Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH] arm64: Restrict ARM64_BTI_KERNEL to clang 12.0.0 and newer | Date | Thu, 8 Jul 2021 17:06:27 -0700 |
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Commit 97fed779f2a6 ("arm64: bti: Provide Kconfig for kernel mode BTI") disabled CONFIG_ARM64_BTI_KERNEL when CONFIG_GCOV_KERNEL was enabled and compilign with clang because of warnings that occur because LLVM was not emitting PAC/BTI instructions for compiler generated functions.
This was an adequate fix to avoid the warnings with allmodconfig until commit 51c2ee6d121c ("Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR"), which prevented CONFIG_GCOV_KERNEL from being selected with clang 12.0.0 and older because it does not support the no_profile_instrument_function attribute. As a result, CONFIG_ARM64_BTI_KERNEL gets enabled and there are more warnings of this nature.
Rather than play whack-a-mole with the config options, just update this condition to require clang 12.0.0, which should have all of the issues ironed out.
Link: https://github.com/ClangBuiltLinux/linux/issues/1428 Link: https://github.com/ClangBuiltLinux/continuous-integration2/runs/3010034706?check_suite_focus=true Link: https://github.com/ClangBuiltLinux/continuous-integration2/runs/3010035725?check_suite_focus=true Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- arch/arm64/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e07e7de9ac49..c2127595980f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1605,7 +1605,8 @@ config ARM64_BTI_KERNEL depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 depends on !CC_IS_GCC || GCC_VERSION >= 100100 - depends on !(CC_IS_CLANG && GCOV_KERNEL) + # https://reviews.llvm.org/D85649 + depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) help Build the kernel with Branch Target Identification annotations base-commit: f55966571d5eb2876a11e48e798b4592fa1ffbb7 -- 2.32.0.93.g670b81a890
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