From: Jiri Slaby <jslaby@xxxxxxx> Subject: ratelimit: fix WARN_ON_RATELIMIT return value The macro is to be used similarly as WARN_ON as: if (WARN_ON_RATELIMIT(condition, state)) do_something(); One would expect only 'condition' to affect the 'if', but WARN_ON_RATELIMIT does internally only: WARN_ON((condition) && __ratelimit(state)) So the 'if' is affected by the ratelimiting state too. Fix this by returning 'condition' in any case. Note that nobody uses WARN_ON_RATELIMIT yet, so there is nothing to worry about. But I was about to use it and was a bit surprised. Link: http://lkml.kernel.org/r/20161215093224.23126-1-jslaby@xxxxxxx Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/ratelimit.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff -puN include/linux/ratelimit.h~ratelimit-fix-warn_on_ratelimit-return-value include/linux/ratelimit.h --- a/include/linux/ratelimit.h~ratelimit-fix-warn_on_ratelimit-return-value +++ a/include/linux/ratelimit.h @@ -77,8 +77,11 @@ extern int ___ratelimit(struct ratelimit #ifdef CONFIG_PRINTK -#define WARN_ON_RATELIMIT(condition, state) \ - WARN_ON((condition) && __ratelimit(state)) +#define WARN_ON_RATELIMIT(condition, state) ({ \ + bool __rtn_cond = !!(condition); \ + WARN_ON(__rtn_cond && __ratelimit(state)); \ + __rtn_cond; \ +}) #define WARN_RATELIMIT(condition, format, ...) \ ({ \ _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
