2011-04-14 21:43:20

by Darren Hart

Subject: [PATCH V4] futex: set FLAGS_HAS_TIMEOUT during demux for FUTEX_WAIT

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()
V4: Correct stupid order of assignment mistake pointed out by Eric

Signed-off-by: Darren Hart <[email protected]>
Reported-by: Tim Smith <[email protected]>
Reported-by: Torsten Hilbrich <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
CC: Eric Dumazet <[email protected]>
CC: John Kacur <[email protected]>
---
kernel/futex.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index bda4157..abd5324 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1886,7 +1886,7 @@ retry:
restart->futex.val = val;
restart->futex.time = abs_time->tv64;
restart->futex.bitset = bitset;
- restart->futex.flags = flags;
+ restart->futex.flags = flags | FLAGS_HAS_TIMEOUT;

ret = -ERESTART_RESTARTBLOCK;

--
1.7.1

2011-04-14 21:50:47

by Eric Dumazet

Subject: Re: [PATCH V4] futex: set FLAGS_HAS_TIMEOUT during demux for FUTEX_WAIT

Le jeudi 14 avril 2011 à 14:43 -0700, Darren Hart a écrit :
> 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()
> V4: Correct stupid order of assignment mistake pointed out by Eric
>
> Signed-off-by: Darren Hart <[email protected]>
> Reported-by: Tim Smith <[email protected]>
> Reported-by: Torsten Hilbrich <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> CC: Eric Dumazet <[email protected]>
> CC: John Kacur <[email protected]>
> ---


Thanks Darren

Acked-by: Eric Dumazet <[email protected]>

2011-04-14 21:57:06

by Greg KH

Subject: Re: [stable] [PATCH V4] futex: set FLAGS_HAS_TIMEOUT during demux for FUTEX_WAIT

On Thu, Apr 14, 2011 at 02:43:01PM -0700, Darren Hart wrote:
> 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()
> V4: Correct stupid order of assignment mistake pointed out by Eric
>
> Signed-off-by: Darren Hart <[email protected]>
> Reported-by: Tim Smith <[email protected]>
> Reported-by: Torsten Hilbrich <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> CC: Eric Dumazet <[email protected]>
> CC: John Kacur <[email protected]>
> ---

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

thanks,

greg k-h

2011-04-14 22:13:52

by Darren Hart

Subject: Re: [stable] [PATCH V4] futex: set FLAGS_HAS_TIMEOUT during demux for FUTEX_WAIT

On 04/14/2011 02:56 PM, Greg KH wrote:
> On Thu, Apr 14, 2011 at 02:43:01PM -0700, Darren Hart wrote:
>> 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()
>> V4: Correct stupid order of assignment mistake pointed out by Eric
>>
>> Signed-off-by: Darren Hart <[email protected]>
>> Reported-by: Tim Smith <[email protected]>
>> Reported-by: Torsten Hilbrich <[email protected]>
>> Cc: Thomas Gleixner <[email protected]>
>> Cc: Peter Zijlstra <[email protected]>
>> Cc: Ingo Molnar <[email protected]>
>> CC: Eric Dumazet <[email protected]>
>> CC: John Kacur <[email protected]>
>> ---
>
> This is not the correct way to submit patches for inclusion in the
> stable kernel tree. Please read Documentation/stable_kernel_rules.txt
> for how to do this properly.

Sigh, apologies. Fixing, will add stable to CC: in changelog. Gives me a
chance to improve the subject anyway.

Ingo, Greg, please ignore this and the previous V[123] patches.

--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel