[PATCH v2 07/62] elfnote: Change ELFNOTE() to use __UNIQUE_ID()
From: Josh Poimboeuf
Date: Fri May 09 2025 - 16:19:22 EST
In preparation for the objtool klp diff subcommand, replace the custom
unique symbol name generation in ELFNOTE() with __UNIQUE_ID().
This standardizes the naming format for all "unique" symbols, which will
allow objtool to properly correlate them. Note this also removes the
"one ELF note per line" limitation.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
include/linux/elfnote.h | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/include/linux/elfnote.h b/include/linux/elfnote.h
index 69b136e4dd2b..bb3dcded055f 100644
--- a/include/linux/elfnote.h
+++ b/include/linux/elfnote.h
@@ -60,23 +60,21 @@
#else /* !__ASSEMBLER__ */
#include <uapi/linux/elf.h>
+#include <linux/compiler.h>
/*
* Use an anonymous structure which matches the shape of
* Elf{32,64}_Nhdr, but includes the name and desc data. The size and
* type of name and desc depend on the macro arguments. "name" must
- * be a literal string, and "desc" must be passed by value. You may
- * only define one note per line, since __LINE__ is used to generate
- * unique symbols.
+ * be a literal string, and "desc" must be passed by value.
*/
-#define _ELFNOTE_PASTE(a,b) a##b
-#define _ELFNOTE(size, name, unique, type, desc) \
+#define ELFNOTE(size, name, type, desc) \
static const struct { \
struct elf##size##_note _nhdr; \
unsigned char _name[sizeof(name)] \
__attribute__((aligned(sizeof(Elf##size##_Word)))); \
typeof(desc) _desc \
__attribute__((aligned(sizeof(Elf##size##_Word)))); \
- } _ELFNOTE_PASTE(_note_, unique) \
+ } __UNIQUE_ID(note) \
__used \
__attribute__((section(".note." name), \
aligned(sizeof(Elf##size##_Word)), \
@@ -89,11 +87,10 @@
name, \
desc \
}
-#define ELFNOTE(size, name, type, desc) \
- _ELFNOTE(size, name, __LINE__, type, desc)
#define ELFNOTE32(name, type, desc) ELFNOTE(32, name, type, desc)
#define ELFNOTE64(name, type, desc) ELFNOTE(64, name, type, desc)
+
#endif /* __ASSEMBLER__ */
#endif /* _LINUX_ELFNOTE_H */
--
2.49.0