The following commit has been merged into the objtool/core branch of tip:
Commit-ID: f1069a8756b9e9f6c055e709740d2d66650f0fb0
Gitweb: https://git.kernel.org/tip/f1069a8756b9e9f6c055e709740d2d66650f0fb0
Author: Vasily Gorbik <gor@xxxxxxxxxxxxx>
AuthorDate: Wed, 19 May 2021 15:03:08 +02:00
Committer: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Wed, 19 May 2021 15:30:58 -05:00
compiler.h: Avoid using inline asm operand modifiers
The expansion of annotate_reachable/annotate_unreachable on s390 will
result in a compiler error if the __COUNTER__ value is high enough.
For example with "i" (154) the "%c0" operand of annotate_reachable
will be expanded to -102:
-102:
.pushsection .discard.reachable
.long -102b - .
.popsection
This is a quirk of the gcc backend for s390, it interprets the %c0
as a signed byte value. Avoid using operand modifiers in this case
by simply converting __COUNTER__ to string, with the same result,
but in an arch assembler independent way.
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/patch-1.thread-1a26be.git-930d1b44844a.your-ad-here.call-01621428935-ext-2104@work.hours
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Miroslav Benes <mbenes@xxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
include/linux/compiler.h | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index df5b405..7704790 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -115,18 +115,24 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
* The __COUNTER__ based labels are a hack to make each instance of the macros
* unique, to convince GCC not to merge duplicate inline asm statements.
*/
-#define annotate_reachable() ({ \
- asm volatile("%c0:\n\t" \
+#define __stringify_label(n) #n
+
+#define __annotate_reachable(c) ({ \
+ asm volatile(__stringify_label(c) ":\n\t" \
".pushsection .discard.reachable\n\t" \
- ".long %c0b - .\n\t" \
- ".popsection\n\t" : : "i" (__COUNTER__)); \
+ ".long " __stringify_label(c) "b - .\n\t" \
+ ".popsection\n\t"); \
})
-#define annotate_unreachable() ({ \
- asm volatile("%c0:\n\t" \
+#define annotate_reachable() __annotate_reachable(__COUNTER__)
+
+#define __annotate_unreachable(c) ({ \
+ asm volatile(__stringify_label(c) ":\n\t" \
".pushsection .discard.unreachable\n\t" \
- ".long %c0b - .\n\t" \
- ".popsection\n\t" : : "i" (__COUNTER__)); \
+ ".long " __stringify_label(c) "b - .\n\t" \
+ ".popsection\n\t"); \
})
+#define annotate_unreachable() __annotate_unreachable(__COUNTER__)
+
#define ASM_UNREACHABLE \
"999:\n\t" \
".pushsection .discard.unreachable\n\t" \
|