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: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120910093018.GO8285@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Robert Richter 2012-07-25 19:12:45 +02:00 committed by Ingo Molnar
parent 35534b201c
commit bad9ac2d7f
2 changed files with 14 additions and 0 deletions

View File

@ -209,6 +209,15 @@ static int perf_ibs_precise_event(struct perf_event *event, u64 *config)
return -EOPNOTSUPP; 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) static int perf_ibs_init(struct perf_event *event)
{ {
struct hw_perf_event *hwc = &event->hw; 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) if (event->pmu != &perf_ibs->pmu)
return -ENOENT; return -ENOENT;
if (perf_flags(&event->attr) & perf_flags(&ibs_notsupp))
return -EINVAL;
if (config & ~perf_ibs->config_mask) if (config & ~perf_ibs->config_mask)
return -EINVAL; return -EINVAL;

View File

@ -274,6 +274,8 @@ struct perf_event_attr {
__u64 branch_sample_type; /* enum branch_sample_type */ __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: * Ioctls that can be done on a perf event fd:
*/ */