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-rw-r--r--tools/objtool/check.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 822a490e6d87..ddfdd138cc2a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2032,6 +2032,17 @@ static int read_unwind_hints(struct objtool_file *file)
insn->hint = true;
+ if (hint->type == UNWIND_HINT_TYPE_SAVE) {
+ insn->hint = false;
+ insn->save = true;
+ continue;
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_RESTORE) {
+ insn->restore = true;
+ continue;
+ }
+
if (hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) {
struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset);
@@ -3329,6 +3340,35 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
state.instr += insn->instr;
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->cfi = save_insn->cfi;
+ nr_cfi_reused++;
+ }
+
state.cfi = *insn->cfi;
} else {
/* XXX track if we actually changed state.cfi */