[tip:x86/pti] objtool: Fix 32-bit build

[tip-bot for Josh Poimboeuf]

Commit-ID:  63474dc4ac7ed3848a4786b9592dd061901f606d
Gitweb:     https://git.kernel.org/tip/63474dc4ac7ed3848a4786b9592dd061901f606d
Author:     Josh Poimboeuf <jpoim...@redhat.com>
AuthorDate: Tue, 6 Mar 2018 17:58:15 -0600
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Wed, 7 Mar 2018 07:50:38 +0100

objtool: Fix 32-bit build

Fix the objtool build when cross-compiling a 64-bit kernel on a 32-bit
host.  This also simplifies read_retpoline_hints() a bit and makes its
implementation similar to most of the other annotation reading
functions.

Reported-by: Sven Joachim <svenj...@gmx.de>
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Fixes: b5bc2231b8ad ("objtool: Add retpoline validation")
Link: 
http://lkml.kernel.org/r/2ca46c636c23aa9c9d57d53c75de4ee3ddf7a7df.1520380691.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 tools/objtool/check.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 46c1d239cc1b..92b6a2c21631 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1116,42 +1116,29 @@ static int read_unwind_hints(struct objtool_file *file)
 
 static int read_retpoline_hints(struct objtool_file *file)
 {
-       struct section *sec, *relasec;
+       struct section *sec;
        struct instruction *insn;
        struct rela *rela;
-       int i;
 
-       sec = find_section_by_name(file->elf, ".discard.retpoline_safe");
+       sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
        if (!sec)
                return 0;
 
-       relasec = sec->rela;
-       if (!relasec) {
-               WARN("missing .rela.discard.retpoline_safe section");
-               return -1;
-       }
-
-       if (sec->len % sizeof(unsigned long)) {
-               WARN("retpoline_safe size mismatch: %d %ld", sec->len, 
sizeof(unsigned long));
-               return -1;
-       }
-
-       for (i = 0; i < sec->len / sizeof(unsigned long); i++) {
-               rela = find_rela_by_dest(sec, i * sizeof(unsigned long));
-               if (!rela) {
-                       WARN("can't find rela for retpoline_safe[%d]", i);
+       list_for_each_entry(rela, &sec->rela_list, list) {
+               if (rela->sym->type != STT_SECTION) {
+                       WARN("unexpected relocation symbol type in %s", 
sec->name);
                        return -1;
                }
 
                insn = find_insn(file, rela->sym->sec, rela->addend);
                if (!insn) {
-                       WARN("can't find insn for retpoline_safe[%d]", i);
+                       WARN("bad .discard.retpoline_safe entry");
                        return -1;
                }
 
                if (insn->type != INSN_JUMP_DYNAMIC &&
                    insn->type != INSN_CALL_DYNAMIC) {
-                       WARN_FUNC("retpoline_safe hint not a indirect 
jump/call",
+                       WARN_FUNC("retpoline_safe hint not an indirect 
jump/call",
                                  insn->sec, insn->offset);
                        return -1;
                }