Messages in this thread Patch in this message | | | Date | Fri, 15 Apr 2011 10:33:00 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH V5] futex: set FLAGS_HAS_TIMEOUT during futex_wait restart setup |
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On Thu, 14 Apr 2011, 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 > V5: Correct subject to match implementation, correct stable submission > > Signed-off-by: Darren Hart <dvhart@linux.intel.com> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > Reported-by: Tim Smith <tsmith201104@yahoo.com> > Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: John Kacur <jkacur@redhat.com> > Cc: stable@kernel.org > --- > 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;
We only get here when a timeout is pending. So why don't we just do the obvious:
--- linux-2.6.orig/kernel/futex.c +++ linux-2.6/kernel/futex.c @@ -1902,16 +1902,13 @@ out: static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = restart->futex.uaddr; - ktime_t t, *tp = NULL; + ktime_t t; - if (restart->futex.flags & FLAGS_HAS_TIMEOUT) { - t.tv64 = restart->futex.time; - tp = &t; - } + t.tv64 = restart->futex.time; restart->fn = do_no_restart_syscall; return (long)futex_wait(uaddr, restart->futex.flags, - restart->futex.val, tp, restart->futex.bitset); + restart->futex.val, &t, restart->futex.bitset); } Thanks,
tglx
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