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| author | Andrew Morton <akpm@linux-foundation.org> | 2012-03-05 14:59:19 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-12 10:32:55 -0700 |
| commit | f148e8a6cf51419b4dc7c99941054ed3ddad5a87 (patch) | |
| tree | 97b3e52b52716a4824199f651b9616ba4d79a0fd /arch/alpha/include | |
| parent | c2235bf93207cbd4d72c8e560d59b6adf36611b2 (diff) | |
| download | kernel_samsung_aries-f148e8a6cf51419b4dc7c99941054ed3ddad5a87.zip kernel_samsung_aries-f148e8a6cf51419b4dc7c99941054ed3ddad5a87.tar.gz kernel_samsung_aries-f148e8a6cf51419b4dc7c99941054ed3ddad5a87.tar.bz2 | |
alpha: fix 32/64-bit bug in futex support
commit 62aca403657fe30e5235c5331e9871e676d9ea0a upstream.
Michael Cree said:
: : I have noticed some user space problems (pulseaudio crashes in pthread
: : code, glibc/nptl test suite failures, java compiler freezes on SMP alpha
: : systems) that arise when using a 2.6.39 or later kernel on Alpha.
: : Bisecting between 2.6.38 and 2.6.39 (using glibc/nptl test suite as
: : criterion for good/bad kernel) eventually leads to:
: :
: : 8d7718aa082aaf30a0b4989e1f04858952f941bc is the first bad commit
: : commit 8d7718aa082aaf30a0b4989e1f04858952f941bc
: : Author: Michel Lespinasse <walken@google.com>
: : Date: Thu Mar 10 18:50:58 2011 -0800
: :
: : futex: Sanitize futex ops argument types
: :
: : Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic
: : prototypes to use u32 types for the futex as this is the data type the
: : futex core code uses all over the place.
: :
: : Looking at the commit I see there is a change of the uaddr argument in
: : the Alpha architecture specific code for futexes from int to u32, but I
: : don't see why this should cause a problem.
Richard Henderson said:
: futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
: u32 oldval, u32 newval)
: ...
: : "r"(uaddr), "r"((long)oldval), "r"(newval)
:
:
: There is no 32-bit compare instruction. These are implemented by
: consistently extending the values to a 64-bit type. Since the
: load instruction sign-extends, we want to sign-extend the other
: quantity as well (despite the fact it's logically unsigned).
:
: So:
:
: - : "r"(uaddr), "r"((long)oldval), "r"(newval)
: + : "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
:
: should do the trick.
Michael said:
: This fixes the glibc test suite failures and the pulseaudio related
: crashes, but it does not fix the java compiiler lockups that I was (and
: are still) observing. That is some other problem.
Reported-by: Michael Cree <mcree@orcon.net.nz>
Tested-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/alpha/include')
| -rw-r--r-- | arch/alpha/include/asm/futex.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h index e8a761a..f939794 100644 --- a/arch/alpha/include/asm/futex.h +++ b/arch/alpha/include/asm/futex.h @@ -108,7 +108,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, " lda $31,3b-2b(%0)\n" " .previous\n" : "+r"(ret), "=&r"(prev), "=&r"(cmp) - : "r"(uaddr), "r"((long)oldval), "r"(newval) + : "r"(uaddr), "r"((long)(int)oldval), "r"(newval) : "memory"); *uval = prev; |