ARM: 9214/1: alignment: advance IT state after emulating Thumb instruction
authorArd Biesheuvel <ardb@kernel.org>
Thu, 30 Jun 2022 15:46:54 +0000 (16:46 +0100)
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Wed, 6 Jul 2022 21:44:49 +0000 (22:44 +0100)
commite5c46fde75e43c15a29b40e5fc5641727f97ae47
tree97b2792805da656e88e39826064b1bc192be03a0
parente4ced82deb5fb17222fb82e092c3f8311955b585
ARM: 9214/1: alignment: advance IT state after emulating Thumb instruction

After emulating a misaligned load or store issued in Thumb mode, we have
to advance the IT state by hand, or it will get out of sync with the
actual instruction stream, which means we'll end up applying the wrong
condition code to subsequent instructions. This might corrupt the
program state rather catastrophically.

So borrow the it_advance() helper from the probing code, and use it on
CPSR if the emulated instruction is Thumb.

Cc: <stable@vger.kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
arch/arm/include/asm/ptrace.h
arch/arm/mm/alignment.c
arch/arm/probes/decode.h