From: Robert Richter Date: Wed, 25 Jul 2012 17:12:45 +0000 (+0200) Subject: perf/x86/ibs: Check syscall attribute flags X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=bad9ac2d7f878a31cf1ae8c1ee3768077d222bcb;p=openwrt%2Fstaging%2Fblogic.git 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: v3.5.. Signed-off-by: Robert Richter Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120910093018.GO8285@erda.amd.com Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c index 7bfb5bec8630..eebd5ffe1bba 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c +++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c @@ -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; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 33ed9d605f91..bdb41612bfec 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -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: */