From 8fdd6c6df7889dc89df3d9fe0f5bbe6733e39f48 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 27 Mar 2006 01:16:26 -0800 Subject: [PATCH] lightweight robust futexes: x86_64 x86_64: add the futex_atomic_cmpxchg_inuser() assembly implementation, and wire up the new syscalls. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Arjan van de Ven Acked-by: Ulrich Drepper Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-x86_64/futex.h | 23 ++++++++++++++++++++++- include/asm-x86_64/unistd.h | 6 +++++- 2 files changed, 27 insertions(+), 2 deletions(-) (limited to 'include/asm-x86_64') diff --git a/include/asm-x86_64/futex.h b/include/asm-x86_64/futex.h index 4f4cb3410d06..7d9eb1a84546 100644 --- a/include/asm-x86_64/futex.h +++ b/include/asm-x86_64/futex.h @@ -97,7 +97,28 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) static inline int futex_atomic_cmpxchg_inuser(int __user *uaddr, int oldval, int newval) { - return -ENOSYS; + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + __asm__ __volatile__( + "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n" + + "2: .section .fixup, \"ax\" \n" + "3: mov %2, %0 \n" + " jmp 2b \n" + " .previous \n" + + " .section __ex_table, \"a\" \n" + " .align 8 \n" + " .quad 1b,3b \n" + " .previous \n" + + : "=a" (oldval), "=m" (*uaddr) + : "i" (-EFAULT), "r" (newval), "0" (oldval) + : "memory" + ); + + return oldval; } #endif diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h index da0341c57949..fcc516353087 100644 --- a/include/asm-x86_64/unistd.h +++ b/include/asm-x86_64/unistd.h @@ -605,8 +605,12 @@ __SYSCALL(__NR_pselect6, sys_ni_syscall) /* for now */ __SYSCALL(__NR_ppoll, sys_ni_syscall) /* for now */ #define __NR_unshare 272 __SYSCALL(__NR_unshare, sys_unshare) +#define __NR_set_robust_list 273 +__SYSCALL(__NR_set_robust_list, sys_set_robust_list) +#define __NR_get_robust_list 274 +__SYSCALL(__NR_get_robust_list, sys_get_robust_list) -#define __NR_syscall_max __NR_unshare +#define __NR_syscall_max __NR_get_robust_list #ifndef __NO_STUBS -- cgit v1.2.3