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2020-12-22arm64: mte: add in-kernel MTE helpersVincenzo Frascino1-0/+16
Provide helper functions to manipulate allocation and pointer tags for kernel addresses. Low-level helper functions (mte_assign_*, written in assembly) operate tag values from the [0x0, 0xF] range. High-level helper functions (mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility with normal kernel pointers that have 0xFF in their top byte. MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header that doesn't have any dependencies and is safe to include into any low-level header. Link: https://lkml.kernel.org/r/c31bf759b4411b2d98cdd801eb928e241584fd1f.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Co-developed-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.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>
2020-12-02arm64: uaccess cleanup macro namingMark Rutland5-22/+22
Now the uaccess primitives use LDTR/STTR unconditionally, the uao_{ldp,stp,user_alternative} asm macros are misnamed, and have a redundant argument. Let's remove the redundant argument and rename these to user_{ldp,stp,ldst} respectively to clean this up. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Robin Murohy <robin.murphy@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201202131558.39270-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02arm64: uaccess: simplify __copy_user_flushcache()Mark Rutland1-3/+1
Currently __copy_user_flushcache() open-codes raw_copy_from_user(), and doesn't use uaccess_mask_ptr() on the user address. Let's have it call raw_copy_from_user(), which is both a simplification and ensures that user pointers are masked under speculation. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201202131558.39270-6-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-09arm64: uaccess: move uao_* alternatives to asm-uaccess.hMark Rutland1-1/+1
The uao_* alternative asm macros are only used by the uaccess assembly routines in arch/arm64/lib/, where they are included indirectly via asm-uaccess.h. Since they're specific to the uaccess assembly (and will lose the alternatives in subsequent patches), let's move them into asm-uaccess.h. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> [will: update #include in mte.S to pull in uao asm macros] Signed-off-by: Will Deacon <will@kernel.org>
2020-10-30arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.SFangrui Song3-6/+3
Commit 39d114ddc682 ("arm64: add KASAN support") added .weak directives to arch/arm64/lib/mem*.S instead of changing the existing SYM_FUNC_START_PI macros. This can lead to the assembly snippet `.weak memcpy ... .globl memcpy` which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since https://reviews.llvm.org/D90108) will error on such an overridden symbol binding. Use the appropriate SYM_FUNC_START_WEAK_PI instead. Fixes: 39d114ddc682 ("arm64: add KASAN support") Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201029181951.1866093-1-maskray@google.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-04arm64: mte: Enable swap of tagged pagesSteven Price1-0/+45
When swapping pages out to disk it is necessary to save any tags that have been set, and restore when swapping back in. Make use of the new page flag (PG_ARCH_2, locally named PG_mte_tagged) to identify pages with tags. When swapping out these pages the tags are stored in memory and later restored when the pages are brought back in. Because shmem can swap pages back in without restoring the userspace PTE it is also necessary to add a hook for shmem. Signed-off-by: Steven Price <steven.price@arm.com> [catalin.marinas@arm.com: move function prototypes to mte.h] [catalin.marinas@arm.com: drop '_tags' from arch_swap_restore_tags()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Will Deacon <will@kernel.org>
2020-09-04arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS supportCatalin Marinas1-0/+53
Add support for bulk setting/getting of the MTE tags in a tracee's address space at 'addr' in the ptrace() syscall prototype. 'data' points to a struct iovec in the tracer's address space with iov_base representing the address of a tracer's buffer of length iov_len. The tags to be copied to/from the tracer's buffer are stored as one tag per byte. On successfully copying at least one tag, ptrace() returns 0 and updates the tracer's iov_len with the number of tags copied. In case of error, either -EIO or -EFAULT is returned, trying to follow the ptrace() man page. Note that the tag copying functions are not performance critical, therefore they lack optimisations found in typical memory copy routines. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Alan Hayward <Alan.Hayward@arm.com> Cc: Luis Machado <luis.machado@linaro.org> Cc: Omair Javaid <omair.javaid@linaro.org>
