[tip: objtool/core] objtool/klp: Fix --debug-checksum for duplicate symbol names

[tip-bot2 for Josh Poimboeuf]

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

Commit-ID:     def5b60dcd2256efab0e66f598419b17c425b8f5
Gitweb:        https://git.kernel.org/tip/def5b60dcd2256efab0e66f598419b17c425b8f5
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Mon, 30 Mar 2026 21:31:47 -07:00
Committer:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Mon, 04 May 2026 21:16:00 -07:00

objtool/klp: Fix --debug-checksum for duplicate symbol names

find_symbol_by_name() only returns the first match, so
--debug-checksum=<func> silently ignores any subsequent duplicately
named functions after the first.

Fix that, along with a new for_each_sym_by_name() helper.

Acked-by: Song Liu <song@xxxxxxxxxx>
Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/check.c               | 15 ++++++++++-----
 tools/objtool/include/objtool/elf.h |  5 +++++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9b11cf3..e3604b1 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3677,18 +3677,23 @@ static int checksum_debug_init(struct objtool_file *file)
 
 	s = dup;
 	while (*s) {
-		struct symbol *func;
+		bool found = false;
+		struct symbol *sym;
 		char *comma;
 
 		comma = strchr(s, ',');
 		if (comma)
 			*comma = '\0';
 
-		func = find_symbol_by_name(file->elf, s);
-		if (!func || !is_func_sym(func))
+		for_each_sym_by_name(file->elf, s, sym) {
+			if (!is_func_sym(sym))
+				continue;
+			sym->debug_checksum = 1;
+			found = true;
+		}
+
+		if (!found)
 			WARN("--debug-checksum: can't find '%s'", s);
-		else
-			func->debug_checksum = 1;
 
 		if (!comma)
 			break;
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index b142984..00b0402 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -489,6 +489,11 @@ static inline void set_sym_next_reloc(struct reloc *reloc, struct reloc *next)
 #define for_each_sym_continue(elf, sym)					\
 	list_for_each_entry_continue(sym, &elf->symbols, global_list)
 
+#define for_each_sym_by_name(elf, _name, sym)				\
+	elf_hash_for_each_possible(elf, symbol_name, sym, name_hash,	\
+				   str_hash_demangled(_name))		\
+		if (strcmp(sym->name, _name)) {} else
+
 #define for_each_sym_by_demangled_name(elf, name, sym)			\
 	elf_hash_for_each_possible(elf, symbol_name, sym, name_hash,	\
 				   str_hash(name))			\