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2021-12-14arm64/xor: use EOR3 instructions when availableArd Biesheuvel1-0/+5
Use the EOR3 instruction to implement xor_blocks() if the instruction is available, which is the case if the CPU implements the SHA-3 extension. This is about 20% faster on Apple M1 when using the 5-way version. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20211213140252.2856053-1-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-10-24kbuild: use more subdir- for visiting subdirectories while cleaningMasahiro Yamada1-7/+0
Documentation/kbuild/makefiles.rst suggests to use "archclean" for cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement. Since commit d92cc4d51643 ("kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for all architectures. This can take advantage of the parallel option (-j) for "make clean". I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep" target no longer exists. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
2021-09-02Merge tag 'arm64-upstream' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Support for 32-bit tasks on asymmetric AArch32 systems (on top of the scheduler changes merged via the tip tree). - More entry.S clean-ups and conversion to C. - MTE updates: allow a preferred tag checking mode to be set per CPU (the overhead of synchronous mode is smaller for some CPUs than others); optimisations for kernel entry/exit path; optionally disable MTE on the kernel command line. - Kselftest improvements for SVE and signal handling, PtrAuth. - Fix unlikely race where a TLBI could use stale ASID on an ASID roll-over (found by inspection). - Miscellaneous fixes: disable trapping of PMSNEVFR_EL1 to higher exception levels; drop unnecessary sigdelsetmask() call in the signal32 handling; remove BUG_ON when failing to allocate SVE state (just signal the process); SYM_CODE annotations. - Other trivial clean-ups: use macros instead of magic numbers, remove redundant returns, typos. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (56 commits) arm64: Do not trap PMSNEVFR_EL1 arm64: mm: fix comment typo of pud_offset_phys() arm64: signal32: Drop pointless call to sigdelsetmask() arm64/sve: Better handle failure to allocate SVE register storage arm64: Document the requirement for SCR_EL3.HCE arm64: head: avoid over-mapping in map_memory arm64/sve: Add a comment documenting the binutils needed for SVE asm arm64/sve: Add some comments for sve_save/load_state() kselftest/arm64: signal: Add a TODO list for signal handling tests kselftest/arm64: signal: Add test case for SVE register state in signals kselftest/arm64: signal: Verify that signals can't change the SVE vector length kselftest/arm64: signal: Check SVE signal frame shows expected vector length kselftest/arm64: signal: Support signal frames with SVE register data kselftest/arm64: signal: Add SVE to the set of features we can check for arm64: replace in_irq() with in_hardirq() kselftest/arm64: pac: Fix skipping of tests on systems without PAC Documentation: arm64: describe asymmetric 32-bit support arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 arm64: Advertise CPUs capable of running 32-bit applications in sysfs ...
2021-08-31Merge remote-tracking branch 'tip/sched/arm64' into for-next/coreCatalin Marinas1-9/+12
* tip/sched/arm64: (785 commits) Documentation: arm64: describe asymmetric 32-bit support arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 arm64: Advertise CPUs capable of running 32-bit applications in sysfs arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 arm64: Implement task_cpu_possible_mask() sched: Introduce dl_task_check_affinity() to check proposed affinity sched: Allow task CPU affinity to be restricted on asymmetric systems sched: Split the guts of sched_setaffinity() into a helper function sched: Introduce task_struct::user_cpus_ptr to track requested affinity sched: Reject CPU affinity changes based on task_cpu_possible_mask() cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 sched: Introduce task_cpu_possible_mask() to limit fallback rq selection sched: Cgroup SCHED_IDLE support sched/topology: Skip updating masks for non-online nodes Linux 5.14-rc6 lib: use PFN_PHYS() in devmem_is_allowed() ...
