linux-kernel - [RFC PATCH 6/6] perf: Disable IRQs in address filter sync path

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]

Message-Id: <20160923112726.5890-7-alexander.shishkin@linux.intel.com>
Date:   Fri, 23 Sep 2016 14:27:26 +0300
From:   Alexander Shishkin <alexander.shishkin@...ux.intel.com>
To:     Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc:     Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
        vince@...ter.net, eranian@...gle.com,
        Arnaldo Carvalho de Melo <acme@...radead.org>,
        tglx@...utronix.de, ak@...ux.intel.com,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Subject: [RFC PATCH 6/6] perf: Disable IRQs in address filter sync path

If PMU callbacks are executed in hardirq context, the address filter
sync code needs to disable interrupts when taking its spinlock to be
consistent with the rest of its users. This may happen if the PMU is
used in AUX sampling.

Signed-off-by: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
---
 kernel/events/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f6582df1c9..047c495c94 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2568,16 +2568,17 @@ static int perf_event_stop(struct perf_event *event, int restart)
 void perf_event_addr_filters_sync(struct perf_event *event)
 {
 	struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
+	unsigned long flags;
 
 	if (!has_addr_filter(event))
 		return;
 
-	raw_spin_lock(&ifh->lock);
+	raw_spin_lock_irqsave(&ifh->lock, flags);
 	if (event->addr_filters_gen != event->hw.addr_filters_gen) {
 		event->pmu->addr_filters_sync(event);
 		event->hw.addr_filters_gen = event->addr_filters_gen;
 	}
-	raw_spin_unlock(&ifh->lock);
+	raw_spin_unlock_irqrestore(&ifh->lock, flags);
 }
 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
 
-- 
2.9.3