On Mon, 11 Feb 2008, Adrian Bunk wrote: > The issue described in [1] is still present and unfixed (and even the > fix there wasn't complete since it didn't cover SMP).
Damn, this slipped through my attention completely. Hotfix (which can be easily backported) below. > Thanks to Riku Voipio for noting that it is still unfixed. > > cu > Adrian > > [1] http://lkml.org/lkml/2007/8/1/474 --------> Subject: futex: disable PI/robust on archs w/o valid implementation From: Thomas Gleixner <[EMAIL PROTECTED]> We have to disable the complete PI/robust functionality for those archs, which do not implement futex_atomic_cmpxchg_inatomic(). The code in question relies on a valid implementation and does not expect -ENOSYS, which is returned by the stub implementation in asm-generic/futex.h Pointed out by: Mikael Pettersson, Riku Voipio and Adrian Bunk This patch is intended for easy backporting and needs to be cleaned up further for current mainline. Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]> Acked-by: Ingo Molnar <[EMAIL PROTECTED]> --- include/asm-generic/futex.h | 2 ++ kernel/futex.c | 13 +++++++++++++ 2 files changed, 15 insertions(+) Index: linux-2.6/include/asm-generic/futex.h =================================================================== --- linux-2.6.orig/include/asm-generic/futex.h +++ linux-2.6/include/asm-generic/futex.h @@ -55,5 +55,7 @@ futex_atomic_cmpxchg_inatomic(int __user return -ENOSYS; } +#define FUTEX_ATOMIC_CMPXCHG_NOT_IMPLEMENTED + #endif #endif Index: linux-2.6/kernel/futex.c =================================================================== --- linux-2.6.orig/kernel/futex.c +++ linux-2.6/kernel/futex.c @@ -1870,6 +1870,9 @@ asmlinkage long sys_set_robust_list(struct robust_list_head __user *head, size_t len) { +#ifdef FUTEX_ATOMIC_CMPXCHG_NOT_IMPLEMENTED + return -ENOSYS; +#else /* * The kernel knows only one size for now: */ @@ -1879,6 +1882,7 @@ sys_set_robust_list(struct robust_list_h current->robust_list = head; return 0; +#endif } /** @@ -1891,6 +1895,9 @@ asmlinkage long sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr, size_t __user *len_ptr) { +#ifdef FUTEX_ATOMIC_CMPXCHG_NOT_IMPLEMENTED + return -ENOSYS; +#else struct robust_list_head __user *head; unsigned long ret; @@ -1920,6 +1927,7 @@ err_unlock: rcu_read_unlock(); return ret; +#endif } /* @@ -2082,6 +2090,9 @@ long do_futex(u32 __user *uaddr, int op, case FUTEX_WAKE_OP: ret = futex_wake_op(uaddr, fshared, uaddr2, val, val2, val3); break; + +#ifndef FUTEX_ATOMIC_CMPXCHG_NOT_IMPLEMENTED + case FUTEX_LOCK_PI: ret = futex_lock_pi(uaddr, fshared, val, timeout, 0); break; @@ -2091,6 +2102,8 @@ long do_futex(u32 __user *uaddr, int op, case FUTEX_TRYLOCK_PI: ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1); break; +#endif + default: ret = -ENOSYS; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