2021-08-11arm64: clean vdso & vdso32 filesAndrew Delgadillo1-0/+2
commit a5b8ca97fbf8 ("arm64: do not descend to vdso directories twice") changes the cleaning behavior of arm64's vdso files, in that vdso.lds, vdso.so, and vdso.so.dbg are not removed upon a 'make clean/mrproper': $ make defconfig ARCH=arm64 $ make ARCH=arm64 $ make mrproper ARCH=arm64 $ git clean -nxdf Would remove arch/arm64/kernel/vdso/vdso.lds Would remove arch/arm64/kernel/vdso/vdso.so Would remove arch/arm64/kernel/vdso/vdso.so.dbg To remedy this, manually descend into arch/arm64/kernel/vdso upon cleaning. After this commit: $ make defconfig ARCH=arm64 $ make ARCH=arm64 $ make mrproper ARCH=arm64 $ git clean -nxdf <empty> Similar results are obtained for the vdso32 equivalent. Signed-off-by: Andrew Delgadillo <adelg@google.com> Cc: stable@vger.kernel.org Fixes: a5b8ca97fbf8 ("arm64: do not descend to vdso directories twice") Link: https://lore.kernel.org/r/20210810231755.1743524-1-adelg@google.com Signed-off-by: Will Deacon <will@kernel.org>
2021-08-03arm64: move the (z)install rules to arch/arm64/MakefileMasahiro Yamada1-2/+5
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>
2021-08-03arm64: move warning about toolchains to archprepareMasahiro Yamada1-9/+12
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>
2021-07-10Merge tag 'kbuild-v5.14' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Increase the -falign-functions alignment for the debug option. - Remove ugly libelf checks from the top Makefile. - Make the silent build (-s) more silent. - Re-compile the kernel if KBUILD_BUILD_TIMESTAMP is specified. - Various script cleanups * tag 'kbuild-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (27 commits) scripts: add generic syscallnr.sh scripts: check duplicated syscall number in syscall table sparc: syscalls: use pattern rules to generate syscall headers parisc: syscalls: use pattern rules to generate syscall headers nds32: add arch/nds32/boot/.gitignore kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set kbuild: modpost: Explicitly warn about unprototyped symbols kbuild: remove trailing slashes from $(KBUILD_EXTMOD) kconfig.h: explain IS_MODULE(), IS_ENABLED() kconfig: constify long_opts scripts/setlocalversion: simplify the short version part scripts/setlocalversion: factor out 12-chars hash construction scripts/setlocalversion: add more comments to -dirty flag detection scripts/setlocalversion: remove workaround for old make-kpkg scripts/setlocalversion: remove mercurial, svn and git-svn supports kbuild: clean up ${quiet} checks in shell scripts kbuild: sink stdout from cmd for silent build init: use $(call cmd,) for generating include/generated/compile.h kbuild: merge scripts/mkmakefile to top Makefile sh: move core-y in arch/sh/Makefile to arch/sh/Kbuild ...
2021-06-15arm64: Add ARM64_PTR_AUTH_KERNEL config optionDaniel Kiss1-1/+1
This patch add the ARM64_PTR_AUTH_KERNEL config and deals with the build aspect of it. Userspace support has no dependency on the toolchain therefore all toolchain checks and build flags are controlled the new config option. The default config behavior will not be changed. Signed-off-by: Daniel Kiss <daniel.kiss@arm.com> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210613092632.93591-2-daniel.kiss@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26kbuild: require all architectures to have arch/$(SRCARCH)/KbuildMasahiro Yamada1-1/+0
arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can use the obj-y syntax. Add an empty file if it is missing in arch/$(SRCARCH)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-05-10arm64: Generate cpucaps.hMark Brown1-0/+3
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>
2021-04-24arm64: move --fix-cortex-a53-843419 linker test to KconfigMasahiro Yamada1-1/+1
Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed"), "make ARCH=arm64 (modules_)install" shows a false positive warning. Move the ld-option test to Kconfig, so that the result can be stored in the .config file, avoiding multiple-time evaluations in the build and installation time. Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2021-01-20arm64: do not descend to vdso directories twiceMasahiro Yamada1-4/+6
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>
2021-01-05arm64: link with -z norelro for LLD or aarch64-elfNick Desaulniers1-3/+7
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>
2020-12-22kasan, arm64: expand CONFIG_KASAN checksAndrey Konovalov1-1/+1
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>
2020-12-22arm64: enable armv8.5-a asm-arch optionVincenzo Frascino1-0/+5
