[PATCH v3.1 18b/26] objtool: Factor out CFI hints

From: Peter Zijlstra
Date: Wed Mar 25 2020 - 10:42:34 EST


Subject: objtool: Factor out CFI hints
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed Mar 25 13:08:17 CET 2020

Move the application of CFI hints into it's own function.
No functional changes intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
tools/objtool/check.c | 66 ++++++++++++++++++++++++++++----------------------
1 file changed, 37 insertions(+), 29 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2033,6 +2033,40 @@ static int validate_return(struct symbol
return 0;
}

+static int apply_insn_hint(struct objtool_file *file, struct section *sec,
+ struct symbol *func, struct instruction *insn,
+ struct insn_state *state)
+{
+ if (insn->restore) {
+ struct instruction *save_insn, *i;
+
+ i = insn;
+ save_insn = NULL;
+ sym_for_each_insn_continue_reverse(file, func, i) {
+ if (i->save) {
+ save_insn = i;
+ break;
+ }
+ }
+
+ if (!save_insn) {
+ WARN_FUNC("no corresponding CFI save for CFI restore",
+ sec, insn->offset);
+ return 1;
+ }
+
+ if (!save_insn->visited) {
+ WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
+ sec, insn->offset);
+ return 1;
+ }
+
+ insn->state = save_insn->state;
+ }
+
+ state = insn->state;
+}
+
/*
* Follow the branch starting at the given instruction, and recursively follow
* any other branches (jumps). Meanwhile, track the frame pointer state at
@@ -2081,35 +2115,9 @@ static int validate_branch(struct objtoo
}

if (insn->hint) {
- if (insn->restore) {
- struct instruction *save_insn, *i;
-
- i = insn;
- save_insn = NULL;
- sym_for_each_insn_continue_reverse(file, func, i) {
- if (i->save) {
- save_insn = i;
- break;
- }
- }
-
- if (!save_insn) {
- WARN_FUNC("no corresponding CFI save for CFI restore",
- sec, insn->offset);
- return 1;
- }
-
- if (!save_insn->visited) {
- WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
- sec, insn->offset);
- return 1;
- }
-
- insn->state = save_insn->state;
- }
-
- state = insn->state;
-
+ ret = apply_insn_hint(file, sec, func, insn, &state);
+ if (ret)
+ return ret;
} else
insn->state = state;