lkml.org 
[lkml]   [2016]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] perf/x86/uncore: remove event_list for snb client uncore IMC
Date
From: Kan Liang <kan.liang@intel.com>

A BUG was found by perf_fuzzer after enabled KASAN.
[ 205.748005] BUG: KASAN: slab-out-of-bounds in
snb_uncore_imc_event_del+0x6c/0xa0 at addr ffff8800caa43768
[ 205.758324] Read of size 8 by task perf_fuzzer/6618
[ 205.763589] CPU: 0 PID: 6618 Comm: perf_fuzzer Not tainted 4.9.0-rc5
#4
[ 205.770721] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS
FBKT72AUS 01/26/2014
[ 205.778689] ffff8800c3c479b8 ffffffff816bb796 ffff88011ec00600
ffff8800caa43580
[ 205.786759] ffff8800c3c479e0 ffffffff812fb961 ffff8800c3c47a78
ffff8800caa43580
[ 205.794850] ffff8800caa43580 ffff8800c3c47a68 ffffffff812fbbd8
ffff8800c3c47a28
[ 205.802911] Call Trace:
[ 205.805559] [<ffffffff816bb796>] dump_stack+0x63/0x8d
[ 205.811135] [<ffffffff812fb961>] kasan_object_err+0x21/0x70
[ 205.817267] [<ffffffff812fbbd8>] kasan_report_error+0x1d8/0x4c0
[ 205.823752] [<ffffffff81133275>] ? __lock_is_held+0x75/0xc0
[ 205.829868] [<ffffffff81025b12>] ?
snb_uncore_imc_read_counter+0x42/0x50
[ 205.837198] [<ffffffff810222e2>] ?
uncore_perf_event_update+0xe2/0x160
[ 205.844337] [<ffffffff812fc319>] kasan_report+0x39/0x40
[ 205.850085] [<ffffffff81025e3c>] ?
snb_uncore_imc_event_del+0x6c/0xa0

It's caused by accessing box->event_list.

For client IMC, there is no generic counters. It defines its own fixed
free running counters. So event_list and n_events are unused. They can
be removed safely.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Kan Liang <kan.liang@intel.com>
---
arch/x86/events/intel/uncore_snb.c | 12 ------------
1 file changed, 12 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c
index 81195cc..a3dcc12 100644
--- a/arch/x86/events/intel/uncore_snb.c
+++ b/arch/x86/events/intel/uncore_snb.c
@@ -490,24 +490,12 @@ static int snb_uncore_imc_event_add(struct perf_event *event, int flags)

snb_uncore_imc_event_start(event, 0);

- box->n_events++;
-
return 0;
}

static void snb_uncore_imc_event_del(struct perf_event *event, int flags)
{
- struct intel_uncore_box *box = uncore_event_to_box(event);
- int i;
-
snb_uncore_imc_event_stop(event, PERF_EF_UPDATE);
-
- for (i = 0; i < box->n_events; i++) {
- if (event == box->event_list[i]) {
- --box->n_events;
- break;
- }
- }
}

int snb_pci2phy_map_init(int devid)
--
2.5.5
\
 
 \ /
  Last update: 2016-11-15 19:41    [W:0.067 / U:1.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site