From faabfa0816916b0a7cfc93f6a9be382830658c80 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 20 Dec 2010 16:58:19 +0000 Subject: [PATCH] ARM: SMP: ensure frame pointer is reinitialized for soft-CPU hotplug When we soft-CPU hotplug a CPU, we reset the stack pointer and jump back to start_secondary(). This allows us to restart as if the CPU was actually reset. However, we weren't resetting the frame pointer, which could cause problems with backtracing. Reset the frame pointer to zero (which means no parent frame) just like the early assembly code also does. Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 6d0c66b..5341b0b 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -286,6 +286,7 @@ void __ref cpu_die(void) * to be repeated to undo the effects of taking the CPU offline. */ __asm__("mov sp, %0\n" + " mov fp, #0\n" " b secondary_start_kernel" : : "r" (task_stack_page(current) + THREAD_SIZE - 8)); -- 2.7.4