ARM: 9464/1: fix input-only operand modification in load_unaligned_zeropad()

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[ Upstream commit edb924a721 ]

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: b9a50f7490 ("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>

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Liyuan Pang 2025-12-09 03:19:45 +01:00 • committed by Greg Kroah-Hartman

parent 8f9e51cf2a

commit fb074e5c4f

1 changed files with 5 additions and 5 deletions

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arch/arm/include/asm/word-at-a-time.h

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