[tip: core/static_call] compiler.h: Make __ADDRESSABLE() symbol truly unique

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the core/static_call branch of tip:

Commit-ID:     563a02b0c9704f69c0364befedd451f57fe88092
Gitweb:        https://git.kernel.org/tip/563a02b0c9704f69c0364befedd451f57fe88092
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Tue, 18 Aug 2020 15:57:40 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 01 Sep 2020 09:58:04 +02:00

compiler.h: Make __ADDRESSABLE() symbol truly unique

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__.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200818135804.564436253@xxxxxxxxxxxxx
---
 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 6810d80..92ef163 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -207,7 +207,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
  */
 #define __ADDRESSABLE(sym) \
 	static void * __section(.discard.addressable) __used \
-		__PASTE(__addressable_##sym, __LINE__) = (void *)&sym;
+		__UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)&sym;
 
 /**
  * offset_to_ptr - convert a relative memory offset to an absolute pointer