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arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
#
# arch/arm64/Makefile
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies.
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1995-2001 by Russell King
arm64: link with -z norelro for LLD or aarch64-elf 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>
2020-12-18 08:24:32 +08:00
LDFLAGS_vmlinux :=--no-undefined -X
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: prevent regressions in compressed kernel image size when upgrading to binutils 2.27 Upon upgrading to binutils 2.27, we found that our lz4 and gzip compressed kernel images were significantly larger, resulting is 10ms boot time regressions. As noted by Rahul: "aarch64 binaries uses RELA relocations, where each relocation entry includes an addend value. This is similar to x86_64. On x86_64, the addend values are also stored at the relocation offset for relative relocations. This is an optimization: in the case where code does not need to be relocated, the loader can simply skip processing relative relocations. In binutils-2.25, both bfd and gold linkers did this for x86_64, but only the gold linker did this for aarch64. The kernel build here is using the bfd linker, which stored zeroes at the relocation offsets for relative relocations. Since a set of zeroes compresses better than a set of non-zero addend values, this behavior was resulting in much better lz4 compression. The bfd linker in binutils-2.27 is now storing the actual addend values at the relocation offsets. The behavior is now consistent with what it does for x86_64 and what gold linker does for both architectures. The change happened in this upstream commit: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613 Since a bunch of zeroes got replaced by non-zero addend values, we see the side effect of lz4 compressed image being a bit bigger. To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs" flag can be used: $ LDFLAGS="--no-apply-dynamic-relocs" make With this flag, the compressed image size is back to what it was with binutils-2.25. If the kernel is using ASLR, there aren't additional runtime costs to --no-apply-dynamic-relocs, as the relocations will need to be applied again anyway after the kernel is relocated to a random address. If the kernel is not using ASLR, then presumably the current default behavior of the linker is better. Since the static linker performed the dynamic relocs, and the kernel is not moved to a different address at load time, it can skip applying the relocations all over again." Some measurements: $ ld -v GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117 ^ $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb $ ld -v GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315 ^ pre patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb post patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb By Siqi's measurement w/ gzip: binutils 2.27 with this patch (with --no-apply-dynamic-relocs): Image 41535488 Image.gz 13404067 binutils 2.27 without this patch (without --no-apply-dynamic-relocs): Image 41535488 Image.gz 14125516 Any compression scheme should be able to get better results from the longer runs of zeros, not just GZIP and LZ4. 10ms boot time savings isn't anything to get excited about, but users of arm64+compression+bfd-2.27 should not have to pay a penalty for no runtime improvement. Reported-by: Gopinath Elanchezhian <gelanchezhian@google.com> Reported-by: Sindhuri Pentyala <spentyala@google.com> Reported-by: Wei Wang <wvw@google.com> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Suggested-by: Rahul Chaudhry <rahulchaudhry@google.com> Suggested-by: Siqi Lin <siqilin@google.com> Suggested-by: Stephen Hines <srhines@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: added comment to Makefile] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-28 00:33:41 +08:00
ifeq ($(CONFIG_RELOCATABLE), y)
# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
# for relative relocs, since this leads to better Image compression
# with the relocation offsets always being zero.
arm64: link with -z norelro regardless of CONFIG_RELOCATABLE 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 <ndesaulniers@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201016175339.2429280-1-ndesaulniers@google.com Signed-off-by: Will Deacon <will@kernel.org>
2020-10-17 01:53:39 +08:00
LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \
arm64: prevent regressions in compressed kernel image size when upgrading to binutils 2.27 Upon upgrading to binutils 2.27, we found that our lz4 and gzip compressed kernel images were significantly larger, resulting is 10ms boot time regressions. As noted by Rahul: "aarch64 binaries uses RELA relocations, where each relocation entry includes an addend value. This is similar to x86_64. On x86_64, the addend values are also stored at the relocation offset for relative relocations. This is an optimization: in the case where code does not need to be relocated, the loader can simply skip processing relative relocations. In binutils-2.25, both bfd and gold linkers did this for x86_64, but only the gold linker did this for aarch64. The kernel build here is using the bfd linker, which stored zeroes at the relocation offsets for relative relocations. Since a set of zeroes compresses better than a set of non-zero addend values, this behavior was resulting in much better lz4 compression. The bfd linker in binutils-2.27 is now storing the actual addend values at the relocation offsets. The behavior is now consistent with what it does for x86_64 and what gold linker does for both architectures. The change happened in this upstream commit: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613 Since a bunch of zeroes got replaced by non-zero addend values, we see the side effect of lz4 compressed image being a bit bigger. To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs" flag can be used: $ LDFLAGS="--no-apply-dynamic-relocs" make With this flag, the compressed image size is back to what it was with binutils-2.25. If the kernel is using ASLR, there aren't additional runtime costs to --no-apply-dynamic-relocs, as the relocations will need to be applied again anyway after the kernel is relocated to a random address. If the kernel is not using ASLR, then presumably the current default behavior of the linker is better. Since the static linker performed the dynamic relocs, and the kernel is not moved to a different address at load time, it can skip applying the relocations all over again." Some measurements: $ ld -v GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117 ^ $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb $ ld -v GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315 ^ pre patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb post patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb By Siqi's measurement w/ gzip: binutils 2.27 with this patch (with --no-apply-dynamic-relocs): Image 41535488 Image.gz 13404067 binutils 2.27 without this patch (without --no-apply-dynamic-relocs): Image 41535488 Image.gz 14125516 Any compression scheme should be able to get better results from the longer runs of zeros, not just GZIP and LZ4. 10ms boot time savings isn't anything to get excited about, but users of arm64+compression+bfd-2.27 should not have to pay a penalty for no runtime improvement. Reported-by: Gopinath Elanchezhian <gelanchezhian@google.com> Reported-by: Sindhuri Pentyala <spentyala@google.com> Reported-by: Wei Wang <wvw@google.com> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Suggested-by: Rahul Chaudhry <rahulchaudhry@google.com> Suggested-by: Siqi Lin <siqilin@google.com> Suggested-by: Stephen Hines <srhines@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: added comment to Makefile] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-28 00:33:41 +08:00
$(call ld-option, --no-apply-dynamic-relocs)
arm64: add support for building vmlinux as a relocatable PIE binary This implements CONFIG_RELOCATABLE, which links the final vmlinux image with a dynamic relocation section, allowing the early boot code to perform a relocation to a different virtual address at runtime. This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-26 16:13:44 +08:00
endif
arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabled Cortex-A53 erratum 843419 is worked around by the linker, although it is a configure-time option to GCC as to whether ld is actually asked to apply the workaround or not. This patch ensures that we pass --fix-cortex-a53-843419 to the linker when both CONFIG_ARM64_ERRATUM_843419=y and the linker supports the option. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-22 18:58:36 +08:00
ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
