linux-kernel - [tip:perf/urgent] perf, x86: P4 PMU - Don't forget to clear cpuc->active

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 22 Apr 2011 12:19:10 GMT
From:	tip-bot for Cyrill Gorcunov <gorcunov@...il.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	gorcunov@...nvz.org, gorcunov@...il.com, ming.m.lin@...el.com,
	tglx@...utronix.de, mingo@...e.hu, dzickus@...hat.com
Subject: [tip:perf/urgent] perf, x86: P4 PMU - Don't forget to clear cpuc->active_mask on overflow

Commit-ID:  1ea5a6afd95a4803900c97ed63a47a883ebe7b3e
Gitweb:     http://git.kernel.org/tip/1ea5a6afd95a4803900c97ed63a47a883ebe7b3e
Author:     Cyrill Gorcunov <gorcunov@...il.com>
AuthorDate: Thu, 21 Apr 2011 11:03:21 -0400
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Fri, 22 Apr 2011 10:21:34 +0200

perf, x86: P4 PMU - Don't forget to clear cpuc->active_mask on overflow

It's not enough to simply disable event on overflow the
cpuc->active_mask should be cleared as well otherwise counter
may stall in "active" even in real being already disabled (which
potentially may lead to the situation that user may not use this
counter further).

Don pointed out that:

 " I also noticed this patch fixed some unknown NMIs
   on a P4 when I stressed the box".

Tested-by: Lin Ming <ming.m.lin@...el.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@...nvz.org>
Acked-by: Don Zickus <dzickus@...hat.com>
Signed-off-by: Don Zickus <dzickus@...hat.com>
Cc: Cyrill Gorcunov <gorcunov@...il.com>
Link: http://lkml.kernel.org/r/1303398203-2918-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@...e.hu>
---
 arch/x86/kernel/cpu/perf_event_p4.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index c2520e1..d1f77e2 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -947,7 +947,7 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
 		if (!x86_perf_event_set_period(event))
 			continue;
 		if (perf_event_overflow(event, 1, &data, regs))
-			p4_pmu_disable_event(event);
+			x86_pmu_stop(event, 0);
 	}
 
 	if (handled) {
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/