From 7a2f91441b2c1d81b77c1cd816a4659f4abc9cbe Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Mon, 29 Mar 2021 18:35:07 +0200 Subject: s390/cpcmd: fix inline assembly register clobbering 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 Acked-by: Ilya Leoshkevich Link: https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Local-Register-Variables.html Signed-off-by: Heiko Carstens --- arch/s390/kernel/cpcmd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch') 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" -- cgit v1.2.3