arm64: move warning about toolchains to archprepare Commit 987fdfec2410 ("arm64: move --fix-cortex-a53-843419 linker test to Kconfig") fixed the false-positive warning in the installation step. Yet, there are some cases where this false-positive is shown. For example, you can see it when you cross 987fdfec2410 during git-bisect. $ git checkout 987fdfec2410^ [ snip ] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] $ git checkout v5.13 [ snip] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum In the stale include/config/auto.config, CONFIG_ARM64_ERRATUM_843419=y is set without CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419, so the warning is displayed while parsing the Makefiles. Make will restart with the updated include/config/auto.config, hence CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419 will be set eventually, but this warning is a surprise for users. Commit 25896d073d8a ("x86/build: Fix compiler support check for CONFIG_RETPOLINE") addressed a similar issue. Move $(warning ...) out of the parse stage of Makefiles. The same applies to CONFIG_ARM64_USE_LSE_ATOMICS. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210801053525.105235-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-08-01 13:35:25 +08:00
ifeq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabled Cortex-A53 erratum 843419 is worked around by the linker, although it is a configure-time option to GCC as to whether ld is actually asked to apply the workaround or not. This patch ensures that we pass --fix-cortex-a53-843419 to the linker when both CONFIG_ARM64_ERRATUM_843419=y and the linker supports the option. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-22 18:58:36 +08:00
LDFLAGS_vmlinux += --fix-cortex-a53-843419
endif
endif
arm64: atomics: Use K constraint when toolchain appears to support it The 'K' constraint is a documented AArch64 machine constraint supported by GCC for matching integer constants that can be used with a 32-bit logical instruction. Unfortunately, some released compilers erroneously accept the immediate '4294967295' for this constraint, which is later refused by GAS at assembly time. This had led us to avoid the use of the 'K' constraint altogether. Instead, detect whether the compiler is up to the job when building the kernel and pass the 'K' constraint to our 32-bit atomic macros when it appears to be supported. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29 21:34:42 +08:00
cc_has_k_constraint := $(call try-run,echo \
'int main(void) { \
asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
return 0; \
}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
arm64: Turn "broken gas inst" into real config option Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST directly, making it available everywhere. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> [will: Drop redundant 'y if' logic] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 22:18:25 +08:00
ifeq ($(CONFIG_BROKEN_GAS_INST),y)
arm64: Add detection code for broken .inst support in binutils Binutils version up to (and including) 2.25 have a pathological behaviour when it comes to mixing .inst directive and arithmetic involving labels. The assembler complains about non-constant expressions and compilation stops pretty quickly. In order to detect this and work around it, let's add a bit of detection code that will set the CONFIG_BROKEN_GAS_INST option should a broken gas be detected. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-12-06 23:27:43 +08:00
$(warning Detected assembler with broken .inst; disassembly will be unreliable)
endif
arm64: Turn "broken gas inst" into real config option Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST directly, making it available everywhere. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> [will: Drop redundant 'y if' logic] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 22:18:25 +08:00
KBUILD_CFLAGS += -mgeneral-regs-only \
arm64: atomics: Use K constraint when toolchain appears to support it The 'K' constraint is a documented AArch64 machine constraint supported by GCC for matching integer constants that can be used with a 32-bit logical instruction. Unfortunately, some released compilers erroneously accept the immediate '4294967295' for this constraint, which is later refused by GAS at assembly time. This had led us to avoid the use of the 'K' constraint altogether. Instead, detect whether the compiler is up to the job when building the kernel and pass the 'K' constraint to our 32-bit atomic macros when it appears to be supported. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29 21:34:42 +08:00
$(compat_vdso) $(cc_has_k_constraint)
arm64: Don't unconditionally add -Wno-psabi to KBUILD_CFLAGS This is a GCC only option, which warns about ABI changes within GCC, so unconditionally adding it breaks Clang with tons of: warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option] and link time failures: ld.lld: error: undefined symbol: __efistub___stack_chk_guard >>> referenced by arm-stub.c:73 (/home/nathan/cbl/linux/drivers/firmware/efi/libstub/arm-stub.c:73) >>> arm-stub.stub.o:(__efistub_install_memreserve_table) in archive ./drivers/firmware/efi/libstub/lib.a These failures come from the lack of -fno-stack-protector, which is added via cc-option in drivers/firmware/efi/libstub/Makefile. When an unknown flag is added to KBUILD_CFLAGS, clang will noisily warn that it is ignoring the option like above, unlike gcc, who will just error. $ echo "int main() { return 0; }" > tmp.c $ clang -Wno-psabi tmp.c; echo $? warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option] 1 warning generated. 0 $ gcc -Wsometimes-uninitialized tmp.c; echo $? gcc: error: unrecognized command line option ‘-Wsometimes-uninitialized’; did you mean ‘-Wmaybe-uninitialized’? 1 For cc-option to work properly with clang and behave like gcc, -Werror is needed, which was done in commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to cc-option to support clang"). $ clang -Werror -Wno-psabi tmp.c; echo $? error: unknown warning option '-Wno-psabi' [-Werror,-Wunknown-warning-option] 1 As a consequence of this, when an unknown flag is unconditionally added to KBUILD_CFLAGS, it will cause cc-option to always fail and those flags will never get added: $ clang -Werror -Wno-psabi -fno-stack-protector tmp.c; echo $? error: unknown warning option '-Wno-psabi' [-Werror,-Wunknown-warning-option] 1 This can be seen when compiling the whole kernel as some warnings that are normally disabled (see below) show up. The full list of flags missing from drivers/firmware/efi/libstub are the following (gathered from diffing .arm64-stub.o.cmd): -fno-delete-null-pointer-checks -Wno-address-of-packed-member -Wframe-larger-than=2048 -Wno-unused-const-variable -fno-strict-overflow -fno-merge-all-constants -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -ffreestanding -fno-stack-protector Use cc-disable-warning so that it gets disabled for GCC and does nothing for Clang. Fixes: ebcc5928c5d9 ("arm64: Silence gcc warnings about arch ABI drift") Link: https://github.com/ClangBuiltLinux/linux/issues/511 Reported-by: Qian Cai <cai@lca.pw> Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-06-12 01:19:32 +08:00
KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
arm64: Turn "broken gas inst" into real config option Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST directly, making it available everywhere. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> [will: Drop redundant 'y if' logic] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 22:18:25 +08:00
KBUILD_AFLAGS += $(compat_vdso)
arm64: atomics: patch in lse instructions when supported by the CPU On CPUs which support the LSE atomic instructions introduced in ARMv8.1, it makes sense to use them in preference to ll/sc sequences. This patch introduces runtime patching of atomic_t and atomic64_t routines so that the call-site for the out-of-line ll/sc sequences is patched with an LSE atomic instruction when we detect that the CPU supports it. If binutils is not recent enough to assemble the LSE instructions, then the ll/sc sequences are inlined as though CONFIG_ARM64_LSE_ATOMICS=n. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-02-04 00:14:13 +08:00
arm64: ensure the kernel is compiled for LP64 The kernel needs to be compiled as a LP64 binary for ARM64, even when using a compiler that defaults to code-generation for the ILP32 ABI. Consequently, we need to explicitly pass '-mabi=lp64' (supported on gcc-4.9 and newer). Signed-off-by: Andrew Pinski <Andrew.Pinski@caviumnetworks.com> Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Reviewed-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-09-18 18:20:20 +08:00
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
arm64/build: Remove .eh_frame* sections due to unwind tables Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS contain -fno-asychronous-unwind-tables and -fno-unwind-tables. With all sources of .eh_frame now removed from the build, drop this DISCARD so we can be alerted in the future if it returns unexpectedly once orphan section warnings have been enabled. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org
