]> 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>
Mon, 19 Jan 2026 12:09:39 +0000 (13:09 +0100)
commita9bfe4eb0103abaebb6a2a806844b0084b3537a1
treee0ff64e8dbacf893b8226196d9b4494ff7367b07
parentceb5dff91c86dcb7ea7ea68dfbba7116d39c5dc8
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