linux/tools/perf/builtin-buildid-cache.c
Arnaldo Carvalho de Melo b843f62ad9 perf symbols: Accept symbols starting at address 0
That is the case of _text on s390, and we have some functions that return an
address, using address zero to report problems, oops.

This would lead the symbol loading routines to not use "_text" as the reference
relocation symbol, or the first symbol for the kernel, but use instead
"_stext", that is at the same address on x86_64 and others, but not on s390:

  [acme@localhost perf-4.11.0-rc6]$ head -15 /proc/kallsyms
  0000000000000000 T _text
  0000000000000418 t iplstart
  0000000000000800 T start
  000000000000080a t .base
  000000000000082e t .sk8x8
  0000000000000834 t .gotr
  0000000000000842 t .cmd
  0000000000000846 t .parm
  000000000000084a t .lowcase
  0000000000010000 T startup
  0000000000010010 T startup_kdump
  0000000000010214 t startup_kdump_relocated
  0000000000011000 T startup_continue
  00000000000112a0 T _ehead
  0000000000100000 T _stext
  [acme@localhost perf-4.11.0-rc6]$

Which in turn would make 'perf test vmlinux' to fail because it wouldn't find
the symbols before "_stext" in kallsyms.

Fix it by using the return value only for errors and storing the
address, when the symbol is successfully found, in a provided pointer
arg.

Before this patch:

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 40693
  Looking at the vmlinux_path (8 entries long)
  Using /usr/lib/debug/lib/modules/3.10.0-654.el7.s390x/vmlinux for symbols
  ERR : 0: _text not on kallsyms
  ERR : 0x418: iplstart not on kallsyms
  ERR : 0x800: start not on kallsyms
  ERR : 0x80a: .base not on kallsyms
  ERR : 0x82e: .sk8x8 not on kallsyms
  ERR : 0x834: .gotr not on kallsyms
  ERR : 0x842: .cmd not on kallsyms
  ERR : 0x846: .parm not on kallsyms
  ERR : 0x84a: .lowcase not on kallsyms
  ERR : 0x10000: startup not on kallsyms
  ERR : 0x10010: startup_kdump not on kallsyms
  ERR : 0x10214: startup_kdump_relocated not on kallsyms
  ERR : 0x11000: startup_continue not on kallsyms
  ERR : 0x112a0: _ehead not on kallsyms
  <SNIP warnings>
  test child finished with -1
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!
  [acme@localhost perf-4.11.0-rc6]$

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 47160
  <SNIP warnings>
  test child finished with 0
  ---- end ----
  vmlinux symtab matches kallsyms: Ok
  [acme@localhost perf-4.11.0-rc6]$

Reported-by: Michael Petlan <mpetlan@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9x9bwgd3btwdk1u51xie93fz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-05-02 18:23:04 -03:00