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>
2020-12-01kbuild: Hoist '--orphan-handling' into KconfigNathan Chancellor1-4/+0
Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-23Merge tag 'arm64-upstream' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull more arm64 updates from Will Deacon: "A small selection of further arm64 fixes and updates. Most of these are fixes that came in during the merge window, with the exception of the HAVE_MOVE_PMD mremap() speed-up which we discussed back in 2018 and somehow forgot to enable upstream. - Improve performance of Spectre-v2 mitigation on Falkor CPUs (if you're lucky enough to have one) - Select HAVE_MOVE_PMD. This has been shown to improve mremap() performance, which is used heavily by the Android runtime GC, and it seems we forgot to enable this upstream back in 2018. - Ensure linker flags are consistent between LLVM and BFD - Fix stale comment in Spectre mitigation rework - Fix broken copyright header - Fix KASLR randomisation of the linear map - Prevent arm64-specific prctl()s from compat tasks (return -EINVAL)" Link: https://lore.kernel.org/kvmarm/20181108181201.88826-3-joelaf@google.com/ * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: proton-pack: Update comment to reflect new function name arm64: spectre-v2: Favour CPU-specific mitigation at EL2 arm64: link with -z norelro regardless of CONFIG_RELOCATABLE arm64: Fix a broken copyright header in gen_vdso_offsets.sh arm64: mremap speedup - Enable HAVE_MOVE_PMD arm64: mm: use single quantity to represent the PA to VA translation arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks
2020-10-22Merge tag 'kbuild-v5.10' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...
2020-10-20arm64: link with -z norelro regardless of CONFIG_RELOCATABLENick Desaulniers1-2/+2
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>
2020-10-12Merge tag 'core-build-2020-10-12' of ↵Linus Torvalds1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull orphan section checking from Ingo Molnar: "Orphan link sections were a long-standing source of obscure bugs, because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms" * tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/boot/compressed: Warn on orphan section placement x86/build: Warn on orphan section placement arm/boot: Warn on orphan section placement arm/build: Warn on orphan section placement arm64/build: Warn on orphan section placement x86/boot/compressed: Add missing debugging sections to output x86/boot/compressed: Remove, discard, or assert for unwanted sections x86/boot/compressed: Reorganize zero-size section asserts x86/build: Add asserts for unwanted sections x86/build: Enforce an empty .got.plt section x86/asm: Avoid generating unused kprobe sections arm/boot: Handle all sections explicitly arm/build: Assert for unwanted sections arm/build: Add missing sections arm/build: Explicitly keep .ARM.attributes sections arm/build: Refactor linker script headers arm64/build: Assert for unwanted sections arm64/build: Add missing DWARF sections arm64/build: Use common DISCARDS in linker script arm64/build: Remove .eh_frame* sections due to unwind tables ...
2020-09-24kbuild: preprocess module linker scriptMasahiro Yamada1-4/+0
There was a request to preprocess the module linker script like we do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512) The difference between vmlinux.lds and module.lds is that the latter is needed for external module builds, thus must be cleaned up by 'make mrproper' instead of 'make clean'. Also, it must be created by 'make modules_prepare'. You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by 'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to arch/$(SRCARCH)/include/asm/module.lds.h, which is included from scripts/module.lds.S. scripts/module.lds is fine because 'make clean' keeps all the build artifacts under scripts/. You can add arch-specific sections in <asm/module.lds.h>. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Jessica Yu <jeyu@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Jessica Yu <jeyu@kernel.org>
2020-09-07arm64: get rid of TEXT_OFFSETArd Biesheuvel1-6/+0
TEXT_OFFSET serves no purpose, and for this reason, it was redefined as 0x0 in the v5.8 timeframe. Since this does not appear to have caused any issues that require us to revisit that decision, let's get rid of the macro entirely, along with any references to it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-03arm64/build: Warn on orphan section placementKees Cook1-0/+4
