From: Guenter Roeck linux@roeck-us.net
mainline inclusion from mainline-v6.9-rc1 commit e5db6a74571a8baf87a116ea39aab946283362ff 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/?i...
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Convert to use real temp variables instead of clobbering processor registers. This aligns the 64-bit inline assembly code with the 32-bit assembly code which was rewritten with commit 427c1073a2a1 ("parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd()").
While at it, fix comment in 32-bit rewrite code. Temporary variables are now used for both 32-bit and 64-bit code, so move their declarations to the function header.
No functional change intended.
Signed-off-by: Guenter Roeck linux@roeck-us.net Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Cheng Yu serein.chengyu@huawei.com --- arch/parisc/kernel/unaligned.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/arch/parisc/kernel/unaligned.c b/arch/parisc/kernel/unaligned.c index 4486186463a2..ec40bdafae7e 100644 --- a/arch/parisc/kernel/unaligned.c +++ b/arch/parisc/kernel/unaligned.c @@ -174,6 +174,7 @@ static int emulate_ldw(struct pt_regs *regs, int toreg, int flop) static int emulate_ldd(struct pt_regs *regs, int toreg, int flop) { unsigned long saddr = regs->ior; + unsigned long shift, temp1; __u64 val = 0; ASM_EXCEPTIONTABLE_VAR(ret);
@@ -185,25 +186,22 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
#ifdef CONFIG_64BIT __asm__ __volatile__ ( -" depd,z %3,60,3,%%r19\n" /* r19=(ofs&7)*8 */ -" mtsp %4, %%sr1\n" -" depd %%r0,63,3,%3\n" -"1: ldd 0(%%sr1,%3),%0\n" -"2: ldd 8(%%sr1,%3),%%r20\n" -" subi 64,%%r19,%%r19\n" -" mtsar %%r19\n" -" shrpd %0,%%r20,%%sar,%0\n" +" depd,z %2,60,3,%3\n" /* shift=(ofs&7)*8 */ +" mtsp %5, %%sr1\n" +" depd %%r0,63,3,%2\n" +"1: ldd 0(%%sr1,%2),%0\n" +"2: ldd 8(%%sr1,%2),%4\n" +" subi 64,%3,%3\n" +" mtsar %3\n" +" shrpd %0,%4,%%sar,%0\n" "3: \n" ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%1") ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%1") - : "=r" (val), "+r" (ret) - : "0" (val), "r" (saddr), "r" (regs->isr) - : "r19", "r20" ); + : "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1) + : "r" (regs->isr) ); #else - { - unsigned long shift, temp1; __asm__ __volatile__ ( -" zdep %2,29,2,%3\n" /* r19=(ofs&3)*8 */ +" zdep %2,29,2,%3\n" /* shift=(ofs&3)*8 */ " mtsp %5, %%sr1\n" " dep %%r0,31,2,%2\n" "1: ldw 0(%%sr1,%2),%0\n" @@ -219,7 +217,6 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop) ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 4b, "%1") : "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1) : "r" (regs->isr) ); - } #endif
DPRINTF("val = 0x%llx\n", val);