tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   2c85ebc57b3e1817b6ce1a6b703928e113a90442
commit: 582f95835a8fc812cd38dce0447fe9386b78913e arm64: entry: convert el0_sync to C
date:   1 year, 2 months ago
config: arm64-randconfig-r021-20201214 (attached as .config)
compiler: aarch64-linux-gcc (GCC) 9.3.0
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/?id=582f95835a8fc812cd38dce0447fe9386b78913e
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 582f95835a8fc812cd38dce0447fe9386b78913e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 

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

All warnings (new ones prefixed by >>):

   arch/arm64/kernel/entry-common.c:68:25: warning: no previous prototype for 'el1_sync_handler' [-Wmissing-prototypes]
      68 | asmlinkage void notrace el1_sync_handler(struct pt_regs *regs)
         |                         ^~~~~~~~~~~~~~~~
>> arch/arm64/kernel/entry-common.c:210:25: warning: no previous prototype for 'el0_sync_handler' [-Wmissing-prototypes]
     210 | asmlinkage void notrace el0_sync_handler(struct pt_regs *regs)
         |                         ^~~~~~~~~~~~~~~~
>> arch/arm64/kernel/entry-common.c:276:25: warning: no previous prototype for 'el0_sync_compat_handler' [-Wmissing-prototypes]
     276 | asmlinkage void notrace el0_sync_compat_handler(struct pt_regs *regs)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~

vim +/el0_sync_handler +210 arch/arm64/kernel/entry-common.c

   209	
 > 210	asmlinkage void notrace el0_sync_handler(struct pt_regs *regs)
   211	{
   212		unsigned long esr = read_sysreg(esr_el1);
   213	
   214		switch (ESR_ELx_EC(esr)) {
   215		case ESR_ELx_EC_SVC64:
   216			el0_svc(regs);
   217			break;
   218		case ESR_ELx_EC_DABT_LOW:
   219			el0_da(regs, esr);
   220			break;
   221		case ESR_ELx_EC_IABT_LOW:
   222			el0_ia(regs, esr);
   223			break;
   224		case ESR_ELx_EC_FP_ASIMD:
   225			el0_fpsimd_acc(regs, esr);
   226			break;
   227		case ESR_ELx_EC_SVE:
   228			el0_sve_acc(regs, esr);
   229			break;
   230		case ESR_ELx_EC_FP_EXC64:
   231			el0_fpsimd_exc(regs, esr);
   232			break;
   233		case ESR_ELx_EC_SYS64:
   234		case ESR_ELx_EC_WFx:
   235			el0_sys(regs, esr);
   236			break;
   237		case ESR_ELx_EC_SP_ALIGN:
   238			el0_sp(regs, esr);
   239			break;
   240		case ESR_ELx_EC_PC_ALIGN:
   241			el0_pc(regs, esr);
   242			break;
   243		case ESR_ELx_EC_UNKNOWN:
   244			el0_undef(regs);
   245			break;
   246		case ESR_ELx_EC_BREAKPT_LOW:
   247		case ESR_ELx_EC_SOFTSTP_LOW:
   248		case ESR_ELx_EC_WATCHPT_LOW:
   249		case ESR_ELx_EC_BRK64:
   250			el0_dbg(regs, esr);
   251			break;
   252		default:
   253			el0_inv(regs, esr);
   254		}
   255	}
   256	NOKPROBE_SYMBOL(el0_sync_handler);
   257	
   258	#ifdef CONFIG_COMPAT
   259	static void notrace el0_cp15(struct pt_regs *regs, unsigned long esr)
   260	{
   261		user_exit_irqoff();
   262		local_daif_restore(DAIF_PROCCTX);
   263		do_cp15instr(esr, regs);
   264	}
   265	NOKPROBE_SYMBOL(el0_cp15);
   266	
   267	static void notrace el0_svc_compat(struct pt_regs *regs)
   268	{
   269		if (system_uses_irq_prio_masking())
   270			gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
   271	
   272		el0_svc_compat_handler(regs);
   273	}
   274	NOKPROBE_SYMBOL(el0_svc_compat);
   275	
 > 276	asmlinkage void notrace el0_sync_compat_handler(struct pt_regs *regs)

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