[ammarfaizi2-block:rostedt/linux-trace/ftrace/core 24/32] kernel/trace/trace_events_trigger.c:1009:26: warning: variable 'trigger_ops' is uninitialized when used here

From: kernel test robot
Date: Sun Jan 09 2022 - 03:32:40 EST

tree: https://github.com/ammarfaizi2/linux-block rostedt/linux-trace/ftrace/core
head: 00a2223605e07cff7df94f5eb49ef5e281dada59
commit: 52f2994bd006dcc3ffb94fd3efa4494513b82646 [24/32] tracing: Have existing event_command.parse() implementations use helpers
config: arm-randconfig-r032-20220109 (https://download.01.org/0day-ci/archive/20220109/202201091641.idUaU4Jg-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f3a344d2125fa37e59bae1b0874442c650a19607)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://github.com/ammarfaizi2/linux-block/commit/52f2994bd006dcc3ffb94fd3efa4494513b82646
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block rostedt/linux-trace/ftrace/core
git checkout 52f2994bd006dcc3ffb94fd3efa4494513b82646
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash kernel/trace/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> kernel/trace/trace_events_trigger.c:1009:26: warning: variable 'trigger_ops' is uninitialized when used here [-Wuninitialized]
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
^~~~~~~~~~~
kernel/trace/trace_events_trigger.c:992:39: note: initialize the variable 'trigger_ops' to silence this warning
struct event_trigger_ops *trigger_ops;
^
= NULL
1 warning generated.
--
>> kernel/trace/trace_events_hist.c:6253:26: warning: variable 'trigger_ops' is uninitialized when used here [-Wuninitialized]
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
^~~~~~~~~~~
kernel/trace/trace_events_hist.c:6158:39: note: initialize the variable 'trigger_ops' to silence this warning
struct event_trigger_ops *trigger_ops;
^
= NULL
1 warning generated.


