Messages in this thread | | | Date | Wed, 6 Jan 2021 16:42:26 +0000 | From | Will Deacon <> | Subject | Re: [PATCH 0/4] arm64: ARMv8.5-A: MTE: Add async mode support |
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On Wed, Jan 06, 2021 at 04:35:29PM +0000, Vincenzo Frascino wrote: > > 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.
If only you worked for payroll ;)
Will
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