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* [PATCH] perf: tests: Disable breakpoint tests on ARM (32-bit)
@ 2018-11-16 22:53 Florian Fainelli
  2018-11-20 11:41 ` Will Deacon
  0 siblings, 1 reply; 2+ messages in thread
From: Florian Fainelli @ 2018-11-16 22:53 UTC (permalink / raw)
  To: linux-kernel
  Cc: will.deacon, linux-arm-kernel, Florian Fainelli, Peter Zijlstra,
	Ingo Molnar, Arnaldo Carvalho de Melo, Alexander Shishkin,
	Jiri Olsa, Namhyung Kim, Hendrik Brueckner, Thomas Richter

breakpoint tests on the ARM 32-bit kernel are broken in several ways.

The breakpoint length requested does not necessarily match whether the
function address has the Thumb bit (bit 0) set or not, and this does
matter to the ARM kernel hw_breakpoint infrastructure. See [1] for
background.

[1]: https://lkml.org/lkml/2018/11/15/205

As Will indicated, the overflow handling would require single-stepping
which is not supported at the moment. Just disable those tests for the
ARM 32-bit platforms.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 tools/perf/tests/bp_signal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
index a467615c5a0e..3b5471ea2331 100644
--- a/tools/perf/tests/bp_signal.c
+++ b/tools/perf/tests/bp_signal.c
@@ -296,7 +296,7 @@ bool test__bp_signal_is_supported(void)
  * instruction breakpoint using the perf event interface.
  * Once it's there we can release this.
  */
-#if defined(__powerpc__) || defined(__s390x__)
+#if defined(__powerpc__) || defined(__s390x__) || defined(__arm__)
 	return false;
 #else
 	return true;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] perf: tests: Disable breakpoint tests on ARM (32-bit)
  2018-11-16 22:53 [PATCH] perf: tests: Disable breakpoint tests on ARM (32-bit) Florian Fainelli
@ 2018-11-20 11:41 ` Will Deacon
  0 siblings, 0 replies; 2+ messages in thread
From: Will Deacon @ 2018-11-20 11:41 UTC (permalink / raw)
  To: Florian Fainelli
  Cc: linux-kernel, linux-arm-kernel, Peter Zijlstra, Ingo Molnar,
	Arnaldo Carvalho de Melo, Alexander Shishkin, Jiri Olsa,
	Namhyung Kim, Hendrik Brueckner, Thomas Richter

On Fri, Nov 16, 2018 at 02:53:07PM -0800, Florian Fainelli wrote:
> breakpoint tests on the ARM 32-bit kernel are broken in several ways.
> 
> The breakpoint length requested does not necessarily match whether the
> function address has the Thumb bit (bit 0) set or not, and this does
> matter to the ARM kernel hw_breakpoint infrastructure. See [1] for
> background.
> 
> [1]: https://lkml.org/lkml/2018/11/15/205
> 
> As Will indicated, the overflow handling would require single-stepping
> which is not supported at the moment. Just disable those tests for the
> ARM 32-bit platforms.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  tools/perf/tests/bp_signal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
> index a467615c5a0e..3b5471ea2331 100644
> --- a/tools/perf/tests/bp_signal.c
> +++ b/tools/perf/tests/bp_signal.c
> @@ -296,7 +296,7 @@ bool test__bp_signal_is_supported(void)
>   * instruction breakpoint using the perf event interface.
>   * Once it's there we can release this.
>   */
> -#if defined(__powerpc__) || defined(__s390x__)
> +#if defined(__powerpc__) || defined(__s390x__) || defined(__arm__)
>  	return false;
>  #else

I'm ok with disabling the test, but the comment above this #if is all about
powerpc.

Will

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2018-11-16 22:53 [PATCH] perf: tests: Disable breakpoint tests on ARM (32-bit) Florian Fainelli
2018-11-20 11:41 ` Will Deacon

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