From e3f2ddeac718c768fdac4b7fe69d465172f788a8 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 29 Jul 2006 05:17:57 +0200 Subject: [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 Signed-off-by: Ingo Molnar Signed-off-by: Ulrich Drepper Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds --- include/linux/futex.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/futex.h b/include/linux/futex.h index 34c3a215f2cd..d097b5b72bc6 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -96,7 +96,8 @@ struct robust_list_head { long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout, u32 __user *uaddr2, u32 val2, u32 val3); -extern int handle_futex_death(u32 __user *uaddr, struct task_struct *curr); +extern int +handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi); #ifdef CONFIG_FUTEX extern void exit_robust_list(struct task_struct *curr); -- cgit v1.2.3