[tip: objtool/core] objtool/klp: Fix is_uncorrelated_static_local() for Clang

[tip: objtool/core] objtool/klp: Fix is_uncorrelated_static_local() for Clang

[tip-bot2 for Joe Lawrence]

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

Commit-ID:     84c304a534b844703d3437811e8f072166e3f116
Gitweb:        https://git.kernel.org/tip/84c304a534b844703d3437811e8f072166e3f116
Author:        Joe Lawrence <joe.lawrence@redhat.com>
AuthorDate:    Wed, 08 Apr 2026 10:49:19 -04:00
Committer:     Josh Poimboeuf <jpoimboe@kernel.org>
CommitterDate: Mon, 04 May 2026 21:15:59 -07:00

objtool/klp: Fix is_uncorrelated_static_local() for Clang

For naming function-local static locals, GCC uses <var>.<id>, e.g.
__already_done.15, while Clang uses <func>.<var> with optional .<id>,
e.g. create_worker.__already_done.111

The existing is_uncorrelated_static_local() check only matches the GCC
convention where the variable name is a prefix.  Handle both cases by
checking for a prefix match (GCC) and by checking after the first dot
separator (Clang).

Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/klp-diff.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
index 0b0d150..b1b068e 100644
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c
@@ -242,16 +242,17 @@ static struct symbol *next_file_symbol(struct elf *elf, struct symbol *sym)
 static bool is_uncorrelated_static_local(struct symbol *sym)
 {
 	static const char * const vars[] = {
-		"__already_done.",
-		"__func__.",
-		"__key.",
-		"__warned.",
-		"_entry.",
-		"_entry_ptr.",
-		"_rs.",
-		"descriptor.",
-		"CSWTCH.",
+		"__already_done",
+		"__func__",
+		"__key",
+		"__warned",
+		"_entry",
+		"_entry_ptr",
+		"_rs",
+		"descriptor",
+		"CSWTCH",
 	};
+	const char *dot;
 
 	if (!is_object_sym(sym) || !is_local_sym(sym))
 		return false;
@@ -259,8 +260,20 @@ static bool is_uncorrelated_static_local(struct symbol *sym)
 	if (!strcmp(sym->sec->name, ".data.once"))
 		return true;
 
+	dot = strchr(sym->name, '.');
+	if (!dot)
+		return false;
+
 	for (int i = 0; i < ARRAY_SIZE(vars); i++) {
-		if (strstarts(sym->name, vars[i]))
+		size_t len = strlen(vars[i]);
+
+		/* GCC: <var>.<id> */
+		if (strstarts(sym->name, vars[i]) && (sym->name[len] == '.'))
+			return true;
+
+		/* Clang: <func>.<var>[.<id>] */
+		if (strstarts(dot + 1, vars[i]) &&
+		    (dot[1 + len] == '.' || dot[1 + len] == '\0'))
 			return true;
 	}