Re: [PATCH v4 01/15] stacktrace/x86: add function for detecting reliable stack traces

Miroslav Benes
2017-01-27T08:48:35Z

> diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
> index 0a34489..8e8b67b 100644
> --- a/include/linux/stacktrace.h
> +++ b/include/linux/stacktrace.h
> @@ -18,6 +18,8 @@ extern void save_stack_trace_regs(struct pt_regs *regs,
> struct stack_trace *trace);
> extern void save_stack_trace_tsk(struct task_struct *tsk,
> struct stack_trace *trace);
> +extern int save_stack_trace_tsk_reliable(struct task_struct *tsk,
> + struct stack_trace *trace);
>
> extern void print_stack_trace(struct stack_trace *trace, int spaces);
> extern int snprint_stack_trace(char *buf, size_t size,
> @@ -29,12 +31,12 @@ extern void save_stack_trace_user(struct stack_trace *trace);
> # define save_stack_trace_user(trace) do { } while (0)
> #endif
>
> -#else
> +#else /* !CONFIG_STACKTRACE */
> # define save_stack_trace(trace) do { } while (0)
> # define save_stack_trace_tsk(tsk, trace) do { } while (0)
> # define save_stack_trace_user(trace) do { } while (0)
> # define print_stack_trace(trace, spaces) do { } while (0)
> # define snprint_stack_trace(buf, size, trace, spaces) do { } while (0)

Is there a reason you did not define empty save_stack_trace_tsk_reliable()
here? Right, it should not be needed now as livepatching is the only user,
but still.

Miroslav