1 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 668569844d37..f1bfa15b6f9b 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -182,6 +182,29 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
 # define unreachable() do { } while (1)
 #endif
 
+/*
+ * KENTRY - kernel entry point
+ * This can be used to annotate symbols (functions or data) that are used
+ * without their linker symbol being referenced explicitly. For example,
+ * interrupt vector handlers, or functions in the kernel image that are found
+ * programatically.
+ *
+ * Not required for symbols exported with EXPORT_SYMBOL, or initcalls. Those
+ * are handled in their own way (with KEEP() in linker scripts).
+ *
+ * KENTRY can be avoided if the symbols in question are marked as KEEP() in the
+ * linker script. For example an architecture could KEEP() its entire
+ * boot/exception vector code rather than annotate each function and data.
+ */
+#ifndef KENTRY
+# define KENTRY(sym)                                            \
+        extern typeof(sym) sym;                                 \
+        static const unsigned long __kentry_##sym               \
+        __used                                                  \
+        __attribute__((section("___kentry" "+" #sym ), used))   \
+        = (unsigned long)&sym;
+#endif
+
 #ifndef RELOC_HIDE
 # define RELOC_HIDE(ptr, off)                                   \
   ({ unsigned long __ptr;                                       \