kernel/arch/arm64/lib/mte.S, branch linux-6.2.y

arm64/sysreg: Remove duplicate definitions from asm/sysreg.h

2022-12-01T17:31:12Z

With the new-fangled generation of asm/sysreg-defs.h, some definitions have ended up being duplicated between the two files. Remove these duplicate definitions, and consolidate the naming for GMID_EL1_BS_WIDTH. Signed-off-by: Will Deacon

arm64/mte: Standardise GMID field name definitions

2022-07-05T10:45:46Z

Usually our defines for bitfields in system registers do not include a SYS_ prefix but those for GMID do. In preparation for automatic generation of defines remove that prefix. No functional change. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20220704170302.2609529-9-broonie@kernel.org Signed-off-by: Will Deacon

arm64: mte: Clean up user tag accessors

2022-05-16T18:11:03Z

Invoking user_ldst to explicitly add a post-increment of 0 is silly. Just use a normal USER() annotation and save the redundant instruction. Signed-off-by: Robin Murphy Reviewed-by: Tong Tiangen Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20220420030418.3189040-6-tongtiangen@huawei.com Signed-off-by: Catalin Marinas

arm64: mte: Define the number of bytes for storing the tags in a page

2022-02-15T22:53:29Z

Rather than explicitly calculating the number of bytes for a compact tag storage format corresponding to a page, just add a MTE_PAGE_TAG_STORAGE macro. With the current MTE implementation of 4 bits per tag, we store 2 tags in a byte. Signed-off-by: Catalin Marinas Acked-by: Luis Machado Link: https://lore.kernel.org/r/20220131165456.2160675-4-catalin.marinas@arm.com Signed-off-by: Will Deacon

arm64: mte: DC {GVA,GZVA} shouldn't be used when DCZID_EL0.DZP == 1

2021-12-06T17:02:10Z

Currently, mte_set_mem_tag_range() and mte_zero_clear_page_tags() use DC {GVA,GZVA} unconditionally. But, they should make sure that DCZID_EL0.DZP, which indicates whether or not use of those instructions is prohibited, is zero when using those instructions. Use ST{G,ZG,Z2G} instead when DCZID_EL0.DZP == 1. Fixes: 013bb59dbb7c ("arm64: mte: handle tags zeroing at page allocation time") Fixes: 3d0cca0b02ac ("kasan: speed up mte_set_mem_tag_range") Signed-off-by: Reiji Watanabe Link: https://lore.kernel.org/r/20211206004736.1520989-3-reijiw@google.com Signed-off-by: Catalin Marinas

arm64: mte: handle tags zeroing at page allocation time

2021-06-04T18:32:21Z

Currently, on an anonymous page fault, the kernel allocates a zeroed page and maps it in user space. If the mapping is tagged (PROT_MTE), set_pte_at() additionally clears the tags. It is, however, more efficient to clear the tags at the same time as zeroing the data on allocation. To avoid clearing the tags on any page (which may not be mapped as tagged), only do this if the vma flags contain VM_MTE. This requires introducing a new GFP flag that is used to determine whether to clear the tags. The DC GZVA instruction with a 0 top byte (and 0 tag) requires top-byte-ignore. Set the TCR_EL1.{TBI1,TBID1} bits irrespective of whether KASAN_HW is enabled. Signed-off-by: Peter Collingbourne Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Link: https://linux-review.googlesource.com/id/Id46dc94e30fe11474f7e54f5d65e7658dbdddb26 Reviewed-by: Catalin Marinas Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20210602235230.3928842-4-pcc@google.com Signed-off-by: Will Deacon

arm64: kasan: simplify and inline MTE functions

2021-02-26T17:41:03Z

This change provides a simpler implementation of mte_get_mem_tag(), mte_get_random_tag(), and mte_set_mem_tag_range(). Simplifications include removing system_supports_mte() checks as these functions are onlye called from KASAN runtime that had already checked system_supports_mte(). Besides that, size and address alignment checks are removed from mte_set_mem_tag_range(), as KASAN now does those. This change also moves these functions into the asm/mte-kasan.h header and implements mte_set_mem_tag_range() via inline assembly to avoid unnecessary functions calls. [vincenzo.frascino@arm.com: fix warning in mte_get_random_tag()] Link: https://lkml.kernel.org/r/20210211152208.23811-1-vincenzo.frascino@arm.com Link: https://lkml.kernel.org/r/a26121b294fdf76e369cb7a74351d1c03a908930.1612546384.git.andreyknvl@google.com Co-developed-by: Vincenzo Frascino Signed-off-by: Vincenzo Frascino Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Marco Elver Cc: Peter Collingbourne Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64: mte: add in-kernel MTE helpers

2020-12-22T20:55:07Z

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 Co-developed-by: Andrey Konovalov Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas Tested-by: Vincenzo Frascino Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Marco Elver Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64: uaccess cleanup macro naming

2020-12-02T19:49:11Z

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 Reviewed-by: Robin Murohy Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: uaccess: move uao_* alternatives to asm-uaccess.h

2020-11-09T21:49:34Z

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 Cc: Catalin Marinas Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon [will: update #include in mte.S to pull in uao asm macros] Signed-off-by: Will Deacon