2020-08-22 03:42:51 +08:00
# Avoid generating .eh_frame* sections.
arm64: unwind: add asynchronous unwind tables to kernel and modules Enable asynchronous unwind table generation for both the core kernel as well as modules, and emit the resulting .eh_frame sections as init code so we can use the unwind directives for code patching at boot or module load time. This will be used by dynamic shadow call stack support, which will rely on code patching rather than compiler codegen to emit the shadow call stack push and pop instructions. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20221027155908.1940624-2-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-10-27 23:59:06 +08:00
ifneq ($(CONFIG_UNWIND_TABLES),y)
arm64/build: Remove .eh_frame* sections due to unwind tables Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS contain -fno-asychronous-unwind-tables and -fno-unwind-tables. With all sources of .eh_frame now removed from the build, drop this DISCARD so we can be alerted in the future if it returns unexpectedly once orphan section warnings have been enabled. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org
2020-08-22 03:42:51 +08:00
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
arm64: unwind: add asynchronous unwind tables to kernel and modules Enable asynchronous unwind table generation for both the core kernel as well as modules, and emit the resulting .eh_frame sections as init code so we can use the unwind directives for code patching at boot or module load time. This will be used by dynamic shadow call stack support, which will rely on code patching rather than compiler codegen to emit the shadow call stack push and pop instructions. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20221027155908.1940624-2-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-10-27 23:59:06 +08:00
else
KBUILD_CFLAGS += -fasynchronous-unwind-tables
KBUILD_AFLAGS += -fasynchronous-unwind-tables
endif
arm64/build: Remove .eh_frame* sections due to unwind tables Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS contain -fno-asychronous-unwind-tables and -fno-unwind-tables. With all sources of .eh_frame now removed from the build, drop this DISCARD so we can be alerted in the future if it returns unexpectedly once orphan section warnings have been enabled. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org
2020-08-22 03:42:51 +08:00
arm64: enable per-task stack canaries This enables the use of per-task stack canary values if GCC has support for emitting the stack canary reference relative to the value of sp_el0, which holds the task struct pointer in the arm64 kernel. The $(eval) extends KBUILD_CFLAGS at the moment the make rule is applied, which means asm-offsets.o (which we rely on for the offset value) is built without the arguments, and everything built afterwards has the options set. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-12 20:08:44 +08:00
ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
prepare: stack_protector_prepare
stack_protector_prepare: prepare0
$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
-mstack-protector-guard-reg=sp_el0 \
-mstack-protector-guard-offset=$(shell \
awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
include/generated/asm-offsets.h))
endif
arm64: bti: Support building kernel C code using BTI When running with BTI enabled we need to ask the compiler to enable generation of BTI landing pads beyond those generated as a result of pointer authentication instructions being landing pads. Since the two features are practically speaking unlikely to be used separately we will make kernel mode BTI depend on pointer authentication in order to simplify the Makefile. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200506195138.22086-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-05-07 03:51:29 +08:00
ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
arm64: pauth: don't sign leaf functions Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4016a7437e ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938e22f8dbf0 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-31 18:58:09 +08:00
KBUILD_CFLAGS += -mbranch-protection=pac-ret+bti
else ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
ifeq ($(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET),y)
KBUILD_CFLAGS += -mbranch-protection=pac-ret
else
KBUILD_CFLAGS += -msign-return-address=non-leaf
endif
arm64: bti: Support building kernel C code using BTI When running with BTI enabled we need to ask the compiler to enable generation of BTI landing pads beyond those generated as a result of pointer authentication instructions being landing pads. Since the two features are practically speaking unlikely to be used separately we will make kernel mode BTI depend on pointer authentication in order to simplify the Makefile. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200506195138.22086-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-05-07 03:51:29 +08:00
else
arm64: pauth: don't sign leaf functions Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4016a7437e ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938e22f8dbf0 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-31 18:58:09 +08:00
KBUILD_CFLAGS += $(call cc-option,-mbranch-protection=none)
arm64: use a common .arch preamble for inline assembly Commit 7c78f67e9bd9 ("arm64: enable tlbi range instructions") breaks LLVM's integrated assembler, because -Wa,-march is only passed to external assemblers and therefore, the new instructions are not enabled when IAS is used. This change adds a common architecture version preamble, which can be used in inline assembly blocks that contain instructions that require a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1 with ARM64_TLB_RANGE. Fixes: 7c78f67e9bd9 ("arm64: enable tlbi range instructions") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1106 Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 04:36:08 +08:00
endif
arm64: unify asm-arch manipulation Assemblers will reject instructions not supported by a target architecture version, and so we must explicitly tell the assembler the latest architecture version for which we want to assemble instructions from. We've added a few AS_HAS_ARMV8_<N> definitions for this, in addition to an inconsistently named AS_HAS_PAC definition, from which arm64's top-level Makefile determines the architecture version that we intend to target, and generates the `asm-arch` variable. To make this a bit clearer and easier to maintain, this patch reworks the Makefile to determine asm-arch in a single if-else-endif chain. AS_HAS_PAC, which is defined when the assembler supports `-march=armv8.3-a`, is renamed to AS_HAS_ARMV8_3. As the logic for armv8.3-a is lifted out of the block handling pointer authentication, `asm-arch` may now be set to armv8.3-a regardless of whether support for pointer authentication is selected. This means that it will be possible to assemble armv8.3-a instructions even if we didn't intend to, but this is consistent with our handling of other architecture versions, and the compiler won't generate armv8.3-a instructions regardless. For the moment there's no need for an CONFIG_AS_HAS_ARMV8_1, as the code for LSE atomics and LDAPR use individual `.arch_extension` entries and do not require the baseline asm arch to be bumped to armv8.1-a. The other armv8.1-a features (e.g. PAN) do not require assembler support. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-31 18:58:08 +08:00
