/*-
* Copyright (c) 2003-2008 Joseph Koshy
* 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.
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/types.h>
#include <sys/cpuset.h>
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/pmc.h>
#include <sys/sysctl.h>
#include <sys/imgact_aout.h>
#include <sys/imgact_elf.h>
#include <netinet/in.h>
#include <assert.h>
#include <err.h>
#include <fcntl.h>
#include <pmc.h>
#include <pmclog.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include "libpmcstat.h"
#define min(A,B) ((A) < (B) ? (A) : (B))
#define max(A,B) ((A) > (B) ? (A) : (B))
/*
* Add the list of symbols in the given section to the list associated
* with the object.
*/
void
pmcstat_image_add_symbols(struct pmcstat_image *image, Elf *e,
Elf_Scn *scn, GElf_Shdr *sh)
{
int firsttime;
size_t n, newsyms, nshsyms, nfuncsyms;
struct pmcstat_symbol *symptr;
char *fnname;
GElf_Sym sym;
Elf_Data *data;
if ((data = elf_getdata(scn, NULL)) == NULL)
return;
/*
* Determine the number of functions named in this
* section.
*/
nshsyms = sh->sh_size / sh->sh_entsize;
for (n = nfuncsyms = 0; n < nshsyms; n++) {
if (gelf_getsym(data, (int) n, &sym) != &sym)
return;
if (GELF_ST_TYPE(sym.st_info) == STT_FUNC)
nfuncsyms++;
}
if (nfuncsyms == 0)
return;
/*
* Allocate space for the new entries.
*/
firsttime = image->pi_symbols == NULL;
symptr = reallocarray(image->pi_symbols,
image->pi_symcount + nfuncsyms, sizeof(*symptr));
if (symptr == image->pi_symbols) /* realloc() failed. */
return;
image->pi_symbols = symptr;
/*
* Append new symbols to the end of the current table.
*/
symptr += image->pi_symcount;
for (n = newsyms = 0; n < nshsyms; n++) {
if (gelf_getsym(data, (int) n, &sym) != &sym)
return;
if (GELF_ST_TYPE(sym.st_info) != STT_FUNC)
continue;
if (sym.st_shndx == STN_UNDEF)
continue;
if (!firsttime && pmcstat_symbol_search(image, sym.st_value))
continue; /* We've seen this symbol already. */
if ((fnname = elf_strptr(e, sh->sh_link, sym.st_name))
== NULL)
continue;
#ifdef __arm__
/* Remove spurious ARM function name. */
if (fnname[0] == '$' &&
(fnname[1] == 'a' || fnname[1] == 't' ||
fnname[1] == 'd') &&
fnname[2] == '\0')
continue;
#endif
symptr->ps_name = pmcstat_string_intern(fnname);
symptr->ps_start = sym.st_value - image->pi_vaddr;
symptr->ps_end = symptr->ps_start + sym.st_size;
symptr++;
newsyms++;
}
image->pi_symcount += newsyms;
if (image->pi_symcount == 0)
return;
assert(newsyms <= nfuncsyms);
/*
* Return space to the system if there were duplicates.
*/
if (newsyms < nfuncsyms)
image->pi_symbols = reallocarray(image->pi_symbols,
image->pi_symcount, sizeof(*symptr));
/*
* Keep the list of symbols sorted.
*/
qsort(image->pi_symbols, image->pi_symcount, sizeof(*symptr),
pmcstat_symbol_compare);
/*
* Deal with function symbols that have a size of 'zero' by
* making them extend to the next higher address. These
* symbols are usually defined in assembly code.
*/
for (symptr = image->pi_symbols;
symptr < image->pi_symbols + (image->pi_symcount - 1);
symptr++)
if (symptr->ps_start == symptr->ps_end)
symptr->ps_end = (symptr+1)->ps_start;
}
/*
* Record the fact that PC values from 'start' to 'end' come from
* image 'image'.
