linux/tools/perf/util/build-id.c

882 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* build-id.c
*
* build-id support
*
* Copyright (C) 2009, 2010 Red Hat Inc.
* Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include "util.h"
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "build-id.h"
#include "event.h"
#include "symbol.h"
#include "thread.h"
#include <linux/kernel.h>
#include "debug.h"
#include "session.h"
#include "tool.h"
#include "header.h"
#include "vdso.h"
#include "path.h"
#include "probe-file.h"
#include "strlist.h"
#include "sane_ctype.h"
static bool no_buildid_cache;
int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
union perf_event *event,
struct perf_sample *sample,
struct perf_evsel *evsel __maybe_unused,
struct machine *machine)
{
struct addr_location al;
struct thread *thread = machine__findnew_thread(machine, sample->pid,
sample->tid);
if (thread == NULL) {
pr_err("problem processing %d event, skipping it.\n",
event->header.type);
return -1;
}
thread__find_addr_map(thread, sample->cpumode, MAP__FUNCTION, sample->ip, &al);
if (al.map != NULL)
al.map->dso->hit = 1;
thread__put(thread);
return 0;
}
static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
union perf_event *event,
struct perf_sample *sample
__maybe_unused,
struct machine *machine)
{
struct thread *thread = machine__findnew_thread(machine,
event->fork.pid,
event->fork.tid);
dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
event->fork.ppid, event->fork.ptid);
if (thread) {
machine__remove_thread(machine, thread);
thread__put(thread);
}
return 0;
}
struct perf_tool build_id__mark_dso_hit_ops = {
.sample = build_id__mark_dso_hit,
.mmap = perf_event__process_mmap,
.mmap2 = perf_event__process_mmap2,
.fork = perf_event__process_fork,
.exit = perf_event__exit_del_thread,
.attr = perf_event__process_attr,
.build_id = perf_event__process_build_id,
.ordered_events = true,
};
int build_id__sprintf(const u8 *build_id, int len, char *bf)
{
char *bid = bf;
const u8 *raw = build_id;
int i;
for (i = 0; i < len; ++i) {
sprintf(bid, "%02x", *raw);
++raw;
bid += 2;
}
return (bid - bf) + 1;
}
int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
{
char notes[PATH_MAX];
u8 build_id[BUILD_ID_SIZE];
int ret;
if (!root_dir)
root_dir = "";
scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
if (ret < 0)
return ret;
return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
}
int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
{
u8 build_id[BUILD_ID_SIZE];
int ret;
ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
if (ret < 0)
return ret;
else if (ret != sizeof(build_id))
return -EINVAL;
return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
}
/* asnprintf consolidates asprintf and snprintf */
static int asnprintf(char **strp, size_t size, const char *fmt, ...)
{
va_list ap;
int ret;
if (!strp)
return -EINVAL;
va_start(ap, fmt);
if (*strp)
ret = vsnprintf(*strp, size, fmt, ap);
else
ret = vasprintf(strp, fmt, ap);
va_end(ap);
return ret;
}
char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
size_t size)
{
bool retry_old = true;
snprintf(bf, size, "%s/%s/%s/kallsyms",
buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
retry:
if (!access(bf, F_OK))
return bf;
if (retry_old) {
/* Try old style kallsyms cache */
snprintf(bf, size, "%s/%s/%s",
buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
retry_old = false;
goto retry;
}
return NULL;
}
char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
{
char *tmp = bf;
int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
sbuild_id, sbuild_id + 2);
if (ret < 0 || (tmp && size < (unsigned int)ret))
return NULL;
return bf;
}
char *build_id_cache__origname(const char *sbuild_id)
{
char *linkname;
char buf[PATH_MAX];
char *ret = NULL, *p;
size_t offs = 5; /* == strlen("../..") */
ssize_t len;
linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
if (!linkname)
return NULL;
len = readlink(linkname, buf, sizeof(buf) - 1);
if (len <= 0)
goto out;
buf[len] = '\0';
/* The link should be "../..<origpath>/<sbuild_id>" */
p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
if (p && (p > buf + offs)) {
*p = '\0';
if (buf[offs + 1] == '[')
offs++; /*
* This is a DSO name, like [kernel.kallsyms].
* Skip the first '/', since this is not the
* cache of a regular file.