We don't want to depend on the linker's orphan section placement heuristics as these can vary between linkers, and may change between versions. All sections need to be explicitly handled in the linker script. With all sections now handled, enable orphan section warnings. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20200902025347.2504702-2-keescook@chromium.org
2020-09-01arm64/build: Remove .eh_frame* sections due to unwind tablesKees Cook1-1/+4
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
2020-08-28arm64: vdso32: make vdso32 install conditionalFrank van der Linden1-1/+2
vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled, since it's not even supposed to be compiled otherwise, and arm64 builds without a 32bit crosscompiler will fail. Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Cc: stable@vger.kernel.org [5.4+] Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28arm64: use a common .arch preamble for inline assemblySami Tolvanen1-3/+8
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>
2020-08-21ARM64: vdso32: Install vdso32 from vdso_installStephen Boyd1-0/+1
Add the 32-bit vdso Makefile to the vdso_install rule so that 'make vdso_install' installs the 32-bit compat vdso when it is compiled. Fixes: a7f71a2c8903 ("arm64: compat: Add vDSO") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Will Deacon <will@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20200818014950.42492-1-swboyd@chromium.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-04Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+7
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 and cross-arch updates from Catalin Marinas: "Here's a slightly wider-spread set of updates for 5.9. Going outside the usual arch/arm64/ area is the removal of read_barrier_depends() series from Will and the MSI/IOMMU ID translation series from Lorenzo. The notable arm64 updates include ARMv8.4 TLBI range operations and translation level hint, time namespace support, and perf. Summary: - Removal of the tremendously unpopular read_barrier_depends() barrier, which is a NOP on all architectures apart from Alpha, in favour of allowing architectures to override READ_ONCE() and do whatever dance they need to do to ensure address dependencies provide LOAD -> LOAD/STORE ordering. This work also offers a potential solution if compilers are shown to convert LOAD -> LOAD address dependencies into control dependencies (e.g. under LTO), as weakly ordered architectures will effectively be able to upgrade READ_ONCE() to smp_load_acquire(). The latter case is not used yet, but will be discussed further at LPC. - Make the MSI/IOMMU input/output ID translation PCI agnostic, augment the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID bus-specific parameter and apply the resulting changes to the device ID space provided by the Freescale FSL bus. - arm64 support for TLBI range operations and translation table level hints (part of the ARMv8.4 architecture version). - Time namespace support for arm64. - Export the virtual and physical address sizes in vmcoreinfo for makedumpfile and crash utilities. - CPU feature handling cleanups and checks for programmer errors (overlapping bit-fields). - ACPI updates for arm64: disallow AML accesses to EFI code regions and kernel memory. - perf updates for arm64. - Miscellaneous fixes and cleanups, most notably PLT counting optimisation for module loading, recordmcount fix to ignore relocations other than R_AARCH64_CALL26, CMA areas reserved for gigantic pages on 16K and 64K configurations. - Trivial typos, duplicate words" Link: http://lkml.kernel.org/r/20200710165203.31284-1-will@kernel.org Link: http://lkml.kernel.org/r/20200619082013.13661-1-lorenzo.pieralisi@arm.com * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (82 commits) arm64: use IRQ_STACK_SIZE instead of THREAD_SIZE for irq stack arm64/mm: save memory access in check_and_switch_context() fast switch path arm64: sigcontext.h: delete duplicated word arm64: ptrace.h: delete duplicated word arm64: pgtable-hwdef.h: delete duplicated words bus: fsl-mc: Add ACPI support for fsl-mc bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver of/irq: Make of_msi_map_rid() PCI bus agnostic of/irq: make of_msi_map_get_device_domain() bus agnostic dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus of/device: Add input id to of_dma_configure() of/iommu: Make of_map_rid() PCI agnostic ACPI/IORT: Add an input ID to acpi_dma_configure() ACPI/IORT: Remove useless PCI bus walk ACPI/IORT: Make iort_msi_map_rid() PCI agnostic ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC arm64: enable time namespace support arm64/vdso: Restrict splitting VVAR VMA arm64/vdso: Handle faults on timens page ...
