[PATCH] perf/x86/amd: Explicitly define PERF_COUNT_HW_REF_CPU_CYCLES as undefined.

[PATCH] perf/x86/amd: Explicitly define PERF_COUNT_HW_REF_CPU_CYCLES as undefined.

[Adam Borowski]

filter_events() relies on the value of 0 to remove events that are not
applicable, like this one.

UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
index 9 is out of range for type 'u64 [9]'
UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
load of address ffffffff81c021c8 with insufficient space
for an object of type 'const u64'

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
---
 arch/x86/events/amd/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 86a9bec..5fa1b8e 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -125,6 +125,7 @@ static const u64 amd_perfmon_event_map[] =
   [PERF_COUNT_HW_BRANCH_MISSES]			= 0x00c3,
   [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= 0x00d0, /* "Decoder empty" event */
   [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= 0x00d1, /* "Dispatch stalls" event */
+  [PERF_COUNT_HW_REF_CPU_CYCLES]		=      0,
 };
 
 static u64 amd_pmu_event_map(int hw_event)
-- 
2.8.1

Re: [PATCH] perf/x86/amd: Explicitly define PERF_COUNT_HW_REF_CPU_CYCLES as undefined.

[Ingo Molnar]

* Adam Borowski <kilobyte@angband.pl> wrote:

> filter_events() relies on the value of 0 to remove events that are not
> applicable, like this one.
> 
> UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
> index 9 is out of range for type 'u64 [9]'
> UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
> load of address ffffffff81c021c8 with insufficient space
> for an object of type 'const u64'
> 
> Signed-off-by: Adam Borowski <kilobyte@angband.pl>
> ---
>  arch/x86/events/amd/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
> index 86a9bec..5fa1b8e 100644
> --- a/arch/x86/events/amd/core.c
> +++ b/arch/x86/events/amd/core.c
> @@ -125,6 +125,7 @@ static const u64 amd_perfmon_event_map[] =
>    [PERF_COUNT_HW_BRANCH_MISSES]			= 0x00c3,
>    [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= 0x00d0, /* "Decoder empty" event */
>    [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= 0x00d1, /* "Dispatch stalls" event */
> +  [PERF_COUNT_HW_REF_CPU_CYCLES]		=      0,
>  };

Hm, I think it would be cleaner and more robust to change this (and all other 
similar, if any) arrays to [PERF_COUNT_HW_MAX] instead.

Thanks,

	Ingo

Re: [PATCH] perf/x86/amd: Explicitly define PERF_COUNT_HW_REF_CPU_CYCLES as undefined.

[Adam Borowski]

On Wed, Apr 27, 2016 at 10:03:45AM +0200, Ingo Molnar wrote:
> * Adam Borowski <kilobyte@angband.pl> wrote:
> > diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
> > index 86a9bec..5fa1b8e 100644
> > --- a/arch/x86/events/amd/core.c
> > +++ b/arch/x86/events/amd/core.c
> > @@ -125,6 +125,7 @@ static const u64 amd_perfmon_event_map[] =
> >    [PERF_COUNT_HW_BRANCH_MISSES]			= 0x00c3,
> >    [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= 0x00d0, /* "Decoder empty" event */
> >    [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= 0x00d1, /* "Dispatch stalls" event */
> > +  [PERF_COUNT_HW_REF_CPU_CYCLES]		=      0,
> >  };
> 
> Hm, I think it would be cleaner and more robust to change this (and all other 
> similar, if any) arrays to [PERF_COUNT_HW_MAX] instead.

Good idea!  Both of Intel's copies (one for p4, one for core+) already set
the size this way.

-- 
A tit a day keeps the vet away.

[PATCH] perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX.

[Adam Borowski]

The entry for PERF_COUNT_HW_REF_CPU_CYCLES is not used on AMD, but is
referenced by filter_events() which expects undefined events to have a
value of 0.

UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
index 9 is out of range for type 'u64 [9]'
UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
load of address ffffffff81c021c8 with insufficient space
for an object of type 'const u64'

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
---
 arch/x86/events/amd/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 86a9bec..bd3e842 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -115,7 +115,7 @@ static __initconst const u64 amd_hw_cache_event_ids
 /*
  * AMD Performance Monitor K7 and later.
  */
-static const u64 amd_perfmon_event_map[] =
+static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
 {
   [PERF_COUNT_HW_CPU_CYCLES]			= 0x0076,
   [PERF_COUNT_HW_INSTRUCTIONS]			= 0x00c0,
-- 
2.8.1

[tip:perf/urgent] perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX

[tip-bot for Adam Borowski]

Commit-ID:  0a25556f84d5f79e68e9502bb1f32a43377ab2bf
Gitweb:     http://git.kernel.org/tip/0a25556f84d5f79e68e9502bb1f32a43377ab2bf
Author:     Adam Borowski <kilobyte@angband.pl>
AuthorDate: Wed, 27 Apr 2016 11:35:31 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 28 Apr 2016 10:20:25 +0200

perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX

The entry for PERF_COUNT_HW_REF_CPU_CYCLES is not used on AMD, but is
referenced by filter_events() which expects undefined events to have a
value of 0.

Found via KASAN:

  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
  index 9 is out of range for type 'u64 [9]'
  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
  load of address ffffffff81c021c8 with insufficient space for an object of type 'const u64'

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1461749731-30979-1-git-send-email-kilobyte@angband.pl
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/events/amd/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 86a9bec..bd3e842 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -115,7 +115,7 @@ static __initconst const u64 amd_hw_cache_event_ids
 /*
  * AMD Performance Monitor K7 and later.
  */
-static const u64 amd_perfmon_event_map[] =
+static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
 {
   [PERF_COUNT_HW_CPU_CYCLES]			= 0x0076,
   [PERF_COUNT_HW_INSTRUCTIONS]			= 0x00c0,