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authorVasily Gorbik <gor@linux.ibm.com>2019-11-25 13:34:59 +0100
committerVasily Gorbik <gor@linux.ibm.com>2019-11-30 10:52:47 +0100
commit4ac24c092b4eef69b2436ee4d478500dc886e8b5 (patch)
treee313e5c73958572c5a3266c0597932aea9403db2 /arch
parents390/test_unwind: require that unwinding ended successfully (diff)
downloadlinux-dev-4ac24c092b4eef69b2436ee4d478500dc886e8b5.tar.xz
linux-dev-4ac24c092b4eef69b2436ee4d478500dc886e8b5.zip
s390: fix register clobbering in CALL_ON_STACK
CALL_ON_STACK defines and initializes register variables. Inline assembly which follows might trigger compiler to generate memory access for "stack" argument (e.g. in case of S390_lowcore.nodat_stack). This memory access produces a function call under kasan with outline instrumentation which clobbers registers. Switch "stack" argument in CALL_ON_STACK helper to use memory reference constraint and perform load instead. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/stacktrace.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index 4725315a9cb1..ee056f4a4fa3 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -112,12 +112,12 @@ struct stack_frame {
\
asm volatile( \
" la %[_prev],0(15)\n" \
- " la 15,0(%[_stack])\n" \
+ " lg 15,%[_stack]\n" \
" stg %[_frame],%[_bc](15)\n" \
" brasl 14,%[_fn]\n" \
" la 15,0(%[_prev])\n" \
: [_prev] "=&a" (prev), CALL_FMT_##nr \
- [_stack] "a" (stack), \
+ [_stack] "R" (stack), \
[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
[_frame] "d" (frame), \
[_fn] "X" (fn) : CALL_CLOBBER_##nr); \