2020-07-25Merge tag 'efi-urgent-2020-07-25' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull EFI fixes from Ingo Molnar: "Various EFI fixes: - Fix the layering violation in the use of the EFI runtime services availability mask in users of the 'efivars' abstraction - Revert build fix for GCC v4.8 which is no longer supported - Clean up some x86 EFI stub details, some of which are borderline bugs that copy around garbage into padding fields - let's fix these out of caution. - Fix build issues while working on RISC-V support - Avoid --whole-archive when linking the stub on arm64" * tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Revert "efi/x86: Fix build with gcc 4" efi/efivars: Expose RT service availability via efivars abstraction efi/libstub: Move the function prototypes to header file efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds efi/libstub/arm64: link stub lib.a conditionally efi/x86: Only copy upto the end of setup_header efi/x86: Remove unused variables
2020-07-15arm64: enable tlbi range instructionsZhenyu Ye1-0/+7
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>
2020-07-09efi/libstub/arm64: link stub lib.a conditionallyMasahiro Yamada1-1/+1
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>
2020-06-15arm64: remove TEXT_OFFSET randomizationArd Biesheuvel1-6/+0
TEXT_OFFSET was recently changed to 0x0, in preparation for its removal at a later stage, and a warning is emitted into the kernel log when the bootloader appears to have failed to take the TEXT_OFFSET image header value into account. Ironically, this warning itself fails to take TEXT_OFFSET into account, and compares the kernel image's alignment modulo 2M against a hardcoded value of 0x0, and so the warning will trigger spuriously when TEXT_OFFSET randomization is enabled. Given the intent to get rid of TEXT_OFFSET entirely, let's fix this oversight by just removing support for TEXT_OFFSET randomization. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200615101939.634391-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-06-06Merge tag 'kbuild-v5.8' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32 - ensure to rebuild all objects when the compiler is upgraded - exclude system headers from dependency tracking and fixdep processing - fix potential bit-size mismatch between the kernel and BPF user-mode helper - add the new syntax 'userprogs' to build user-space programs for the target architecture (the same arch as the kernel) - compile user-space sample code under samples/ for the target arch instead of the host arch - make headers_install fail if a CONFIG option is leaked to user-space - sanitize the output format of scripts/checkstack.pl - handle ARM 'push' instruction in scripts/checkstack.pl - error out before modpost if a module name conflict is found - error out when multiple directories are passed to M= because this feature is broken for a long time - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info - a lot of cleanups of modpost - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the second pass of modpost - do not run the second pass of modpost if nothing in modules is updated - install modules.builtin(.modinfo) by 'make install' as well as by 'make modules_install' because it is useful even when CONFIG_MODULES=n - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ to allow users to use alternatives such as pigz, pbzip2, etc. * tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits) kbuild: add variables for compression tools Makefile: install modules.builtin even if CONFIG_MODULES=n mksysmap: Fix the mismatch of '.L' symbols in System.map kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS modpost: change elf_info->size to size_t modpost: remove is_vmlinux() helper modpost: strip .o from modname before calling new_module() modpost: set have_vmlinux in new_module() modpost: remove mod->skip struct member modpost: add mod->is_vmlinux struct member modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}() modpost: remove mod->is_dot_o struct member modpost: move -d option in scripts/Makefile.modpost modpost: remove -s option modpost: remove get_next_text() and make {grab,release_}file static modpost: use read_text_file() and get_line() for reading text files modpost: avoid false-positive file open error modpost: fix potential mmap'ed file overrun in get_src_version() modpost: add read_text_file() and get_line() helpers modpost: do not call get_modinfo() for vmlinux(.o) ...
