arch/arm64/kernel/proton-pack.c:558:13: warning: no previous prototype for function 'spectre_v4_patch_fw_mitigation_enable'

From: kernel test robot
Date: Mon Sep 27 2021 - 10:38:16 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 92477dd1faa650e50bd3bb35a6c0b8d09198cc35
commit: c28762070ca651fe7a981b8f31d972c9b7d2c386 arm64: Rewrite Spectre-v4 mitigation code
date: 12 months ago
config: arm64-randconfig-r016-20210927 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project dc6e8dfdfe7efecfda318d43a06fae18b40eb498)
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
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c28762070ca651fe7a981b8f31d972c9b7d2c386
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout c28762070ca651fe7a981b8f31d972c9b7d2c386
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm64

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

All warnings (new ones prefixed by >>):

arch/arm64/kernel/proton-pack.c:288:2: error: implicit declaration of function 'install_bp_hardening_cb' [-Werror,-Wimplicit-function-declaration]
install_bp_hardening_cb(cb);
^
arch/arm64/kernel/proton-pack.c:304:2: error: implicit declaration of function 'install_bp_hardening_cb' [-Werror,-Wimplicit-function-declaration]
install_bp_hardening_cb(qcom_link_stack_sanitisation);
^
>> arch/arm64/kernel/proton-pack.c:558:13: warning: no previous prototype for function 'spectre_v4_patch_fw_mitigation_enable' [-Wmissing-prototypes]
void __init spectre_v4_patch_fw_mitigation_enable(struct alt_instr *alt,
^
arch/arm64/kernel/proton-pack.c:558:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __init spectre_v4_patch_fw_mitigation_enable(struct alt_instr *alt,
^
static
>> arch/arm64/kernel/proton-pack.c:578:13: warning: no previous prototype for function 'spectre_v4_patch_fw_mitigation_conduit' [-Wmissing-prototypes]
void __init spectre_v4_patch_fw_mitigation_conduit(struct alt_instr *alt,
^
arch/arm64/kernel/proton-pack.c:578:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __init spectre_v4_patch_fw_mitigation_conduit(struct alt_instr *alt,
^
static
2 warnings and 2 errors generated.


vim +/spectre_v4_patch_fw_mitigation_enable +558 arch/arm64/kernel/proton-pack.c

553
554 /*
555 * Patch a branch over the Spectre-v4 mitigation code with a NOP so that
556 * we fallthrough and check whether firmware needs to be called on this CPU.
557 */
> 558 void __init spectre_v4_patch_fw_mitigation_enable(struct alt_instr *alt,
559 __le32 *origptr,
560 __le32 *updptr, int nr_inst)
561 {
562 BUG_ON(nr_inst != 1); /* Branch -> NOP */
563
564 if (spectre_v4_mitigations_off())
565 return;
566
567 if (cpus_have_final_cap(ARM64_SSBS))
568 return;
569
570 if (spectre_v4_mitigations_dynamic())
571 *updptr = cpu_to_le32(aarch64_insn_gen_nop());
572 }
573
574 /*
575 * Patch a NOP in the Spectre-v4 mitigation code with an SMC/HVC instruction
576 * to call into firmware to adjust the mitigation state.
577 */
> 578 void __init spectre_v4_patch_fw_mitigation_conduit(struct alt_instr *alt,
579 __le32 *origptr,
580 __le32 *updptr, int nr_inst)
581 {
582 u32 insn;
583
584 BUG_ON(nr_inst != 1); /* NOP -> HVC/SMC */
585
586 switch (arm_smccc_1_1_get_conduit()) {
587 case SMCCC_CONDUIT_HVC:
588 insn = aarch64_insn_get_hvc_value();
589 break;
590 case SMCCC_CONDUIT_SMC:
591 insn = aarch64_insn_get_smc_value();
592 break;
593 default:
594 return;
595 }
596
597 *updptr = cpu_to_le32(insn);
598 }
599

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

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