[tip: perf/urgent] perf/x86/amd/ibs: Fix reading of the IBS OpData register and thus precise RIP validity
From: tip-bot2 for Kim Phillips
Date: Mon Oct 28 2019 - 07:42:08 EST
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: 317b96bb14303c7998dbcd5bc606bd8038fdd4b4
Gitweb: https://git.kernel.org/tip/317b96bb14303c7998dbcd5bc606bd8038fdd4b4
Author: Kim Phillips <kim.phillips@xxxxxxx>
AuthorDate: Wed, 23 Oct 2019 10:09:54 -05:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 28 Oct 2019 11:01:59 +01:00
perf/x86/amd/ibs: Fix reading of the IBS OpData register and thus precise RIP validity
The loop that reads all the IBS MSRs into *buf stopped one MSR short of
reading the IbsOpData register, which contains the RipInvalid status bit.
Fix the offset_max assignment so the MSR gets read, so the RIP invalid
evaluation is based on what the IBS h/w output, instead of what was
left in memory.
Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Fixes: d47e8238cd76 ("perf/x86-ibs: Take instruction pointer from ibs sample")
Link: https://lkml.kernel.org/r/20191023150955.30292-1-kim.phillips@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/events/amd/ibs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 5b35b7e..98ba21a 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -614,7 +614,7 @@ fail:
if (event->attr.sample_type & PERF_SAMPLE_RAW)
offset_max = perf_ibs->offset_max;
else if (check_rip)
- offset_max = 2;
+ offset_max = 3;
else
offset_max = 1;
do {