Hi Peter,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on arm-perf/for-next/perf]
[also build test WARNING on linus/master v5.7-rc6]
[cannot apply to arm64/for-next/core next-20200519]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Peter-Collingbourne/arm64-Expose-FAR_EL1-tag-bits-in-sigcontext/20200521-103345
base:   https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git for-next/perf
config: arm64-randconfig-r005-20200520 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <redacted>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

quoted

arch/arm64/kernel/traps.c:283:55: warning: format specifies type 'unsigned int' but the argument has type 'unsigned long' [-Wformat]

WARN(1, "ESR 0x%x is not DABT or IABT from EL0n", esr);
~~                                  ^~~
%lx
include/asm-generic/bug.h:124:29: note: expanded from macro 'WARN'
__WARN_printf(TAINT_WARN, format);                                                                   ^~~~~~
include/asm-generic/bug.h:92:17: note: expanded from macro '__WARN_printf'
__warn_printk(arg);                                                                      ^~~
arch/arm64/kernel/traps.c:826:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_UNKNOWN]            = "Unknown/Uncategorized",
^~~~~~~~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:827:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_WFx]                = "WFI/WFE",
^~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:828:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP15_32]            = "CP15 MCR/MRC",
^~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:829:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP15_64]            = "CP15 MCRR/MRRC",
^~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:830:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP14_MR]            = "CP14 MCR/MRC",
^~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:831:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP14_LS]            = "CP14 LDC/STC",
^~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:832:27: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_FP_ASIMD]           = "ASIMD",
^~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:833:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP10_ID]            = "CP10 MRC/VMRS",
^~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:834:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_PAC]                = "PAC",
^~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:835:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_CP14_64]            = "CP14 MCRR/MRRC",
^~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:836:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_ILL]                = "PSTATE.IL",
^~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:837:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_SVC32]              = "SVC (AArch32)",
^~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:838:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_HVC32]              = "HVC (AArch32)",
^~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:839:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_SMC32]              = "SMC (AArch32)",
^~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:840:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
[ESR_ELx_EC_SVC64]              = "SVC (AArch64)",
^~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:825:28: note: previous initialization is here
[0 ... ESR_ELx_EC_MAX]          = "UNRECOGNIZED EC",
^~~~~~~~~~~~~~~~~
arch/arm64/kernel/traps.c:841:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]

vim +283 arch/arm64/kernel/traps.c

   236	
   237	static unsigned long esr_to_error_code(unsigned long esr, unsigned long far)
   238	{
   239		/*
   240		 * If the faulting address is in the kernel, we must sanitize the ESR.
   241		 * From userspace's point of view, kernel-only mappings don't exist
   242		 * at all, so we report them as level 0 translation faults.
   243		 * (This is not quite the way that "no mapping there at all" behaves:
   244		 * an alignment fault not caused by the memory type would take
   245		 * precedence over translation fault for a real access to empty
   246		 * space. Unfortunately we can't easily distinguish "alignment fault
   247		 * not caused by memory type" from "alignment fault caused by memory
   248		 * type", so we ignore this wrinkle and just return the translation
   249		 * fault.)
   250		 */
   251		if (!is_ttbr0_addr(untagged_addr(far))) {
   252			switch (ESR_ELx_EC(esr)) {
   253			case ESR_ELx_EC_DABT_LOW:
   254				/*
   255				 * These bits provide only information about the
   256				 * faulting instruction, which userspace knows already.
   257				 * We explicitly clear bits which are architecturally
   258				 * RES0 in case they are given meanings in future.
   259				 * We always report the ESR as if the fault was taken
   260				 * to EL1 and so ISV and the bits in ISS[23:14] are
   261				 * clear. (In fact it always will be a fault to EL1.)
   262				 */
   263				esr &= ESR_ELx_EC_MASK | ESR_ELx_IL |
   264					ESR_ELx_CM | ESR_ELx_WNR;
   265				esr |= ESR_ELx_FSC_FAULT;
   266				break;
   267			case ESR_ELx_EC_IABT_LOW:
   268				/*
   269				 * Claim a level 0 translation fault.
   270				 * All other bits are architecturally RES0 for faults
   271				 * reported with that DFSC value, so we clear them.
   272				 */
   273				esr &= ESR_ELx_EC_MASK | ESR_ELx_IL;
   274				esr |= ESR_ELx_FSC_FAULT;
   275				break;
   276			default:
   277				/*
   278				 * This should never happen (entry.S only brings us
   279				 * into this code for insn and data aborts from a lower
   280				 * exception level). Fail safe by not providing an ESR
   281				 * context record at all.
   282				 */
 > 283				WARN(1, "ESR 0x%x is not DABT or IABT from EL0\n", esr);
   284				esr = 0;
   285				break;
   286			}
   287		}
   288	
   289		if (is_compat_task()) {
   290			/* Use the compat FSR WnR */
   291			return !!(esr & ESR_ELx_WNR) << FSR_WRITE_SHIFT;
   292		}
   293	
   294		return esr;
   295	}
   296	

---
0-DAY CI Kernel Test Service, Intel Corporation
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