tree 5428532dc6c87710c35a71858425f6d726f0e44c
parent 627371d73cdd04ed23fe098755b4f855138ad9e0
author Ingo Molnar <mingo@elte.hu> 1154143077 +0200
committer Linus Torvalds <torvalds@g5.osdl.org> 1154145720 -0700

[PATCH] pi-futex: robust-futex exit

Fix robust PI-futexes to be properly unlocked on unexpected exit.

For this to work the kernel has to know whether a futex is a PI or a
non-PI one, because the semantics are different.  Since the space in
relevant glibc data structures is extremely scarce, the best solution is
to encode the 'PI' information in bit 0 of the robust list pointer.
Existing (non-PI) glibc robust futexes have this bit always zero, so the
ABI is kept.  New glibc with PI-robust-futexes will set this bit.

Further fixes from Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>