vim +/trigger_ops +1009 kernel/trace/trace_events_trigger.c

f5bcc5c959c0d4 Tom Zanussi 2021-12-14 965
f5bcc5c959c0d4 Tom Zanussi 2021-12-14 966 /*
f5bcc5c959c0d4 Tom Zanussi 2021-12-14 967 * End event trigger parsing helper functions.
f5bcc5c959c0d4 Tom Zanussi 2021-12-14 968 */
f5bcc5c959c0d4 Tom Zanussi 2021-12-14 969
2a2df321158817 Tom Zanussi 2013-10-24 970 /**
4dfe5dff80a4a8 Tom Zanussi 2021-12-14 971 * event_trigger_parse - Generic event_command @parse implementation
2a2df321158817 Tom Zanussi 2013-10-24 972 * @cmd_ops: The command ops, used for trigger registration
7f1d2f8210195c Steven Rostedt (Red Hat 2015-05-05 973) * @file: The trace_event_file associated with the event
2a2df321158817 Tom Zanussi 2013-10-24 974 * @glob: The raw string used to register the trigger
2a2df321158817 Tom Zanussi 2013-10-24 975 * @cmd: The cmd portion of the string used to register the trigger
52f2994bd006dc Tom Zanussi 2021-12-14 976 * @param_and_filter: The param and filter portion of the string used to register the trigger
2a2df321158817 Tom Zanussi 2013-10-24 977 *
2a2df321158817 Tom Zanussi 2013-10-24 978 * Common implementation for event command parsing and trigger
2a2df321158817 Tom Zanussi 2013-10-24 979 * instantiation.
2a2df321158817 Tom Zanussi 2013-10-24 980 *
4dfe5dff80a4a8 Tom Zanussi 2021-12-14 981 * Usually used directly as the @parse method in event command
2a2df321158817 Tom Zanussi 2013-10-24 982 * implementations.
2a2df321158817 Tom Zanussi 2013-10-24 983 *
2a2df321158817 Tom Zanussi 2013-10-24 984 * Return: 0 on success, errno otherwise
2a2df321158817 Tom Zanussi 2013-10-24 985 */
2a2df321158817 Tom Zanussi 2013-10-24 986 static int
4dfe5dff80a4a8 Tom Zanussi 2021-12-14 987 event_trigger_parse(struct event_command *cmd_ops,
7f1d2f8210195c Steven Rostedt (Red Hat 2015-05-05 988) struct trace_event_file *file,
52f2994bd006dc Tom Zanussi 2021-12-14 989 char *glob, char *cmd, char *param_and_filter)
2a2df321158817 Tom Zanussi 2013-10-24 990 {
2a2df321158817 Tom Zanussi 2013-10-24 991 struct event_trigger_data *trigger_data;
2a2df321158817 Tom Zanussi 2013-10-24 992 struct event_trigger_ops *trigger_ops;
52f2994bd006dc Tom Zanussi 2021-12-14 993 char *param, *filter;
52f2994bd006dc Tom Zanussi 2021-12-14 994 bool remove;
2a2df321158817 Tom Zanussi 2013-10-24 995 int ret;
2a2df321158817 Tom Zanussi 2013-10-24 996
52f2994bd006dc Tom Zanussi 2021-12-14 997 remove = event_trigger_check_remove(glob);
2a2df321158817 Tom Zanussi 2013-10-24 998
52f2994bd006dc Tom Zanussi 2021-12-14 999 ret = event_trigger_separate_filter(param_and_filter, &param, &filter, false);
52f2994bd006dc Tom Zanussi 2021-12-14 1000 if (ret)
52f2994bd006dc Tom Zanussi 2021-12-14 1001 return ret;
2a2df321158817 Tom Zanussi 2013-10-24 1002
2a2df321158817 Tom Zanussi 2013-10-24 1003 ret = -ENOMEM;
52f2994bd006dc Tom Zanussi 2021-12-14 1004 trigger_data = event_trigger_alloc(cmd_ops, cmd, param, file);
2a2df321158817 Tom Zanussi 2013-10-24 1005 if (!trigger_data)
2a2df321158817 Tom Zanussi 2013-10-24 1006 goto out;
2a2df321158817 Tom Zanussi 2013-10-24 1007
52f2994bd006dc Tom Zanussi 2021-12-14 1008 if (remove) {
2a2df321158817 Tom Zanussi 2013-10-24 @1009 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
2a2df321158817 Tom Zanussi 2013-10-24 1010 kfree(trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1011 ret = 0;
2a2df321158817 Tom Zanussi 2013-10-24 1012 goto out;
2a2df321158817 Tom Zanussi 2013-10-24 1013 }
2a2df321158817 Tom Zanussi 2013-10-24 1014
52f2994bd006dc Tom Zanussi 2021-12-14 1015 ret = event_trigger_parse_num(param, trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1016 if (ret)
2a2df321158817 Tom Zanussi 2013-10-24 1017 goto out_free;
2a2df321158817 Tom Zanussi 2013-10-24 1018
52f2994bd006dc Tom Zanussi 2021-12-14 1019 ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1020 if (ret < 0)
2a2df321158817 Tom Zanussi 2013-10-24 1021 goto out_free;
2a2df321158817 Tom Zanussi 2013-10-24 1022
1863c387259b62 Steven Rostedt (VMware 2018-07-24 1023) /* Up the trigger_data count to make sure reg doesn't free it on failure */
1863c387259b62 Steven Rostedt (VMware 2018-07-24 1024) event_trigger_init(trigger_ops, trigger_data);
52f2994bd006dc Tom Zanussi 2021-12-14 1025
52f2994bd006dc Tom Zanussi 2021-12-14 1026 ret = event_trigger_register(cmd_ops, file, glob, cmd, param, trigger_data, NULL);
52f2994bd006dc Tom Zanussi 2021-12-14 1027 if (ret)
52f2994bd006dc Tom Zanussi 2021-12-14 1028 goto out_free;
1863c387259b62 Steven Rostedt (VMware 2018-07-24 1029)
1863c387259b62 Steven Rostedt (VMware 2018-07-24 1030) /* Down the counter of trigger_data or free it if not used anymore */
1863c387259b62 Steven Rostedt (VMware 2018-07-24 1031) event_trigger_free(trigger_ops, trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1032 out:
2a2df321158817 Tom Zanussi 2013-10-24 1033 return ret;
2a2df321158817 Tom Zanussi 2013-10-24 1034 out_free:
52f2994bd006dc Tom Zanussi 2021-12-14 1035 event_trigger_reset_filter(cmd_ops, trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1036 kfree(trigger_data);
2a2df321158817 Tom Zanussi 2013-10-24 1037 goto out;
2a2df321158817 Tom Zanussi 2013-10-24 1038 }
2a2df321158817 Tom Zanussi 2013-10-24 1039

:::::: The code at line 1009 was first introduced by commit
:::::: 2a2df321158817811c5dc206dce808e0aa9f6d89 tracing: Add 'traceon' and 'traceoff' event trigger commands

:::::: TO: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
:::::: CC: Steven Rostedt <rostedt@xxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx