If CONFIG_DEBUG_INFO_SPLIT is not set but CONFIG_DEBUG_INFO is,
the kernel makefile just adds "-g" and the scripts/gcc-goto.sh test for
the "asm goto ("" :::: entry)" support succedes and adds
-DCC_HAVE_ASM_GOTO to KBUILD_CFLAGS/KBUILD_AFLAGS. This effectively
makes OPAL_BRANCH() a noop (or something similar).
With CONFIG_DEBUG_INFO_SPLIT=y, the makefile adds "-gsplit-dwarf" which
somehow makes the scripts/gcc-goto.sh test fail and not have
CC_HAVE_ASM_GOTO defined so the alternative OPAL_BRANCH() is used
and this particular chunk clobbers r12 where the parenting code -
OPAL_CALL() - stores MSR; as the result, the kernel oops'es right after
early_setup() because of broken MSR.
This replaces r12 with r11 which is overwritten right after
OPAL_BRANCH(opal_tracepoint_entry) anyway.
I used gcc 5.4.1 20161205 built from sha1 ffadbf3ae29.
Fixes: ab9bad0ead9a ("powerpc/powernv: Remove separate entry for OPAL real mode
calls")
Suggested-by: Paul Mackerras <pau...@samba.org>
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
arch/powerpc/platforms/powernv/opal-wrappers.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S
b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 6693f75e93d1..da8a0f7a035c 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -39,8 +39,8 @@ opal_tracepoint_refcount:
BEGIN_FTR_SECTION; \
b 1f; \
END_FTR_SECTION(0, 1); \
- ld r12,opal_tracepoint_refcount@toc(r2); \
- cmpdi r12,0; \
+ ld r11,opal_tracepoint_refcount@toc(r2); \
+ cmpdi r11,0; \
bne- LABEL; \
1:
--
2.11.0
