From: Alexander Gordeev agordeev@linux.ibm.com
[ Upstream commit 7a2f91441b2c1d81b77c1cd816a4659f4abc9cbe ]
Register variables initialized using arithmetic. That leads to kasan instrumentaton code corrupting the registers contents. Follow GCC guidlines and use temporary variables for assigning init values to register variables.
Fixes: 94c12cc7d196 ("[S390] Inline assembly cleanup.") Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Acked-by: Ilya Leoshkevich iii@linux.ibm.com Link: https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Local-Register-Variables.html Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kernel/cpcmd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c index af013b4244d3..2da027359798 100644 --- a/arch/s390/kernel/cpcmd.c +++ b/arch/s390/kernel/cpcmd.c @@ -37,10 +37,12 @@ static int diag8_noresponse(int cmdlen)
static int diag8_response(int cmdlen, char *response, int *rlen) { + unsigned long _cmdlen = cmdlen | 0x40000000L; + unsigned long _rlen = *rlen; register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; register unsigned long reg3 asm ("3") = (addr_t) response; - register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; - register unsigned long reg5 asm ("5") = *rlen; + register unsigned long reg4 asm ("4") = _cmdlen; + register unsigned long reg5 asm ("5") = _rlen;
asm volatile( " diag %2,%0,0x8\n"