mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-15 15:15:47 +00:00
Code Issues Releases Wiki Activity

s390/cpcmd: fix inline assembly register clobbering

Browse source 
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: 94c12cc7d1 ("[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>
This commit is contained in:
Alexander Gordeev 2021-03-29 18:35:07 +02:00 committed by Heiko Carstens
parent 84d572e634
commit 7a2f91441b
1 changed files with 4 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
arch/s390/kernel/cpcmd.c
View file

@ -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"