2020-09-04arm64: mte: Tags-aware copy_{user_,}highpage() implementationsVincenzo Frascino1-0/+19
When the Memory Tagging Extension is enabled, the tags need to be preserved across page copy (e.g. for copy-on-write, page migration). Introduce MTE-aware copy_{user_,}highpage() functions to copy tags to the destination if the source page has the PG_mte_tagged flag set. copy_user_page() does not need to handle tag copying since, with this patch, it is only called by the DAX code where there is no source page structure (and no source tags). Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Co-developed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
2020-09-04arm64: mte: Clear the tags when a page is mapped in user-space with PROT_MTECatalin Marinas2-0/+36
Pages allocated by the kernel are not guaranteed to have the tags zeroed, especially as the kernel does not (yet) use MTE itself. To ensure the user can still access such pages when mapped into its address space, clear the tags via set_pte_at(). A new page flag - PG_mte_tagged (PG_arch_2) - is used to track pages with valid allocation tags. Since the zero page is mapped as pte_special(), it won't be covered by the above set_pte_at() mechanism. Clear its tags during early MTE initialisation. Co-developed-by: Steven Price <steven.price@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
2020-06-10Merge branch 'rwonce/rework' of ↵Linus Torvalds1-8/+12
git://git.kernel.org/pub/scm/linux/kernel/git/will/linux Pull READ/WRITE_ONCE rework from Will Deacon: "This the READ_ONCE rework I've been working on for a while, which bumps the minimum GCC version and improves code-gen on arm64 when stack protector is enabled" [ Side note: I'm _really_ tempted to raise the minimum gcc version to 4.9, so that we can just say that we require _Generic() support. That would allow us to more cleanly handle a lot of the cases where we depend on very complex macros with 'sizeof' or __builtin_choose_expr() with __builtin_types_compatible_p() etc. This branch has a workaround for sparse not handling _Generic(), either, but that was already fixed in the sparse development branch, so it's really just gcc-4.9 that we'd require. - Linus ] * 'rwonce/rework' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux: compiler_types.h: Use unoptimized __unqual_scalar_typeof for sparse compiler_types.h: Optimize __unqual_scalar_typeof compilation time compiler.h: Enforce that READ_ONCE_NOCHECK() access size is sizeof(long) compiler-types.h: Include naked type in __pick_integer_type() match READ_ONCE: Fix comment describing 2x32-bit atomicity gcov: Remove old GCC 3.4 support arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros READ_ONCE: Drop pointer qualifiers when reading from scalar types READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE() arm64: csum: Disable KASAN for do_csum() fault_inject: Don't rely on "return value" from WRITE_ONCE() net: tls: Avoid assigning 'const' pointer to non-const pointer netfilter: Avoid assigning 'const' pointer to non-const pointer compiler/gcc: Raise minimum GCC version for kernel builds to 4.8
2020-04-29arm64: Reorder the macro arguments in the copy routinesCatalin Marinas4-64/+64
The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28arm64: lib: Consistently enable crc32 extensionMark Brown1-1/+1
Currently most of the assembly files that use architecture extensions enable them using the .arch directive but crc32.S uses .cpu instead. Move that over to .arch for consistency. Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200414182843.31664-1-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-04-15arm64: csum: Disable KASAN for do_csum()Will Deacon1-8/+12
do_csum() over-reads the source buffer and therefore abuses READ_ONCE_NOCHECK() to avoid tripping up KASAN. In preparation for READ_ONCE_NOCHECK() becoming a macro, and therefore losing its '__no_sanitize_address' annotation, just annotate do_csum() explicitly and fall back to normal loads. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-03-17arm64: fix spelling mistake "ca not" -> "cannot"韩科才1-1/+1
There is a spelling mistake in the comment, Fix it. Signed-off-by: hankecai <hankecai@bbktel.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09arm64: csum: Optimise IPv6 header checksumRobin Murphy1-0/+27
Throwing our __uint128_t idioms at csum_ipv6_magic() makes it about 1.3x-2x faster across a range of microarchitecture/compiler combinations. Not much in absolute terms, but every little helps. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-01-22Merge branch 'for-next/asm-annotations' into for-next/coreWill Deacon19-50/+50
* for-next/asm-annotations: (6 commits) arm64: kernel: Correct annotation of end of el0_sync ...
