Re: [PATCH 1/5] tracing: Fix checking of freed trace_event_file for hist files

[Steven Rostedt]

On Wed, 11 Feb 2026 01:40:48 +0800
kernel test robot <lkp@xxxxxxxxx> wrote:

> url:    https://github.com/intel-lab-lkp/linux/commits/Petr-Pavlu/tracing-Fix-checking-of-freed-trace_event_file-for-hist-files/20260210-194023
> base:   05f7e89ab9731565d8a62e3b5d1ec206485eeb0b
> patch link:    https://lore.kernel.org/r/20260210113427.1068932-2-petr.pavlu%40suse.com
> patch subject: [PATCH 1/5] tracing: Fix checking of freed trace_event_file for hist files
> config: x86_64-buildonly-randconfig-004-20260210 (https://download.01.org/0day-ci/archive/20260211/202602110125.71oIfNm0-lkp@xxxxxxxxx/config)

CONFIG_FTRACE is not set, and histograms have this as a dependency.

> compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260211/202602110125.71oIfNm0-lkp@xxxxxxxxx/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602110125.71oIfNm0-lkp@xxxxxxxxx/
> 
> All errors (new ones prefixed by >>):
> 
>    kernel/trace/trace_events.c: In function 'remove_event_file_dir':
> >> kernel/trace/trace_events.c:1300:9: error: implicit declaration of function 'hist_poll_wakeup' [-Wimplicit-function-declaration]  
>     1300 |         hist_poll_wakeup();
>          |         ^~~~~~~~~~~~~~~~
> 

This needs:

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 0a2b8229b999..8c627524c1d4 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -683,6 +683,8 @@ static inline void hist_poll_wakeup(void)
 
 #define hist_poll_wait(file, wait)	\
 	poll_wait(file, &hist_poll_wq, wait)
+#else
+# define hist_poll_wait(file, wait) do{ } while (0)
 #endif
 
 #define __TRACE_EVENT_FLAGS(name, value)				\


-- Steve