1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 202710420d6d..f8734fca54ce 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -187,6 +187,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 
 /* Unreachable code */
 #ifdef CONFIG_STACK_VALIDATION
+/*
+ * These macros help objtool understand GCC code flow for unreachable code.
+ * 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("%c0:\n\t"                                                  \
             ".pushsection .discard.reachable\n\t"                       \