2020-01-22Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', ↵Will Deacon3-22/+148
'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core * for-next/acpi: ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map() * for-next/cpufeatures: (2 commits) arm64: Introduce ID_ISAR6 CPU register ... * for-next/csum: (2 commits) arm64: csum: Fix pathological zero-length calls ... * for-next/e0pd: (7 commits) arm64: kconfig: Fix alignment of E0PD help text ... * for-next/entry: (5 commits) arm64: entry: cleanup sp_el0 manipulation ... * for-next/kbuild: (4 commits) arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean' ... * for-next/kexec/cleanup: (11 commits) Revert "arm64: kexec: make dtb_mem always enabled" ... * for-next/kexec/file-kdump: (2 commits) arm64: kexec_file: add crash dump support ... * for-next/misc: (12 commits) arm64: entry: Avoid empty alternatives entries ... * for-next/nofpsimd: (7 commits) arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanly ... * for-next/perf: (2 commits) perf/imx_ddr: Fix cpu hotplug state cleanup ... * for-next/scs: (6 commits) arm64: kernel: avoid x18 in __cpu_soft_restart ...
2020-01-17arm64: csum: Fix pathological zero-length callsRobin Murphy1-0/+3
In validating the checksumming results of the new routine, I sadly neglected to test its not-checksumming results. Thus it slipped through that the one case where @buff is already dword-aligned and @len = 0 manages to defeat the tail-masking logic and behave as if @len = 8. For a zero length it doesn't make much sense to deference @buff anyway, so just add an early return (which has essentially zero impact on performance). Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16arm64/lib: copy_page: avoid x18 register in assembler codeArd Biesheuvel1-19/+19
Register x18 will no longer be used as a caller save register in the future, so stop using it in the copy_page() code. Link: https://patchwork.kernel.org/patch/9836869/ Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [Sami: changed the offset and bias to be explicit] Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16arm64: Implement optimised checksum routineRobin Murphy2-3/+126
Apparently there exist certain workloads which rely heavily on software checksumming, for which the generic do_csum() implementation becomes a significant bottleneck. Therefore let's give arm64 its own optimised version - for ease of maintenance this foregoes assembly or intrisics, and is thus not actually arm64-specific, but does rely heavily on C idioms that translate well to the A64 ISA and the typical load/store capabilities of most ARMv8 CPU cores. The resulting increase in checksum throughput scales nicely with buffer size, tending towards 4x for a small in-order core (Cortex-A53), and up to 6x or more for an aggressive big core (Ampere eMAG). Reported-by: Lingyan Huang <huanglingyan2@huawei.com> Tested-by: Lingyan Huang <huanglingyan2@huawei.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: lib: Use modern annotations for assembly functionsMark Brown19-50/+50
In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC and also add a new annotation for static functions which previously had no ENTRY equivalent. Update the annotations in the library code to the new macros. Signed-off-by: Mark Brown <broonie@kernel.org> [will: Use SYM_FUNC_START_WEAK_PI] Signed-off-by: Will Deacon <will@kernel.org>
2019-11-20arm64: uaccess: Remove uaccess_*_not_uao asm macrosPavel Tatashin5-13/+5
It is safer and simpler to drop the uaccess assembly macros in favour of inline C functions. Although this bloats the Image size slightly, it aligns our user copy routines with '{get,put}_user()' and generally makes the code a lot easier to reason about. Cc: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> [will: tweaked commit message and changed temporary variable names] Signed-off-by: Will Deacon <will@kernel.org>
2019-11-20arm64: uaccess: Ensure PAN is re-enabled after unhandled uaccess faultPavel Tatashin4-0/+4
