| Message ID | 20201110015632.2509254-1-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: Link with '-z norelro' | expand |
On Mon, Nov 9, 2020 at 5:56 PM Nathan Chancellor <natechancellor@gmail.com> wrote: > > When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with > LD=ld.lld, the following error occurs: > > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage > ld.lld: error: section: .exit.data is not contiguous with other relro sections > > LLD defaults to '-z relro', which is unneeded for the kernel because > program headers are not used nor is there any position independent code > generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to > avoid this error. > > Link: https://github.com/ClangBuiltLinux/linux/issues/1189 > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Thanks for the patch! See also: https://lore.kernel.org/linux-arm-kernel/20201016175339.2429280-1-ndesaulniers@google.com/ where we just did the same thing for aarch64. > --- > arch/arm/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/Makefile b/arch/arm/Makefile > index 4d76eab2b22d..3c0a64cefe52 100644 > --- a/arch/arm/Makefile > +++ b/arch/arm/Makefile > @@ -10,7 +10,7 @@ > # > # Copyright (C) 1995-2001 by Russell King > > -LDFLAGS_vmlinux := --no-undefined -X --pic-veneer > +LDFLAGS_vmlinux := --no-undefined -X --pic-veneer -z norelro > ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) > LDFLAGS_vmlinux += --be8 > KBUILD_LDFLAGS_MODULE += --be8 > > base-commit: a0796429c6abecf8afaeb65b1db286af1fb579d1 > -- > 2.29.2
On Mon, Nov 9, 2020 at 6:05 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Mon, Nov 9, 2020 at 5:56 PM Nathan Chancellor > <natechancellor@gmail.com> wrote: > > > > When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with > > LD=ld.lld, the following error occurs: > > > > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage > > ld.lld: error: section: .exit.data is not contiguous with other relro sections > > > > LLD defaults to '-z relro', which is unneeded for the kernel because > > program headers are not used nor is there any position independent code > > generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to > > avoid this error. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1189 > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > Tested-by: Nick Desaulniers <ndesaulniers@google.com> > > Thanks for the patch! > See also: https://lore.kernel.org/linux-arm-kernel/20201016175339.2429280-1-ndesaulniers@google.com/ > where we just did the same thing for aarch64. I was thinking more about this last night. If we're going to be playing whack-a-mole for each architecture with this, would it be worthwhile for us to raise this up to the top level Makefile?
On Tue, Nov 10, 2020 at 10:49:32AM -0800, Nick Desaulniers wrote: > On Mon, Nov 9, 2020 at 6:05 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > > > On Mon, Nov 9, 2020 at 5:56 PM Nathan Chancellor > > <natechancellor@gmail.com> wrote: > > > > > > When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with > > > LD=ld.lld, the following error occurs: > > > > > > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage > > > ld.lld: error: section: .exit.data is not contiguous with other relro sections > > > > > > LLD defaults to '-z relro', which is unneeded for the kernel because > > > program headers are not used nor is there any position independent code > > > generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to > > > avoid this error. > > > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1189 > > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > > > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > Tested-by: Nick Desaulniers <ndesaulniers@google.com> > > > > Thanks for the patch! > > See also: https://lore.kernel.org/linux-arm-kernel/20201016175339.2429280-1-ndesaulniers@google.com/ > > where we just did the same thing for aarch64. > > I was thinking more about this last night. If we're going to be > playing whack-a-mole for each architecture with this, would it be > worthwhile for us to raise this up to the top level Makefile? Sure, I can send a patch along tomorrow that adds '-z norelro' to LDFLAGS_vmlinux in the top level Makefile. Cheers, Nathan
Does this need to get submitted to https://www.armlinux.org.uk/developer/patches/section.php?section=0 since `-z norelro` will produce warnings in ld.bfd for architectures that don't support that (the results of the thread on adding it globally)? On Wed, Nov 11, 2020 at 6:52 PM Nathan Chancellor <natechancellor@gmail.com> wrote: > > On Tue, Nov 10, 2020 at 10:49:32AM -0800, Nick Desaulniers wrote: > > On Mon, Nov 9, 2020 at 6:05 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > > > > > On Mon, Nov 9, 2020 at 5:56 PM Nathan Chancellor > > > <natechancellor@gmail.com> wrote: > > > > > > > > When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with > > > > LD=ld.lld, the following error occurs: > > > > > > > > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage > > > > ld.lld: error: section: .exit.data is not contiguous with other relro sections > > > > > > > > LLD defaults to '-z relro', which is unneeded for the kernel because > > > > program headers are not used nor is there any position independent code > > > > generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to > > > > avoid this error. > > > > > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1189 > > > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > > > > > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > > Tested-by: Nick Desaulniers <ndesaulniers@google.com> > > > > > > Thanks for the patch! > > > See also: https://lore.kernel.org/linux-arm-kernel/20201016175339.2429280-1-ndesaulniers@google.com/ > > > where we just did the same thing for aarch64. > > > > I was thinking more about this last night. If we're going to be > > playing whack-a-mole for each architecture with this, would it be > > worthwhile for us to raise this up to the top level Makefile? > > Sure, I can send a patch along tomorrow that adds '-z norelro' to > LDFLAGS_vmlinux in the top level Makefile. > > Cheers, > Nathan
diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 4d76eab2b22d..3c0a64cefe52 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -10,7 +10,7 @@ # # Copyright (C) 1995-2001 by Russell King -LDFLAGS_vmlinux := --no-undefined -X --pic-veneer +LDFLAGS_vmlinux := --no-undefined -X --pic-veneer -z norelro ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) LDFLAGS_vmlinux += --be8 KBUILD_LDFLAGS_MODULE += --be8
When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with LD=ld.lld, the following error occurs: $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage ld.lld: error: section: .exit.data is not contiguous with other relro sections LLD defaults to '-z relro', which is unneeded for the kernel because program headers are not used nor is there any position independent code generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to avoid this error. Link: https://github.com/ClangBuiltLinux/linux/issues/1189 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- arch/arm/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: a0796429c6abecf8afaeb65b1db286af1fb579d1