# Tell the assembler to support instructions from the latest target
# architecture.
#
# For non-integrated assemblers we'll pass this on the command line, and for
# integrated assemblers we'll define ARM64_ASM_ARCH and ARM64_ASM_PREAMBLE for
# inline usage.
#
# We cannot pass the same arch flag to the compiler as this would allow it to
# freely generate instructions which are not supported by earlier architecture
# versions, which would prevent a single kernel image from working on earlier
# hardware.
arm64: enable armv8.5-a asm-arch option Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) which is an armv8.5-a architecture extension. Enable the correct asm option when the compiler supports it in order to allow the usage of ALTERNATIVE()s with MTE instructions. Link: https://lkml.kernel.org/r/d03d1157124ea3532eaeb77507988733f5734986.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-23 04:01:24 +08:00
ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
arm64: unify asm-arch manipulation Assemblers will reject instructions not supported by a target architecture version, and so we must explicitly tell the assembler the latest architecture version for which we want to assemble instructions from. We've added a few AS_HAS_ARMV8_<N> definitions for this, in addition to an inconsistently named AS_HAS_PAC definition, from which arm64's top-level Makefile determines the architecture version that we intend to target, and generates the `asm-arch` variable. To make this a bit clearer and easier to maintain, this patch reworks the Makefile to determine asm-arch in a single if-else-endif chain. AS_HAS_PAC, which is defined when the assembler supports `-march=armv8.3-a`, is renamed to AS_HAS_ARMV8_3. As the logic for armv8.3-a is lifted out of the block handling pointer authentication, `asm-arch` may now be set to armv8.3-a regardless of whether support for pointer authentication is selected. This means that it will be possible to assemble armv8.3-a instructions even if we didn't intend to, but this is consistent with our handling of other architecture versions, and the compiler won't generate armv8.3-a instructions regardless. For the moment there's no need for an CONFIG_AS_HAS_ARMV8_1, as the code for LSE atomics and LDAPR use individual `.arch_extension` entries and do not require the baseline asm arch to be bumped to armv8.1-a. The other armv8.1-a features (e.g. PAN) do not require assembler support. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-31 18:58:08 +08:00
asm-arch := armv8.5-a
else ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
asm-arch := armv8.4-a
else ifeq ($(CONFIG_AS_HAS_ARMV8_3), y)
asm-arch := armv8.3-a
else ifeq ($(CONFIG_AS_HAS_ARMV8_2), y)
asm-arch := armv8.2-a
arm64: enable armv8.5-a asm-arch option Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) which is an armv8.5-a architecture extension. Enable the correct asm option when the compiler supports it in order to allow the usage of ALTERNATIVE()s with MTE instructions. Link: https://lkml.kernel.org/r/d03d1157124ea3532eaeb77507988733f5734986.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-23 04:01:24 +08:00
endif
arm64: use a common .arch preamble for inline assembly Commit 7c78f67e9bd9 ("arm64: enable tlbi range instructions") breaks LLVM's integrated assembler, because -Wa,-march is only passed to external assemblers and therefore, the new instructions are not enabled when IAS is used. This change adds a common architecture version preamble, which can be used in inline assembly blocks that contain instructions that require a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1 with ARM64_TLB_RANGE. Fixes: 7c78f67e9bd9 ("arm64: enable tlbi range instructions") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1106 Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 04:36:08 +08:00
ifdef asm-arch
KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \
-DARM64_ASM_ARCH='"$(asm-arch)"'
arm64: enable tlbi range instructions TLBI RANGE feature instoduces new assembly instructions and only support by binutils >= 2.30. Add necessary Kconfig logic to allow this to be enabled and pass '-march=armv8.4-a' to KBUILD_CFLAGS. Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com> Link: https://lore.kernel.org/r/20200715071945.897-3-yezhenyu2@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-15 15:19:44 +08:00
endif
arm64: Reserve register x18 from general allocation with SCS Reserve the x18 register from general allocation when SCS is enabled, because the compiler uses the register to store the current task's shadow stack pointer. Note that all external kernel modules must also be compiled with -ffixed-x18 if the kernel has SCS enabled. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 00:00:11 +08:00
ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
KBUILD_CFLAGS += -ffixed-x18
endif
arm64: big-endian: add big-endian support to top-level arch Makefile This patch adds big-endian support to the AArch64 top-level Makefile. This currently just passes the relevant flags to the toolchain and is predicated on a Kconfig option that will be introduced later on. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-10-11 21:52:08 +08:00
ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
KBUILD_CPPFLAGS += -mbig-endian
arm64: pass endianness info to sparse ARM64 depends on the macro __AARCH64EB__ being defined or not to correctly select or define endian-specific macros, structures or pieces of code. This macro is predefined by the compiler but sparse knows nothing about it and thus may pre-process files differently from what gcc would. Fix this by passing '-D__AARCH64EL__' or '-D__AARCH64EB__' to sparse depending of the endianness of the kernel, like defined by GCC. Note: In most case it won't change anything since most arm64 use little-endian (but an allyesconfig would use big-endian!). CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-24 23:42:11 +08:00
CHECKFLAGS += -D__AARCH64EB__
arm64: build with baremetal linker target instead of Linux when available Not all toolchains have the baremetal elf targets, RedHat/Fedora ones in particular. So, probe for whether it's available and use the previous (linux) targets if it isn't. Reported-by: Laura Abbott <labbott@redhat.com> Tested-by: Laura Abbott <labbott@redhat.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Paul Kocialkowski <contact@paulk.fr> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-13 23:30:33 +08:00
