From: Russell King Date: Mon, 20 Dec 2010 16:58:19 +0000 (+0000) Subject: ARM: SMP: ensure frame pointer is reinitialized for soft-CPU hotplug X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=faabfa0816916b0a7cfc93f6a9be382830658c80;p=deliverable%2Flinux.git 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 --- diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 6d0c66bc434d..5341b0b19701 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));