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Message-ID: <202510161858.5hz4HLnc-lkp@intel.com>
Date: Thu, 16 Oct 2025 19:05:27 +0800
From: kernel test robot <lkp@...el.com>
To: Steven Rostedt <rostedt@...dmis.org>, linux-kernel@...r.kernel.org,
linux-trace-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Cc: oe-kbuild-all@...ts.linux.dev, Masami Hiramatsu <mhiramat@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Linux Memory Management List <linux-mm@...ck.org>,
Peter Zijlstra <peterz@...radead.org>,
Namhyung Kim <namhyung@...nel.org>,
Takaya Saeki <takayas@...gle.com>, Tom Zanussi <zanussi@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ian Rogers <irogers@...gle.com>,
Douglas Raillard <douglas.raillard@....com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Jiri Olsa <jolsa@...nel.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Ingo Molnar <mingo@...hat.com>
Subject: Re: [PATCH v3 03/13] perf: tracing: Simplify
perf_sysenter_enable/disable() with guards
Hi Steven,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.18-rc1 next-20251015]
[cannot apply to trace/for-next acme/perf/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Make-trace_user_fault_read-exposed-to-rest-of-tracing/20251016-014059
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20251015173548.540984239%40kernel.org
patch subject: [PATCH v3 03/13] perf: tracing: Simplify perf_sysenter_enable/disable() with guards
config: x86_64-randconfig-r073-20251016 (https://download.01.org/0day-ci/archive/20251016/202510161858.5hz4HLnc-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251016/202510161858.5hz4HLnc-lkp@intel.com/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@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510161858.5hz4HLnc-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/trace/trace_syscalls.c:1018:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
1018 | if (!sys_perf_refcount_enter) {
| ^~~~~~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_syscalls.c:1027:9: note: uninitialized use occurs here
1027 | return ret;
| ^~~
kernel/trace/trace_syscalls.c:1018:2: note: remove the 'if' if its condition is always true
1018 | if (!sys_perf_refcount_enter) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_syscalls.c:1012:9: note: initialize the variable 'ret' to silence this warning
1012 | int ret;
| ^
| = 0
kernel/trace/trace_syscalls.c:1123:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
1123 | if (!sys_perf_refcount_exit) {
| ^~~~~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_syscalls.c:1132:9: note: uninitialized use occurs here
1132 | return ret;
| ^~~
kernel/trace/trace_syscalls.c:1123:2: note: remove the 'if' if its condition is always true
1123 | if (!sys_perf_refcount_exit) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_syscalls.c:1117:9: note: initialize the variable 'ret' to silence this warning
1117 | int ret;
| ^
| = 0
2 warnings generated.
vim +1018 kernel/trace/trace_syscalls.c
1009
1010 static int perf_sysenter_enable(struct trace_event_call *call)
1011 {
1012 int ret;
1013 int num;
1014
1015 num = ((struct syscall_metadata *)call->data)->syscall_nr;
1016
1017 guard(mutex)(&syscall_trace_lock);
> 1018 if (!sys_perf_refcount_enter) {
1019 ret = register_trace_sys_enter(perf_syscall_enter, NULL);
1020 if (ret) {
1021 pr_info("event trace: Could not activate syscall entry trace point");
1022 return ret;
1023 }
1024 }
1025 set_bit(num, enabled_perf_enter_syscalls);
1026 sys_perf_refcount_enter++;
1027 return ret;
1028 }
1029
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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