# Prefer the baremetal ELF build target, but not all toolchains include
# it so fall back to the standard linux version if needed.
arm64: link with -z norelro for LLD or aarch64-elf 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>
2020-12-18 08:24:32 +08:00
KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
arm64: Set UTS_MACHINE in the Makefile The make rpm target depends on proper UTS_MACHINE definition. Also, use the variable in arch/arm64/kernel/setup.c, so that it's not accidentally removed in the future. Reported-and-tested-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-30 16:31:35 +08:00
UTS_MACHINE := aarch64_be
arm64: big-endian: add big-endian support to top-level arch Makefile This patch adds big-endian support to the AArch64 top-level Makefile. This currently just passes the relevant flags to the toolchain and is predicated on a Kconfig option that will be introduced later on. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-10-11 21:52:08 +08:00
else
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
KBUILD_CPPFLAGS += -mlittle-endian
arm64: pass endianness info to sparse ARM64 depends on the macro __AARCH64EB__ being defined or not to correctly select or define endian-specific macros, structures or pieces of code. This macro is predefined by the compiler but sparse knows nothing about it and thus may pre-process files differently from what gcc would. Fix this by passing '-D__AARCH64EL__' or '-D__AARCH64EB__' to sparse depending of the endianness of the kernel, like defined by GCC. Note: In most case it won't change anything since most arm64 use little-endian (but an allyesconfig would use big-endian!). CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-24 23:42:11 +08:00
CHECKFLAGS += -D__AARCH64EL__
arm64: build with baremetal linker target instead of Linux when available Not all toolchains have the baremetal elf targets, RedHat/Fedora ones in particular. So, probe for whether it's available and use the previous (linux) targets if it isn't. Reported-by: Laura Abbott <labbott@redhat.com> Tested-by: Laura Abbott <labbott@redhat.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Paul Kocialkowski <contact@paulk.fr> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-13 23:30:33 +08:00
# Same as above, prefer ELF but fall back to linux target if needed.
arm64: link with -z norelro for LLD or aarch64-elf 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>
2020-12-18 08:24:32 +08:00
KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
arm64: Set UTS_MACHINE in the Makefile The make rpm target depends on proper UTS_MACHINE definition. Also, use the variable in arch/arm64/kernel/setup.c, so that it's not accidentally removed in the future. Reported-and-tested-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-30 16:31:35 +08:00
UTS_MACHINE := aarch64
arm64: big-endian: add big-endian support to top-level arch Makefile This patch adds big-endian support to the AArch64 top-level Makefile. This currently just passes the relevant flags to the toolchain and is predicated on a Kconfig option that will be introduced later on. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-10-11 21:52:08 +08:00
endif
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: link with -z norelro for LLD or aarch64-elf 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>
2020-12-18 08:24:32 +08:00
ifeq ($(CONFIG_LD_IS_LLD), y)
KBUILD_LDFLAGS += -z norelro
endif
kbuild: add machine size to CHECKFLAGS By default, sparse assumes a 64bit machine when compiled on x86-64 and 32bit when compiled on anything else. This can of course create all sort of problems for the other archs, like issuing false warnings ('shift too big (32) for type unsigned long'), or worse, failing to emit legitimate warnings. Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT, to CHECKFLAGS in the main Makefile (and so for all archs). Also, remove the now unneeded -m32/-m64 in arch specific Makefiles. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-31 04:48:38 +08:00
CHECKFLAGS += -D__aarch64__
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS This patch enables support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64. This allows each ftrace callsite to provide an ftrace_ops to the common ftrace trampoline, allowing each callsite to invoke distinct tracer functions without the need to fall back to list processing or to allocate custom trampolines for each callsite. This significantly speeds up cases where multiple distinct trace functions are used and callsites are mostly traced by a single tracer. The main idea is to place a pointer to the ftrace_ops as a literal at a fixed offset from the function entry point, which can be recovered by the common ftrace trampoline. Using a 64-bit literal avoids branch range limitations, and permits the ops to be swapped atomically without special considerations that apply to code-patching. In future this will also allow for the implementation of DYNAMIC_FTRACE_WITH_DIRECT_CALLS without branch range limitations by using additional fields in struct ftrace_ops. As noted in the core patch adding support for DYNAMIC_FTRACE_WITH_CALL_OPS, this approach allows for directly invoking ftrace_ops::func even for ftrace_ops which are dynamically-allocated (or part of a module), without going via ftrace_ops_list_func. Currently, this approach is not compatible with CLANG_CFI, as the presence/absence of pre-function NOPs changes the offset of the pre-function type hash, and there's no existing mechanism to ensure a consistent offset for instrumented and uninstrumented functions. When CLANG_CFI is enabled, the existing scheme with a global ops->func pointer is used, and there should be no functional change. I am currently working with others to allow the two to work together in future (though this will liekly require updated compiler support). I've benchamrked this with the ftrace_ops sample module [1], which is not currently upstream, but available at: https://lore.kernel.org/lkml/20230103124912.2948963-1-mark.rutland@arm.com git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git ftrace-ops-sample-20230109 Using that module I measured the total time taken for 100,000 calls to a trivial instrumented function, with a number of tracers enabled with relevant filters (which would apply to the instrumented function) and a number of tracers enabled with irrelevant filters (which would not apply to the instrumented function). I tested on an M1 MacBook Pro, running under a HVF-accelerated QEMU VM (i.e. on real hardware). Before this patch: Number of tracers || Total time | Per-call average time (ns) Relevant | Irrelevant || (ns) | Total | Overhead =========+============++=============+==============+============ 0 | 0 || 94,583 | 0.95 | - 0 | 1 || 93,709 | 0.94 | - 0 | 2 || 93,666 | 0.94 | - 0 | 10 || 93,709 | 0.94 | - 0 | 100 || 93,792 | 0.94 | - ---------+------------++-------------+--------------+------------ 1 | 1 || 6,467,833 | 64.68 | 63.73 1 | 2 || 7,509,708 | 75.10 | 74.15 1 | 10 || 23,786,792 | 237.87 | 236.92 1 | 100 || 106,432,500 | 1,064.43 | 1063.38 ---------+------------++-------------+--------------+------------ 1 | 0 || 1,431,875 | 14.32 | 13.37 2 | 0 || 6,456,334 | 64.56 | 63.62 10 | 0 || 22,717,000 | 227.17 | 226.22 100 | 0 || 103,293,667 | 1032.94 | 1031.99 ---------+------------++-------------+--------------+-------------- Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. After this patch Number of tracers || Total time | Per-call average time (ns) Relevant | Irrelevant || (ns) | Total | Overhead =========+============++=============+==============+============ 0 | 0 || 94,541 | 0.95 | - 0 | 1 || 93,666 | 0.94 | - 0 | 2 || 93,709 | 0.94 | - 0 | 10 || 93,667 | 0.94 | - 0 | 100 || 93,792 | 0.94 | - ---------+------------++-------------+--------------+------------ 1 | 1 || 281,000 | 2.81 | 1.86 1 | 2 || 281,042 | 2.81 | 1.87 1 | 10 || 280,958 | 2.81 | 1.86 1 | 100 || 281,250 | 2.81 | 1.87 ---------+------------++-------------+--------------+------------ 1 | 0 || 280,959 | 2.81 | 1.86 2 | 0 || 6,502,708 | 65.03 | 64.08 10 | 0 || 18,681,209 | 186.81 | 185.87 100 | 0 || 103,550,458 | 1,035.50 | 1034.56 ---------+------------++-------------+--------------+------------ Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. As can be seen from the above: a) Whenever there is a single relevant tracer function associated with a tracee, the overhead of invoking the tracer is constant, and does not scale with the number of tracers which are *not* associated with that tracee. b) The overhead for a single relevant tracer has dropped to ~1/7 of the overhead prior to this series (from 13.37ns to 1.86ns). This is largely due to permitting calls to dynamically-allocated ftrace_ops without going through ftrace_ops_list_func. I've run the ftrace selftests from v6.2-rc3, which reports: | # of passed: 110 | # of failed: 0 | # of unresolved: 3 | # of untested: 0 | # of unsupported: 0 | # of xfailed: 1 | # of undefined(test bug): 0 ... where the unresolved entries were the tests for DIRECT functions (which are not supported), and the checkbashisms selftest (which is irrelevant here): | [8] Test ftrace direct functions against tracers [UNRESOLVED] | [9] Test ftrace direct functions against kprobes [UNRESOLVED] | [62] Meta-selftest: Checkbashisms [UNRESOLVED] ... with all other tests passing (or failing as expected). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Florent Revest <revest@chromium.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230123134603.1064407-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-23 21:46:03 +08:00
ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS),y)
KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
CC_FLAGS_FTRACE := -fpatchable-function-entry=4,2
else ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_ARGS),y)
arm64: implement ftrace with regs This patch implements FTRACE_WITH_REGS for arm64, which allows a traced function's arguments (and some other registers) to be captured into a struct pt_regs, allowing these to be inspected and/or modified. This is a building block for live-patching, where a function's arguments may be forwarded to another function. This is also necessary to enable ftrace and in-kernel pointer authentication at the same time, as it allows the LR value to be captured and adjusted prior to signing. Using GCC's -fpatchable-function-entry=N option, we can have the compiler insert a configurable number of NOPs between the function entry point and the usual prologue. This also ensures functions are AAPCS compliant (e.g. disabling inter-procedural register allocation). For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the following: | unsigned long bar(void); | | unsigned long foo(void) | { | return bar() + 1; | } ... to: | <foo>: | nop | nop | stp x29, x30, [sp, #-16]! | mov x29, sp | bl 0 <bar> | add x0, x0, #0x1 | ldp x29, x30, [sp], #16 | ret This patch builds the kernel with -fpatchable-function-entry=2, prefixing each function with two NOPs. To trace a function, we replace these NOPs with a sequence that saves the LR into a GPR, then calls an ftrace entry assembly function which saves this and other relevant registers: | mov x9, x30 | bl <ftrace-entry> Since patchable functions are AAPCS compliant (and the kernel does not use x18 as a platform register), x9-x18 can be safely clobbered in the patched sequence and the ftrace entry code. There are now two ftrace entry functions, ftrace_regs_entry (which saves all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is allocated for each within modules. Signed-off-by: Torsten Duwe <duwe@suse.de> [Mark: rework asm, comments, PLTs, initialization, commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Torsten Duwe <duwe@suse.de> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Tested-by: Torsten Duwe <duwe@suse.de> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Julien Thierry <jthierry@redhat.com> Cc: Will Deacon <will@kernel.org>
2019-02-08 23:10:19 +08:00
KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
CC_FLAGS_FTRACE := -fpatchable-function-entry=2
endif
kasan, arm64: adjust shadow size for tag-based mode Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it requires 1/16th of the kernel virtual address space for the shadow memory. This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN mode is enabled. Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 16:29:57 +08:00
ifeq ($(CONFIG_KASAN_SW_TAGS), y)
KASAN_SHADOW_SCALE_SHIFT := 4
kasan, arm64: expand CONFIG_KASAN checks Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes (either related to shadow memory or compiler instrumentation). Expand those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS. Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-23 04:02:06 +08:00
else ifeq ($(CONFIG_KASAN_GENERIC), y)
kasan, arm64: adjust shadow size for tag-based mode Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it requires 1/16th of the kernel virtual address space for the shadow memory. This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN mode is enabled. Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 16:29:57 +08:00
KASAN_SHADOW_SCALE_SHIFT := 3
endif
KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
libs-y := arch/arm64/lib/ $(libs-y)
efi/libstub/arm64: link stub lib.a conditionally Since commit 799c43415442 ("kbuild: thin archives make default for all archs"), core-y is passed to the linker with --whole-archive. Hence, the whole of stub library is linked to vmlinux. Use libs-y so that lib.a is passed after --no-whole-archive for conditional linking. The unused drivers/firmware/efi/libstub/relocate.o will be dropped for ARCH=arm64. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20200604022031.164207-1-masahiroy@kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-04 10:20:30 +08:00
libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
# Default target when executing plain make
arm64: Use full path in KBUILD_IMAGE definition The KBUILD_IMAGE variable is used by the rpm and deb-pkg targets, which expect it to point to the image file in the build directory. The builddeb script has a workaround for architectures which only provide the basename, but let's provide a clean interface for packaging tools. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Michal Marek <mmarek@suse.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-11-23 05:34:29 +08:00
boot := arch/arm64/boot
arm64: efi: enable generic EFI compressed boot Wire up the generic EFI zboot support for arm64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-02 07:10:03 +08:00
ifeq ($(CONFIG_EFI_ZBOOT),)
arm64: Use full path in KBUILD_IMAGE definition The KBUILD_IMAGE variable is used by the rpm and deb-pkg targets, which expect it to point to the image file in the build directory. The builddeb script has a workaround for architectures which only provide the basename, but let's provide a clean interface for packaging tools. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Michal Marek <mmarek@suse.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-11-23 05:34:29 +08:00
KBUILD_IMAGE := $(boot)/Image.gz
arm64: efi: enable generic EFI compressed boot Wire up the generic EFI zboot support for arm64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-02 07:10:03 +08:00
else
KBUILD_IMAGE := $(boot)/vmlinuz.efi
endif
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: efi: enable generic EFI compressed boot Wire up the generic EFI zboot support for arm64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-02 07:10:03 +08:00
all: $(notdir $(KBUILD_IMAGE))
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: add dependency between vmlinuz.efi and Image A common issue in Makefile is a race in parallel building. You need to be careful to prevent multiple threads from writing to the same file simultaneously. Commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not generate invalid images") addressed such a bad scenario. A similar symptom occurs with the following command: $ make -j$(nproc) ARCH=arm64 Image vmlinuz.efi [ snip ] SORTTAB vmlinux OBJCOPY arch/arm64/boot/Image OBJCOPY arch/arm64/boot/Image AS arch/arm64/boot/zboot-header.o PAD arch/arm64/boot/vmlinux.bin GZIP arch/arm64/boot/vmlinuz OBJCOPY arch/arm64/boot/vmlinuz.o LD arch/arm64/boot/vmlinuz.efi.elf OBJCOPY arch/arm64/boot/vmlinuz.efi The log "OBJCOPY arch/arm64/boot/Image" is displayed twice. It indicates that two threads simultaneously enter arch/arm64/boot/ and write to arch/arm64/boot/Image. It occasionally leads to a build failure: $ make -j$(nproc) ARCH=arm64 Image vmlinuz.efi [ snip ] SORTTAB vmlinux OBJCOPY arch/arm64/boot/Image PAD arch/arm64/boot/vmlinux.bin truncate: Invalid number: 'arch/arm64/boot/vmlinux.bin' make[2]: *** [drivers/firmware/efi/libstub/Makefile.zboot:13: arch/arm64/boot/vmlinux.bin] Error 1 make[2]: *** Deleting file 'arch/arm64/boot/vmlinux.bin' make[1]: *** [arch/arm64/Makefile:163: vmlinuz.efi] Error 2 make[1]: *** Waiting for unfinished jobs.... make: *** [Makefile:234: __sub-make] Error 2 vmlinuz.efi depends on Image, but such a dependency is not specified in arch/arm64/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: SImon Glass <sjg@chromium.org> Link: https://lore.kernel.org/r/20231119053234.2367621-1-masahiroy@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-11-19 13:32:34 +08:00
