This is a note to let you know that I've just added the patch titled
powerpc/perf: Fix oops when grouping different pmu events
to the 4.4-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:
powerpc-perf-fix-oops-when-grouping-different-pmu-events.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Feb 23 11:58:50 CET 2018
From: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
Date: Thu, 30 Nov 2017 14:03:22 +0530
Subject: powerpc/perf: Fix oops when grouping different pmu events
From: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 5aa04b3eb6fca63d2e9827be656dcadc26d54e11 ]
When user tries to group imc (In-Memory Collections) event with
normal event, (sometime) kernel crashes with following log:
Faulting instruction address: 0x00000000
[link register ] c00000000010ce88 power_check_constraints+0x128/0x980
...
c00000000010e238 power_pmu_event_init+0x268/0x6f0
c0000000002dc60c perf_try_init_event+0xdc/0x1a0
c0000000002dce88 perf_event_alloc+0x7b8/0xac0
c0000000002e92e0 SyS_perf_event_open+0x530/0xda0
c00000000000b004 system_call+0x38/0xe0
'event_base' field of 'struct hw_perf_event' is used as flags for
normal hw events and used as memory address for imc events. While
grouping these two types of events, collect_events() tries to
interpret imc 'event_base' as a flag, which causes a corruption
resulting in a crash.
Consider only those events which belongs to 'perf_hw_context' in
collect_events().
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
Reviewed-By: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/perf/core-book3s.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1381,7 +1381,7 @@ static int collect_events(struct perf_ev
int n = 0;
struct perf_event *event;
- if (!is_software_event(group)) {
+ if (group->pmu->task_ctx_nr == perf_hw_context) {
if (n >= max_count)
return -1;
ctrs[n] = group;
@@ -1389,7 +1389,7 @@ static int collect_events(struct perf_ev
events[n++] = group->hw.config;
}
list_for_each_entry(event, &group->sibling_list, group_entry) {
- if (!is_software_event(event) &&
+ if (event->pmu->task_ctx_nr == perf_hw_context &&
event->state != PERF_EVENT_STATE_OFF) {
if (n >= max_count)
return -1;
Patches currently in stable-queue which might be from ravi.bangoria@xxxxxxxxxxxxxxxxxx are
queue-4.4/perf-top-fix-window-dimensions-change-handling.patch
queue-4.4/powerpc-perf-fix-oops-when-grouping-different-pmu-events.patch