Re: [Patch -tip 1/3] Tracing/ftrace: Relay unhandled entry output

[Ingo Molnar <mingo@elte.hu>]

* Frédéric Weisbecker <fweisbec@gmail.com> wrote:

> Hi!
> 
> I tried to figure out the origin of the bug reported by Pekka Paalanen
> about the broken pipe:
> http://kerneltrap.org/mailarchive/linux-kernel/2008/9/15/3305224
> 
> When I add a trace_mark with the boot tracer, I had this same problem
> but this time it was easy to reproduce.
> 
> When it calls a tracer's print_line callback, the print_trace_line function 
> in trace.c returns whithout verifying if it could handle the entry properly.
> And actually the seq could be empty.
> 
> For example the boot_tracer don't handle TRACE_PRINT. Nevertheless it
> wants them to be printed as a default way.
> 
> So print_trace_line function should relay on the other functions which could handle
> an output if one of them fail.
> 
> Reported-by: Pekka Paalanen <pq@iki.fi>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

ah, nice! Applied to tip/tracing/ftrace.

Small nit: could you please send another patch on top of this patch that 
cleans up the checkpatch failures below?

checkpatch usage: you can run it like this:

  scripts/checkpatch.pl --file kernel/trace/*.c

and/or you can run it over patches as well before you submit them.

	Ingo

------------->
ERROR: do not use assignment in if condition
#43: FILE: kernel/trace/trace.c:1910:
+		if ((ret = iter->trace->print_line(iter)))

ERROR: do not use assignment in if condition
#48: FILE: kernel/trace/trace.c:1914:
+		if ((ret = print_bin_fmt(iter)))

ERROR: do not use assignment in if condition
#53: FILE: kernel/trace/trace.c:1918:
+		if ((ret = print_hex_fmt(iter)))

ERROR: do not use assignment in if condition
#58: FILE: kernel/trace/trace.c:1922:
+		if ((ret = print_raw_fmt(iter)))

ERROR: do not use assignment in if condition
#63: FILE: kernel/trace/trace.c:1926:
+		if ((ret = print_lat_fmt(iter, iter->idx, iter->cpu)))

total: 5 errors, 0 warnings, 0 checks, 32 lines checked