A number of our uaccess routines ('__arch_clear_user()' and '__arch_copy_{in,from,to}_user()') fail to re-enable PAN if they encounter an unhandled fault whilst accessing userspace. For CPUs implementing both hardware PAN and UAO, this bug has no effect when both extensions are in use by the kernel. For CPUs implementing hardware PAN but not UAO, this means that a kernel using hardware PAN may execute portions of code with PAN inadvertently disabled, opening us up to potential security vulnerabilities that rely on userspace access from within the kernel which would usually be prevented by this mechanism. In other words, parts of the kernel run the same way as they would on a CPU without PAN implemented/emulated at all. For CPUs not implementing hardware PAN and instead relying on software emulation via 'CONFIG_ARM64_SW_TTBR0_PAN=y', the impact is unfortunately much worse. Calling 'schedule()' with software PAN disabled means that the next task will execute in the kernel using the page-table and ASID of the previous process even after 'switch_mm()', since the actual hardware switch is deferred until return to userspace. At this point, or if there is a intermediate call to 'uaccess_enable()', the page-table and ASID of the new process are installed. Sadly, due to the changes introduced by KPTI, this is not an atomic operation and there is a very small window (two instructions) where the CPU is configured with the page-table of the old task and the ASID of the new task; a speculative access in this state is disastrous because it would corrupt the TLB entries for the new task with mappings from the previous address space. As Pavel explains: | I was able to reproduce memory corruption problem on Broadcom's SoC | ARMv8-A like this: | | Enable software perf-events with PERF_SAMPLE_CALLCHAIN so userland's | stack is accessed and copied. | | The test program performed the following on every CPU and forking | many processes: | | unsigned long *map = mmap(NULL, PAGE_SIZE, PROT_READ|PROT_WRITE, | MAP_SHARED | MAP_ANONYMOUS, -1, 0); | map[0] = getpid(); | sched_yield(); | if (map[0] != getpid()) { | fprintf(stderr, "Corruption detected!"); | } | munmap(map, PAGE_SIZE); | | From time to time I was getting map[0] to contain pid for a | different process. Ensure that PAN is re-enabled when returning after an unhandled user fault from our uaccess routines. Cc: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> Fixes: 338d4f49d6f7 ("arm64: kernel: Add support for Privileged Access Never") Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> [will: rewrote commit message] Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30Merge branch 'for-next/atomics' into for-next/coreWill Deacon2-22/+0
* for-next/atomics: (10 commits) Rework LSE instruction selection to use static keys instead of alternatives
2019-08-29arm64: atomics: Remove atomic_ll_sc compilation unitAndrew Murray2-22/+0
We no longer fall back to out-of-line atomics on systems with CONFIG_ARM64_LSE_ATOMICS where ARM64_HAS_LSE_ATOMICS is not set. Remove the unused compilation unit which provided these symbols. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07arm64: Add support for function error injectionLeo Yan2-0/+20
Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"), this patch supports function error injection for Arm64. This patch mainly support two functions: one is regs_set_return_value() which is used to overwrite the return value; the another function is override_function_with_return() which is to override the probed function returning and jump to its caller. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2-8/+2
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner20-249/+20
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-09arm64: Makefile: Replace -pg with CC_FLAGS_FTRACETorsten Duwe1-1/+1
In preparation for arm64 supporting ftrace built on other compiler options, let's have the arm64 Makefiles remove the $(CC_FLAGS_FTRACE) flags, whatever these may be, rather than assuming '-pg'. There should be no functional change as a result of this patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: string: use asm EXPORT_SYMBOL()Mark Rutland11-0/+14
For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the string routine exports to the assembly files the functions are defined in. Routines which should only be exported for !KASAN builds are exported using the EXPORT_SYMBOL_NOKASAN() helper. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: uaccess: use asm EXPORT_SYMBOL()Mark Rutland4-3/+11
