Re: [PATCH 2/2] perf, tools, stat: Reset ids counter when retrying events
From: Arnaldo Carvalho de Melo
Date: Wed Feb 21 2018 - 09:00:18 EST
Em Thu, Oct 05, 2017 at 07:00:29PM -0700, Andi Kleen escreveu:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> perf stat can retry opening events. After opening an file descriptor
> it adds the ids to the ecsel. Each event keeps a running
> count of ids.
Ok, and that is done in perf_evlist__id_add() where we also add things
to the evlist->heads hashtable, shouldn't we remove all these before
retrying? I.e. perf_evlist__close() shouldn't be resetting that
hashtable?
I.e. like in the following patch? Jiri? Namhyung?
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 7b7d535396f7..e8942456106e 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -37,13 +37,18 @@
#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
#define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
-void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
- struct thread_map *threads)
+static void perf_evlist__init_heads(struct perf_evlist *evlist)
{
int i;
for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
INIT_HLIST_HEAD(&evlist->heads[i]);
+}
+
+void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
+ struct thread_map *threads)
+{
+ perf_evlist__init_heads(evlist);
INIT_LIST_HEAD(&evlist->entries);
perf_evlist__set_maps(evlist, cpus, threads);
fdarray__init(&evlist->pollfd, 64);
@@ -1381,8 +1386,11 @@ void perf_evlist__close(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
- evlist__for_each_entry_reverse(evlist, evsel)
+ evlist__for_each_entry_reverse(evlist, evsel) {
perf_evsel__close(evsel);
+ }
+
+ perf_evlist__init_heads(evlist);
}
static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ef351688b797..fba708bc9d98 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1932,6 +1932,7 @@ void perf_evsel__close(struct perf_evsel *evsel)
perf_evsel__close_fd(evsel);
perf_evsel__free_fd(evsel);
+ evsel->ids = 0;
}
int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
> When we decide to close an evsel and retry
> with a different configuration this count needs to be reset,
> otherwise it can overflow the buffer.
>
> Always reset the ids count.
>
> This fixes the following problem, triggered by a complex perf
> stat configuration.
>
> ==666== ERROR: AddressSanitizer: heap-buffer-overflow on address 0x600600001500 at pc 0x59dfd7 bp 0x7ffc6b397000 sp 0x7ffc6b396ff8
> WRITE of size 8 at 0x600600001500 thread T0
> #0 0x59dfd6 in perf_evlist__id_add /home/ak/hle/linux-hle-2.6/tools/perf/util/evlist.c:515
> #1 0x59e291 in perf_evlist__id_add_fd /home/ak/hle/linux-hle-2.6/tools/perf/util/evlist.c:555
> #2 0x4865c6 in __store_counter_ids /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:570
> #3 0x4867d0 in store_counter_ids /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:587
> #4 0x487521 in __run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:703
> #5 0x487d6d in run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:805
> #6 0x492914 in cmd_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:2839
> #7 0x57479a in run_builtin /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:296
> #8 0x574b5f in handle_internal_command /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:348
> #9 0x574e3c in run_argv /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:392
> #10 0x575401 in main /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:536
> #11 0x7f7597af96e4 in __libc_start_main (/lib64/libc.so.6+0x206e4)
> #12 0x444598 in _start /home/abuild/rpmbuild/BUILD/glibc-2.22/csu/../sysdeps/x86_64/start.S:118
> 0x600600001500 is located 0 bytes to the right of 32-byte region [0x6006000014e0,0x600600001500)
> allocated by thread T0 here:
> #0 0x7f759a698ab5 in calloc (/usr/lib64/libasan.so.0+0x15ab5)
> #1 0x5a6045 in zalloc /home/ak/hle/linux-hle-2.6/tools/perf/util/util.h:22
> #2 0x5ab51a in perf_evsel__alloc_id /home/ak/hle/linux-hle-2.6/tools/perf/util/evsel.c:1158
> #3 0x4867ae in store_counter_ids /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:584
> #4 0x487521 in __run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:703
> #5 0x487d6d in run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:805
> #6 0x492914 in cmd_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:2839
> #7 0x57479a in run_builtin /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:296
> #8 0x574b5f in handle_internal_command /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:348
> #9 0x574e3c in run_argv /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:392
> #10 0x575401 in main /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:536
> #11 0x7f7597af96e4 in __libc_start_main (/lib64/libc.so.6+0x206e4)
> SUMMARY: AddressSanitizer: heap-buffer-overflow /home/ak/hle/linux-hle-2.6/tools/perf/util/evlist.c:515 perf_evlist__id_add
> Shadow bytes around the buggy address:
> 0x0c013fff8250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
> 0x0c013fff8260: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
> 0x0c013fff8270: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
> 0x0c013fff8280: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
> 0x0c013fff8290: fa fa fa fa fa fa fa fa fa fa fa fa 00 00 00 00
> =>0x0c013fff82a0:[fa]fa 00 00 00 00 fa fa 00 00 00 00 fa fa 00 00
> 0x0c013fff82b0: 00 00 fa fa 00 00 00 00 fa fa 00 00 00 00 fa fa
> 0x0c013fff82c0: 00 00 00 00 fa fa 00 00 00 00 fa fa 00 00 00 00
> 0x0c013fff82d0: fa fa 00 00 00 00 fa fa 00 00 00 00 fa fa 00 00
> 0x0c013fff82e0: 00 00 fa fa 00 00 00 00 fa fa 00 00 00 00 fa fa
> 0x0c013fff82f0: 00 00 00 00 fa fa 00 00 00 00 fa fa 00 00 00 00
> Shadow byte legend (one shadow byte represents 8 application bytes):
> Addressable: 00
> Partially addressable: 01 02 03 04 05 06 07
> Heap left redzone: fa
> Heap righ redzone: fb
> Freed Heap region: fd
> Stack left redzone: f1
> Stack mid redzone: f2
> Stack right redzone: f3
> Stack partial redzone: f4
> Stack after return: f5
> Stack use after scope: f8
> Global redzone: f9
> Global init order: f6
> Poisoned by user: f7
> ASan internal: fe
>
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> ---
> tools/perf/builtin-stat.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 3c697118e44b..b54ec8497f97 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -652,6 +652,7 @@ static int __run_perf_stat(int argc, const char **argv)
>
> evlist__for_each_entry(evsel_list, counter) {
> try_again:
> + counter->ids = 0;
> if (create_perf_stat_counter(counter) < 0) {
>
> /* Weak group failed. Reset the group. */
> --
> 2.13.6