This is a note to let you know that I've just added the patch titled
perf env: Avoid recursively taking env->bpf_progs.lock
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-env-avoid-recursively-taking-env-bpf_progs.lock.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1362ac275757503e6614245428d7e3202b47e865
Author: Ian Rogers <irogers@xxxxxxxxxx>
Date: Wed Dec 6 17:46:55 2023 -0800
perf env: Avoid recursively taking env->bpf_progs.lock
[ Upstream commit 9c51f8788b5d4e9f46afbcf563255cfd355690b3 ]
Add variants of perf_env__insert_bpf_prog_info(), perf_env__insert_btf()
and perf_env__find_btf prefixed with __ to indicate the
env->bpf_progs.lock is assumed held.
Call these variants when the lock is held to avoid recursively taking it
and potentially having a thread deadlock with itself.
Fixes: f8dfeae009effc0b ("perf bpf: Show more BPF program info in print_bpf_prog_info()")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ming Wang <wangming01@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Link: https://lore.kernel.org/r/20231207014655.1252484-1-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 4eb02762104b..c50d2c7a264f 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -533,9 +533,9 @@ int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env)
return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
}
-void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
- struct perf_env *env,
- FILE *fp)
+void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
+ struct perf_env *env,
+ FILE *fp)
{
__u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
__u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
@@ -551,7 +551,7 @@ void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
if (info->btf_id) {
struct btf_node *node;
- node = perf_env__find_btf(env, info->btf_id);
+ node = __perf_env__find_btf(env, info->btf_id);
if (node)
btf = btf__new((__u8 *)(node->data),
node->data_size);
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 68f315c3df5b..50f7412464df 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -34,9 +34,9 @@ struct btf_node {
int machine__process_bpf(struct machine *machine, union perf_event *event,
struct perf_sample *sample);
int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env);
-void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
- struct perf_env *env,
- FILE *fp);
+void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
+ struct perf_env *env,
+ FILE *fp);
#else
static inline int machine__process_bpf(struct machine *machine __maybe_unused,
union perf_event *event __maybe_unused,
@@ -51,9 +51,9 @@ static inline int evlist__add_bpf_sb_event(struct evlist *evlist __maybe_unused,
return 0;
}
-static inline void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info __maybe_unused,
- struct perf_env *env __maybe_unused,
- FILE *fp __maybe_unused)
+static inline void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info __maybe_unused,
+ struct perf_env *env __maybe_unused,
+ FILE *fp __maybe_unused)
{
}
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index d81ed1bc14bd..ed2a42abe127 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -17,13 +17,19 @@ struct perf_env perf_env;
void perf_env__insert_bpf_prog_info(struct perf_env *env,
struct bpf_prog_info_node *info_node)
+{
+ down_write(&env->bpf_progs.lock);
+ __perf_env__insert_bpf_prog_info(env, info_node);
+ up_write(&env->bpf_progs.lock);
+}
+
+void __perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node)
{
__u32 prog_id = info_node->info_linear->info.id;
struct bpf_prog_info_node *node;
struct rb_node *parent = NULL;
struct rb_node **p;
- down_write(&env->bpf_progs.lock);
p = &env->bpf_progs.infos.rb_node;
while (*p != NULL) {
@@ -35,15 +41,13 @@ void perf_env__insert_bpf_prog_info(struct perf_env *env,
p = &(*p)->rb_right;
} else {
pr_debug("duplicated bpf prog info %u\n", prog_id);
- goto out;
+ return;
}
}
rb_link_node(&info_node->rb_node, parent, p);
rb_insert_color(&info_node->rb_node, &env->bpf_progs.infos);
env->bpf_progs.infos_cnt++;
-out:
- up_write(&env->bpf_progs.lock);
}
struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
@@ -72,14 +76,22 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
}
bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)
+{
+ bool ret;
+
+ down_write(&env->bpf_progs.lock);
+ ret = __perf_env__insert_btf(env, btf_node);
+ up_write(&env->bpf_progs.lock);
+ return ret;
+}
+
+bool __perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)
{
struct rb_node *parent = NULL;
__u32 btf_id = btf_node->id;
struct btf_node *node;
struct rb_node **p;
- bool ret = true;
- down_write(&env->bpf_progs.lock);
p = &env->bpf_progs.btfs.rb_node;
while (*p != NULL) {
@@ -91,25 +103,31 @@ bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)
p = &(*p)->rb_right;
} else {
pr_debug("duplicated btf %u\n", btf_id);
- ret = false;
- goto out;
+ return false;
}
}
rb_link_node(&btf_node->rb_node, parent, p);
rb_insert_color(&btf_node->rb_node, &env->bpf_progs.btfs);
env->bpf_progs.btfs_cnt++;
-out:
- up_write(&env->bpf_progs.lock);
- return ret;
+ return true;
}
struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
+{
+ struct btf_node *res;
+
+ down_read(&env->bpf_progs.lock);
+ res = __perf_env__find_btf(env, btf_id);
+ up_read(&env->bpf_progs.lock);
+ return res;
+}
+
+struct btf_node *__perf_env__find_btf(struct perf_env *env, __u32 btf_id)
{
struct btf_node *node = NULL;
struct rb_node *n;
- down_read(&env->bpf_progs.lock);
n = env->bpf_progs.btfs.rb_node;
while (n) {
@@ -119,13 +137,9 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
else if (btf_id > node->id)
n = n->rb_right;
else
- goto out;
+ return node;
}
- node = NULL;
-
-out:
- up_read(&env->bpf_progs.lock);
- return node;
+ return NULL;
}
/* purge data in bpf_progs.infos tree */
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 01378a955dd5..ef0fd544cd67 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -139,12 +139,16 @@ const char *perf_env__raw_arch(struct perf_env *env);
int perf_env__nr_cpus_avail(struct perf_env *env);
void perf_env__init(struct perf_env *env);
+void __perf_env__insert_bpf_prog_info(struct perf_env *env,
+ struct bpf_prog_info_node *info_node);
void perf_env__insert_bpf_prog_info(struct perf_env *env,
struct bpf_prog_info_node *info_node);
struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
__u32 prog_id);
bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);
+bool __perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);
struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id);
+struct btf_node *__perf_env__find_btf(struct perf_env *env, __u32 btf_id);
int perf_env__numa_node(struct perf_env *env, int cpu);
#endif /* __PERF_ENV_H */
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index dd06770b43f1..d2812d98968d 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1655,8 +1655,8 @@ static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
node = rb_entry(next, struct bpf_prog_info_node, rb_node);
next = rb_next(&node->rb_node);
- bpf_event__print_bpf_prog_info(&node->info_linear->info,
- env, fp);
+ __bpf_event__print_bpf_prog_info(&node->info_linear->info,
+ env, fp);
}
up_read(&env->bpf_progs.lock);
@@ -2927,7 +2927,7 @@ static int process_bpf_prog_info(struct feat_fd *ff, void *data __maybe_unused)
/* after reading from file, translate offset to address */
bpf_program__bpil_offs_to_addr(info_linear);
info_node->info_linear = info_linear;
- perf_env__insert_bpf_prog_info(env, info_node);
+ __perf_env__insert_bpf_prog_info(env, info_node);
}
up_write(&env->bpf_progs.lock);
@@ -2980,7 +2980,7 @@ static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused)
if (__do_read(ff, node->data, data_size))
goto out;
- perf_env__insert_btf(env, node);
+ __perf_env__insert_btf(env, node);
node = NULL;
}
