kernel.git/arch/arm64/Makefile, branch linux-5.4.y

arm64: link with -z norelro for LLD or aarch64-elf

2021-06-30T12:47:44Z

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: # 5.0.x- Reported-by: kernelci.org bot Reported-by: Quentin Perret Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Acked-by: Ard Biesheuvel Cc: Alan Modra Cc: Fāng-ruì Sòng Link: https://lore.kernel.org/r/20201218002432.788499-1-ndesaulniers@google.com Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: link with -z norelro regardless of CONFIG_RELOCATABLE

2020-11-01T11:01:02Z

commit 3b92fa7485eba16b05166fddf38ab42f2ff6ab95 upstream. With CONFIG_EXPERT=y, CONFIG_KASAN=y, CONFIG_RANDOMIZE_BASE=n, CONFIG_RELOCATABLE=n, we observe the following failure when trying to link the kernel image with LD=ld.lld: error: section: .exit.data is not contiguous with other relro sections ld.lld defaults to -z relro while ld.bfd defaults to -z norelro. This was previously fixed, but only for CONFIG_RELOCATABLE=y. Fixes: 3bbd3db86470 ("arm64: relocatable: fix inconsistencies in linker script and options") Signed-off-by: Nick Desaulniers Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201016175339.2429280-1-ndesaulniers@google.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

arm64: vdso32: make vdso32 install conditional

2020-09-03T09:27:05Z

commit 5d28ba5f8a0cfa3a874fa96c33731b8fcd141b3a upstream. vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled, since it's not even supposed to be compiled otherwise, and arm64 builds without a 32bit crosscompiler will fail. Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install") Signed-off-by: Frank van der Linden Cc: stable@vger.kernel.org [5.4+] Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

ARM64: vdso32: Install vdso32 from vdso_install

2020-08-26T08:41:05Z

[ Upstream commit 8d75785a814241587802655cc33e384230744f0c ] Add the 32-bit vdso Makefile to the vdso_install rule so that 'make vdso_install' installs the 32-bit compat vdso when it is compiled. Fixes: a7f71a2c8903 ("arm64: compat: Add vDSO") Signed-off-by: Stephen Boyd Reviewed-by: Vincenzo Frascino Acked-by: Will Deacon Cc: Vincenzo Frascino Link: https://lore.kernel.org/r/20200818014950.42492-1-swboyd@chromium.org Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm64: Always force a branch protection mode when the compiler has one

2020-04-17T08:50:23Z

commit b8fdef311a0bd9223f10754f94fdcf1a594a3457 upstream. Compilers with branch protection support can be configured to enable it by default, it is likely that distributions will do this as part of deploying branch protection system wide. As well as the slight overhead from having some extra NOPs for unused branch protection features this can cause more serious problems when the kernel is providing pointer authentication to userspace but not built for pointer authentication itself. In that case our switching of keys for userspace can affect the kernel unexpectedly, causing pointer authentication instructions in the kernel to corrupt addresses. To ensure that we get consistent and reliable behaviour always explicitly initialise the branch protection mode, ensuring that the kernel is built the same way regardless of the compiler defaults. [This is a reworked version of b8fdef311a0bd9223f1075 ("arm64: Always force a branch protection mode when the compiler has one") for backport. Kernels prior to 74afda4016a7 ("arm64: compile the kernel with ptrauth return address signing") don't have any Makefile machinery for forcing on pointer auth but still have issues if the compiler defaults it on so need this reworked version. -- broonie] Fixes: 7503197562567 (arm64: add basic pointer authentication support) Reported-by: Szabolcs Nagy Signed-off-by: Mark Brown Cc: stable@vger.kernel.org [catalin.marinas@arm.com: remove Kconfig option in favour of Makefile check] Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: Kconfig: Make CONFIG_COMPAT_VDSO a proper Kconfig option

2019-10-07T12:32:15Z

CONFIG_COMPAT_VDSO is defined by passing '-DCONFIG_COMPAT_VDSO' to the compiler when the generic compat vDSO code is in use. It's much cleaner and simpler to expose this as a proper Kconfig option (like x86 does), so do that and remove the bodge. Acked-by: Catalin Marinas Signed-off-by: Will Deacon

arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile

2019-10-07T12:32:02Z

There's no need to export COMPATCC, so just define it locally in the vdso32/Makefile, which is the only place where it is used. Acked-by: Catalin Marinas Signed-off-by: Will Deacon

arm64: Default to building compat vDSO with clang when CONFIG_CC_IS_CLANG

2019-10-07T12:31:45Z

Rather than force the use of GCC for the compat cross-compiler, instead extract the target from CROSS_COMPILE_COMPAT and pass it to clang if the main compiler is clang. Acked-by: Catalin Marinas Signed-off-by: Will Deacon

arm64: vdso32: Fix broken compat vDSO build warnings

2019-10-07T10:07:16Z

The .config file and the generated include/config/auto.conf can end up out of sync after a set of commands since CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly. The sequence can be reproduced as follows: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig [...] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Which results in: arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built even though the compat vDSO has been built: $ file arch/arm64/kernel/vdso32/vdso.so arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped A similar case that involves changing the configuration parameter multiple times can be reconducted to the same family of problems. Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and instead rely on the cross-compiler prefix coming from the environment via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel. Cc: Will Deacon Cc: Catalin Marinas Reported-by: Will Deacon Signed-off-by: Vincenzo Frascino Signed-off-by: Will Deacon

Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-09-20T15:36:47Z

Pull Kbuild updates from Masahiro Yamada: - add modpost warn exported symbols marked as 'static' because 'static' and EXPORT_SYMBOL is an odd combination - break the build early if gold linker is used - optimize the Bison rule to produce .c and .h files by a single pattern rule - handle PREEMPT_RT in the module vermagic and UTS_VERSION - warn CONFIG options leaked to the user-space except existing ones - make single targets work properly - rebuild modules when module linker scripts are updated - split the module final link stage into scripts/Makefile.modfinal - fix the missed error code in merge_config.sh - improve the error message displayed on the attempt of the O= build in unclean source tree - remove 'clean-dirs' syntax - disable -Wimplicit-fallthrough warning for Clang - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC - remove ARCH_{CPP,A,C}FLAGS variables - add $(BASH) to run bash scripts - change *CFLAGS_.o to take the relative path to $(obj) instead of the basename - stop suppressing Clang's -Wunused-function warnings when W=1 - fix linux/export.h to avoid genksyms calculating CRC of trimmed exported symbols - misc cleanups * tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits) genksyms: convert to SPDX License Identifier for lex.l and parse.y modpost: use __section in the output to *.mod.c modpost: use MODULE_INFO() for __module_depends export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols export.h: remove defined(__KERNEL__), which is no longer needed kbuild: allow Clang to find unused static inline functions for W=1 build kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN kbuild: refactor scripts/Makefile.extrawarn merge_config.sh: ignore unwanted grep errors kbuild: change *FLAGS_.o to take the path relative to $(obj) modpost: add NOFAIL to strndup modpost: add guid_t type definition kbuild: add $(BASH) to run scripts with bash-extension kbuild: remove ARCH_{CPP,A,C}FLAGS kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC kbuild: Do not enable -Wimplicit-fallthrough for clang for now kbuild: clean up subdir-ymn calculation in Makefile.clean kbuild: remove unneeded '+' marker from cmd_clean kbuild: remove clean-dirs syntax kbuild: check clean srctree even earlier ...