objtool: Make unreachable annotation inline asms explicitly volatile

Add 'volatile' to the unreachable annotation macro inline asm
statements.  They're already implicitly volatile because they don't have
output constraints, but it's clearer and more robust to make them
explicitly volatile.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/28659257b7a6adf4a7f65920dad70b2b0226e996.1509974104.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f8734fca54ce1572b9ad175d36c2f5a9d8202521..4fac29cdffd15707860c68f16f1b6a3cc684448c 100644 (file)
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -193,16 +193,16 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
  * unique, to convince GCC not to merge duplicate inline asm statements.
  */
 #define annotate_reachable() ({                                                \
-       asm("%c0:\n\t"                                                  \
-           ".pushsection .discard.reachable\n\t"                       \
-           ".long %c0b - .\n\t"                                        \
-           ".popsection\n\t" : : "i" (__COUNTER__));                   \
+       asm volatile("%c0:\n\t"                                         \
+                    ".pushsection .discard.reachable\n\t"              \
+                    ".long %c0b - .\n\t"                               \
+                    ".popsection\n\t" : : "i" (__COUNTER__));          \
 })
 #define annotate_unreachable() ({                                      \
-       asm("%c0:\n\t"                                                  \
-           ".pushsection .discard.unreachable\n\t"                     \
-           ".long %c0b - .\n\t"                                        \
-           ".popsection\n\t" : : "i" (__COUNTER__));                   \
+       asm volatile("%c0:\n\t"                                         \
+                    ".pushsection .discard.unreachable\n\t"            \
+                    ".long %c0b - .\n\t"                               \
+                    ".popsection\n\t" : : "i" (__COUNTER__));          \
 })
 #define ASM_UNREACHABLE                                                        \
        "999:\n\t"                                                      \