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: Arnaldo 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: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 24ec5be..0e9820a 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -245,7 +245,7 @@
*/
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),
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index b31e0ae..1b65fed 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -237,11 +237,13 @@
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 @@
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);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 71d23e1..ae61e9f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -383,13 +383,14 @@
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 @@
* 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 @@
}
-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 @@
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 @@
*/
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 @@
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) {
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 594156e..36b7c71 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -144,8 +144,9 @@
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);
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index f3c0798..f068584 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -32,6 +32,33 @@
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 @@
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;