Commit 9e201442 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by Ingo Molnar
Browse files

perf symbols: Cache /proc/kallsyms files by build-id



So that when we don't have a vmlinux handy we can store the
kallsyms for later use by 'perf report'.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1263501006-14185-3-git-send-email-acme@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8d0591f6
......@@ -245,7 +245,7 @@ int event__synthesize_kernel_mmap(event__handler_t process,
*/
struct process_symbol_args args = { .name = symbol_name, };
if (kallsyms__parse(&args, find_symbol_cb) <= 0)
if (kallsyms__parse("/proc/kallsyms", &args, find_symbol_cb) <= 0)
return -ENOENT;
size = snprintf(ev.mmap.filename, sizeof(ev.mmap.filename),
......
......@@ -237,11 +237,13 @@ static int dso__cache_build_id(struct dso *self, const char *debugdir)
char *filename = malloc(size),
*linkname = malloc(size), *targetname, *sbuild_id;
int len, err = -1;
bool is_kallsyms = self->kernel && self->long_name[0] != '/';
if (filename == NULL || linkname == NULL)
goto out_free;
len = snprintf(filename, size, "%s%s", debugdir, self->long_name);
len = snprintf(filename, size, "%s%s%s",
debugdir, is_kallsyms ? "/" : "", self->long_name);
if (mkdir_p(filename, 0755))
goto out_free;
......@@ -249,9 +251,14 @@ static int dso__cache_build_id(struct dso *self, const char *debugdir)
sbuild_id = filename + len;
build_id__sprintf(self->build_id, sizeof(self->build_id), sbuild_id);
if (access(filename, F_OK) && link(self->long_name, filename) &&
copyfile(self->long_name, filename))
goto out_free;
if (access(filename, F_OK)) {
if (is_kallsyms) {
if (copyfile("/proc/kallsyms", filename))
goto out_free;
} else if (link(self->long_name, filename) &&
copyfile(self->long_name, filename))
goto out_free;
}
len = snprintf(linkname, size, "%s/.build-id/%.2s",
debugdir, sbuild_id);
......
......@@ -383,13 +383,14 @@ size_t dso__fprintf(struct dso *self, enum map_type type, FILE *fp)
return ret;
}
int kallsyms__parse(void *arg, int (*process_symbol)(void *arg, const char *name,
int kallsyms__parse(const char *filename, void *arg,
int (*process_symbol)(void *arg, const char *name,
char type, u64 start))
{
char *line = NULL;
size_t n;
int err = 0;
FILE *file = fopen("/proc/kallsyms", "r");
FILE *file = fopen(filename, "r");
if (file == NULL)
goto out_failure;
......@@ -466,10 +467,11 @@ static int map__process_kallsym_symbol(void *arg, const char *name,
* so that we can in the next step set the symbol ->end address and then
* call kernel_maps__split_kallsyms.
*/
static int dso__load_all_kallsyms(struct dso *self, struct map *map)
static int dso__load_all_kallsyms(struct dso *self, const char *filename,
struct map *map)
{
struct process_kallsyms_args args = { .map = map, .dso = self, };
return kallsyms__parse(&args, map__process_kallsym_symbol);
return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}
/*
......@@ -556,10 +558,10 @@ discard_symbol: rb_erase(&pos->rb_node, root);
}
static int dso__load_kallsyms(struct dso *self, struct map *map,
static int dso__load_kallsyms(struct dso *self, const char *filename, struct map *map,
struct perf_session *session, symbol_filter_t filter)
{
if (dso__load_all_kallsyms(self, map) < 0)
if (dso__load_all_kallsyms(self, filename, map) < 0)
return -1;
symbols__fixup_end(&self->symbols[map->type]);
......@@ -1580,7 +1582,8 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
struct perf_session *session, symbol_filter_t filter)
{
int err;
bool is_kallsyms;
const char *kallsyms_filename = NULL;
char *kallsyms_allocated_filename = NULL;
if (vmlinux_path != NULL) {
int i;
......@@ -1606,19 +1609,37 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
*/
if (self->has_build_id) {
u8 kallsyms_build_id[BUILD_ID_SIZE];
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
sizeof(kallsyms_build_id)) == 0) {
is_kallsyms = dso__build_id_equal(self, kallsyms_build_id);
if (is_kallsyms)
if (dso__build_id_equal(self, kallsyms_build_id)) {
kallsyms_filename = "/proc/kallsyms";
goto do_kallsyms;
}
}
build_id__sprintf(self->build_id, sizeof(self->build_id),
sbuild_id);
if (asprintf(&kallsyms_allocated_filename,
"%s/.debug/[kernel.kallsyms]/%s",
getenv("HOME"), sbuild_id) != -1) {
if (access(kallsyms_filename, F_OK)) {
kallsyms_filename = kallsyms_allocated_filename;
goto do_kallsyms;
}
free(kallsyms_allocated_filename);
kallsyms_allocated_filename = NULL;
}
goto do_vmlinux;
}
is_kallsyms = self->long_name[0] == '[';
if (is_kallsyms)
if (self->long_name[0] == '[') {
kallsyms_filename = "/proc/kallsyms";
goto do_kallsyms;
}
do_vmlinux:
err = dso__load_vmlinux(self, map, session, self->long_name, filter);
......@@ -1629,9 +1650,10 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
pr_info("The file %s cannot be used, "
"trying to use /proc/kallsyms...", self->long_name);
do_kallsyms:
err = dso__load_kallsyms(self, map, session, filter);
if (err > 0 && !is_kallsyms)
err = dso__load_kallsyms(self, kallsyms_filename, map, session, filter);
if (err > 0 && kallsyms_filename == NULL)
dso__set_long_name(self, strdup("[kernel.kallsyms]"));
free(kallsyms_allocated_filename);
}
if (err > 0) {
......
......@@ -144,8 +144,9 @@ int filename__read_build_id(const char *filename, void *bf, size_t size);
int sysfs__read_build_id(const char *filename, void *bf, size_t size);
bool dsos__read_build_ids(void);
int build_id__sprintf(u8 *self, int len, char *bf);
int kallsyms__parse(void *arg, int (*process_symbol)(void *arg, const char *name,
char type, u64 start));
int kallsyms__parse(const char *filename, void *arg,
int (*process_symbol)(void *arg, const char *name,
char type, u64 start));
int symbol__init(void);
bool symbol_type__is_a(char symbol_type, enum map_type map_type);
......
......@@ -32,6 +32,33 @@ int mkdir_p(char *path, mode_t mode)
return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
}
static int slow_copyfile(const char *from, const char *to)
{
int err = 0;
char *line = NULL;
size_t n;
FILE *from_fp = fopen(from, "r"), *to_fp;
if (from_fp == NULL)
goto out;
to_fp = fopen(to, "w");
if (to_fp == NULL)
goto out_fclose_from;
while (getline(&line, &n, from_fp) > 0)
if (fputs(line, to_fp) == EOF)
goto out_fclose_to;
err = 0;
out_fclose_to:
fclose(to_fp);
free(line);
out_fclose_from:
fclose(from_fp);
out:
return err;
}
int copyfile(const char *from, const char *to)
{
int fromfd, tofd;
......@@ -42,6 +69,9 @@ int copyfile(const char *from, const char *to)
if (stat(from, &st))
goto out;
if (st.st_size == 0) /* /proc? do it slowly... */
return slow_copyfile(from, to);
fromfd = open(from, O_RDONLY);
if (fromfd < 0)
goto out;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment