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| author |  Vasily Gorbik <gor@linux.ibm.com>
| 2021-05-19 15:03:13 +0200 |
|---|---|---|
| committer |  Josh Poimboeuf <jpoimboe@redhat.com>
| 2021-05-19 15:30:59 -0500 |
| commit | c199f64ff93c48a45add92eee4456ffcabfc838e (patch) | |
| tree | b5de0c0d2863dd48b9ad50f9e15d3259b0b44ad4 | |
| parent | compiler.h: Avoid using inline asm operand modifiers (diff) | |
| download | linux-c199f64ff93c.tar.gz linux-c199f64ff93c.tar.bz2 linux-c199f64ff93c.zip | |
instrumentation.h: Avoid using inline asm operand modifiers
The expansion of instrumentation_begin/instrumentation_end 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.instr_begin
.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@linux.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/patch-2.thread-1a26be.git-1a26be80cb18.your-ad-here.call-01621428935-ext-2104@work.hours
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: linux-kernel@vger.kernel.org
| -rw-r--r-- | include/linux/instrumentation.h | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h index 93e2ad67fc10..fa2cd8c63dcc 100644 --- a/include/linux/instrumentation.h +++ b/include/linux/instrumentation.h @@ -4,13 +4,16 @@ #if defined(CONFIG_DEBUG_ENTRY) && defined(CONFIG_STACK_VALIDATION) +#include <linux/stringify.h> + /* Begin/end of an instrumentation safe region */ -#define instrumentation_begin() ({ \ - asm volatile("%c0: nop\n\t" \ +#define __instrumentation_begin(c) ({ \ + asm volatile(__stringify(c) ": nop\n\t" \ ".pushsection .discard.instr_begin\n\t" \ - ".long %c0b - .\n\t" \ - ".popsection\n\t" : : "i" (__COUNTER__)); \ + ".long " __stringify(c) "b - .\n\t" \ + ".popsection\n\t"); \ }) +#define instrumentation_begin() __instrumentation_begin(__COUNTER__) /* * Because instrumentation_{begin,end}() can nest, objtool validation considers @@ -43,12 +46,13 @@ * To avoid this, have _end() be a NOP instruction, this ensures it will be * part of the condition block and does not escape. */ -#define instrumentation_end() ({ \ - asm volatile("%c0: nop\n\t" \ +#define __instrumentation_end(c) ({ \ + asm volatile(__stringify(c) ": nop\n\t" \ ".pushsection .discard.instr_end\n\t" \ - ".long %c0b - .\n\t" \ - ".popsection\n\t" : : "i" (__COUNTER__)); \ + ".long " __stringify(c) "b - .\n\t" \ + ".popsection\n\t"); \ }) +#define instrumentation_end() __instrumentation_end(__COUNTER__) #else # define instrumentation_begin() do { } while(0) # define instrumentation_end() do { } while(0) |