Fix below build warning: aarch64-linux-gnu-ld: warning: -z norelro ignored
Since v1 - Backport a preparation patch as pointed out by Nick Desaulniers
Nick Desaulniers (1): arm64: link with -z norelro for LLD or aarch64-elf
Sami Tolvanen (1): kbuild: add CONFIG_LD_IS_LLD
arch/arm64/Makefile | 10 +++++++--- init/Kconfig | 3 +++ 2 files changed, 10 insertions(+), 3 deletions(-)
From: Sami Tolvanen samitolvanen@google.com
commit b744b43f79cc758127042e71f9ad7b1afda30f84 upstream.
Similarly to the CC_IS_CLANG config, add LD_IS_LLD to avoid GNU ld specific logic such as ld-version or ld-ifversion and gain the ability to select potential features that depend on the linker at configuration time such as LTO.
Signed-off-by: Sami Tolvanen samitolvanen@google.com Acked-by: Masahiro Yamada masahiroy@kernel.org [nc: Reword commit message] Signed-off-by: Nathan Chancellor natechancellor@gmail.com Tested-by: Sedat Dilek sedat.dilek@gmail.com Reviewed-by: Sedat Dilek sedat.dilek@gmail.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de --- init/Kconfig | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/init/Kconfig b/init/Kconfig index 4f9fd78e2200..f23e90d9935f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -20,6 +20,9 @@ config GCC_VERSION config CC_IS_CLANG def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
+config LD_IS_LLD + def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD) + config CLANG_VERSION int default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
From: Nick Desaulniers ndesaulniers@google.com
commit 311bea3cb9ee20ef150ca76fc60a592bf6b159f5 upstream.
With GNU binutils 2.35+, linking with BFD produces warnings for vmlinux: aarch64-linux-gnu-ld: warning: -z norelro ignored
BFD can produce this warning when the target emulation mode does not support RELRO program headers, and -z relro or -z norelro is passed.
Alan Modra clarifies: The default linker emulation for an aarch64-linux ld.bfd is -maarch64linux, the default for an aarch64-elf linker is -maarch64elf. They are not equivalent. If you choose -maarch64elf you get an emulation that doesn't support -z relro.
The ARCH=arm64 kernel prefers -maarch64elf, but may fall back to -maarch64linux based on the toolchain configuration.
LLD will always create RELRO program header regardless of target emulation.
To avoid the above warning when linking with BFD, pass -z norelro only when linking with LLD or with -maarch64linux.
Fixes: 3b92fa7485eb ("arm64: link with -z norelro regardless of CONFIG_RELOCATABLE") Fixes: 3bbd3db86470 ("arm64: relocatable: fix inconsistencies in linker script and options") Cc: stable@vger.kernel.org # 5.0.x- Reported-by: kernelci.org bot bot@kernelci.org Reported-by: Quentin Perret qperret@google.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Ard Biesheuvel ardb@kernel.org Cc: Alan Modra amodra@gmail.com Cc: Fāng-ruì Sòng maskray@google.com Link: https://lore.kernel.org/r/20201218002432.788499-1-ndesaulniers@google.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com --- arch/arm64/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index cd8f3cdabfd0..d227cf87c48f 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -10,7 +10,7 @@ # # Copyright (C) 1995-2001 by Russell King
-LDFLAGS_vmlinux :=--no-undefined -X -z norelro +LDFLAGS_vmlinux :=--no-undefined -X CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET) GZFLAGS :=-9
@@ -82,17 +82,21 @@ CHECKFLAGS += -D__AARCH64EB__ AS += -EB # Prefer the baremetal ELF build target, but not all toolchains include # it so fall back to the standard linux version if needed. -KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb) +KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro) UTS_MACHINE := aarch64_be else KBUILD_CPPFLAGS += -mlittle-endian CHECKFLAGS += -D__AARCH64EL__ AS += -EL # Same as above, prefer ELF but fall back to linux target if needed. -KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux) +KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro) UTS_MACHINE := aarch64 endif
+ifeq ($(CONFIG_LD_IS_LLD), y) +KBUILD_LDFLAGS += -z norelro +endif + CHECKFLAGS += -D__aarch64__
ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
On Fri, Jun 25, 2021 at 03:47:37PM +0800, Jisheng Zhang wrote:
Fix below build warning: aarch64-linux-gnu-ld: warning: -z norelro ignored
Since v1
- Backport a preparation patch as pointed out by Nick Desaulniers
Nick Desaulniers (1): arm64: link with -z norelro for LLD or aarch64-elf
Sami Tolvanen (1): kbuild: add CONFIG_LD_IS_LLD
arch/arm64/Makefile | 10 +++++++--- init/Kconfig | 3 +++ 2 files changed, 10 insertions(+), 3 deletions(-)
-- 2.32.0
Took this series instead, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg Kroah-Hartman -
Jisheng Zhang