tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 8ab774587903771821b59471cc723bba6d893942 commit: ccbb5239d495923cb24b84a73eb814626c5bfa57 sh: remove -Werror from Makefiles date: 1 year, 3 months ago config: sh-randconfig-r031-20211116 (attached as .config) compiler: sh4-linux-gcc (GCC) 11.2.0 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout ccbb5239d495923cb24b84a73eb814626c5bfa57 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sh If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 565 | int is_dsp_inst(struct pt_regs *regs) | ^~~~~~~~~~~ arch/sh/kernel/traps_32.c:729:6: warning: no previous prototype for 'per_cpu_trap_init' [-Wmissing-prototypes] 729 | void per_cpu_trap_init(void) | ^~~~~~~~~~~~~~~~~ vim +/is_dsp_inst +565 arch/sh/kernel/traps_32.c ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 560 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 561 #ifdef CONFIG_SH_DSP ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 562 /* ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 563 * SH-DSP support gerg(a)snapgear.com. ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 564 */ ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 @565 int is_dsp_inst(struct pt_regs *regs) ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 566 { 882c12c4e1a95e arch/sh/kernel/traps.c Paul Mundt 2007-05-14 567 unsigned short inst = 0; ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 568 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 569 /* ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 570 * Safe guard if DSP mode is already enabled or we're lacking ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 571 * the DSP altogether. ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 572 */ 11c1965687b0a4 arch/sh/kernel/traps.c Paul Mundt 2006-12-25 573 if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP)) ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 574 return 0; ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 575 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 576 get_user(inst, ((unsigned short *) regs->pc)); ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 577 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 578 inst &= 0xf000; ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 579 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 580 /* Check for any type of DSP or support instruction */ ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 581 if ((inst == 0xf000) || (inst == 0x4000)) ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 582 return 1; ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 583 ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 584 return 0; ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 585 } ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 586 #else ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 587 #define is_dsp_inst(regs) (0) ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 588 #endif /* CONFIG_SH_DSP */ ^1da177e4c3f41 arch/sh/kernel/traps.c Linus Torvalds 2005-04-16 589 :::::: The code at line 565 was first introduced by commit :::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2 :::::: TO: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; :::::: CC: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org