Messages in this thread Patch in this message | | | Date | Tue, 21 Apr 2009 08:12:42 GMT | From | tip-bot for Rusty Russell <> | Subject | [tip:x86/urgent] x86: avoid theoretical spurious NMI backtraces with CONFIG_CPUMASK_OFFSTACK=y |
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Commit-ID: fcc5c4a2feea3886dc058498b28508b2731720d5 Gitweb: http://git.kernel.org/tip/fcc5c4a2feea3886dc058498b28508b2731720d5 Author: Rusty Russell <rusty@rustcorp.com.au> AuthorDate: Tue, 21 Apr 2009 16:03:41 +0930 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Tue, 21 Apr 2009 10:09:50 +0200
x86: avoid theoretical spurious NMI backtraces with CONFIG_CPUMASK_OFFSTACK=y
In theory (though not shown in practice) alloc_cpumask_var() doesn't zero memory, so CPUs might print an "NMI backtrace for cpu %d" once on boot.
(Bug introduced in fcef8576d8a64fc603e719c97d423f9f6d4e0e8b).
[ Impact: avoid theoretical syslog noise in rare configs ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <alpine.DEB.2.00.0904202113520.10097@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- arch/x86/kernel/apic/nmi.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c index 2ba52f3..ce4fbfa 100644 --- a/arch/x86/kernel/apic/nmi.c +++ b/arch/x86/kernel/apic/nmi.c @@ -138,7 +138,7 @@ int __init check_nmi_watchdog(void) if (!prev_nmi_count) goto error; - alloc_cpumask_var(&backtrace_mask, GFP_KERNEL); + alloc_cpumask_var(&backtrace_mask, GFP_KERNEL|__GFP_ZERO); printk(KERN_INFO "Testing NMI watchdog ... "); #ifdef CONFIG_SMP
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