]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
arm64: errata: Remove AES hwcap for COMPAT tasks
authorJames Morse <james.morse@arm.com>
Thu, 14 Jul 2022 16:15:23 +0000 (17:15 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 3 Nov 2022 14:50:50 +0000 (23:50 +0900)
commit06035fd1efb772a178f4a0848d20731ba0973860
tree8410ce8475544b9e8ee5219b022c1f299eec1b7e
parent62ab3d75d320d491a9a0b5c0a05ac590cd782880
arm64: errata: Remove AES hwcap for COMPAT tasks

commit 44b3834b2eed595af07021b1c64e6f9bc396398b upstream.

Cortex-A57 and Cortex-A72 have an erratum where an interrupt that
occurs between a pair of AES instructions in aarch32 mode may corrupt
the ELR. The task will subsequently produce the wrong AES result.

The AES instructions are part of the cryptographic extensions, which are
optional. User-space software will detect the support for these
instructions from the hwcaps. If the platform doesn't support these
instructions a software implementation should be used.

Remove the hwcap bits on affected parts to indicate user-space should
not use the AES instructions.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20220714161523.279570-3-james.morse@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[florian: resolved conflicts in arch/arm64/tools/cpucaps and cpu_errata.c]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/arm64/silicon-errata.txt
arch/arm64/Kconfig
arch/arm64/include/asm/cpucaps.h
arch/arm64/kernel/cpu_errata.c
arch/arm64/kernel/cpufeature.c