2020-05-28Merge branch 'for-next/scs' into for-next/coreWill Deacon1-0/+4
Support for Clang's Shadow Call Stack in the kernel (Sami Tolvanen and Will Deacon) * for-next/scs: arm64: entry-ftrace.S: Update comment to indicate that x18 is live scs: Move DEFINE_SCS macro into core code scs: Remove references to asm/scs.h from core code scs: Move scs_overflow_check() out of architecture code arm64: scs: Use 'scs_sp' register alias for x18 scs: Move accounting into alloc/free functions arm64: scs: Store absolute SCS stack pointer value in thread_info efi/libstub: Disable Shadow Call Stack arm64: scs: Add shadow stacks for SDEI arm64: Implement Shadow Call Stack arm64: Disable SCS for hypervisor code arm64: vdso: Disable Shadow Call Stack arm64: efi: Restore register x18 if it was corrupted arm64: Preserve register x18 when CPU is suspended arm64: Reserve register x18 from general allocation with SCS scs: Disable when function graph tracing is enabled scs: Add support for stack usage debugging scs: Add page accounting for shadow call stack allocations scs: Add support for Clang's Shadow Call Stack (SCS)
2020-05-28Merge branch 'for-next/bti' into for-next/coreWill Deacon1-0/+7
Support for Branch Target Identification (BTI) in user and kernel (Mark Brown and others) * for-next/bti: (39 commits) arm64: vdso: Fix CFI directives in sigreturn trampoline arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction arm64: bti: Fix support for userspace only BTI arm64: kconfig: Update and comment GCC version check for kernel BTI arm64: vdso: Map the vDSO text with guarded pages when built for BTI arm64: vdso: Force the vDSO to be linked as BTI when built for BTI arm64: vdso: Annotate for BTI arm64: asm: Provide a mechanism for generating ELF note for BTI arm64: bti: Provide Kconfig for kernel mode BTI arm64: mm: Mark executable text as guarded pages arm64: bpf: Annotate JITed code for BTI arm64: Set GP bit in kernel page tables to enable BTI for the kernel arm64: asm: Override SYM_FUNC_START when building the kernel with BTI arm64: bti: Support building kernel C code using BTI arm64: Document why we enable PAC support for leaf functions arm64: insn: Report PAC and BTI instructions as skippable arm64: insn: Don't assume unrecognized HINTs are skippable arm64: insn: Provide a better name for aarch64_insn_is_nop() arm64: insn: Add constants for new HINT instruction decode arm64: Disable old style assembly annotations ...
2020-05-15arm64: Reserve register x18 from general allocation with SCSSami Tolvanen1-0/+4
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>
2020-05-12kbuild: remove unused AS assignmentMasahiro Yamada1-2/+0
$(AS) is not used anywhere in the kernel build, hence commit aa824e0c962b ("kbuild: remove AS variable") killed it. Remove the left-over code in arch/{arm,arm64}/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Will Deacon <will@kernel.org>
2020-05-07arm64: bti: Support building kernel C code using BTIMark Brown1-0/+4
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>
2020-05-07arm64: Document why we enable PAC support for leaf functionsMark Brown1-0/+3
Document the fact that we enable pointer authentication protection for leaf functions since there is some narrow potential for ROP protection benefits and little overhead has been observed. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200506195138.22086-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28arm64: set TEXT_OFFSET to 0x0 in preparation for removing it entirelyArd Biesheuvel1-1/+1
TEXT_OFFSET on arm64 is a historical artifact from the early days of the arm64 port where the boot protocol was basically 'copy this image to the base of memory + 512k', giving us 512 KB of guaranteed BSS space to put the swapper page tables. When the arm64 Image header was added in v3.10, it already carried the actual value of TEXT_OFFSET, to allow the bootloader to discover it dynamically rather than hardcode it to 512 KB. Today, this memory window is not used for any particular purpose, and it is simply handed to the page allocator at boot. The only reason it still exists is because of the 512k misalignment it causes with respect to the 2 MB aligned virtual base address of the kernel, which affects the virtual addresses of all statically allocated objects in the kernel image. However, with the introduction of KASLR in v4.6, we added the concept of relocatable kernels, which rewrite all absolute symbol references at boot anyway, and so the placement of such kernels in the physical address space is irrelevant, provided that the minimum segment alignment is honoured (64 KB in most cases, 128 KB for 64k pages kernels with vmap'ed stacks enabled). This makes 0x0 and 512 KB equally suitable values for TEXT_OFFSET on the off chance that we are dealing with boot loaders that ignore the value passed via the header entirely. Considering that the distros as well as Android ship KASLR-capable kernels today, and the fact that TEXT_OFFSET was discoverable from the Image header from the very beginning, let's change this value to 0x0, in preparation for removing it entirely at a later date. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200415082922.32709-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28arm64: drop GZFLAGS definition and exportArd Biesheuvel1-2/+1
