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| author | Linus Walleij <linus.walleij@linaro.org> | 2024-11-11 00:17:03 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2024-11-13 00:51:05 +0100 |
| commit | 4aea16b7cfb76bd3361858ceee6893ef5c9b5570 (patch) | |
| tree | 12b819bbba49b7050669d82168fc437590c4f772 /arch/arm | |
| parent | ARM: 9420/1: smp: Fix SMP for xip kernels (diff) | |
| download | linux-4aea16b7cfb76bd3361858ceee6893ef5c9b5570.tar.xz linux-4aea16b7cfb76bd3361858ceee6893ef5c9b5570.zip | |
ARM: 9434/1: cfi: Fix compilation corner case
When enabling expert mode CONFIG_EXPERT and using that power
user mode to disable the branch prediction hardening
!CONFIG_HARDEN_BRANCH_PREDICTOR, the assembly linker
in CLANG notices that some assembly in proc-v7.S does
not have corresponding C call sites, i.e. the prototypes
in proc-v7-bugs.c are enclosed in ifdef
CONFIG_HARDEN_BRANCH_PREDICTOR so this assembly:
SYM_TYPED_FUNC_START(cpu_v7_smc_switch_mm)
SYM_TYPED_FUNC_START(cpu_v7_hvc_switch_mm)
Results in:
ld.lld: error: undefined symbol: __kcfi_typeid_cpu_v7_smc_switch_mm
>>> referenced by proc-v7.S:94 (.../arch/arm/mm/proc-v7.S:94)
>>> arch/arm/mm/proc-v7.o:(.text+0x108) in archive vmlinux.a
ld.lld: error: undefined symbol: __kcfi_typeid_cpu_v7_hvc_switch_mm
>>> referenced by proc-v7.S:105 (.../arch/arm/mm/proc-v7.S:105)
>>> arch/arm/mm/proc-v7.o:(.text+0x124) in archive vmlinux.a
Fix this by adding an additional requirement that
CONFIG_HARDEN_BRANCH_PREDICTOR has to be enabled to compile
these assembly calls.
Closes: https://lore.kernel.org/oe-kbuild-all/202411041456.ZsoEiD7T-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 5fb9a6aecb00..2cd933342679 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -94,7 +94,7 @@ SYM_TYPED_FUNC_START(cpu_v7_dcache_clean_area) ret lr SYM_FUNC_END(cpu_v7_dcache_clean_area) -#ifdef CONFIG_ARM_PSCI +#if defined(CONFIG_ARM_PSCI) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR) .arch_extension sec SYM_TYPED_FUNC_START(cpu_v7_smc_switch_mm) stmfd sp!, {r0 - r3} |