[PATCH] init.h: discard exitcall symbols early

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Any __exitcall() and built-in module_exit() handler is marked as __used,
which leads to the code being included in the object file and later
discarded at link time.

As far as I can tell, this was originally added at the same time
as initcalls were marked the same way, to prevent them from getting
dropped with gcc-3.4, but it was never actaully necessary to keep exit
functions around.

Mark them as __maybe_unused instead, which lets the compiler treat
the exitcalls as entirely unused, and make better decisions about
dropping specializing static functions called from these.

Link: https://lore.kernel.org/all/acruxMNdnUlyRHiy@google.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/init.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/init.h b/include/linux/init.h
index 5db55c660124..ad5c19763034 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -47,7 +47,7 @@
 #define __initdata	__section(".init.data")
 #define __initconst	__section(".init.rodata")
 #define __exitdata	__section(".exit.data")
-#define __exit_call	__used __section(".exitcall.exit")
+#define __exit_call	__maybe_unused __section(".exitcall.exit")
 
 /*
  * modpost check for section mismatches during the kernel build.
-- 
2.39.5