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tracing: Fix double CPP substitution in TRACE_EVENT_FN 

TRACE_EVENT_FN relays on TRACE_EVENT by reprocessing its parameters
into the ftrace events CPP macro. This leads to a double substitution
in some cases.

For example, a bad consequence is a format always prefixed by
"%s, %s\n" for every TRACE_EVENT_FN based events.

Eg:
	cat /debug/tracing/events/syscalls/sys_enter/format
	[...]
	print fmt: "%s, %s\n", "\"NR %ld (%lx, %lx, %lx, %lx, %lx, %lx)\"",\
	"REC->id, REC->args[0], REC->args[1], REC->args[2], REC->args[3],\
	REC->args[4], REC->args[5]"

This creates a failure in post-processing tools such as perf trace or
trace-cmd.

Then drop this double substitution and replace it by a new __cpparg()
macro that relays CPP arguments containing commas.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Josh Stone <jistone@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
LKML-Reference: <1251413406-6704-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2009-08-28 00:50:06 +02:00 committed by Ingo Molnar
parent 66c6e29f24
commit 0dd7b74787
1 changed files with 7 additions and 6 deletions
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13
include/trace/ftrace.h
View File

@ -45,14 +45,15 @@
}; \
static struct ftrace_event_call event_##name
#undef __cpparg
#define __cpparg(arg...) arg
/* Callbacks are meaningless to ftrace. */
#undef TRACE_EVENT_FN
#define TRACE_EVENT_FN(name, proto, args, tstruct, \
assign, print, reg, unreg) \
TRACE_EVENT(name, TP_PROTO(proto), TP_ARGS(args), \
TP_STRUCT__entry(tstruct), \
TP_fast_assign(assign), \
TP_printk(print))
#define TRACE_EVENT_FN(name, proto, args, tstruct, \
assign, print, reg, unreg) \
TRACE_EVENT(name, __cpparg(proto), __cpparg(args), \
__cpparg(tstruct), __cpparg(assign), __cpparg(print)) \
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)