Commit 364fed35 authored by Elena Reshetova's avatar Elena Reshetova Committed by Arnaldo Carvalho de Melo
Browse files

perf thread_map: Convert thread_map.refcnt from atomic_t to refcount_t 



The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.

Signed-off-by: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Kook <keescook@chromium.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-10-git-send-email-elena.reshetova@intel.com


[ Did missing tests/thread-map.c conversion ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e34f5b11

tools/perf/tests/thread-map.c

+3 −3
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ int test__thread_map(int subtest __maybe_unused) 
			thread_map__comm(map, 0) &&

			!strcmp(thread_map__comm(map, 0), NAME));

	TEST_ASSERT_VAL("wrong refcnt",

			atomic_read(&map->refcnt) == 1);

			refcount_read(&map->refcnt) == 1);

	thread_map__put(map);



	/* test dummy pid */
@@ -44,7 +44,7 @@ int test__thread_map(int subtest __maybe_unused) 
			thread_map__comm(map, 0) &&

			!strcmp(thread_map__comm(map, 0), "dummy"));

	TEST_ASSERT_VAL("wrong refcnt",

			atomic_read(&map->refcnt) == 1);

			refcount_read(&map->refcnt) == 1);

	thread_map__put(map);

	return 0;

}
@@ -71,7 +71,7 @@ static int process_event(struct perf_tool *tool __maybe_unused, 
			thread_map__comm(threads, 0) &&

			!strcmp(thread_map__comm(threads, 0), NAME));

	TEST_ASSERT_VAL("wrong refcnt",

			atomic_read(&threads->refcnt) == 1);

			refcount_read(&threads->refcnt) == 1);

	thread_map__put(threads);

	return 0;

}

tools/perf/util/thread_map.c

+10 −10
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ struct thread_map *thread_map__new_by_pid(pid_t pid) 
		for (i = 0; i < items; i++)

			thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));

		threads->nr = items;

		atomic_set(&threads->refcnt, 1);

		refcount_set(&threads->refcnt, 1);

	}



	for (i=0; i<items; i++)
@@ -83,7 +83,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid) 
	if (threads != NULL) {

		thread_map__set_pid(threads, 0, tid);

		threads->nr = 1;

		atomic_set(&threads->refcnt, 1);

		refcount_set(&threads->refcnt, 1);

	}



	return threads;
@@ -105,7 +105,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid) 
		goto out_free_threads;



	threads->nr = 0;

	atomic_set(&threads->refcnt, 1);

	refcount_set(&threads->refcnt, 1);



	while ((dirent = readdir(proc)) != NULL) {

		char *end;
@@ -235,7 +235,7 @@ static struct thread_map *thread_map__new_by_pid_str(const char *pid_str) 
out:

	strlist__delete(slist);

	if (threads)

		atomic_set(&threads->refcnt, 1);

		refcount_set(&threads->refcnt, 1);

	return threads;



out_free_namelist:
@@ -255,7 +255,7 @@ struct thread_map *thread_map__new_dummy(void) 
	if (threads != NULL) {

		thread_map__set_pid(threads, 0, -1);

		threads->nr = 1;

		atomic_set(&threads->refcnt, 1);

		refcount_set(&threads->refcnt, 1);

	}

	return threads;

}
@@ -300,7 +300,7 @@ struct thread_map *thread_map__new_by_tid_str(const char *tid_str) 
	}

out:

	if (threads)

		atomic_set(&threads->refcnt, 1);

		refcount_set(&threads->refcnt, 1);

	return threads;



out_free_threads:
@@ -326,7 +326,7 @@ static void thread_map__delete(struct thread_map *threads) 
	if (threads) {

		int i;



		WARN_ONCE(atomic_read(&threads->refcnt) != 0,

		WARN_ONCE(refcount_read(&threads->refcnt) != 0,

			  "thread map refcnt unbalanced\n");

		for (i = 0; i < threads->nr; i++)

			free(thread_map__comm(threads, i));
@@ -337,13 +337,13 @@ static void thread_map__delete(struct thread_map *threads) 
struct thread_map *thread_map__get(struct thread_map *map)

{

	if (map)

		atomic_inc(&map->refcnt);

		refcount_inc(&map->refcnt);

	return map;

}



void thread_map__put(struct thread_map *map)

{

	if (map && atomic_dec_and_test(&map->refcnt))

	if (map && refcount_dec_and_test(&map->refcnt))

		thread_map__delete(map);

}
@@ -423,7 +423,7 @@ static void thread_map__copy_event(struct thread_map *threads, 
		threads->map[i].comm = strndup(event->entries[i].comm, 16);

	}



	atomic_set(&threads->refcnt, 1);

	refcount_set(&threads->refcnt, 1);

}



struct thread_map *thread_map__new_event(struct thread_map_event *event)

tools/perf/util/thread_map.h

+2 −2
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ 


#include <sys/types.h>

#include <stdio.h>

#include <linux/atomic.h>

#include <linux/refcount.h>



struct thread_map_data {

	pid_t    pid;
@@ -11,7 +11,7 @@ struct thread_map_data { 
};



struct thread_map {

	atomic_t refcnt;

	refcount_t refcnt;

	int nr;

	struct thread_map_data map[];

};

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