*/
ret = strdup(buf + offs); /* Skip "../..[/]" */
}
out:
free(linkname);
return ret;
}
/* Check if the given build_id cache is valid on current running system */
static bool build_id_cache__valid_id(char *sbuild_id)
{
char real_sbuild_id[SBUILD_ID_SIZE] = "";
char *pathname;
int ret = 0;
bool result = false;
pathname = build_id_cache__origname(sbuild_id);
if (!pathname)
return false;
if (!strcmp(pathname, DSO__NAME_KALLSYMS))
ret = sysfs__sprintf_build_id("/", real_sbuild_id);
else if (pathname[0] == '/')
ret = filename__sprintf_build_id(pathname, real_sbuild_id);
else
ret = -EINVAL; /* Should we support other special DSO cache? */
if (ret >= 0)
result = (strcmp(sbuild_id, real_sbuild_id) == 0);
free(pathname);
return result;
}
static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
bool is_debug)
{
return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
"debug" : "elf"));
}
char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
bool is_debug)
{
bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
bool is_vdso = dso__is_vdso((struct dso *)dso);
char sbuild_id[SBUILD_ID_SIZE];
char *linkname;
bool alloc = (bf == NULL);
int ret;
if (!dso->has_build_id)
return NULL;
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
if (!linkname)
return NULL;
/* Check if old style build_id cache */
if (is_regular_file(linkname))
ret = asnprintf(&bf, size, "%s", linkname);
else
ret = asnprintf(&bf, size, "%s/%s", linkname,
build_id_cache__basename(is_kallsyms, is_vdso,
is_debug));
if (ret < 0 || (!alloc && size < (unsigned int)ret))
bf = NULL;
free(linkname);
return bf;
}
#define dsos__for_each_with_build_id(pos, head) \
list_for_each_entry(pos, head, node) \
if (!pos->has_build_id) \
continue; \
else
static int write_buildid(const char *name, size_t name_len, u8 *build_id,
pid_t pid, u16 misc, struct feat_fd *fd)
{
int err;
struct build_id_event b;
size_t len;
len = name_len + 1;
len = PERF_ALIGN(len, NAME_ALIGN);
memset(&b, 0, sizeof(b));
memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
b.pid = pid;
b.header.misc = misc;
b.header.size = sizeof(b) + len;
err = do_write(fd, &b, sizeof(b));
if (err < 0)
return err;
return write_padded(fd, name, name_len + 1, len);
}
static int machine__write_buildid_table(struct machine *machine,
struct feat_fd *fd)
{
int err = 0;
char nm[PATH_MAX];
struct dso *pos;
u16 kmisc = PERF_RECORD_MISC_KERNEL,
umisc = PERF_RECORD_MISC_USER;
if (!machine__is_host(machine)) {
kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
umisc = PERF_RECORD_MISC_GUEST_USER;
}
dsos__for_each_with_build_id(pos, &machine->dsos.head) {
const char *name;
size_t name_len;
bool in_kernel = false;
if (!pos->hit && !dso__is_vdso(pos))
continue;
if (dso__is_vdso(pos)) {
name = pos->short_name;
name_len = pos->short_name_len;
} else if (dso__is_kcore(pos)) {
machine__mmap_name(machine, nm, sizeof(nm));
name = nm;
name_len = strlen(nm);
} else {
name = pos->long_name;
name_len = pos->long_name_len;
}
in_kernel = pos->kernel ||
is_kernel_module(name,
PERF_RECORD_MISC_CPUMODE_UNKNOWN);
err = write_buildid(name, name_len, pos->build_id, machine->pid,
in_kernel ? kmisc : umisc, fd);
if (err)
break;
}
return err;
}
int perf_session__write_buildid_table(struct perf_session *session,
struct feat_fd *fd)
{
struct rb_node *nd;
int err = machine__write_buildid_table(&session->machines.host, fd);
if (err)
return err;
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
err = machine__write_buildid_table(pos, fd);
if (err)
break;
}
return err;
}
static int __dsos__hit_all(struct list_head *head)
{
struct dso *pos;
list_for_each_entry(pos, head, node)
pos->hit = true;
return 0;
}
static int machine__hit_all_dsos(struct machine *machine)
{
return __dsos__hit_all(&machine->dsos.head);
}
int dsos__hit_all(struct perf_session *session)
{
struct rb_node *nd;
int err;
err = machine__hit_all_dsos(&session->machines.host);
if (err)
return err;
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
err = machine__hit_all_dsos(pos);
if (err)
return err;
}
return 0;
}
void disable_buildid_cache(void)
{
no_buildid_cache = true;
}
static bool lsdir_bid_head_filter(const char *name __maybe_unused,
struct dirent *d)
{
return (strlen(d->d_name) == 2) &&
isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
}
static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
struct dirent *d)
{
int i = 0;
while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
i++;
return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
}
struct strlist *build_id_cache__list_all(bool validonly)
{
struct strlist *toplist, *linklist = NULL, *bidlist;
struct str_node *nd, *nd2;
char *topdir, *linkdir = NULL;
char sbuild_id[SBUILD_ID_SIZE];
/* for filename__ functions */
if (validonly)
symbol__init(NULL);
/* Open the top-level directory */
if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
return NULL;
bidlist = strlist__new(NULL, NULL);
if (!bidlist)
goto out;
toplist = lsdir(topdir, lsdir_bid_head_filter);
if (!toplist) {
pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