vmlinuz.efi: Image
arm64: efi: enable generic EFI compressed boot Wire up the generic EFI zboot support for arm64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-02 07:10:03 +08:00
Image vmlinuz.efi: vmlinux
arm64: enable more compressed Image formats Plumb up Makefile arguments for the already supported formats in the kbuild system: lz4, bzip2, lzma, and lzo. Note that just as with Image.gz, these images are not self-decompressing and the booting firmware still needs to handle decompression before launching the kernel image. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-17 04:26:16 +08:00
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
arm64: fix boot image dependencies to not generate invalid images I fixed boot image dependencies for arch/arm in commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not generate invalid images"). I see a similar problem for arch/arm64; "make -jN Image Image.gz" would sometimes end up generating bad images where N > 1. Fix the dependency in arch/arm64/Makefile to avoid the race between "make Image" and "make Image.*". Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-21 09:44:00 +08:00
Image.%: Image
arm64: Add dtbs target for building all the enabled dtb files Based on Rob Herring's patches for arch/arm, this patch adds a dtbs target to arch/arm64/boot/Makefile. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
2012-12-04 07:17:21 +08:00
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
kbuild: factor out the common installation code into scripts/install.sh Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-03 10:47:16 +08:00
install: KBUILD_IMAGE := $(boot)/Image
arm64: move the (z)install rules to arch/arm64/Makefile Currently, the (z)install targets in arch/arm64/Makefile descend into arch/arm64/boot/Makefile to invoke the shell script, but there is no good reason to do so. arch/arm64/Makefile can run the shell script directly. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210729140527.443116-1-masahiroy@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-29 22:05:27 +08:00
install zinstall:
kbuild: factor out the common installation code into scripts/install.sh Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-03 10:47:16 +08:00
$(call cmd,install)
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
arm64: Generate cpucaps.h The arm64 code allocates an internal constant to every CPU feature it can detect, distinct from the public hwcap numbers we use to expose some features to userspace. Currently this is maintained manually which is an irritating source of conflicts when working on new features, to avoid this replace the header with a simple text file listing the names we've assigned and sort it to minimise conflicts. As part of doing this we also do the Kbuild hookup required to hook up an arch tools directory and to generate header files in there. This will result in a renumbering and reordering of the existing constants, since they are all internal only the values should not be important. The reordering will impact the order in which some steps in enumeration handle features but the algorithm is not intended to depend on this and I haven't seen any issues when testing. Due to the UAO cpucap having been removed in the past we end up with ARM64_NCAPS being 1 smaller than it was before. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210428121231.11219-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-28 20:12:31 +08:00
archprepare:
$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
arm64: move warning about toolchains to archprepare Commit 987fdfec2410 ("arm64: move --fix-cortex-a53-843419 linker test to Kconfig") fixed the false-positive warning in the installation step. Yet, there are some cases where this false-positive is shown. For example, you can see it when you cross 987fdfec2410 during git-bisect. $ git checkout 987fdfec2410^ [ snip ] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] $ git checkout v5.13 [ snip] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum In the stale include/config/auto.config, CONFIG_ARM64_ERRATUM_843419=y is set without CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419, so the warning is displayed while parsing the Makefiles. Make will restart with the updated include/config/auto.config, hence CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419 will be set eventually, but this warning is a surprise for users. Commit 25896d073d8a ("x86/build: Fix compiler support check for CONFIG_RETPOLINE") addressed a similar issue. Move $(warning ...) out of the parse stage of Makefiles. The same applies to CONFIG_ARM64_USE_LSE_ATOMICS. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210801053525.105235-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-08-01 13:35:25 +08:00
ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
@echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
endif
endif
ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
@echo "warning: LSE atomics not supported by binutils" >&2
endif
endif
arm64: makefile fix build of .i file in external module case After 'a66649dab350 arm64: fix vdso-offsets.h dependency' if one will try to build .i file in case of external kernel module, build fails complaining that prepare0 target is missing. This issue came up with SystemTap when it tries to build variety of .i files for its own generated kernel modules trying to figure given kernel features/capabilities. The issue is that prepare0 is defined in top level Makefile only if KBUILD_EXTMOD is not defined. .i file rule depends on prepare and in case KBUILD_EXTMOD defined top level Makefile contains empty rule for prepare. But after mentioned commit arch/arm64/Makefile would introduce dependency on prepare0 through its own prepare target. Fix it to put proper ifdef KBUILD_EXTMOD around code introduced by mentioned commit. It matches what top level Makefile does. Acked-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-31 07:37:10 +08:00
ifeq ($(KBUILD_EXTMOD),)
arm64: fix vdso-offsets.h dependency arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any file that includes asm/vdso.h. Therefore, vdso-offsets.h must be generated before these files are compiled. The current rules in arm64/kernel/Makefile do not actually enforce this, because even though $(obj)/vdso is listed as a prerequisite for vdso-offsets.h, this does not result in the intended effect of building the vdso subdirectory (before all the other objects). As a consequence, depending on the order in which the rules are followed, vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o are built. The current rules also impose an unnecessary dependency on vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary rebuilds. This is made obvious when using make -j: touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel will sometimes result in none of arm64/kernel/*.o being rebuilt, sometimes all of them, or even just some of them. It is quite difficult to ensure that a header is generated before it is used with recursive Makefiles by using normal rules. Instead, arch-specific generated headers are normally built in the archprepare recipe in the arch Makefile (see for instance arch/ia64/Makefile). Unfortunately, asm-offsets.h is included in gettimeofday.S, and must therefore be generated before vdso-offsets.h, which is not the case if archprepare is used. For this reason, a rule run after archprepare has to be used. This commit adds rules in arm64/Makefile to build vdso-offsets.h during the prepare step, ensuring that vdso-offsets.h is generated before building anything. It also removes the now-unnecessary dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it removes the duplication of asm-offsets.h between arm64/kernel/vdso/ and include/generated/ and makes include/generated/vdso-offsets.h a target in arm64/kernel/vdso/Makefile. Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-05-13 00:39:15 +08:00
