[PATCH] lightweight robust futexes: i386

i386: add the futex_atomic_cmpxchg_inuser() assembly implementation, and wire
up the new syscalls.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ingo Molnar 2006-03-27 01:16:25 -08:00 committed by Linus Torvalds
parent 34f192c652
commit dfd4e3ec24
3 changed files with 27 additions and 2 deletions

View File

@ -310,3 +310,5 @@ ENTRY(sys_call_table)
.long sys_pselect6
.long sys_ppoll
.long sys_unshare /* 310 */
.long sys_set_robust_list
.long sys_get_robust_list

View File

@ -107,7 +107,28 @@ 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"
" .long 1b,3b \n"
" .previous \n"
: "=a" (oldval), "=m" (*uaddr)
: "i" (-EFAULT), "r" (newval), "0" (oldval)
: "memory"
);
return oldval;
}
#endif

View File

@ -316,8 +316,10 @@
#define __NR_pselect6 308
#define __NR_ppoll 309
#define __NR_unshare 310
#define __NR_set_robust_list 311
#define __NR_get_robust_list 312
#define NR_syscalls 311
#define NR_syscalls 313
/*
* user-visible error numbers are in the range -1 - -128: see