/* If there is no buildid cache, return an empty list */
if (errno == ENOENT)
goto out;
goto err_out;
}
strlist__for_each_entry(nd, toplist) {
if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
goto err_out;
/* Open the lower-level directory */
linklist = lsdir(linkdir, lsdir_bid_tail_filter);
if (!linklist) {
pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
goto err_out;
}
strlist__for_each_entry(nd2, linklist) {
if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
goto err_out;
if (validonly && !build_id_cache__valid_id(sbuild_id))
continue;
if (strlist__add(bidlist, sbuild_id) < 0)
goto err_out;
}
strlist__delete(linklist);
zfree(&linkdir);
}
out_free:
strlist__delete(toplist);
out:
free(topdir);
return bidlist;
err_out:
strlist__delete(linklist);
zfree(&linkdir);
strlist__delete(bidlist);
bidlist = NULL;
goto out_free;
}
static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
{
size_t i;
for (i = 0; i < len; i++) {
if (!isxdigit(maybe_sbuild_id[i]))
return false;
}
return true;
}
/* Return the valid complete build-id */
char *build_id_cache__complement(const char *incomplete_sbuild_id)
{
struct strlist *bidlist;
struct str_node *nd, *cand = NULL;
char *sbuild_id = NULL;
size_t len = strlen(incomplete_sbuild_id);
if (len >= SBUILD_ID_SIZE ||
!str_is_build_id(incomplete_sbuild_id, len))
return NULL;
bidlist = build_id_cache__list_all(true);
if (!bidlist)
return NULL;
strlist__for_each_entry(nd, bidlist) {
if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
continue;
if (cand) { /* Error: There are more than 2 candidates. */
cand = NULL;
break;
}
cand = nd;
}
if (cand)
sbuild_id = strdup(cand->s);
strlist__delete(bidlist);
return sbuild_id;
}
char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
struct nsinfo *nsi, bool is_kallsyms,
bool is_vdso)
{
char *realname = (char *)name, *filename;
bool slash = is_kallsyms || is_vdso;
if (!slash) {
realname = nsinfo__realpath(name, nsi);
if (!realname)
return NULL;
}
if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
is_vdso ? DSO__NAME_VDSO : realname,
sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
filename = NULL;
if (!slash)
free(realname);
return filename;
}
int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
struct strlist **result)
{
char *dir_name;
int ret = 0;
dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
if (!dir_name)
return -ENOMEM;
*result = lsdir(dir_name, lsdir_no_dot_filter);
if (!*result)
ret = -errno;
free(dir_name);
return ret;
}
#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
static int build_id_cache__add_sdt_cache(const char *sbuild_id,
const char *realname,
struct nsinfo *nsi)
{
struct probe_cache *cache;
int ret;
struct nscookie nsc;
cache = probe_cache__new(sbuild_id, nsi);
if (!cache)
return -1;
nsinfo__mountns_enter(nsi, &nsc);
ret = probe_cache__scan_sdt(cache, realname);
nsinfo__mountns_exit(&nsc);
if (ret >= 0) {
pr_debug4("Found %d SDTs in %s\n", ret, realname);
if (probe_cache__commit(cache) < 0)
ret = -1;
}
probe_cache__delete(cache);
return ret;
}
#else
#define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
#endif
static char *build_id_cache__find_debug(const char *sbuild_id,
struct nsinfo *nsi)
{
char *realname = NULL;
char *debugfile;
struct nscookie nsc;
size_t len = 0;
debugfile = calloc(1, PATH_MAX);
if (!debugfile)
goto out;
len = __symbol__join_symfs(debugfile, PATH_MAX,
"/usr/lib/debug/.build-id/");
snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
sbuild_id + 2);
nsinfo__mountns_enter(nsi, &nsc);
realname = realpath(debugfile, NULL);
if (realname && access(realname, R_OK))
zfree(&realname);
nsinfo__mountns_exit(&nsc);
out:
free(debugfile);
return realname;
}
int build_id_cache__add_s(const char *sbuild_id, const char *name,
struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
{
const size_t size = PATH_MAX;
char *realname = NULL, *filename = NULL, *dir_name = NULL,
*linkname = zalloc(size), *tmp;
char *debugfile = NULL;
int err = -1;
if (!is_kallsyms) {
if (!is_vdso)
realname = nsinfo__realpath(name, nsi);
else
realname = realpath(name, NULL);
if (!realname)
goto out_free;
}
dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms,
is_vdso);
if (!dir_name)
goto out_free;
/* Remove old style build-id cache */
if (is_regular_file(dir_name))
if (unlink(dir_name))
goto out_free;
if (mkdir_p(dir_name, 0755))
goto out_free;
/* Save the allocated buildid dirname */
if (asprintf(&filename, "%s/%s", dir_name,
build_id_cache__basename(is_kallsyms, is_vdso,
false)) < 0) {
filename = NULL;
goto out_free;
}
if (access(filename, F_OK)) {
if (is_kallsyms) {
if (copyfile("/proc/kallsyms", filename))
goto out_free;
} else if (nsi && nsi->need_setns) {
if (copyfile_ns(name, filename, nsi))
goto out_free;
} else if (link(realname, filename) && errno != EEXIST &&
copyfile(name, filename))
goto out_free;
}
/* Some binaries are stripped, but have .debug files with their symbol
* table. Check to see if we can locate one of those, since the elf
* file itself may not be very useful to users of our tools without a
* symtab.
