[PATCH v3 1/6] compiler.h: Make __ADDRESSABLE() symbol truly unique

From: Josh Poimboeuf
Date: Wed Jan 09 2019 - 17:59:59 EST


The __ADDRESSABLE() macro uses the __LINE__ macro to create a temporary
symbol which has a unique name. However, if the macro is used multiple
times from within another macro, the line number will always be the
same, resulting in duplicate symbols.

Make the temporary symbols truly unique by using __UNIQUE_ID instead of
__LINE__.

Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
include/linux/compiler.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index fc5004a4b07d..5e45bc988b1e 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -291,7 +291,7 @@ unsigned long read_word_at_a_time(const void *addr)
*/
#define __ADDRESSABLE(sym) \
static void * __section(".discard.addressable") __used \
- __PASTE(__addressable_##sym, __LINE__) = (void *)&sym;
+ __UNIQUE_ID(__addressable_##sym) = (void *)&sym;

/**
* offset_to_ptr - convert a relative memory offset to an absolute pointer
--
2.17.2