From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Thu, 21 Jan 2021 21:29:20 +0000 (-0600)
Subject: objtool: Support retpoline jump detection for vmlinux.o
X-Git-Tag: v5.12-rc1~69^2~17
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=31a7424bc58063a8e0466c3c10f31a52ec2be4f6;p=linux-block.git

objtool: Support retpoline jump detection for vmlinux.o

Objtool converts direct retpoline jumps to type INSN_JUMP_DYNAMIC, since
that's what they are semantically.

That conversion doesn't work in vmlinux.o validation because the
indirect thunk function is present in the object, so the intra-object
jump check succeeds before the retpoline jump check gets a chance.

Rearrange the checks: check for a retpoline jump before checking for an
intra-object jump.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/4302893513770dde68ddc22a9d6a2a04aca491dd.1611263461.git.jpoimboe@redhat.com
---

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index c964cd56b557..5f5949951ca7 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -781,10 +781,6 @@ static int add_jump_destinations(struct objtool_file *file)
 		} else if (reloc->sym->type == STT_SECTION) {
 			dest_sec = reloc->sym->sec;
 			dest_off = arch_dest_reloc_offset(reloc->addend);
-		} else if (reloc->sym->sec->idx) {
-			dest_sec = reloc->sym->sec;
-			dest_off = reloc->sym->sym.st_value +
-				   arch_dest_reloc_offset(reloc->addend);
 		} else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
 			   !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
 			/*
@@ -798,6 +794,10 @@ static int add_jump_destinations(struct objtool_file *file)
 
 			insn->retpoline_safe = true;
 			continue;
+		} else if (reloc->sym->sec->idx) {
+			dest_sec = reloc->sym->sec;
+			dest_off = reloc->sym->sym.st_value +
+				   arch_dest_reloc_offset(reloc->addend);
 		} else {
 			/* external sibling call */
 			insn->call_dest = reloc->sym;