]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/commit
arm64: mte: switch GCR_EL1 in kernel entry and exit
authorVincenzo Frascino <vincenzo.frascino@arm.com>
Tue, 22 Dec 2020 20:01:45 +0000 (12:01 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Dec 2020 20:55:07 +0000 (12:55 -0800)
commitbad1e1c663e0a72f9cf7b230a00d821678f80455
treecd623e54bc02bc56da1fe75bd71c3adcb7eab75e
parent620954a67bcec6ca6b902baaaa1e3f2601b371a7
arm64: mte: switch GCR_EL1 in kernel entry and exit

When MTE is present, the GCR_EL1 register contains the tags mask that
allows to exclude tags from the random generation via the IRG instruction.

With the introduction of the new Tag-Based KASAN API that provides a
mechanism to reserve tags for special reasons, the MTE implementation has
to make sure that the GCR_EL1 setting for the kernel does not affect the
userspace processes and viceversa.

Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit.

Link: https://lkml.kernel.org/r/578b03294708cc7258fad0dc9c2a2e809e5a8214.1606161801.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>
arch/arm64/include/asm/mte-def.h
arch/arm64/include/asm/mte-kasan.h
arch/arm64/include/asm/mte.h
arch/arm64/kernel/asm-offsets.c
arch/arm64/kernel/entry.S
arch/arm64/kernel/mte.c