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| author | Nathan Chancellor <nathan@kernel.org> | 2022-06-17 11:08:46 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-07-11 08:49:39 +0200 |
| commit | 1b8667812b3a1304f3db736ac4905d6ad77d721e (patch) | |
| tree | ccb2d8b1016069baac6e98952e221561d8eda306 | |
| parent | 32346491ddf24599decca06190ebca03ff9de7f8 (diff) | |
| download | linux-1b8667812b3a1304f3db736ac4905d6ad77d721e.tar.bz2 | |
x86/Kconfig: Fix CONFIG_CC_HAS_SANE_STACKPROTECTOR when cross compiling with clang
Chimera Linux notes that CONFIG_CC_HAS_SANE_STACKPROTECTOR cannot be
enabled when cross compiling an x86_64 kernel with clang, even though it
does work when natively compiling.
When building on aarch64:
$ make -sj"$(nproc)" ARCH=x86_64 LLVM=1 defconfig
$ grep STACKPROTECTOR .config
When building on x86_64:
$ make -sj"$(nproc)" ARCH=x86_64 LLVM=1 defconfig
$ grep STACKPROTECTOR .config
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
CONFIG_HAVE_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y
When clang is invoked without a '--target' flag, code is generated for
the default target, which is usually the host (it is configurable via
cmake). As a result, the has-stack-protector scripts will generate code
for the default target but check for x86 specific segment registers,
which cannot succeed if the default target is not x86.
$(CLANG_FLAGS) contains an explicit '--target' flag so pass that
variable along to the has-stack-protector scripts so that the stack
protector can be enabled when cross compiling with clang. The 32-bit
stack protector cannot currently be enabled with clang, as it does not
support '-mstack-protector-guard-symbol', so this results in no
functional change for ARCH=i386 when cross compiling.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://github.com/chimera-linux/cports/commit/0fb7e506d5f83fdf2104feb22cdac34934561226
Link: https://github.com/llvm/llvm-project/issues/48553
Link: https://lkml.kernel.org/r/20220617180845.2788442-1-nathan@kernel.org
| -rw-r--r-- | arch/x86/Kconfig | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index be0b95e51df6..076adde7ead9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -391,8 +391,8 @@ config PGTABLE_LEVELS config CC_HAS_SANE_STACKPROTECTOR bool - default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT - default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) + default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT + default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) help We have to make sure stack protector is unconditionally disabled if the compiler produces broken code or if it does not let us control |