[tip: objtool/core] objtool/klp: Correlate locals to globals

[tip-bot2 for Song Liu]

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

Commit-ID:     4b57e97be22fb8332d05ee1d0fe3c0dd43c828bf
Gitweb:        https://git.kernel.org/tip/4b57e97be22fb8332d05ee1d0fe3c0dd43c828bf
Author:        Song Liu <song@xxxxxxxxxx>
AuthorDate:    Thu, 05 Mar 2026 15:15:31 -08:00
Committer:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Fri, 06 Mar 2026 08:08:34 -08:00

objtool/klp: Correlate locals to globals

Allow correlating original locals to patched globals, and vice versa.
This is needed when:

1. User adds/removes "static" for a function.
2. CONFIG_LTO_CLANG_THIN promotes local functions and objects to global
   and add .llvm.<hash> suffix.

Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://patch.msgid.link/20260305231531.3847295-8-song@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/klp-diff.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
index 46afbf4..85281b3 100644
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c
@@ -517,6 +517,36 @@ static int correlate_symbols(struct elfs *e)
 		}
 	}
 
+	/* Correlate original locals with patched globals */
+	for_each_sym(e->orig, sym1) {
+		if (sym1->twin || dont_correlate(sym1) || !is_local_sym(sym1))
+			continue;
+
+		sym2 = find_global_symbol_by_name(e->patched, sym1->name);
+		if (!sym2 && find_global_symbol_by_demangled_name(e->patched, sym1, &sym2))
+			return -1;
+
+		if (sym2 && !sym2->twin) {
+			sym1->twin = sym2;
+			sym2->twin = sym1;
+		}
+	}
+
+	/* Correlate original globals with patched locals */
+	for_each_sym(e->patched, sym2) {
+		if (sym2->twin || dont_correlate(sym2) || !is_local_sym(sym2))
+			continue;
+
+		sym1 = find_global_symbol_by_name(e->orig, sym2->name);
+		if (!sym1 && find_global_symbol_by_demangled_name(e->orig, sym2, &sym1))
+			return -1;
+
+		if (sym1 && !sym1->twin) {
+			sym2->twin = sym1;
+			sym1->twin = sym2;
+		}
+	}
+
 	for_each_sym(e->orig, sym1) {
 		if (sym1->twin || dont_correlate(sym1))
 			continue;