Messages in this thread | | | Subject | Re: [kbuild-all] Re: arch/powerpc/kernel/signal_32.c:297:2: warning: Value stored to 'msr' is never read [clang-analyzer-deadcode.DeadStores] | From | Rong Chen <> | Date | Wed, 25 Aug 2021 16:48:23 +0800 |
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On 8/24/21 3:29 PM, Christophe Leroy wrote: > > > Le 24/08/2021 à 08:59, Chen, Rong A a écrit : >> >> >> On 8/23/2021 10:35 PM, Christophe Leroy wrote: >>> >>> >>> Le 23/08/2021 à 12:59, kernel test robot a écrit : >>>> tree: >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >>>> master >>>> head: e22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93 >>>> commit: ef75e73182949a94bde169a774de1b62ae21fbbc powerpc/signal32: >>>> Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version >>>> date: 9 months ago >>>> config: powerpc-randconfig-c003-20210821 (attached as .config) >>>> compiler: clang version 14.0.0 >>>> (https://github.com/llvm/llvm-project >>>> d9c5613e856cf2addfbf892fc4c1ce9ef9feceaa) >>>> 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 powerpc cross compiling tool for clang build >>>> # apt-get install binutils-powerpc-linux-gnu >>>> # >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ef75e73182949a94bde169a774de1b62ae21fbbc >>>> >>>> git remote add linus >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >>>> git fetch --no-tags linus master >>>> git checkout ef75e73182949a94bde169a774de1b62ae21fbbc >>>> # save the attached .config to linux build tree >>>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross >>>> ARCH=powerpc clang-analyzer >>>> >>>> If you fix the issue, kindly add following tag as appropriate >>>> Reported-by: kernel test robot <lkp@intel.com> >>>> >>>> >>>> clang-analyzer warnings: (new ones prefixed by >>) >>>> ^ >>>>>> arch/powerpc/kernel/signal_32.c:297:2: warning: Value stored to >>>>>> 'msr' is never read [clang-analyzer-deadcode.DeadStores] >>>> msr &= ~MSR_VSX; >>>> ^ ~~~~~~~~ >>>> arch/powerpc/kernel/signal_32.c:297:2: note: Value stored to >>>> 'msr' is never read >>>> msr &= ~MSR_VSX; >>>> ^ ~~~~~~~~ >>> >>> >>> This is wrong. >>> >>> msr is used at line 326: >>> >>> ef75e73182949a arch/powerpc/kernel/signal_32.c Christophe Leroy >>> 2020-08-18 326 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed); >> >> Hi Christophe, >> >> The usage is under CONFIG_VSX, the test config >> (powerpc-randconfig-c003-20210821) didn't enable it which triggered >> this warning. > > > No no, the 'unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed) ' > at line 326 is not under CONFIG_VSX as far as I can see. > > > Christophe
Hi Christophe,
It's my fault, I didn't see it correctly, and I have no idea why clang-analyzer reported it as a issue, we'll double check such warning next time.
Best Regards, Rong Chen
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