Re: [PATCH V3] futex: set FLAGS_HAS_TIMEOUT during demux forFUTEX_WAIT

From: Eric Dumazet
Date: Thu Apr 14 2011 - 16:43:26 EST


Le jeudi 14 avril 2011 Ã 13:39 -0700, Darren Hart a Ãcrit :
> The FLAGS_HAS_TIMEOUT flag was not getting set, causing the restart_block to
> restart futex_wait() without a timeout after a signal.
>
> Commit b41277dc7a18ee332d in 2.6.38 introduced the regression by accidentally
> removing the the FLAGS_HAS_TIMEOUT assignment from futex_wait() during the setup
> of the restart block. Restore the originaly behavior.
>
> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=32922
>
> V2: Added references to commit message.
> V3: Set flag during restart block instead of do_futex()
>
> Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx>
> Reported-by: Tim Smith <tsmith201104@xxxxxxxxx>
> Reported-by: Torsten Hilbrich <torsten.hilbrich@xxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> CC: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> CC: John Kacur <jkacur@xxxxxxxxxx>
> ---
> kernel/futex.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index bda4157..9d9c476 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -1887,6 +1887,7 @@ retry:
> restart->futex.time = abs_time->tv64;
> restart->futex.bitset = bitset;
> restart->futex.flags = flags;
> + flags |= FLAGS_HAS_TIMEOUT;
>
> ret = -ERESTART_RESTARTBLOCK;
>


Hmmm, I am sorry but this wont work... please try :

- restart->futex.flags = flags;
+ restart->futex.flags = flags | FLAGS_HAS_TIMEOUT;


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