diff options
Diffstat (limited to 'arch/arm/kernel/kprobes.c')
| -rw-r--r-- | arch/arm/kernel/kprobes.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c index f692efddd449..60c62c377fa9 100644 --- a/arch/arm/kernel/kprobes.c +++ b/arch/arm/kernel/kprobes.c @@ -22,6 +22,7 @@ #include <linux/kernel.h> #include <linux/kprobes.h> #include <linux/module.h> +#include <linux/stop_machine.h> #include <linux/stringify.h> #include <asm/traps.h> #include <asm/cacheflush.h> @@ -83,10 +84,24 @@ void __kprobes arch_arm_kprobe(struct kprobe *p) flush_insns(p->addr, 1); } +/* + * The actual disarming is done here on each CPU and synchronized using + * stop_machine. This synchronization is necessary on SMP to avoid removing + * a probe between the moment the 'Undefined Instruction' exception is raised + * and the moment the exception handler reads the faulting instruction from + * memory. + */ +int __kprobes __arch_disarm_kprobe(void *p) +{ + struct kprobe *kp = p; + *kp->addr = kp->opcode; + flush_insns(kp->addr, 1); + return 0; +} + void __kprobes arch_disarm_kprobe(struct kprobe *p) { - *p->addr = p->opcode; - flush_insns(p->addr, 1); + stop_machine(__arch_disarm_kprobe, p, &cpu_online_map); } void __kprobes arch_remove_kprobe(struct kprobe *p) |