For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the uaccess exports to the assembly files the functions are defined in. As we have to include <asm/assembler.h>, the existing includes are fixed to follow the usual ordering conventions. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: page: use asm EXPORT_SYMBOL()Mark Rutland2-0/+2
For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the copy_page and clear_page exports to the assembly files the functions are defined in. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: tishift: use asm EXPORT_SYMBOL()Mark Rutland1-0/+5
For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the tishift exports to the assembly file the functions are defined in. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06arm64: crypto: add NEON accelerated XOR implementationJackie Liu2-0/+190
This is a NEON acceleration method that can improve performance by approximately 20%. I got the following data from the centos 7.5 on Huawei's HISI1616 chip: [ 93.837726] xor: measuring software checksum speed [ 93.874039] 8regs : 7123.200 MB/sec [ 93.914038] 32regs : 7180.300 MB/sec [ 93.954043] arm64_neon: 9856.000 MB/sec [ 93.954047] xor: using function: arm64_neon (9856.000 MB/sec) I believe this code can bring some optimization for all arm64 platform. thanks for Ard Biesheuvel's suggestions. Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-11-30arm64/lib: improve CRC32 performance for deep pipelinesArd Biesheuvel1-5/+49
Improve the performance of the crc32() asm routines by getting rid of most of the branches and small sized loads on the common path. Instead, use a branchless code path involving overlapping 16 byte loads to process the first (length % 32) bytes, and process the remainder using a loop that processes 32 bytes at a time. Tested using the following test program: #include <stdlib.h> extern void crc32_le(unsigned short, char const*, int); int main(void) { static const char buf[4096]; srand(20181126); for (int i = 0; i < 100 * 1000 * 1000; i++) crc32_le(0, buf, rand() % 1024); return 0; } On Cortex-A53 and Cortex-A57, the performance regresses but only very slightly. On Cortex-A72 however, the performance improves from $ time ./crc32 real 0m10.149s user 0m10.149s sys 0m0.000s to $ time ./crc32 real 0m7.915s user 0m7.915s sys 0m0.000s Cc: Rui Sun <sunrui26@huawei.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-10-26arm64: lib: use C string functions with KASAN enabledAndrey Ryabinin8-8/+8
ARM64 has asm implementation of memchr(), memcmp(), str[r]chr(), str[n]cmp(), str[n]len(). KASAN don't see memory accesses in asm code, thus it can potentially miss many bugs. Ifdef out __HAVE_ARCH_* defines of these functions when KASAN is enabled, so the generic implementations from lib/string.c will be used. We can't just remove the asm functions because efistub uses them. And we can't have two non-weak functions either, so declare the asm functions as weak. Link: http://lkml.kernel.org/r/20180920135631.23833-2-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Kyeongdon Kim <kyeongdon.kim@lge.com> Cc: Alexander Potapenko <glider@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.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>
2018-09-24arm64: lse: remove -fcall-used-x0 flagTri Vo1-1/+1
x0 is not callee-saved in the PCS. So there is no need to specify -fcall-used-x0. Clang doesn't currently support -fcall-used flags. This patch will help building the kernel with clang. Tested-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Tri Vo <trong@android.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-10arm64/lib: add accelerated crc32 routinesArd Biesheuvel2-0/+62
Unlike crc32c(), which is wired up to the crypto API internally so the optimal driver is selected based on the platform's capabilities, crc32_le() is implemented as a library function using a slice-by-8 table based C implementation. Even though few of the call sites may be bottlenecks, calling a time variant implementation with a non-negligible D-cache footprint is a bit of a waste, given that ARMv8.1 and up mandates support for the CRC32 instructions that were optional in ARMv8.0, but are already widely available, even on the Cortex-A53 based Raspberry Pi. So implement routines that use these instructions if available, and fall back to the existing generic routines otherwise. The selection is based on alternatives patching. Note that this unconditionally selects CONFIG_CRC32 as a builtin. Since CRC32 is relied upon by core functionality such as CONFIG_OF_FLATTREE, this just codifies the status quo. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-21locking/atomics/arm64: Replace our atomic/lock bitop implementations with ↵Will Deacon2-77/+1
