On Tue, Nov 23, 2021 at 01:37:20PM -0600, madvenka at linux.microsoft.com wrote:
> From: "Madhavan T. Venkataraman" <madvenka at linux.microsoft.com>
>
> Rename unwinder functions for consistency and better naming.
>
> - Rename start_backtrace() to unwind_start().
> - Rename unwind_frame() to unwind_next().
> - Rename walk_stackframe() to unwind().
Super trivial, but could we s/unwind_start/unwind_init/ ? That makes it
slightly clearer that it's not performing an unwind step.
Otherwise, this looks good to me.
For the rename:
Acked-by: Mark Rutland <mark.rutland at arm.com>
It's be nice if we could also clean up 'struct stackframe' into 'struct
unwind_state', but that can be a follow-up, and this is fine as it is, modulo
the super trivial comment above.
Thanks,
Mark.
>
> Signed-off-by: Madhavan T. Venkataraman <madvenka at linux.microsoft.com>
> ---
> arch/arm64/kernel/stacktrace.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 7217c4f63ef7..918852cd2681 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -33,8 +33,8 @@
> */
>
>
> -static void start_backtrace(struct stackframe *frame, unsigned long fp,
> - unsigned long pc)
> +static void unwind_start(struct stackframe *frame, unsigned long fp,
> + unsigned long pc)
> {
> frame->fp = fp;
> frame->pc = pc;
> @@ -45,7 +45,7 @@ static void start_backtrace(struct stackframe *frame, unsigned long fp,
> /*
> * Prime the first unwind.
> *
> - * In unwind_frame() we'll check that the FP points to a valid stack,
> + * In unwind_next() we'll check that the FP points to a valid stack,
> * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
> * treated as a transition to whichever stack that happens to be. The
> * prev_fp value won't be used, but we set it to 0 such that it is
> @@ -63,8 +63,8 @@ static void start_backtrace(struct stackframe *frame, unsigned long fp,
> * records (e.g. a cycle), determined based on the location and fp value of A
> * and the location (but not the fp value) of B.
> */
> -static int notrace unwind_frame(struct task_struct *tsk,
> - struct stackframe *frame)
> +static int notrace unwind_next(struct task_struct *tsk,
> + struct stackframe *frame)
> {
> unsigned long fp = frame->fp;
> struct stack_info info;
> @@ -104,7 +104,7 @@ static int notrace unwind_frame(struct task_struct *tsk,
>
> /*
> * Record this frame record's values and location. The prev_fp and
> - * prev_type are only meaningful to the next unwind_frame() invocation.
> + * prev_type are only meaningful to the next unwind_next() invocation.
> */
> frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
> frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
> @@ -137,27 +137,27 @@ static int notrace unwind_frame(struct task_struct *tsk,
>
> return 0;
> }
> -NOKPROBE_SYMBOL(unwind_frame);
> +NOKPROBE_SYMBOL(unwind_next);
>
> -static void notrace walk_stackframe(struct task_struct *tsk,
> - unsigned long fp, unsigned long pc,
> - bool (*fn)(void *, unsigned long), void *data)
> +static void notrace unwind(struct task_struct *tsk,
> + unsigned long fp, unsigned long pc,
> + bool (*fn)(void *, unsigned long), void *data)
> {
> struct stackframe frame;
>
> - start_backtrace(&frame, fp, pc);
> + unwind_start(&frame, fp, pc);
>
> while (1) {
> int ret;
>
> if (!fn(data, frame.pc))
> break;
> - ret = unwind_frame(tsk, &frame);
> + ret = unwind_next(tsk, &frame);
> if (ret < 0)
> break;
> }
> }
> -NOKPROBE_SYMBOL(walk_stackframe);
> +NOKPROBE_SYMBOL(unwind);
>
> static bool dump_backtrace_entry(void *arg, unsigned long where)
> {
> @@ -210,5 +210,5 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
> fp = thread_saved_fp(task);
> pc = thread_saved_pc(task);
> }
> - walk_stackframe(task, fp, pc, consume_entry, cookie);
> + unwind(task, fp, pc, consume_entry, cookie);
> }
> --
> 2.25.1
>