properly cope with -z norelro
Subsystems (2)
v2 cover properly cope with -z norelro
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(-)
Signature · 1 line
2.32.0
PATCH v2 1/2 kbuild: add CONFIG_LD_IS_LLD
From: Sami Tolvanen <[email protected]>
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.
--- init/Kconfig | 3 +++ 1 file changed, 3 insertions(+)
init/Kconfig +3 -0
@@ -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))
Signature · 1 line
2.32.0
Patch "kbuild: add CONFIG_LD_IS_LLD" has been added to the 5.4-stable tree
This is a note to let you know that I've just added the patch titled
kbuild: add CONFIG_LD_IS_LLD
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kbuild-add-config_ld_is_lld.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
From foo@baz Fri Jun 25 12:15:34 PM CEST 2021
From: Jisheng Zhang <[email protected]>
Date: Fri, 25 Jun 2021 15:48:35 +0800
Subject: kbuild: add CONFIG_LD_IS_LLD
To: Nick Desaulniers <[email protected]>, [email protected], Greg Kroah-Hartman <[email protected]>, Nathan Chancellor <[email protected]>, Ard Biesheuvel <[email protected]>, Sami Tolvanen <[email protected]>, Masahiro Yamada <[email protected]>, Sedat Dilek <[email protected]>, Thomas Bogendoerfer <[email protected]>
Cc: "Catalin Marinas" <[email protected]>, "Will Deacon" <[email protected]>, "Alan Modra" <[email protected]>, "Fāng-ruì Sòng" <[email protected]>, "Quentin Perret" <[email protected]>, [email protected]
Message-ID: <[email protected]>
From: Sami Tolvanen <[email protected]>
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.
--- init/Kconfig | 3 +++ 1 file changed, 3 insertions(+)
init/Kconfig +3 -0
@@ -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 $(CC))
Patches currently in stable-queue which might be from [email protected] are
queue-5.4/arm64-link-with-z-norelro-for-lld-or-aarch64-elf.patch queue-5.4/kbuild-add-config_ld_is_lld.patch
_______________________________________________
linux-arm-kernel mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
PATCH v2 2/2 arm64: link with -z norelro for LLD or aarch64-elf
In reply to Jisheng ZhangFrom: Nick Desaulniers <[email protected]>
commit 311bea3cb9ee20ef150ca76fc60a592bf6b159f5 upstream.
With GNU binutils 2.35+, linking with BFD produces warnings for vmlinux:
aarch64-linux-gnu-ld: warning: -z norelro ignored
BFD can produce this warning when the target emulation mode does not support RELRO program headers, and -z relro or -z norelro is passed.
Alan Modra clarifies:
The default linker emulation for an aarch64-linux ld.bfd is -maarch64linux, the default for an aarch64-elf linker is -maarch64elf. They are not equivalent. If you choose -maarch64elf you get an emulation that doesn't support -z relro.
The ARCH=arm64 kernel prefers -maarch64elf, but may fall back to -maarch64linux based on the toolchain configuration.
LLD will always create RELRO program header regardless of target emulation.
To avoid the above warning when linking with BFD, pass -z norelro only when linking with LLD or with -maarch64linux.
--- arch/arm64/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
arch/arm64/Makefile +7 -3
@@ -10,7 +10,7 @@ # # Copyright (C) 1995-2001 by Russell King -LDFLAGS_vmlinux :=--no-undefined -X -z norelro +LDFLAGS_vmlinux :=--no-undefined -X CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(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)
Signature · 1 line
2.32.0
Patch "arm64: link with -z norelro for LLD or aarch64-elf" has been added to the 5.4-stable tree
This is a note to let you know that I've just added the patch titled
arm64: link with -z norelro for LLD or aarch64-elf
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-link-with-z-norelro-for-lld-or-aarch64-elf.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
From foo@baz Fri Jun 25 12:15:34 PM CEST 2021
From: Jisheng Zhang <[email protected]>
Date: Fri, 25 Jun 2021 15:50:12 +0800
Subject: arm64: link with -z norelro for LLD or aarch64-elf
To: Nick Desaulniers <[email protected]>, [email protected], Greg Kroah-Hartman <[email protected]>, Nathan Chancellor <[email protected]>, Ard Biesheuvel <[email protected]>, Sami Tolvanen <[email protected]>, Masahiro Yamada <[email protected]>, Sedat Dilek <[email protected]>, Thomas Bogendoerfer <[email protected]>
Cc: "Catalin Marinas" <[email protected]>, "Will Deacon" <[email protected]>, "Alan Modra" <[email protected]>, "Fāng-ruì Sòng" <[email protected]>, "Quentin Perret" <[email protected]>, [email protected]
Message-ID: <[email protected]>
From: Nick Desaulniers <[email protected]>
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.
--- arch/arm64/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
arch/arm64/Makefile +7 -3
@@ -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)
Patches currently in stable-queue which might be from [email protected] are
queue-5.4/arm64-link-with-z-norelro-for-lld-or-aarch64-elf.patch queue-5.4/kbuild-add-config_ld_is_lld.patch
_______________________________________________
linux-arm-kernel mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Greg Kroah-Hartman
maintainerQuoted 9 lines · Jisheng Zhang
Fix below build warning:
aarch64-linux-gnu-ld: warning: -z norelro ignoredSince v1
- Backport a preparation patch as pointed out by Nick DesaulniersNick Desaulniers (1):
arm64: link with -z norelro for LLD or aarch64-elf
Quoted 10 lines
Sami Tolvanen (1):
kbuild: addCONFIG_LD_IS_LLDarch/arm64/Makefile | 10 +++++++--- init/Kconfig | 3 +++ 2 files changed, 10 insertions(+), 3 deletions(-)Signature · 1 line
2.32.0
Took this series instead, thanks.
greg k-h