Messages in this thread Patch in this message | | | Date | Tue, 21 Feb 2006 09:47:01 +0100 | From | Ingo Molnar <> | Subject | [patch 5/6] lightweight robust futexes: i386 |
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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>
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arch/i386/kernel/syscall_table.S | 2 ++ include/asm-i386/futex.h | 23 ++++++++++++++++++++++- include/asm-i386/unistd.h | 4 +++- 3 files changed, 27 insertions(+), 2 deletions(-)
Index: linux/arch/i386/kernel/syscall_table.S =================================================================== --- linux.orig/arch/i386/kernel/syscall_table.S +++ linux/arch/i386/kernel/syscall_table.S @@ -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 Index: linux/include/asm-i386/futex.h =================================================================== --- linux.orig/include/asm-i386/futex.h +++ linux/include/asm-i386/futex.h @@ -107,7 +107,28 @@ futex_atomic_op_inuser (int encoded_op, 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 Index: linux/include/asm-i386/unistd.h =================================================================== --- linux.orig/include/asm-i386/unistd.h +++ linux/include/asm-i386/unistd.h @@ -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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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