On Thu, Aug 05, 2021 at 04:23:40PM -0700, Nick Desaulniers wrote: > On Thu, Aug 5, 2021 at 1:24 PM kernel test robot <lkp@xxxxxxxxx> wrote: > > > > Hi Nick, > > > > First bad commit (maybe != root cause): > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.19.y > > head: 7457eed4b647560ae1b1800c295efc5f1db22e4b > > commit: 7c29fd831799d09474dfdae556207b7102647a45 [1181/1498] lib/string.c: implement stpcpy > > config: x86_64-randconfig-r024-20210805 (attached as .config) > > compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 31a71a393f65d9e07b5b0756fef9dd16690950ee) > > 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 > > # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=7c29fd831799d09474dfdae556207b7102647a45 > > 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-4.19.y > > git checkout 7c29fd831799d09474dfdae556207b7102647a45 > > # 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@xxxxxxxxx> > > > > All errors (new ones prefixed by >>): > > > > >> ERROR: "__compiletime_assert_491" [drivers/gpu/drm/i915/i915.ko] undefined! > > ^ I'm actively trying to improve these diagnostics in LLVM at the > moment. Hopefully that will make this report clearer! > https://reviews.llvm.org/D106030 It does help :) drivers/gpu/drm/i915/intel_engine_cs.c:466:2: error: call to '__compiletime_assert_491' declared with attribute error: BUILD_BUG_ON failed: (execlists_num_ports(execlists)) == 0 || (((execlists_num_ports(execlists)) & ((execlists_num_ports(execlists)) - 1)) != 0) BUILD_BUG_ON_NOT_POWER_OF_2(execlists_num_ports(execlists)); ^ include/linux/build_bug.h:21:2: note: expanded from macro 'BUILD_BUG_ON_NOT_POWER_OF_2' BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) ^ include/linux/build_bug.h:69:2: note: expanded from macro 'BUILD_BUG_ON' BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) ^ include/linux/build_bug.h:45:37: note: expanded from macro 'BUILD_BUG_ON_MSG' #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^ note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) include/linux/compiler.h:336:2: note: expanded from macro '_compiletime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^ include/linux/compiler.h:329:4: note: expanded from macro '__compiletime_assert' prefix ## suffix(); \ ^ <scratch space>:83:1: note: expanded from here __compiletime_assert_491 ^ 4 warnings and 1 error generated. As it turns out, this has come up before and it was fixed by commit 410ed5731a65 ("drm/i915: Ensure intel_engine_init_execlist() builds with Clang"). Greg and Sasha, could this be picked up for 4.19? Cheers, Nathan