# We need to generate vdso-offsets.h before compiling certain files in kernel/.
# In order to do that, we should use the archprepare target, but we can't since
# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
# Therefore we need to generate the header after prepare0 has been made, hence
# this hack.
prepare: vdso_prepare
vdso_prepare: prepare0
arm64: do not descend to vdso directories twice arm64 descends into each vdso directory twice; first in vdso_prepare, second during the ordinary build process. PPC mimicked it and uncovered a problem [1]. In the first descend, Kbuild directly visits the vdso directories, therefore it does not inherit subdir-ccflags-y from upper directories. This means the command line parameters may differ between the two. If it happens, the offset values in the generated headers might be different from real offsets of vdso.so in the kernel. This potential danger should be avoided. The vdso directories are built in the vdso_prepare stage, so the second descend is unneeded. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73a Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-12-18 10:45:40 +08:00
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
ifdef CONFIG_COMPAT_VDSO
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so
endif
arm64: makefile fix build of .i file in external module case After 'a66649dab350 arm64: fix vdso-offsets.h dependency' if one will try to build .i file in case of external kernel module, build fails complaining that prepare0 target is missing. This issue came up with SystemTap when it tries to build variety of .i files for its own generated kernel modules trying to figure given kernel features/capabilities. The issue is that prepare0 is defined in top level Makefile only if KBUILD_EXTMOD is not defined. .i file rule depends on prepare and in case KBUILD_EXTMOD defined top level Makefile contains empty rule for prepare. But after mentioned commit arch/arm64/Makefile would introduce dependency on prepare0 through its own prepare target. Fix it to put proper ifdef KBUILD_EXTMOD around code introduced by mentioned commit. It matches what top level Makefile does. Acked-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-31 07:37:10 +08:00
endif
arm64: fix vdso-offsets.h dependency arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any file that includes asm/vdso.h. Therefore, vdso-offsets.h must be generated before these files are compiled. The current rules in arm64/kernel/Makefile do not actually enforce this, because even though $(obj)/vdso is listed as a prerequisite for vdso-offsets.h, this does not result in the intended effect of building the vdso subdirectory (before all the other objects). As a consequence, depending on the order in which the rules are followed, vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o are built. The current rules also impose an unnecessary dependency on vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary rebuilds. This is made obvious when using make -j: touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel will sometimes result in none of arm64/kernel/*.o being rebuilt, sometimes all of them, or even just some of them. It is quite difficult to ensure that a header is generated before it is used with recursive Makefiles by using normal rules. Instead, arch-specific generated headers are normally built in the archprepare recipe in the arch Makefile (see for instance arch/ia64/Makefile). Unfortunately, asm-offsets.h is included in gettimeofday.S, and must therefore be generated before vdso-offsets.h, which is not the case if archprepare is used. For this reason, a rule run after archprepare has to be used. This commit adds rules in arm64/Makefile to build vdso-offsets.h during the prepare step, ensuring that vdso-offsets.h is generated before building anything. It also removes the now-unnecessary dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it removes the duplication of asm-offsets.h between arm64/kernel/vdso/ and include/generated/ and makes include/generated/vdso-offsets.h a target in arm64/kernel/vdso/Makefile. Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-05-13 00:39:15 +08:00
kbuild: unify vdso_install rules Currently, there is no standard implementation for vdso_install, leading to various issues: 1. Code duplication Many architectures duplicate similar code just for copying files to the install destination. Some architectures (arm, sparc, x86) create build-id symlinks, introducing more code duplication. 2. Unintended updates of in-tree build artifacts The vdso_install rule depends on the vdso files to install. It may update in-tree build artifacts. This can be problematic, as explained in commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"). 3. Broken code in some architectures Makefile code is often copied from one architecture to another without proper adaptation. 'make vdso_install' for parisc does not work. 'make vdso_install' for s390 installs vdso64, but not vdso32. To address these problems, this commit introduces a generic vdso_install rule. Architectures that support vdso_install need to define vdso-install-y in arch/*/Makefile. vdso-install-y lists the files to install. For example, arch/x86/Makefile looks like this: vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix, if exists, stripped away. vdso-install-y can optionally take the second field after the colon separator. This is needed because some architectures install a vdso file as a different base name. The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so This will rename vdso.so.dbg to vdso32.so during installation. If such architectures change their implementation so that the base names match, this workaround will go away. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390 Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Guo Ren <guoren@kernel.org> Acked-by: Helge Deller <deller@gmx.de> # parisc Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-14 18:54:35 +08:00
vdso-install-y += arch/arm64/kernel/vdso/vdso.so.dbg
vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so
arm64: configs: Add virtconfig Provide a slimline configuration intended to be booted on virtual machines, with the goal of providing a light configuration which will boot on and enable features available in mach-virt. This is defined in terms of the standard defconfig, with an additional virt.config fragment which disables options unneeded in a virtual configuration. As a first step we just disable all the ARCH_ configuration options, disabling the build of all the SoC specific drivers. This results in a kernel that builds about 25% faster in my testing, if this approach works for people we can add further options. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20230203-arm64-defconfigs-v1-3-cd0694a05f13@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-02-11 03:52:49 +08:00
include $(srctree)/scripts/Makefile.defconf
PHONY += virtconfig
virtconfig:
$(call merge_into_defconfig_override,defconfig,virt)
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-04-20 21:45:54 +08:00
define archhelp
echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
echo ' install - Install uncompressed kernel'
echo ' zinstall - Install compressed kernel'
echo ' Install using (your) ~/bin/installkernel or'
echo ' (distribution) /sbin/installkernel or'
echo ' install to $$(INSTALL_PATH) and run lilo'
endef
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