linux-kernel - [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup

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: <20100816140829.GA5225@swordfish.minsk.epam.com>
Date:	Mon, 16 Aug 2010 17:08:29 +0300
From:	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Don Zickus <dzickus@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org
Subject: [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and
 touch_softlockup_watchdog

Fix: acpi_os_stall calls touch_nmi_watchdog and touch_softlockup_watchdog
with preemption enabled causing 'BUG: using smp_processor_id() in preemptible
code'.
     
Patch also removes double smp_processor_id call (smp_processor_id itself and in
__get_cpu_var) in __touch_watchdog.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>

---

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 613bc1f..8822f1e 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -116,13 +116,14 @@ static unsigned long get_sample_period(void)
 static void __touch_watchdog(void)
 {
 	int this_cpu = smp_processor_id();
-
-	__get_cpu_var(watchdog_touch_ts) = get_timestamp(this_cpu);
+	per_cpu(watchdog_touch_ts, this_cpu) = get_timestamp(this_cpu);
 }
 
 void touch_softlockup_watchdog(void)
 {
-	__get_cpu_var(watchdog_touch_ts) = 0;
+	int this_cpu = get_cpu();
+	per_cpu(watchdog_touch_ts, this_cpu) = 0;
+	put_cpu();
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -142,7 +143,9 @@ void touch_all_softlockup_watchdogs(void)
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 void touch_nmi_watchdog(void)
 {
-	__get_cpu_var(watchdog_nmi_touch) = true;
+	int this_cpu = get_cpu();
+	per_cpu(watchdog_nmi_touch, this_cpu) = true;
+	put_cpu();
 	touch_softlockup_watchdog();
 }
 EXPORT_SYMBOL(touch_nmi_watchdog);

--
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/