Commit dfd4e3ec authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[PATCH] lightweight robust futexes: i386 



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

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
Acked-by: default avatarUlrich Drepper <drepper@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 34f192c6

arch/i386/kernel/syscall_table.S

+2 −0
Original line number Diff line number Diff line
@@ -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

include/asm-i386/futex.h

+22 −1
Original line number Diff line number Diff line
@@ -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

include/asm-i386/unistd.h

+3 −1
Original line number Diff line number Diff line
@@ -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

CRA Git | Maintained and supported by SUSTech CRA and CCSE