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31d8edb535
Patch series "introduce kasan.write_only option in hw-tags", v8. Hardware tag based KASAN is implemented using the Memory Tagging Extension (MTE) feature. MTE is built on top of the ARMv8.0 virtual address tagging TBI (Top Byte Ignore) feature and allows software to access a 4-bit allocation tag for each 16-byte granule in the physical address space. A logical tag is derived from bits 59-56 of the virtual address used for the memory access. A CPU with MTE enabled will compare the logical tag against the allocation tag and potentially raise an tag check fault on mismatch, subject to system registers configuration. Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag check fault on store operation only. Using this feature (FEAT_MTE_STORE_ONLY), introduce KASAN write-only mode which restricts KASAN check write (store) operation only. This mode omits KASAN check for read (fetch/load) operation. Therefore, it might be used not only debugging purpose but also in normal environment. This patch (of 2): Since Armv8.9, FEATURE_MTE_STORE_ONLY feature is introduced to restrict raise of tag check fault on store operation only. Introduce KASAN write only mode based on this feature. KASAN write only mode restricts KASAN checks operation for write only and omits the checks for fetch/read operations when accessing memory. So it might be used not only debugging enviroment but also normal enviroment to check memory safty. This features can be controlled with "kasan.write_only" arguments. When "kasan.write_only=on", KASAN checks write operation only otherwise KASAN checks all operations. This changes the MTE_STORE_ONLY feature as BOOT_CPU_FEATURE like ARM64_MTE_ASYMM so that makes it initialise in kasan_init_hw_tags() with other function together. Link: https://lkml.kernel.org/r/20250916222755.466009-1-yeoreum.yun@arm.com Link: https://lkml.kernel.org/r/20250916222755.466009-2-yeoreum.yun@arm.com Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Breno Leitao <leitao@debian.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: D Scott Phillips <scott@os.amperecomputing.com> Cc: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io> Cc: James Morse <james.morse@arm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: levi.yun <yeoreum.yun@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Pankaj Gupta <pankaj.gupta@amd.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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| .. | ||
| kunit | ||
| autofdo.rst | ||
| checkpatch.rst | ||
| checkuapi.rst | ||
| clang-format.rst | ||
| coccinelle.rst | ||
| gcov.rst | ||
| gpio-sloppy-logic-analyzer.rst | ||
| index.rst | ||
| kasan.rst | ||
| kcov.rst | ||
| kcsan.rst | ||
| kfence.rst | ||
| kmemleak.rst | ||
| kmsan.rst | ||
| kselftest.rst | ||
| ktap.rst | ||
| propeller.rst | ||
| sparse.rst | ||
| testing-devices.rst | ||
| testing-overview.rst | ||
| ubsan.rst | ||