[PATCH 4.15 102/146] objtool: Fix 32-bit build

From: Greg Kroah-Hartman
Date: Tue Mar 13 2018 - 12:27:56 EST


4.15-stable review patch. If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

commit 63474dc4ac7ed3848a4786b9592dd061901f606d upstream.

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 <svenjoac@xxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: b5bc2231b8ad ("objtool: Add retpoline validation")
Link: http://lkml.kernel.org/r/2ca46c636c23aa9c9d57d53c75de4ee3ddf7a7df.1520380691.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
tools/objtool/check.c | 27 +++++++--------------------
1 file changed, 7 insertions(+), 20 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1115,42 +1115,29 @@ static int read_unwind_hints(struct objt

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;
}