From: Heiko Carstens hca@linux.ibm.com
commit 89aba4c26fae4e459f755a18912845c348ee48f3 upstream.
Add missing earlyclobber annotation to size, to, and tmp2 operands of the __clear_user() inline assembly since they are modified or written to before the last usage of all input operands. This can lead to incorrect register allocation for the inline assembly.
Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.") Reported-by: Mark Rutland mark.rutland@arm.com Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/ Cc: stable@vger.kernel.org Reviewed-by: Gerald Schaefer gerald.schaefer@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/lib/uaccess.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -227,7 +227,7 @@ static inline unsigned long clear_user_m "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b) - : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) + : "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2) : "a" (empty_zero_page), [spec] "K" (0x81UL) : "cc", "memory", "0"); return size;