[PATCH net-next 1/2] net: add EXPORT_INDIRECT_CALLABLE wrapper

From: Brian Vazquez
Date: Thu Feb 04 2021 - 12:22:15 EST


When a static function is annotated with INDIRECT_CALLABLE_SCOPE and
CONFIG_RETPOLINE is set, the static keyword is removed. Sometimes the
function needs to be exported but EXPORT_SYMBOL can't be used because if
CONFIG_RETPOLINE is not set, we will attempt to export a static symbol.

This patch introduces a new indirect call wrapper:
EXPORT_INDIRECT_CALLABLE. This basically does EXPORT_SYMBOL when
CONFIG_RETPOLINE is set, but does nothing when it's not.

Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Brian Vazquez <brianvv@xxxxxxxxxx>
---
include/linux/indirect_call_wrapper.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/linux/indirect_call_wrapper.h b/include/linux/indirect_call_wrapper.h
index 54c02c84906a..a8345c8a613d 100644
--- a/include/linux/indirect_call_wrapper.h
+++ b/include/linux/indirect_call_wrapper.h
@@ -36,6 +36,7 @@

#define INDIRECT_CALLABLE_DECLARE(f) f
#define INDIRECT_CALLABLE_SCOPE
+#define EXPORT_INDIRECT_CALLABLE(f) EXPORT_SYMBOL(f)

#else
#define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__)
@@ -44,6 +45,7 @@
#define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__)
#define INDIRECT_CALLABLE_DECLARE(f)
#define INDIRECT_CALLABLE_SCOPE static
+#define EXPORT_INDIRECT_CALLABLE(f)
#endif

/*
--
2.30.0.365.g02bc693789-goog