]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
ARM: 9464/1: fix input-only operand modification in load_unaligned_zeropad()
authorLiyuan Pang <pangliyuan1@huawei.com>
Tue, 9 Dec 2025 02:19:45 +0000 (03:19 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 18 Dec 2025 13:00:13 +0000 (14:00 +0100)
commit0ad68757cd6fcf5a96226a35c71c36b03f102a17
tree8ca1140cd96ed529cb46410ec9a53881121f37a1
parentdf692cf2b601a54b34edfdb9e683d67483aa8ce1
ARM: 9464/1: fix input-only operand modification in load_unaligned_zeropad()

[ Upstream commit edb924a7211c9aa7a4a415e03caee4d875e46b8e ]

In the inline assembly inside load_unaligned_zeropad(), the "addr" is
constrained as input-only operand. The compiler assumes that on exit
from the asm statement these operands contain the same values as they
had before executing the statement, but when kernel page fault happened, the assembly fixup code "bic %2 %2, #0x3" modify the value of "addr", which may lead to an unexpected behavior.

Use a temporary variable "tmp" to handle it, instead of modifying the
input-only operand, just like what arm64's load_unaligned_zeropad()
does.

Fixes: b9a50f74905a ("ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs")
Co-developed-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Liyuan Pang <pangliyuan1@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
arch/arm/include/asm/word-at-a-time.h