[PATCH] kcsan: fix section mismatch for __write_once_size/blacklisted_initcalls

From: Arnd Bergmann
Date: Tue May 05 2020 - 10:12:20 EST


Moving __write_once_size out of line causes a section mismatch warning
with clang in one instance:

WARNING: modpost: vmlinux.o(.text+0x8dc): Section mismatch in reference from the function __write_once_size() to the variable .init.data:blacklisted_initcalls
The function __write_once_size() references
the variable __initdata blacklisted_initcalls.
This is often because __write_once_size lacks a __initdata
annotation or the annotation of blacklisted_initcalls is wrong.

Remove the __init_or_module annotation from the variable as a workaround.

Fixes: dfd402a4c4ba ("kcsan: Add Kernel Concurrency Sanitizer infrastructure")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
So far, my randconfig checks found two such instances, one for read_once
and one for write_once. There are probably a couple more in random
configurations, but I guess they are rare enough that we can just work
around them like this.
---
init/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/main.c b/init/main.c
index 8f78399697e3..441c384a73cd 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1020,7 +1020,7 @@ struct blacklist_entry {
char *buf;
};

-static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
+static LIST_HEAD(blacklisted_initcalls);

static int __init initcall_blacklist(char *str)
{
--
2.26.0