Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bad9ac2d authored by Robert Richter's avatar Robert Richter Committed by Ingo Molnar
Browse files

perf/x86/ibs: Check syscall attribute flags 



Current implementation simply ignores attribute flags. Thus, there is
no notification to userland of unsupported features. Check syscall's
attribute flags to let userland know if a feature is supported by the
kernel. This is also needed to distinguish between future kernels what
might support a feature.

Cc: <stable@vger.kernel.org> v3.5..
Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120910093018.GO8285@erda.amd.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 35534b20

arch/x86/kernel/cpu/perf_event_amd_ibs.c

+12 −0
Original line number Diff line number Diff line
@@ -209,6 +209,15 @@ static int perf_ibs_precise_event(struct perf_event *event, u64 *config) 
	return -EOPNOTSUPP;

}



static const struct perf_event_attr ibs_notsupp = {

	.exclude_user	= 1,

	.exclude_kernel	= 1,

	.exclude_hv	= 1,

	.exclude_idle	= 1,

	.exclude_host	= 1,

	.exclude_guest	= 1,

};



static int perf_ibs_init(struct perf_event *event)

{

	struct hw_perf_event *hwc = &event->hw;
@@ -229,6 +238,9 @@ static int perf_ibs_init(struct perf_event *event) 
	if (event->pmu != &perf_ibs->pmu)

		return -ENOENT;



	if (perf_flags(&event->attr) & perf_flags(&ibs_notsupp))

		return -EINVAL;



	if (config & ~perf_ibs->config_mask)

		return -EINVAL;

include/linux/perf_event.h

+2 −0
Original line number Diff line number Diff line
@@ -274,6 +274,8 @@ struct perf_event_attr { 
	__u64	branch_sample_type; /* enum branch_sample_type */

};



#define perf_flags(attr)	(*(&(attr)->read_format + 1))



/*

 * Ioctls that can be done on a perf event fd:

 */