430 lines
10 KiB
C

/*
* builtin-buildid-cache.c
*
* Builtin buildid-cache command: Manages build-id cache
*
* Copyright (C) 2010, Red Hat Inc.
* Copyright (C) 2010, Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include "builtin.h"
#include "perf.h"
#include "util/cache.h"
#include "util/debug.h"
#include "util/header.h"
#include <subcmd/parse-options.h>
#include "util/strlist.h"
#include "util/build-id.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/time-utils.h"
static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
{
char root_dir[PATH_MAX];
char *p;
strlcpy(root_dir, proc_dir, sizeof(root_dir));
p = strrchr(root_dir, '/');
if (!p)
return -1;
*p = '\0';
return sysfs__sprintf_build_id(root_dir, sbuildid);
}
static int build_id_cache__kcore_dir(char *dir, size_t sz)
{
return fetch_current_timestamp(dir, sz);
}
static bool same_kallsyms_reloc(const char *from_dir, char *to_dir)
{
char from[PATH_MAX];
char to[PATH_MAX];
const char *name;
u64 addr1 = 0, addr2 = 0;
int i, err = -1;
scnprintf(from, sizeof(from), "%s/kallsyms", from_dir);
scnprintf(to, sizeof(to), "%s/kallsyms", to_dir);
for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
err = kallsyms__get_function_start(from, name, &addr1);
if (!err)
break;
}
if (err)
return false;
if (kallsyms__get_function_start(to, name, &addr2))
return false;
return addr1 == addr2;
}
static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
size_t to_dir_sz)
{
char from[PATH_MAX];
char to[PATH_MAX];
char to_subdir[PATH_MAX];
struct dirent *dent;
int ret = -1;
DIR *d;
d = opendir(to_dir);
if (!d)
return -1;
scnprintf(from, sizeof(from), "%s/modules", from_dir);
while (1) {
dent = readdir(d);
if (!dent)
break;
if (dent->d_type != DT_DIR)
continue;
scnprintf(to, sizeof(to), "%s/%s/modules", to_dir,
dent->d_name);
scnprintf(to_subdir, sizeof(to_subdir), "%s/%s",
to_dir, dent->d_name);
if (!compare_proc_modules(from, to) &&
same_kallsyms_reloc(from_dir, to_subdir)) {
strlcpy(to_dir, to_subdir, to_dir_sz);
ret = 0;
break;
}
}
closedir(d);
return ret;
}
static int build_id_cache__add_kcore(const char *filename, bool force)
{
char dir[32], sbuildid[SBUILD_ID_SIZE];
char from_dir[PATH_MAX], to_dir[PATH_MAX];
char *p;
strlcpy(from_dir, filename, sizeof(from_dir));
p = strrchr(from_dir, '/');
if (!p || strcmp(p + 1, "kcore"))
return -1;
*p = '\0';
if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
return -1;
scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
buildid_dir, DSO__NAME_KCORE, sbuildid);
if (!force &&
!build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) {
pr_debug("same kcore found in %s\n", to_dir);
return 0;
}
if (build_id_cache__kcore_dir(dir, sizeof(dir)))
return -1;
scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s/%s",
buildid_dir, DSO__NAME_KCORE, sbuildid, dir);
if (mkdir_p(to_dir, 0755))
return -1;
if (kcore_copy(from_dir, to_dir)) {
/* Remove YYYYmmddHHMMSShh directory */
if (!rmdir(to_dir)) {
p = strrchr(to_dir, '/');
if (p)
*p = '\0';
/* Try to remove buildid directory */
if (!rmdir(to_dir)) {
p = strrchr(to_dir, '/');
if (p)
*p = '\0';
/* Try to remove [kernel.kcore] directory */
rmdir(to_dir);
}
}
return -1;
}
pr_debug("kcore added to build-id cache directory %s\n", to_dir);
return 0;
}
static int build_id_cache__add_file(const char *filename)
{
char sbuild_id[SBUILD_ID_SIZE];
u8 build_id[BUILD_ID_SIZE];
int err;
if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
pr_debug("Couldn't read a build-id in %s\n", filename);
return -1;
}
build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
err = build_id_cache__add_s(sbuild_id, filename,
false, false);
pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
err ? "FAIL" : "Ok");
return err;
}
static int build_id_cache__remove_file(const char *filename)
{
u8 build_id[BUILD_ID_SIZE];
char sbuild_id[SBUILD_ID_SIZE];
int err;
if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
pr_debug("Couldn't read a build-id in %s\n", filename);
return -1;
}
build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
err = build_id_cache__remove_s(sbuild_id);
pr_debug("Removing %s %s: %s\n", sbuild_id, filename,
err ? "FAIL" : "Ok");
return err;
}
static int build_id_cache__purge_path(const char *pathname)
{
struct strlist *list;
struct str_node *pos;
int err;
err = build_id_cache__list_build_ids(pathname, &list);
if (err)
goto out;
strlist__for_each_entry(pos, list) {
err = build_id_cache__remove_s(pos->s);
pr_debug("Removing %s %s: %s\n", pos->s, pathname,
err ? "FAIL" : "Ok");
if (err)
break;
}
strlist__delete(list);
out:
pr_debug("Purging %s: %s\n", pathname, err ? "FAIL" : "Ok");
return err;
}
static bool dso__missing_buildid_cache(struct dso *dso, int parm __maybe_unused)
