Re: [Qemu-devel] [PATCH] Make qemu_shutdown_requested signal-safe

[Jan Kiszka <jan.kiszka@web.de>]

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On 2014-10-27 10:09, Paolo Bonzini wrote:
> On 10/26/2014 10:32 AM, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> qemu_shutdown_requested may be interrupted by qemu_system_killed. 
>> If the latter sets shutdown_requested after qemu_shutdown_requested
>> has read it but before it was cleared, the shutdown event is lost.
>> Fix this by using atomic_xchg.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> --- vl.c | 4 
>> +--- 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/vl.c b/vl.c index 2f81384..f6b3546 100644 --- a/vl.c 
>> +++ b/vl.c @@ -1609,9 +1609,7 @@ int 
>> qemu_reset_requested_get(void)
>>
>> static int qemu_shutdown_requested(void) { -    int r = 
>> shutdown_requested; -    shutdown_requested = 0; -    return r; + 
>> return atomic_xchg(&shutdown_requested, 0); }
>>
>> static void qemu_kill_report(void)
>>
> 
> Cc: qemu-stable@nongnu.org
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> 
> Are you going to send a pull request yourself?
> 

I was assuming Peter would merge (and decide about the ordering).

Jan


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