Re: [for-next][PATCH 05/30] arm64: function_graph: Remove use of FTRACE_NOTRACE_DEPTH

From: Will Deacon
Date: Thu Dec 06 2018 - 10:49:14 EST


On Wed, Dec 05, 2018 at 06:47:54PM -0500, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
>
> Functions in the set_graph_notrace no longer subtract FTRACE_NOTRACE_DEPTH
> from curr_ret_stack, as that is now implemented via the trace_recursion
> flags. Access to curr_ret_stack no longer needs to worry about checking for
> this. curr_ret_stack is still initialized to -1, when there's not a shadow
> stack allocated.
>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> ---
> arch/arm64/kernel/stacktrace.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 4989f7ea1e59..7723dadf25be 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -61,9 +61,6 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
> (frame->pc == (unsigned long)return_to_handler)) {
> if (WARN_ON_ONCE(frame->graph == -1))
> return -EINVAL;
> - if (frame->graph < -1)
> - frame->graph += FTRACE_NOTRACE_DEPTH;
> -

Acked-by: Will Deacon <will.deacon@xxxxxxx>

Will