Re: [PATCH 1/3] tracing: add ftrace_trace_stack into __trace_puts/__trace_bputs

Steven Rostedt
2014-07-09T18:40:17Z

Wow! I some how missed your emails. I'm cleaning up my inbox and just
stumbled over them now.

I tell people, they can either ping me a few times (keep doing it until
you see a response, but spread them out). Otherwise, I will still get
to their email. Just a year later ;-)

Yeah, this looks fine. I can queue it up for 3.17.

-- Steve

On Thu, 18 Jul 2013 16:31:05 +0800
"zhangwei(Jovi)" <jovi.zhangwei@huawei.com> wrote:

> Currently trace option stacktrace is not applicable for
> trace_printk with constant string argument, the reason is
> there missed ftrace_trace_stack in __trace_puts/__trace_bputs.
>
> In contrast, when using trace_printk with not constant string
> argument(will call into __trace_printk/__trace_bprintk), then
> trace option stacktrace is workable, this inconstant result
> will confusing user a lot.
>
> Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
> ---
> kernel/trace/trace.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 3d5a931..4d70cc5 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -363,13 +363,16 @@ int __trace_puts(unsigned long ip, const char *str, int size)
> struct print_entry *entry;
> unsigned long irq_flags;
> int alloc;
> + int pc;
> +
> + pc = preempt_count();
>
> alloc = sizeof(*entry) + size + 2; /* possible \n added */
>
> local_save_flags(irq_flags);
> buffer = global_trace.trace_buffer.buffer;
> event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
> - irq_flags, preempt_count());
> + irq_flags, pc);
> if (!event)
> return 0;
>
> @@ -386,6 +389,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
> entry->buf[size] = '\0';
>
> __buffer_unlock_commit(buffer, event);
> + ftrace_trace_stack(buffer, irq_flags, 4, pc);
>
> return size;
> }
> @@ -403,11 +407,14 @@ int __trace_bputs(unsigned long ip, const char *str)
> struct bputs_entry *entry;
> unsigned long irq_flags;
> int size = sizeof(struct bputs_entry);
> + int pc;
> +
> + pc = preempt_count();
>
> local_save_flags(irq_flags);
> buffer = global_trace.trace_buffer.buffer;
> event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
> - irq_flags, preempt_count());
> + irq_flags, pc);
> if (!event)
> return 0;
>
> @@ -416,6 +423,7 @@ int __trace_bputs(unsigned long ip, const char *str)
> entry->str = str;
>
> __buffer_unlock_commit(buffer, event);
> + ftrace_trace_stack(buffer, irq_flags, 4, pc);
>
> return 1;
> }