[PATCH v2 2/6] s390/tools/relocs: Ignore __kcfi_typeid_ relocations

This is the s390 variant of commit ca7e10bff196 ("x86/tools/relocs: Ignore
__kcfi_typeid_ relocations"):

"The compiler generates __kcfi_typeid_ symbols for annotating assembly
functions with type information. These are constants that can be referenced
in assembly code and are resolved by the linker. Ignore them in relocs."

Reviewed-by: Jens Remus <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
---
 arch/s390/tools/relocs.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/s390/tools/relocs.c b/arch/s390/tools/relocs.c
index a2774176d38f..72178dc90a4c 100644
--- a/arch/s390/tools/relocs.c
+++ b/arch/s390/tools/relocs.c
@@ -405,6 +405,22 @@ static int do_reloc(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 	case R_390_GOTPCDBL:
 	case R_390_GOTOFF64:
 		break;
+	case R_390_32: {
+		static const char kcfipfx[] = "__kcfi_typeid_";
+
+		if (sym->st_shndx != SHN_ABS)
+			die("Unsupported relocation type: %d\n", r_type);
+		/*
+		 * Symbols with __kcfi_typeid_ prefix have constant values,
+		 * which do not change if bzImage is loaded at a different
+		 * physical address than the address for which it has been
+		 * compiled.
+		 */
+		if (!strncmp(kcfipfx, symname, sizeof(kcfipfx) - 1))
+			break;
+		die("Invalid absolute R_390_32 relocation: %s\n", symname);
+		break;
+	}
 	case R_390_64:
 		add_reloc(&relocs64, offset);
 		break;
-- 
2.53.0