[gustavoars-linux:testing/clang/fallthrough 1/2] arch/mips/kernel/uprobes.c:176:2: warning: unannotated fall-through between switch labels

From: kernel test robot
Date: Thu Nov 12 2020 - 19:44:11 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git testing/clang/fallthrough
head: d16b79b21df4c592423c69b59b31a6a9ec6b0fd6
commit: 09b39705b81484347c7561a5528e08b2a70e67a6 [1/2] Revert "kbuild: Do not enable -Wimplicit-fallthrough for clang for now"
config: mips-randconfig-r016-20201111 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a7b65741441556d295079fc4f2391d99fd1c1111)
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 mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=09b39705b81484347c7561a5528e08b2a70e67a6
git remote add gustavoars-linux https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git
git fetch --no-tags gustavoars-linux testing/clang/fallthrough
git checkout 09b39705b81484347c7561a5528e08b2a70e67a6
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips

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

All warnings (new ones prefixed by >>):

>> arch/mips/kernel/uprobes.c:176:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
default:
^
arch/mips/kernel/uprobes.c:176:2: note: insert 'break;' to avoid fall-through
default:
^
break;
1 warning generated.

vim +176 arch/mips/kernel/uprobes.c

40e084a506eba78 Ralf Baechle 2015-07-29 153
40e084a506eba78 Ralf Baechle 2015-07-29 154 int arch_uprobe_exception_notify(struct notifier_block *self,
40e084a506eba78 Ralf Baechle 2015-07-29 155 unsigned long val, void *data)
40e084a506eba78 Ralf Baechle 2015-07-29 156 {
40e084a506eba78 Ralf Baechle 2015-07-29 157 struct die_args *args = data;
40e084a506eba78 Ralf Baechle 2015-07-29 158 struct pt_regs *regs = args->regs;
40e084a506eba78 Ralf Baechle 2015-07-29 159
40e084a506eba78 Ralf Baechle 2015-07-29 160 /* regs == NULL is a kernel bug */
40e084a506eba78 Ralf Baechle 2015-07-29 161 if (WARN_ON(!regs))
40e084a506eba78 Ralf Baechle 2015-07-29 162 return NOTIFY_DONE;
40e084a506eba78 Ralf Baechle 2015-07-29 163
40e084a506eba78 Ralf Baechle 2015-07-29 164 /* We are only interested in userspace traps */
40e084a506eba78 Ralf Baechle 2015-07-29 165 if (!user_mode(regs))
40e084a506eba78 Ralf Baechle 2015-07-29 166 return NOTIFY_DONE;
40e084a506eba78 Ralf Baechle 2015-07-29 167
40e084a506eba78 Ralf Baechle 2015-07-29 168 switch (val) {
2809328f6ef2139 Marcin Nowakowski 2016-08-11 169 case DIE_UPROBE:
40e084a506eba78 Ralf Baechle 2015-07-29 170 if (uprobe_pre_sstep_notifier(regs))
40e084a506eba78 Ralf Baechle 2015-07-29 171 return NOTIFY_STOP;
40e084a506eba78 Ralf Baechle 2015-07-29 172 break;
40e084a506eba78 Ralf Baechle 2015-07-29 173 case DIE_UPROBE_XOL:
40e084a506eba78 Ralf Baechle 2015-07-29 174 if (uprobe_post_sstep_notifier(regs))
40e084a506eba78 Ralf Baechle 2015-07-29 175 return NOTIFY_STOP;
40e084a506eba78 Ralf Baechle 2015-07-29 @176 default:
40e084a506eba78 Ralf Baechle 2015-07-29 177 break;
40e084a506eba78 Ralf Baechle 2015-07-29 178 }
40e084a506eba78 Ralf Baechle 2015-07-29 179
40e084a506eba78 Ralf Baechle 2015-07-29 180 return 0;
40e084a506eba78 Ralf Baechle 2015-07-29 181 }
40e084a506eba78 Ralf Baechle 2015-07-29 182

:::::: The code at line 176 was first introduced by commit
:::::: 40e084a506eba78310cd5e8ab700fd1226c6130a MIPS: Add uprobes support.

:::::: TO: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
:::::: CC: Ralf Baechle <ralf@xxxxxxxxxxxxxx>

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

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