {
+ switch (dyn->d_tag) {
+ case DT_PLTGOT:
+ case DT_HASH:
+ case DT_STRTAB:
+ case DT_SYMTAB:
+ case DT_RELA:
+ case DT_INIT:
+ case DT_FINI:
+ case DT_REL:
+ case DT_DEBUG:
+ case DT_JMPREL:
+ case DT_VERSYM:
+ case DT_VERDEF:
+ case DT_VERNEED:
+ case DT_ADDRRNGLO ... DT_ADDRRNGHI:
+ dyn->d_un.d_ptr += vdso_adjust;
+ break;
+ case DT_ENCODING ... DT_LOOS-1:
+ case DT_LOOS ... DT_HIOS:
+ if (dyn->d_tag >= DT_ENCODING &&
+ (dyn->d_tag & 1) == 0)
+ dyn->d_un.d_ptr += vdso_adjust;
+ break;
+ default:
+ break;
+ }
+ }
+ }
+
+ /* sections */
+ shdr = (Elf_Shdr *)((caddr_t)ehdr + ehdr->e_shoff);
+ for(i = 0; i < ehdr->e_shnum; i++) {
+ if (!(shdr[i].sh_flags & SHF_ALLOC))
+ continue;
+ shdr[i].sh_addr += vdso_adjust;
+ if (shdr[i].sh_type != SHT_SYMTAB &&
+ shdr[i].sh_type != SHT_DYNSYM)
+ continue;
+
+ sym = (Elf_Sym *)((caddr_t)ehdr + shdr[i].sh_offset);
+ symcnt = shdr[i].sh_size / sizeof(*sym);
+
+ for(i = 0; i < symcnt; i++, sym++) {
+ if (sym->st_shndx == SHN_UNDEF ||
+ sym->st_shndx == SHN_ABS)
+ continue;
+ sym->st_value += vdso_adjust;
+ }
+ }
+ }
+
+ SLIST_FOREACH(lsym, &__elfN(linux_vdso_syms), sym)
+ __elfN(linux_vdso_lookup)(ehdr, lsym);
+}
+
+static void
+__elfN(linux_vdso_lookup)(Elf_Ehdr *ehdr, struct linux_vdso_sym *vsym)
+{
+ vm_offset_t strtab, symname;
+ uint32_t symcnt;
+ Elf_Shdr *shdr;
+ int i;
+
+ shdr = (Elf_Shdr *) ((caddr_t)ehdr + ehdr->e_shoff);
+
+ strtab = (vm_offset_t)((caddr_t)ehdr +
+ shdr[__elfN(symstrindex)].sh_offset);
+ Elf_Sym *sym = (Elf_Sym *)((caddr_t)ehdr +
+ shdr[__elfN(symtabindex)].sh_offset);
+ symcnt = shdr[__elfN(symtabindex)].sh_size / sizeof(*sym);
+
+ for (i = 0; i < symcnt; ++i, ++sym) {
+ symname = strtab + sym->st_name;
+ if (strncmp(vsym->symname, (char *)symname, vsym->size) == 0) {
+ *vsym->ptr = (uintptr_t)sym->st_value;
+ break;
+ }
+ }
+}