[jolsa-perf:bpf/tracing_multi_new_2 14/21] kernel/bpf/trampoline.c:1075:16: warning: variable 'ip' set but not used

From: kernel test robot
Date: Sun Aug 07 2022 - 00:41:27 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/tracing_multi_new_2
head: c0620f064b5146578de80c7bb00febc697cc4890
commit: 4d3060dcb11c6c79779105d68c1fd8e0efdbef5a [14/21] bpf: Add support to attach multi trampolines
config: riscv-randconfig-r042-20220804 (https://download.01.org/0day-ci/archive/20220807/202208071225.24zEKaj6-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 26dd42705c2af0b8f6e5d6cdb32c9bd5ed9524eb)
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 riscv cross compiling tool for clang build
# apt-get install binutils-riscv-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/commit/?id=4d3060dcb11c6c79779105d68c1fd8e0efdbef5a
git remote add jolsa-perf https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
git fetch --no-tags jolsa-perf bpf/tracing_multi_new_2
git checkout 4d3060dcb11c6c79779105d68c1fd8e0efdbef5a
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash kernel/bpf/

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

All warnings (new ones prefixed by >>):

>> kernel/bpf/trampoline.c:1075:16: warning: variable 'ip' set but not used [-Wunused-but-set-variable]
unsigned long ip, image_new, image_old;
^
>> kernel/bpf/trampoline.c:1074:9: warning: variable 'rollback_cnt' set but not used [-Wunused-but-set-variable]
int i, rollback_cnt = 0, err = -EINVAL;
^
2 warnings generated.


vim +/ip +1075 kernel/bpf/trampoline.c

1070
1071 static int bpf_tramp_update_set(struct list_head *upd)
1072 {
1073 struct bpf_trampoline *tr, *trm = NULL;
> 1074 int i, rollback_cnt = 0, err = -EINVAL;
> 1075 unsigned long ip, image_new, image_old;
1076
1077 list_for_each_entry(tr, upd, update.list) {
1078 if (tr->multi.id_multi) {
1079 trm = tr;
1080 continue;
1081 }
1082
1083 ip = (unsigned long) tr->func.addr;
1084 image_new = tr->update.im ? (unsigned long) tr->update.im->image : 0;
1085 image_old = tr->cur_image ? (unsigned long) tr->cur_image->image : 0;
1086
1087 switch (tr->update.action) {
1088 case BPF_TRAMP_UPDATE_REG:
1089 err = register_ftrace_direct_multi(tr->fops, image_new);
1090 break;
1091 case BPF_TRAMP_UPDATE_MODIFY:
1092 err = modify_ftrace_direct_multi(tr->fops, image_new);
1093 break;
1094 case BPF_TRAMP_UPDATE_UNREG:
1095 err = unregister_ftrace_direct_multi(tr->fops, image_old);
1096 break;
1097 }
1098 if (err)
1099 goto out_rollback;
1100 rollback_cnt++;
1101 }
1102
1103 if (!trm)
1104 return 0;
1105
1106 if (trm->update.action == BPF_TRAMP_UPDATE_REG) {
1107 for (i = 0; i < trm->multi.id_multi->cnt; i++) {
1108 ip = (unsigned long) trm->multi.id_multi->addr[i];
1109 err = ftrace_set_filter_ip(trm->fops, ip, 0, 0);
1110 if (err)
1111 goto out_rollback;
1112 }
1113 }
1114
1115 image_new = trm->update.im ? (unsigned long) trm->update.im->image : 0;
1116 image_old = trm->cur_image ? (unsigned long) trm->cur_image->image : 0;
1117
1118 switch (trm->update.action) {
1119 case BPF_TRAMP_UPDATE_REG:
1120 err = register_ftrace_direct_multi(trm->fops, image_new);
1121 break;
1122 case BPF_TRAMP_UPDATE_MODIFY:
1123 err = modify_ftrace_direct_multi(trm->fops, image_new);
1124 break;
1125 case BPF_TRAMP_UPDATE_UNREG:
1126 err = unregister_ftrace_direct_multi(trm->fops, image_old);
1127 break;
1128 default:
1129 break;
1130 }
1131
1132 if (!err)
1133 return 0;
1134
1135 out_rollback:
1136 list_for_each_entry(tr, upd, update.list) {
1137 if (tr->multi.id_multi)
1138 continue;
1139
1140 ip = (unsigned long) tr->func.addr;
1141 image_new = tr->update.im ? (unsigned long) tr->update.im->image : 0;
1142 image_old = tr->cur_image ? (unsigned long) tr->cur_image->image : 0;
1143
1144 switch (tr->update.action) {
1145 case BPF_TRAMP_UPDATE_REG:
1146 err = unregister_ftrace_direct_multi(tr->fops, image_new);
1147 break;
1148 case BPF_TRAMP_UPDATE_MODIFY:
1149 err = modify_ftrace_direct_multi(tr->fops, image_old);
1150 break;
1151 case BPF_TRAMP_UPDATE_UNREG:
1152 err = register_ftrace_direct_multi(tr->fops, image_old);
1153 break;
1154 }
1155 i++;
1156 }
1157
1158 return err;
1159 }
1160

--
0-DAY CI Kernel Test Service
https://01.org/lkp