lkml.org 
[lkml]   [2019]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 76/87] perf/ioctl: Add check for the sample_period value
3.16.75-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>

commit 913a90bc5a3a06b1f04c337320e9aeee2328dd77 upstream.

perf_event_open() limits the sample_period to 63 bits. See:

0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits")

Make ioctl() consistent with it.

Also on PowerPC, negative sample_period could cause a recursive
PMIs leading to a hang (reported when running perf-fuzzer).

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: maddy@linux.vnet.ibm.com
Cc: mpe@ellerman.id.au
Fixes: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits")
Link: https://lkml.kernel.org/r/20190604042953.914-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
kernel/events/core.c | 3 +++
1 file changed, 3 insertions(+)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3823,6 +3823,9 @@ static int perf_event_period(struct perf
if (perf_event_check_period(event, value))
return -EINVAL;

+ if (!event->attr.freq && (value & (1ULL << 63)))
+ return -EINVAL;
+
task = ctx->task;
pe.value = value;

\
 
 \ /
  Last update: 2019-10-02 21:09    [W:0.192 / U:10.572 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site