Drop the definition and export of GZFLAGS, which was never referenced on arm64, and whose last recorded use in the ARM port (on which arm64 was based original) was removed by patch commit 5e89d379edb5ae08b57f39dd8d91697275245cbf [*] Author: Russell King <rmk@flint.arm.linux.org.uk> Date: Wed Oct 16 14:32:17 2002 +0100 [ARM] Convert ARM makefiles to new kbuild (Sam Ravnborg, Kai, rmk) [*] git commit ID based on Thomas Gleixner's historical GIT repository at git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200415123049.25504-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-04-01arm64: Always force a branch protection mode when the compiler has oneMark Brown1-1/+6
Compilers with branch protection support can be configured to enable it by default, it is likely that distributions will do this as part of deploying branch protection system wide. As well as the slight overhead from having some extra NOPs for unused branch protection features this can cause more serious problems when the kernel is providing pointer authentication to userspace but not built for pointer authentication itself. In that case our switching of keys for userspace can affect the kernel unexpectedly, causing pointer authentication instructions in the kernel to corrupt addresses. To ensure that we get consistent and reliable behaviour always explicitly initialise the branch protection mode, ensuring that the kernel is built the same way regardless of the compiler defaults. Fixes: 7503197562567 (arm64: add basic pointer authentication support) Reported-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org [catalin.marinas@arm.com: remove Kconfig option in favour of Makefile check] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18arm64: compile the kernel with ptrauth return address signingKristina Martsenko1-0/+11
Compile all functions with two ptrauth instructions: PACIASP in the prologue to sign the return address, and AUTIASP in the epilogue to authenticate the return address (from the stack). If authentication fails, the return will cause an instruction abort to be taken, followed by an oops and killing the task. This should help protect the kernel against attacks using return-oriented programming. As ptrauth protects the return address, it can also serve as a replacement for CONFIG_STACKPROTECTOR, although note that it does not protect other parts of the stack. The new instructions are in the HINT encoding space, so on a system without ptrauth they execute as NOPs. CONFIG_ARM64_PTR_AUTH now not only enables ptrauth for userspace and KVM guests, but also automatically builds the kernel with ptrauth instructions if the compiler supports it. If there is no compiler support, we do not warn that the kernel was built without ptrauth instructions. GCC 7 and 8 support the -msign-return-address option, while GCC 9 deprecates that option and replaces it with -mbranch-protection. Support both options. Clang uses an external assembler hence this patch makes sure that the correct parameters (-march=armv8.3-a) are passed down to help it recognize the ptrauth instructions. Ftrace function tracer works properly with Ptrauth only when patchable-function-entry feature is present and is ensured by the Kconfig dependency. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> # not co-dev parts Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: Cover leaf function, comments, Ftrace Kconfig] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-01-15arm64: Turn "broken gas inst" into real config optionVladimir Murzin1-7/+3
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>
2020-01-15arm64: Move the LSE gas support detection to KconfigCatalin Marinas1-7/+4
As the Kconfig syntax gained support for $(as-instr) tests, move the LSE gas support detection from Makefile to the main arm64 Kconfig and remove the additional CONFIG_AS_LSE definition and check. Cc: Will Deacon <will@kernel.org> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-11-06arm64: implement ftrace with regsTorsten Duwe1-0/+5
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>
2019-10-07arm64: Kconfig: Make CONFIG_COMPAT_VDSO a proper Kconfig optionWill Deacon1-5/+0
CONFIG_COMPAT_VDSO is defined by passing '-DCONFIG_COMPAT_VDSO' to the compiler when the generic compat vDSO code is in use. It's much cleaner and simpler to expose this as a proper Kconfig option (like x86 does), so do that and remove the bodge. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07arm64: vdso32: Move definition of COMPATCC into vdso32/MakefileWill Deacon1-7/+0
There's no need to export COMPATCC, so just define it locally in the vdso32/Makefile, which is the only place where it is used. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07arm64: Default to building compat vDSO with clang when CONFIG_CC_IS_CLANGWill Deacon1-0/+4
Rather than force the use of GCC for the compat cross-compiler, instead extract the target from CROSS_COMPILE_COMPAT and pass it to clang if the main compiler is clang. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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