[PATCH] arm64: Mark start_backtrace() notrace and NOKPROBE_SYMBOL

From: Masami Hiramatsu
Date: Mon Jan 24 2022 - 03:18:01 EST


Mark the start_backtrace() as notrace and NOKPROBE_SYMBOL
because this function is called from ftrace and lockdep to
get the caller address via return_address(). The lockdep
is used in kprobes, it should also be NOKPROBE_SYMBOL.

Fixes: b07f3499661c ("arm64: stacktrace: Move start_backtrace() out of the header")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
arch/arm64/kernel/stacktrace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 94f83cd44e50..b0f21677764d 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -33,7 +33,7 @@
*/


-void start_backtrace(struct stackframe *frame, unsigned long fp,
+void notrace start_backtrace(struct stackframe *frame, unsigned long fp,
unsigned long pc)
{
frame->fp = fp;
@@ -55,6 +55,7 @@ void start_backtrace(struct stackframe *frame, unsigned long fp,
frame->prev_fp = 0;
frame->prev_type = STACK_TYPE_UNKNOWN;
}
+NOKPROBE_SYMBOL(start_backtrace);

/*
* Unwind from one frame record (A) to the next frame record (B).