*/
void
pmcstat_image_link(struct pmcstat_process *pp, struct pmcstat_image *image,
uintfptr_t start)
{
struct pmcstat_pcmap *pcm, *pcmnew;
uintfptr_t offset;
#ifdef __powerpc__
unsigned long kernbase;
size_t kernbase_len;
#endif
assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN &&
image->pi_type != PMCSTAT_IMAGE_INDETERMINABLE);
if ((pcmnew = malloc(sizeof(*pcmnew))) == NULL)
err(EX_OSERR, "ERROR: Cannot create a map entry");
/*
* PowerPC kernel is of DYN type and it has a base address
* where it is initially loaded, before being relocated.
* As the address in 'start' is where the kernel was relocated to,
* but the symbols always use the original base address, we need to
* subtract it to get the correct offset.
*/
#ifdef __powerpc__
if (pp->pp_pid == -1) {
kernbase = 0;
kernbase_len = sizeof(kernbase);
if (sysctlbyname("kern.base_address", &kernbase, &kernbase_len,
NULL, 0) == -1)
warnx(
"WARNING: Could not retrieve kernel base address");
else
start -= kernbase;
}
#endif
/*
* Adjust the map entry to only cover the text portion
* of the object.
*/
offset = start - image->pi_vaddr;
pcmnew->ppm_lowpc = image->pi_start + offset;
pcmnew->ppm_highpc = image->pi_end + offset;
pcmnew->ppm_image = image;
assert(pcmnew->ppm_lowpc < pcmnew->ppm_highpc);
/* Overlapped mmap()'s are assumed to never occur. */
TAILQ_FOREACH(pcm, &pp->pp_map, ppm_next)
if (pcm->ppm_lowpc >= pcmnew->ppm_highpc)
break;
if (pcm == NULL)
TAILQ_INSERT_TAIL(&pp->pp_map, pcmnew, ppm_next);
else
TAILQ_INSERT_BEFORE(pcm, pcmnew, ppm_next);
}
/*
* Determine whether a given executable image is an A.OUT object, and
* if so, fill in its parameters from the text file.
* Sets image->pi_type.
*/
void
pmcstat_image_get_aout_params(struct pmcstat_image *image,
struct pmcstat_args *args)
{
int fd;
ssize_t nbytes;
struct exec ex;
const char *path;
char buffer[PATH_MAX];
path = pmcstat_string_unintern(image->pi_execpath);
assert(path != NULL);
if (image->pi_iskernelmodule)
errx(EX_SOFTWARE,
"ERROR: a.out kernel modules are unsupported \"%s\"", path);
(void) snprintf(buffer, sizeof(buffer), "%s%s",
args->pa_fsroot, path);
if ((fd = open(buffer, O_RDONLY, 0)) < 0 ||
(nbytes = read(fd, &ex, sizeof(ex))) < 0) {
if (args->pa_verbosity >= 2)
warn("WARNING: Cannot determine type of \"%s\"",
path);
image->pi_type = PMCSTAT_IMAGE_INDETERMINABLE;
if (fd != -1)
(void) close(fd);
return;
}
(void) close(fd);
if ((unsigned) nbytes != sizeof(ex) ||
N_BADMAG(ex))
return;
image->pi_type = PMCSTAT_IMAGE_AOUT;
/* TODO: the rest of a.out processing */
return;
}
/*
* Examine an ELF file to determine the size of its text segment.
* Sets image->pi_type if anything conclusive can be determined about
* this image.
