lkml.org 
[lkml]   [2017]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] tracing: Fix kmemleak in tracing_map_array_free
Date
kmemleak reported the below leak when I was doing clear of the hist
trigger. With this patch, the kmeamleak is gone.

unreferenced object 0xffff94322b63d760 (size 32):
comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
hex dump (first 32 bytes):
00 01 00 00 04 00 00 00 08 00 00 00 ff 00 00 00 ................
10 00 00 00 00 00 00 00 80 a8 7a f2 31 94 ff ff ..........z.1...
backtrace:
[<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
[<ffffffff9e424cba>] kmem_cache_alloc_trace+0xca/0x1d0
[<ffffffff9e377736>] tracing_map_array_alloc+0x26/0x140
[<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
[<ffffffff9e38b935>] create_hist_data+0x535/0x750
[<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
[<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
[<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
[<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
[<ffffffff9e450b85>] SyS_write+0x55/0xc0
[<ffffffff9e203857>] do_syscall_64+0x67/0x150
[<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
[<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff9431f27aa880 (size 128):
comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
hex dump (first 32 bytes):
00 00 8c 2a 32 94 ff ff 00 f0 8b 2a 32 94 ff ff ...*2......*2...
00 e0 8b 2a 32 94 ff ff 00 d0 8b 2a 32 94 ff ff ...*2......*2...
backtrace:
[<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
[<ffffffff9e425348>] __kmalloc+0xe8/0x220
[<ffffffff9e3777c1>] tracing_map_array_alloc+0xb1/0x140
[<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
[<ffffffff9e38b935>] create_hist_data+0x535/0x750
[<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
[<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
[<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
[<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
[<ffffffff9e450b85>] SyS_write+0x55/0xc0
[<ffffffff9e203857>] do_syscall_64+0x67/0x150
[<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
---
kernel/trace/tracing_map.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 0a689bb..305039b 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -221,16 +221,19 @@ void tracing_map_array_free(struct tracing_map_array *a)
if (!a)
return;

- if (!a->pages) {
- kfree(a);
- return;
- }
+ if (!a->pages)
+ goto free;

for (i = 0; i < a->n_pages; i++) {
if (!a->pages[i])
break;
free_page((unsigned long)a->pages[i]);
}
+
+ kfree(a->pages);
+
+ free:
+ kfree(a);
}

struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
--
1.8.3.1
\
 
 \ /
  Last update: 2017-08-14 12:19    [W:0.062 / U:4.560 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site