asm-generic The <asm-generic/bitops/{atomic,lock}.h> implementations are built around the atomic-fetch ops, which we implement efficiently for both LSE and LL/SC systems. Use that instead of our hand-rolled, out-of-line bitops.S. Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: yamada.masahiro@socionext.com Link: https://lore.kernel.org/lkml/1529412794-17720-9-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-21arm64: export tishift functions to modulesJason A. Donenfeld1-13/+2
Otherwise modules that use these arithmetic operations will fail to link. We accomplish this with the usual EXPORT_SYMBOL, which on most architectures goes in the .S file but the ARM64 maintainers prefer that insead it goes into arm64ksyms. While we're at it, we also fix this up to use SPDX, and I personally choose to relicense this as GPL2||BSD so that these symbols don't need to be export_symbol_gpl, so all modules can use the routines, since these are important general purpose compiler-generated function calls. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reported-by: PaX Team <pageexec@freemail.hu> Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-27arm64: avoid instrumenting atomic_ll_sc.oMark Rutland1-0/+4
Our out-of-line atomics are built with a special calling convention, preventing pointless stack spilling, and allowing us to patch call sites with ARMv8.1 atomic instructions. Instrumentation inserted by the compiler may result in calls to functions not following this special calling convention, resulting in registers being unexpectedly clobbered, and various problems resulting from this. For example, if a kernel is built with KCOV and ARM64_LSE_ATOMICS, the compiler inserts calls to __sanitizer_cov_trace_pc in the prologues of the atomic functions. This has been observed to result in spurious cmpxchg failures, leading to a hang early on in the boot process. This patch avoids such issues by preventing instrumentation of our out-of-line atomics. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-05Merge tag 'devicetree-for-4.17' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull DeviceTree updates from Rob Herring: - Sync dtc to upstream version v1.4.6-9-gaadd0b65c987. This adds a bunch more warnings (hidden behind W=1). - Build dtc lexer and parser files instead of using shipped versions. - Rework overlay apply API to take an FDT as input and apply overlays in a single step. - Add a phandle lookup cache. This improves boot time by hundreds of msec on systems with large DT. - Add trivial mcp4017/18/19 potentiometers bindings. - Remove VLA stack usage in DT code. * tag 'devicetree-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (26 commits) of: unittest: fix an error code in of_unittest_apply_overlay() of: unittest: move misplaced function declaration of: unittest: Remove VLA stack usage of: overlay: Fix forgotten reference to of_overlay_apply() of: Documentation: Fix forgotten reference to of_overlay_apply() of: unittest: local return value variable related cleanups of: unittest: remove unneeded local return value variables dt-bindings: trivial: add various mcp4017/18/19 potentiometers of: unittest: fix an error test in of_unittest_overlay_8() of: cache phandle nodes to reduce cost of of_find_node_by_phandle() dt-bindings: rockchip-dw-mshc: use consistent clock names MAINTAINERS: Add linux/of_*.h headers to appropriate subsystems scripts: turn off some new dtc warnings by default scripts/dtc: Update to upstream version v1.4.6-9-gaadd0b65c987 scripts/dtc: generate lexer and parser during build instead of shipping powerpc: boot: add strrchr function of: overlay: do not include path in full_name of added nodes of: unittest: clean up changeset test arm64/efi: Make strrchr() available to the EFI namespace ARM: boot: add strrchr function ...
