markers: add an if(0) to __mark_check_format()
Wrap __mark_check_format() into an if(0) to make sure that parameters such as
trace_mark(mm_page_alloc, "order %u pfn %lu", order, page?page_to_pfn(page):0);
(where page_to_pfn() has side-effects) won't generate code because of the
__mark_check_format().
Thanks to Jan Kiszka for reporting this.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/marker.h b/include/linux/marker.h
index 5df879d..430f6ad 100644
--- a/include/linux/marker.h
+++ b/include/linux/marker.h
@@ -104,10 +104,16 @@
#define MARK_NOARGS " "
/* To be used for string format validity checking with gcc */
-static inline void __printf(1, 2) __mark_check_format(const char *fmt, ...)
+static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
{
}
+#define __mark_check_format(format, args...) \
+ do { \
+ if (0) \
+ ___mark_check_format(format, ## args); \
+ } while (0)
+
extern marker_probe_func __mark_empty_function;
extern void marker_probe_cb(const struct marker *mdata,