On 07.09.12 18:56:27, Peter Zijlstra wrote:
> > @@ -215,6 +215,14 @@ static int perf_ibs_init(struct perf_event *event)
> > struct perf_ibs *perf_ibs;
> > u64 max_cnt, config;
> > int ret;
> > + struct perf_event_attr notsupp = {
>
> static const ?
>
> > + .exclude_user = 1,
> > + .exclude_kernel = 1,
> > + .exclude_hv = 1,
> > + .exclude_idle = 1,
> > + .exclude_host = 1,
> > + .exclude_guest = 1,
Version 2 below with static const used.
-Robert
>From faf80df002709ec95178cf8a6f3f7298200ac1a7 Mon Sep 17 00:00:00 2001
From: Robert Richter <robert.rich...@amd.com>
Date: Wed, 25 Jul 2012 19:12:45 +0200
Subject: [PATCH] perf, 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: <sta...@vger.kernel.org> v3.5..
Signed-off-by: Robert Richter <robert.rich...@amd.com>
---
arch/x86/kernel/cpu/perf_event_amd_ibs.c | 12 ++++++++++++
include/linux/perf_event.h | 2 ++
2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index 7bfb5be..eebd5ff 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 28f9cee..c36a04f 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -304,6 +304,8 @@ struct perf_event_attr {
__u32 __reserved_2;
};
+#define perf_flags(attr) (*(&(attr)->read_format + 1))
+
/*
* Ioctls that can be done on a perf event fd:
*/
--
1.7.8.6
--
Advanced Micro Devices, Inc.
Operating System Research Center
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