From cc20d42986d5807cbe4f5c7c8e3dab2e59ea0db3 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 9 Nov 2009 23:53:29 +0000 Subject: 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: Russell King Acked-by: Nicolas Pitre --- arch/arm/include/asm/unistd.h | 9 +++++++++ arch/arm/kernel/entry-armv.S | 7 ++++--- arch/arm/kernel/traps.c | 2 +- 3 files changed, 14 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 7020217fc49f..4e506d09e5f9 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -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. */ diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 0022b4d57f8b..d2903e3bc861 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -21,6 +21,7 @@ #include #include #include +#include #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 diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 1bbda04a5380..3f361a783f43 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -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); -- cgit v1.2.2