The patch titled
Subject: arch: enable HAS_LTO_CLANG with KASAN and KCOV
has been added to the -mm mm-nonmm-unstable branch. Its filename is
arch-enable-has_lto_clang-with-kasan-and-kcov.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arch-enable-has_lto_clang-with-kasan-and-kcov.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Jakob Koschel <jkl820.git@xxxxxxxxx>
Subject: arch: enable HAS_LTO_CLANG with KASAN and KCOV
Date: Wed, 19 Jul 2023 00:29:12 +0200
Both KASAN and KCOV had issues with LTO_CLANG if DEBUG_INFO is enabled.
With LTO inlinable function calls are required to have debug info if they
are inlined into a function that has debug info.
Starting with LLVM 17 this will be fixed ([1],[2]) and enabling LTO with
KASAN/KCOV and DEBUG_INFO doesn't cause linker errors anymore.
Link: https://github.com/llvm/llvm-project/commit/913f7e93dac67ecff47bade862ba42f27cb68ca9
Link: https://github.com/llvm/llvm-project/commit/4a8b1249306ff11f229320abdeadf0c215a00400
Link: https://lkml.kernel.org/r/20230717-enable-kasan-lto1-v3-1-650e1efc19d1@xxxxxxxxx
Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Jakob Koschel <jkl820.git@xxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/Kconfig | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/Kconfig~arch-enable-has_lto_clang-with-kasan-and-kcov
+++ a/arch/Kconfig
@@ -732,7 +732,9 @@ config HAS_LTO_CLANG
depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
depends on ARCH_SUPPORTS_LTO_CLANG
depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
- depends on !KASAN || KASAN_HW_TAGS
+ # https://github.com/ClangBuiltLinux/linux/issues/1721
+ depends on (!KASAN || KASAN_HW_TAGS || CLANG_VERSION >= 170000) || !DEBUG_INFO
+ depends on (!KCOV || CLANG_VERSION >= 170000) || !DEBUG_INFO
depends on !GCOV_KERNEL
help
The compiler and Kconfig options support building with Clang's
_
Patches currently in -mm which might be from jkl820.git@xxxxxxxxx are
arch-enable-has_lto_clang-with-kasan-and-kcov.patch
