Messages in this thread | | | Subject | Re: [PATCH 0/4] arm64: ARMv8.5-A: MTE: Add async mode support | From | Vincenzo Frascino <> | Date | Wed, 6 Jan 2021 16:35:29 +0000 |
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On 1/6/21 11:55 AM, Vincenzo Frascino wrote: > This patchset implements the asynchronous mode support for ARMv8.5-A > Memory Tagging Extension (MTE), which is a debugging feature that allows > to detect with the help of the architecture the C and C++ programmatic > memory errors like buffer overflow, use-after-free, use-after-return, etc. > > MTE is built on top of the AArch64 v8.0 virtual address tagging TBI > (Top Byte Ignore) feature and allows a task to set a 4 bit tag on any > subset of its address space that is multiple of a 16 bytes granule. MTE > is based on a lock-key mechanism where the lock is the tag associated to > the physical memory and the key is the tag associated to the virtual > address. > When MTE is enabled and tags are set for ranges of address space of a task, > the PE will compare the tag related to the physical memory with the tag > related to the virtual address (tag check operation). Access to the memory > is granted only if the two tags match. In case of mismatch the PE will raise > an exception. > > The exception can be handled synchronously or asynchronously. When the > asynchronous mode is enabled: > - Upon fault the PE updates the TFSR_EL1 register. > - The kernel detects the change during one of the following: > - Context switching > - Return to user/EL0 > - Kernel entry from EL1 > - Kernel exit to EL1 > - If the register has been updated by the PE the kernel clears it and > reports the error. > > The series contains as well an optimization to mte_assign_mem_tag_range(). > > The series is based on linux 5.11-rc2. > > To simplify the testing a tree with the new patches on top has been made > available at [1]. > > [1] https://git.gitlab.arm.com/linux-arm/linux-vf.git mte/v10.async > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will.deacon@arm.com>
Will is not in arm anymore :( Sorry Will... I will fix this in v2.
> Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > Cc: Alexander Potapenko <glider@google.com> > Cc: Marco Elver <elver@google.com> > Cc: Evgenii Stepanov <eugenis@google.com> > Cc: Branislav Rankov <Branislav.Rankov@arm.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > > Vincenzo Frascino (4): > kasan, arm64: Add KASAN light mode > arm64: mte: Add asynchronous mode support > arm64: mte: Enable async tag check fault > arm64: mte: Optimize mte_assign_mem_tag_range() > > arch/arm64/include/asm/memory.h | 2 +- > arch/arm64/include/asm/mte-kasan.h | 5 ++- > arch/arm64/include/asm/mte.h | 27 +++++++++++- > arch/arm64/kernel/entry-common.c | 6 +++ > arch/arm64/kernel/mte.c | 67 ++++++++++++++++++++++++++++-- > arch/arm64/lib/mte.S | 15 ------- > include/linux/kasan.h | 1 + > include/linux/kasan_def.h | 39 +++++++++++++++++ > mm/kasan/hw_tags.c | 24 ++--------- > mm/kasan/kasan.h | 2 +- > 10 files changed, 145 insertions(+), 43 deletions(-) > create mode 100644 include/linux/kasan_def.h >
-- Regards, Vincenzo
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