*/
void
pmcstat_image_get_elf_params(struct pmcstat_image *image,
struct pmcstat_args *args)
{
int fd;
size_t i, nph, nsh;
const char *path, *elfbase;
char *p, *endp;
uintfptr_t minva, maxva;
Elf *e;
Elf_Scn *scn;
GElf_Ehdr eh;
GElf_Phdr ph;
GElf_Shdr sh;
enum pmcstat_image_type image_type;
char buffer[PATH_MAX];
char buffer_modules[PATH_MAX];
assert(image->pi_type == PMCSTAT_IMAGE_UNKNOWN);
image->pi_start = minva = ~(uintfptr_t) 0;
image->pi_end = maxva = (uintfptr_t) 0;
image->pi_type = image_type = PMCSTAT_IMAGE_INDETERMINABLE;
image->pi_isdynamic = 0;
image->pi_dynlinkerpath = NULL;
image->pi_vaddr = 0;
path = pmcstat_string_unintern(image->pi_execpath);
assert(path != NULL);
/*
* Look for kernel modules under FSROOT/KERNELPATH/NAME and
* FSROOT/boot/modules/NAME, and user mode executable objects
* under FSROOT/PATHNAME.
*/
if (image->pi_iskernelmodule) {
(void) snprintf(buffer, sizeof(buffer), "%s%s/%s",
args->pa_fsroot, args->pa_kernel, path);
(void) snprintf(buffer_modules, sizeof(buffer_modules),
"%s/boot/modules/%s", args->pa_fsroot, path);
} else {
(void) snprintf(buffer, sizeof(buffer), "%s%s",
args->pa_fsroot, path);
}
e = NULL;
fd = open(buffer, O_RDONLY, 0);
if (fd < 0 && !image->pi_iskernelmodule) {
warnx("WARNING: Cannot open \"%s\".",
buffer);
goto done;
}
if (fd < 0 && (fd = open(buffer_modules, O_RDONLY, 0)) < 0) {
warnx("WARNING: Cannot open \"%s\" or \"%s\".",
buffer, buffer_modules);
goto done;
}
if (elf_version(EV_CURRENT) == EV_NONE) {
warnx("WARNING: failed to init elf\n");
goto done;
}
if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
warnx("WARNING: Cannot read \"%s\".",
buffer);
goto done;
}
if (elf_kind(e) != ELF_K_ELF) {
if (args->pa_verbosity >= 2)
warnx("WARNING: Cannot determine the type of \"%s\".",
buffer);
goto done;
}
if (gelf_getehdr(e, &eh) != &eh) {
warnx(
"WARNING: Cannot retrieve the ELF Header for \"%s\": %s.",
buffer, elf_errmsg(-1));
goto done;
}
if (eh.e_type != ET_EXEC && eh.e_type != ET_DYN &&
!(image->pi_iskernelmodule && eh.e_type == ET_REL)) {
warnx("WARNING: \"%s\" is of an unsupported ELF type.",
buffer);
goto done;
}
image_type = eh.e_ident[EI_CLASS] == ELFCLASS32 ?
PMCSTAT_IMAGE_ELF32 : PMCSTAT_IMAGE_ELF64;
/*
* Determine the virtual address where an executable would be
* loaded. Additionally, for dynamically linked executables,
* save the pathname to the runtime linker.
*/
if (eh.e_type == ET_EXEC) {
if (elf_getphnum(e, &nph) == 0) {
warnx(
"WARNING: Could not determine the number of program headers in \"%s\": %s.",
buffer,
elf_errmsg(-1));
goto done;
}
for (i = 0; i < eh.e_phnum; i++) {
if (gelf_getphdr(e, i, &ph) != &ph) {
warnx(
"WARNING: Retrieval of PHDR entry #%ju in \"%s\" failed: %s.",
(uintmax_t) i, buffer, elf_errmsg(-1));
goto done;
}
switch (ph.p_type) {
case PT_DYNAMIC:
image->pi_isdynamic = 1;
break;
case PT_INTERP:
if ((elfbase = elf_rawfile(e, NULL)) == NULL) {
warnx(
"WARNING: Cannot retrieve the interpreter for \"%s\": %s.",
buffer, elf_errmsg(-1));
goto done;
}
image->pi_dynlinkerpath =
pmcstat_string_intern(elfbase +
ph.p_offset);
break;
case PT_LOAD:
if ((ph.p_flags & PF_X) != 0 &&
(ph.p_offset & (-ph.p_align)) == 0)
image->pi_vaddr = ph.p_vaddr & (-ph.p_align);
break;
}
}
}
/*
* Get the min and max VA associated with this ELF object.
