Commit ad09115a authored by Helge Deller's avatar Helge Deller Committed by Cheng Yu
Browse files

parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd() 

mainline inclusion
from mainline-v5.18-rc1
commit 427c1073
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2GP
CVE: CVE-2024-26706

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=427c1073a2a14fe38ef0fc98d3635be51d7f7818



--------------------------------

Convert to use real temp variables instead of clobbering processor
registers.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarCheng Yu <serein.chengyu@huawei.com>
parent e8a4b9f7

arch/parisc/kernel/unaligned.c

+13 −15
Original line number Diff line number Diff line
@@ -201,26 +201,24 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop) 
	: "r19", "r20" );

#else

    {

	unsigned long valh=0,vall=0;

	unsigned long shift, temp1;

	__asm__ __volatile__  (

"	zdep	%5,29,2,%%r19\n"		/* r19=(ofs&3)*8 */

"	mtsp	%6, %%sr1\n"

"	dep	%%r0,31,2,%5\n"

"1:	ldw	0(%%sr1,%5),%0\n"

"2:	ldw	4(%%sr1,%5),%1\n"

"3:	ldw	8(%%sr1,%5),%%r20\n"

"	subi	32,%%r19,%%r19\n"

"	mtsar	%%r19\n"

"	vshd	%0,%1,%0\n"

"	vshd	%1,%%r20,%1\n"

"	zdep	%2,29,2,%3\n"		/* r19=(ofs&3)*8 */

"	mtsp	%5, %%sr1\n"

"	dep	%%r0,31,2,%2\n"

"1:	ldw	0(%%sr1,%2),%0\n"

"2:	ldw	4(%%sr1,%2),%R0\n"

"3:	ldw	8(%%sr1,%2),%4\n"

"	subi	32,%3,%3\n"

"	mtsar	%3\n"

"	vshd	%0,%R0,%0\n"

"	vshd	%R0,%4,%R0\n"

"4:	\n"

	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 4b)

	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 4b)

	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 4b)

	: "=r" (valh), "=r" (vall), "+r" (ret)

	: "0" (valh), "1" (vall), "r" (saddr), "r" (regs->isr)

	: "r19", "r20" );

	val=((__u64)valh<<32)|(__u64)vall;

	: "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1)

	: "r" (regs->isr) );

    }

#endif