2018-03-06arm64: lse: Pass -fomit-frame-pointer to out-of-line ll/sc atomicsWill Deacon1-1/+2
In cases where x30 is used as a temporary in the out-of-line ll/sc atomics (e.g. atomic_fetch_add), the compiler tends to put out a full stackframe, which included pointing the x29 at the new frame. Since these things aren't traceable anyway, we can pass -fomit-frame-pointer to reduce the work when spilling. Since this is incompatible with -pg, we also remove that from the CFLAGS for this file. Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-05arm64/efi: Make strrchr() available to the EFI namespaceRob Herring1-1/+1
libfdt gained a new dependency on strrchr, so make it available to the EFI namespace before we update libfdt. Thanks to Ard for providing this fix. Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-02-06arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_userWill Deacon2-5/+6
Like we've done for get_user and put_user, ensure that user pointers are masked before invoking the underlying __arch_{clear,copy_*}_user operations. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: kpti: Fix the interaction between ASID switching and software PANCatalin Marinas4-4/+4
With ARM64_SW_TTBR0_PAN enabled, the exception entry code checks the active ASID to decide whether user access was enabled (non-zero ASID) when the exception was taken. On return from exception, if user access was previously disabled, it re-instates TTBR0_EL1 from the per-thread saved value (updated in switch_mm() or efi_set_pgd()). Commit 7655abb95386 ("arm64: mm: Move ASID from TTBR0 to TTBR1") makes a TTBR0_EL1 + ASID switching non-atomic. Subsequently, commit 27a921e75711 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") changes the __uaccess_ttbr0_disable() function and asm macro to first write the reserved TTBR0_EL1 followed by the ASID=0 update in TTBR1_EL1. If an exception occurs between these two, the exception return code will re-instate a valid TTBR0_EL1. Similar scenario can happen in cpu_switch_mm() between setting the reserved TTBR0_EL1 and the ASID update in cpu_do_switch_mm(). This patch reverts the entry.S check for ASID == 0 to TTBR0_EL1 and disables the interrupts around the TTBR0_EL1 and ASID switching code in __uaccess_ttbr0_disable(). It also ensures that, when returning from the EFI runtime services, efi_set_pgd() doesn't leave a non-zero ASID in TTBR1_EL1 by using uaccess_ttbr0_{enable,disable}. The accesses to current_thread_info()->ttbr0 are updated to use READ_ONCE/WRITE_ONCE. As a safety measure, __uaccess_ttbr0_enable() always masks out any existing non-zero ASID TTBR1_EL1 before writing in the new ASID. Fixes: 27a921e75711 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") Acked-by: Will Deacon <will.deacon@arm.com> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Co-developed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-02arm64: make label allocation style consistent in tishiftJason A. Donenfeld1-4/+4
This is entirely cosmetic, but somehow it was missed when sending differing versions of this patch. This just makes the file a bit more uniform. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-11arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PANWill Deacon4-4/+4
With the ASID now installed in TTBR1, we can re-enable ARM64_SW_TTBR0_PAN by ensuring that we switch to a reserved ASID of zero when disabling user access and restore the active user ASID on the uaccess enable path. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-15Merge tag 'arm64-upstream' of ↵Linus Torvalds3-5/+100
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...
2017-11-13arm64: Implement __lshrti3 library functionJason A. Donenfeld1-0/+21
Commit fb8722735f50 ("arm64: support __int128 on gcc 5+") added support for the __int128 data type, but this breaks the build in some configurations where GCC ends up emitting calls to the __lshrti3 helper in libgcc, which results in a link error: kernel/sched/fair.o: In function `__calc_delta': fair.c:(.text+0xca0): undefined reference to `__lshrti3' kernel/time/timekeeping.o: In function `timekeeping_resume': timekeeping.c:(.text+0x3f60): undefined reference to `__lshrti3' make: *** [vmlinux] Error 1 Fix the build by providing an implementation of __lshrti3, like we do already for __ashlti3 and __ashrti3. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Will Deacon <will.deacon@arm.com>