*/
if (!is_kallsyms && !is_vdso &&
strncmp(".ko", name + strlen(name) - 3, 3)) {
debugfile = build_id_cache__find_debug(sbuild_id, nsi);
if (debugfile) {
zfree(&filename);
if (asprintf(&filename, "%s/%s", dir_name,
build_id_cache__basename(false, false, true)) < 0) {
filename = NULL;
goto out_free;
}
if (access(filename, F_OK)) {
if (nsi && nsi->need_setns) {
if (copyfile_ns(debugfile, filename,
nsi))
goto out_free;
} else if (link(debugfile, filename) &&
errno != EEXIST &&
copyfile(debugfile, filename))
goto out_free;
}
}
}
if (!build_id_cache__linkname(sbuild_id, linkname, size))
goto out_free;
tmp = strrchr(linkname, '/');
*tmp = '\0';
if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
goto out_free;
*tmp = '/';
tmp = dir_name + strlen(buildid_dir) - 5;
memcpy(tmp, "../..", 5);
if (symlink(tmp, linkname) == 0)
err = 0;
/* Update SDT cache : error is just warned */
if (realname &&
build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
out_free:
if (!is_kallsyms)
free(realname);
free(filename);
free(debugfile);
free(dir_name);
free(linkname);
return err;
}
static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
const char *name, struct nsinfo *nsi,
bool is_kallsyms, bool is_vdso)
{
char sbuild_id[SBUILD_ID_SIZE];
build_id__sprintf(build_id, build_id_size, sbuild_id);
return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
is_vdso);
}
bool build_id_cache__cached(const char *sbuild_id)
{
bool ret = false;
char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
if (filename && !access(filename, F_OK))
ret = true;
free(filename);
return ret;
}
int build_id_cache__remove_s(const char *sbuild_id)
{
const size_t size = PATH_MAX;
char *filename = zalloc(size),
*linkname = zalloc(size), *tmp;
int err = -1;
if (filename == NULL || linkname == NULL)
goto out_free;
if (!build_id_cache__linkname(sbuild_id, linkname, size))
goto out_free;
if (access(linkname, F_OK))
goto out_free;
if (readlink(linkname, filename, size - 1) < 0)
goto out_free;
if (unlink(linkname))
goto out_free;
/*
* Since the link is relative, we must make it absolute:
*/
tmp = strrchr(linkname, '/') + 1;
snprintf(tmp, size - (tmp - linkname), "%s", filename);
if (rm_rf(linkname))
goto out_free;
err = 0;
out_free:
free(filename);
free(linkname);
return err;
}
static int dso__cache_build_id(struct dso *dso, struct machine *machine)
{
bool is_kallsyms = dso__is_kallsyms(dso);
bool is_vdso = dso__is_vdso(dso);
const char *name = dso->long_name;
char nm[PATH_MAX];
if (dso__is_kcore(dso)) {
is_kallsyms = true;
machine__mmap_name(machine, nm, sizeof(nm));
name = nm;
}
return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
dso->nsinfo, is_kallsyms, is_vdso);
}
static int __dsos__cache_build_ids(struct list_head *head,
struct machine *machine)
{
struct dso *pos;
int err = 0;
dsos__for_each_with_build_id(pos, head)
if (dso__cache_build_id(pos, machine))
err = -1;
return err;
}
static int machine__cache_build_ids(struct machine *machine)
{
return __dsos__cache_build_ids(&machine->dsos.head, machine);
}
int perf_session__cache_build_ids(struct perf_session *session)
{
struct rb_node *nd;
int ret;
if (no_buildid_cache)
return 0;
if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
return -1;
ret = machine__cache_build_ids(&session->machines.host);
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
ret |= machine__cache_build_ids(pos);
}
return ret ? -1 : 0;
}
static bool machine__read_build_ids(struct machine *machine, bool with_hits)
{
return __dsos__read_build_ids(&machine->dsos.head, with_hits);
}
bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
{
struct rb_node *nd;
bool ret = machine__read_build_ids(&session->machines.host, with_hits);
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
ret |= machine__read_build_ids(pos, with_hits);
}
return ret;
}