{
char filename[PATH_MAX];
u8 build_id[BUILD_ID_SIZE];
if (dso__build_id_filename(dso, filename, sizeof(filename)) &&
filename__read_build_id(filename, build_id,
sizeof(build_id)) != sizeof(build_id)) {
if (errno == ENOENT)
return false;
pr_warning("Problems with %s file, consider removing it from the cache\n",
filename);
} else if (memcmp(dso->build_id, build_id, sizeof(dso->build_id))) {
pr_warning("Problems with %s file, consider removing it from the cache\n",
filename);
}
return true;
}
static int build_id_cache__fprintf_missing(struct perf_session *session, FILE *fp)
{
perf_session__fprintf_dsos_buildid(session, fp, dso__missing_buildid_cache, 0);
return 0;
}
static int build_id_cache__update_file(const char *filename)
{
u8 build_id[BUILD_ID_SIZE];
char sbuild_id[SBUILD_ID_SIZE];
int err = 0;
if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
pr_debug("Couldn't read a build-id in %s\n", filename);
return -1;
}
build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
if (build_id_cache__cached(sbuild_id))
err = build_id_cache__remove_s(sbuild_id);
if (!err)
err = build_id_cache__add_s(sbuild_id, filename, false, false);
pr_debug("Updating %s %s: %s\n", sbuild_id, filename,
err ? "FAIL" : "Ok");
return err;
}
int cmd_buildid_cache(int argc, const char **argv)
{
struct strlist *list;
struct str_node *pos;
int ret = 0;
bool force = false;
char const *add_name_list_str = NULL,
*remove_name_list_str = NULL,
*purge_name_list_str = NULL,
*missing_filename = NULL,
*update_name_list_str = NULL,
*kcore_filename = NULL;
char sbuf[STRERR_BUFSIZE];
struct perf_data_file file = {
.mode = PERF_DATA_MODE_READ,
};
struct perf_session *session = NULL;
const struct option buildid_cache_options[] = {
OPT_STRING('a', "add", &add_name_list_str,
"file list", "file(s) to add"),
OPT_STRING('k', "kcore", &kcore_filename,
"file", "kcore file to add"),
OPT_STRING('r', "remove", &remove_name_list_str, "file list",
"file(s) to remove"),
OPT_STRING('p', "purge", &purge_name_list_str, "path list",
"path(s) to remove (remove old caches too)"),
OPT_STRING('M', "missing", &missing_filename, "file",
"to find missing build ids in the cache"),
OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
OPT_STRING('u', "update", &update_name_list_str, "file list",
"file(s) to update"),
OPT_INCR('v', "verbose", &verbose, "be more verbose"),
OPT_END()
};
const char * const buildid_cache_usage[] = {
"perf buildid-cache [<options>]",
NULL
};
argc = parse_options(argc, argv, buildid_cache_options,
buildid_cache_usage, 0);
if (argc || (!add_name_list_str && !kcore_filename &&
!remove_name_list_str && !purge_name_list_str &&
!missing_filename && !update_name_list_str))
usage_with_options(buildid_cache_usage, buildid_cache_options);
if (missing_filename) {
file.path = missing_filename;
file.force = force;
session = perf_session__new(&file, false, NULL);
if (session == NULL)
return -1;
}
if (symbol__init(session ? &session->header.env : NULL) < 0)
goto out;
setup_pager();
if (add_name_list_str) {
list = strlist__new(add_name_list_str, NULL);
if (list) {
strlist__for_each_entry(pos, list)
if (build_id_cache__add_file(pos->s)) {
if (errno == EEXIST) {
pr_debug("%s already in the cache\n",
pos->s);
continue;
}
pr_warning("Couldn't add %s: %s\n",
pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
}
strlist__delete(list);
}
}
if (remove_name_list_str) {
list = strlist__new(remove_name_list_str, NULL);
if (list) {
strlist__for_each_entry(pos, list)
if (build_id_cache__remove_file(pos->s)) {
if (errno == ENOENT) {
pr_debug("%s wasn't in the cache\n",
pos->s);
continue;
}
pr_warning("Couldn't remove %s: %s\n",
pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
}
strlist__delete(list);
}
}
if (purge_name_list_str) {
list = strlist__new(purge_name_list_str, NULL);
if (list) {
strlist__for_each_entry(pos, list)
if (build_id_cache__purge_path(pos->s)) {
if (errno == ENOENT) {
pr_debug("%s wasn't in the cache\n",
pos->s);
continue;
}
pr_warning("Couldn't remove %s: %s\n",
pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
}
strlist__delete(list);
}
}
if (missing_filename)
ret = build_id_cache__fprintf_missing(session, stdout);
if (update_name_list_str) {
list = strlist__new(update_name_list_str, NULL);
if (list) {
strlist__for_each_entry(pos, list)
if (build_id_cache__update_file(pos->s)) {
if (errno == ENOENT) {
pr_debug("%s wasn't in the cache\n",
pos->s);
continue;
}
pr_warning("Couldn't update %s: %s\n",
pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
}
strlist__delete(list);
}
}
if (kcore_filename && build_id_cache__add_kcore(kcore_filename, force))
pr_warning("Couldn't add %s\n", kcore_filename);
out:
perf_session__delete(session);
return ret;
}