*/
if (elf_getshnum(e, &nsh) == 0) {
warnx(
"WARNING: Could not determine the number of sections for \"%s\": %s.",
buffer, elf_errmsg(-1));
goto done;
}
for (i = 0; i < nsh; i++) {
if ((scn = elf_getscn(e, i)) == NULL ||
gelf_getshdr(scn, &sh) != &sh) {
warnx(
"WARNING: Could not retrieve section header #%ju in \"%s\": %s.",
(uintmax_t) i, buffer, elf_errmsg(-1));
goto done;
}
if (sh.sh_flags & SHF_EXECINSTR) {
minva = min(minva, sh.sh_addr);
maxva = max(maxva, sh.sh_addr + sh.sh_size);
}
if (sh.sh_type == SHT_SYMTAB || sh.sh_type == SHT_DYNSYM)
pmcstat_image_add_symbols(image, e, scn, &sh);
}
image->pi_start = minva;
image->pi_end = maxva;
image->pi_type = image_type;
image->pi_fullpath = pmcstat_string_intern(buffer);
/* Build display name
*/
endp = buffer;
for (p = buffer; *p; p++)
if (*p == '/')
endp = p+1;
image->pi_name = pmcstat_string_intern(endp);
done:
(void) elf_end(e);
if (fd >= 0)
(void) close(fd);
return;
}
/*
* Given an image descriptor, determine whether it is an ELF, or AOUT.
* If no handler claims the image, set its type to 'INDETERMINABLE'.
*/
void
pmcstat_image_determine_type(struct pmcstat_image *image,
struct pmcstat_args *args)
{
assert(image->pi_type == PMCSTAT_IMAGE_UNKNOWN);
/* Try each kind of handler in turn */
if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
pmcstat_image_get_elf_params(image, args);
if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
pmcstat_image_get_aout_params(image, args);
/*
* Otherwise, remember that we tried to determine
* the object's type and had failed.
*/
if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
image->pi_type = PMCSTAT_IMAGE_INDETERMINABLE;
}
/*
* Locate an image descriptor given an interned path, adding a fresh
* descriptor to the cache if necessary. This function also finds a
* suitable name for this image's sample file.
*
* We defer filling in the file format specific parts of the image
* structure till the time we actually see a sample that would fall
* into this image.
*/
struct pmcstat_image *
pmcstat_image_from_path(pmcstat_interned_string internedpath,
int iskernelmodule, struct pmcstat_args *args,
struct pmc_plugins *plugins)
{
int hash;
struct pmcstat_image *pi;
hash = pmcstat_string_lookup_hash(internedpath);
/* First, look for an existing entry. */
LIST_FOREACH(pi, &pmcstat_image_hash[hash], pi_next)
if (pi->pi_execpath == internedpath &&
pi->pi_iskernelmodule == iskernelmodule)
return (pi);
/*
* Allocate a new entry and place it at the head of the hash
* and LRU lists.
*/
pi = malloc(sizeof(*pi));
if (pi == NULL)
return (NULL);
pi->pi_type = PMCSTAT_IMAGE_UNKNOWN;
pi->pi_execpath = internedpath;
pi->pi_start = ~0;
pi->pi_end = 0;
pi->pi_entry = 0;
pi->pi_vaddr = 0;
pi->pi_isdynamic = 0;
pi->pi_iskernelmodule = iskernelmodule;
pi->pi_dynlinkerpath = NULL;
pi->pi_symbols = NULL;
pi->pi_symcount = 0;
pi->pi_addr2line = NULL;
if (plugins[args->pa_pplugin].pl_initimage != NULL)
plugins[args->pa_pplugin].pl_initimage(pi);
if (plugins[args->pa_plugin].pl_initimage != NULL)
plugins[args->pa_plugin].pl_initimage(pi);
LIST_INSERT_HEAD(&pmcstat_image_hash[hash], pi, pi_next);
return (pi);
}
