On Tue, Feb 23, 2021 at 11:56:29AM -0800, Nick Desaulniers wrote:

On Mon, Feb 15, 2021 at 2:49 AM kernel test robot lkp@intel.com wrote:

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Hi Nick,

First bad commit (maybe != root cause):

tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y head: 642aa3284e09f63bf1d4832798dd787b4320ca64 commit: f05f667f8764f9ec834ca3e412ed7f5a20dea3bf [2231/4843] lib/string.c: implement stpcpy config: x86_64-randconfig-a005-20210215 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/c... git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git fetch --no-tags linux-stable-rc linux-5.4.y git checkout f05f667f8764f9ec834ca3e412ed7f5a20dea3bf # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot lkp@intel.com

All errors (new ones prefixed by >>):

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ERROR: "__memcat_p" [drivers/hwtracing/stm/stm_core.ko] undefined!

This error is unrelated to the referenced commit, but we did fix this error finally in 5.7: https://github.com/ClangBuiltLinux/linux/issues/515. This is not a regression, but something that never worked with LLD until 5.7.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... looks like the commit of interest, though I seem to have left a comment implying there were dependencies: https://github.com/ClangBuiltLinux/linux/issues/515#issuecomment-612999929 (I no longer recall what they were).

Some other commits in tree reference that bug from the issue tracker. https://github.com/0day-ci/linux/commit/0cf9baa2dbb8ca29f30ac8a1afb69de51f22... https://github.com/0day-ci/linux/commit/565508bb949dd72638b52522fb6ac6ec04ec... https://github.com/0day-ci/linux/commit/0d0537aa772566473bd5310be3874060cbff...

Not sure whether all 4 of the above worth backporting to 4.4.y? Thoughts? (Perhaps these would allow us to add x86_64 allmodconfig CI coverage with LLD for 4.4.y)

If someone wants to backport them to 4.4.y, please feel free to submit it!

thanks,

greg k-h