Re: [PATCH] arm64: disable kasan when accessing frame->fp in unwind_frame

On 02/06/2016 02:04 AM, Yang Shi wrote:

#include <asm/irq.h> #include <asm/stacktrace.h> @@ -64,7 +65,9 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) return -EINVAL; frame->sp = fp + 0x10;

• kasan_disable_current(); frame->fp = *(unsigned long *)(fp);

It would be better to use READ_ONCE_NOCHECK() here. See f7d27c35ddff7 ("x86/mm, kasan: Silence KASAN warnings in get_wchan()") which solves the same problem for x86.

• kasan_enable_current(); frame->pc = *(unsigned long *)(fp + 8);

Why you left frame->pc out of scope? This line could trigger kasan as well.

#ifdef CONFIG_FUNCTION_GRAPH_TRACER