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Commit cc20d429 authored by Russell King's avatar Russell King
Browse files

ARM: Use a definition for the userspace cmpxchg emulation syscall 



Use a definition for the cmpxchg SWI instead of hard-coding the number.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarNicolas Pitre <nico@fluxnic.net>
parent bfd2e29f

arch/arm/include/asm/unistd.h

+9 −0
Original line number Diff line number Diff line
@@ -402,6 +402,15 @@ 
#define __ARM_NR_usr32			(__ARM_NR_BASE+4)

#define __ARM_NR_set_tls		(__ARM_NR_BASE+5)



/*

 * *NOTE*: This is a ghost syscall private to the kernel.  Only the

 * __kuser_cmpxchg code in entry-armv.S should be aware of its

 * existence.  Don't ever use this from user code.

 */

#ifdef __KERNEL__

#define __ARM_NR_cmpxchg		(__ARM_NR_BASE+0x00fff0)

#endif



/*

 * The following syscalls are obsolete and no longer available for EABI.

 */

arch/arm/kernel/entry-armv.S

+4 −3
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <mach/entry-macro.S>

#include <asm/thread_notify.h>

#include <asm/unwind.h>

#include <asm/unistd.h>



#include "entry-header.S"
@@ -908,10 +909,10 @@ __kuser_cmpxchg: @ 0xffff0fc0 
	 * A special ghost syscall is used for that (see traps.c).

	 */

	stmfd	sp!, {r7, lr}

	mov	r7, #0xff00		@ 0xfff0 into r7 for EABI

	orr	r7, r7, #0xf0

	swi	#0x9ffff0

	ldr	r7, =1f			@ it's 20 bits

	swi	__ARM_NR_cmpxchg

	ldmfd	sp!, {r7, pc}

1:	.word	__ARM_NR_cmpxchg



#elif __LINUX_ARM_ARCH__ < 6

arch/arm/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -528,7 +528,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs) 
	 * __kuser_cmpxchg code in entry-armv.S should be aware of its

	 * existence.  Don't ever use this from user code.

	 */

	case 0xfff0:

	case NR(cmpxchg):

	for (;;) {

		extern void do_DataAbort(unsigned long addr, unsigned int fsr,

					 struct pt_regs *regs);