Merge tag 'objtool-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fix from Ingo Molnar:
 "Fix a segfault that occurs when built with Clang"

* tag 'objtool-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix seg fault with Clang non-section symbols

1 files changed, 26 insertions, 0 deletions

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 4e1d7460574b..be89c741ba9a 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -262,6 +262,32 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns
 	return find_reloc_by_dest_range(elf, sec, offset, 1);
 }
 
+void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,
+			      struct reloc *reloc)
+{
+	if (sec->sym) {
+		reloc->sym = sec->sym;
+		reloc->addend = offset;
+		return;
+	}
+
+	/*
+	 * The Clang assembler strips section symbols, so we have to reference
+	 * the function symbol instead:
+	 */
+	reloc->sym = find_symbol_containing(sec, offset);
+	if (!reloc->sym) {
+		/*
+		 * Hack alert.  This happens when we need to reference the NOP
+		 * pad insn immediately after the function.
+		 */
+		reloc->sym = find_symbol_containing(sec, offset - 1);
+	}
+
+	if (reloc->sym)
+		reloc->addend = offset - reloc->sym->offset;
+}
+
 static int read_sections(struct elf *elf)
 {
 	Elf_Scn *s = NULL;