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-rw-r--r--tools/objtool/check.c86
1 files changed, 55 insertions, 31 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5264a305d658..8118361295dd 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -515,7 +515,8 @@ static int add_jump_destinations(struct objtool_file *file)
continue;
} else {
/* sibling call */
- insn->jump_dest = 0;
+ insn->call_dest = rela->sym;
+ insn->jump_dest = NULL;
continue;
}
@@ -537,25 +538,38 @@ static int add_jump_destinations(struct objtool_file *file)
}
/*
- * For GCC 8+, create parent/child links for any cold
- * subfunctions. This is _mostly_ redundant with a similar
- * initialization in read_symbols().
- *
- * If a function has aliases, we want the *first* such function
- * in the symbol table to be the subfunction's parent. In that
- * case we overwrite the initialization done in read_symbols().
- *
- * However this code can't completely replace the
- * read_symbols() code because this doesn't detect the case
- * where the parent function's only reference to a subfunction
- * is through a switch table.
+ * Cross-function jump.
*/
if (insn->func && insn->jump_dest->func &&
- insn->func != insn->jump_dest->func &&
- !strstr(insn->func->name, ".cold.") &&
- strstr(insn->jump_dest->func->name, ".cold.")) {
- insn->func->cfunc = insn->jump_dest->func;
- insn->jump_dest->func->pfunc = insn->func;
+ insn->func != insn->jump_dest->func) {
+
+ /*
+ * For GCC 8+, create parent/child links for any cold
+ * subfunctions. This is _mostly_ redundant with a
+ * similar initialization in read_symbols().
+ *
+ * If a function has aliases, we want the *first* such
+ * function in the symbol table to be the subfunction's
+ * parent. In that case we overwrite the
+ * initialization done in read_symbols().
+ *
+ * However this code can't completely replace the
+ * read_symbols() code because this doesn't detect the
+ * case where the parent function's only reference to a
+ * subfunction is through a switch table.
+ */
+ if (!strstr(insn->func->name, ".cold.") &&
+ strstr(insn->jump_dest->func->name, ".cold.")) {
+ insn->func->cfunc = insn->jump_dest->func;
+ insn->jump_dest->func->pfunc = insn->func;
+
+ } else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
+ insn->jump_dest->offset == insn->jump_dest->func->offset) {
+
+ /* sibling class */
+ insn->call_dest = insn->jump_dest->func;
+ insn->jump_dest = NULL;
+ }
}
}
@@ -1785,6 +1799,17 @@ static bool insn_state_match(struct instruction *insn, struct insn_state *state)
return false;
}
+static int validate_sibling_call(struct instruction *insn, struct insn_state *state)
+{
+ if (has_modified_stack_frame(state)) {
+ WARN_FUNC("sibling call from callable instruction with modified stack frame",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* Follow the branch starting at the given instruction, and recursively follow
* any other branches (jumps). Meanwhile, track the frame pointer state at
@@ -1935,9 +1960,14 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
- if (insn->jump_dest &&
- (!func || !insn->jump_dest->func ||
- insn->jump_dest->func->pfunc == func)) {
+ if (func && !insn->jump_dest) {
+ ret = validate_sibling_call(insn, &state);
+ if (ret)
+ return ret;
+
+ } else if (insn->jump_dest &&
+ (!func || !insn->jump_dest->func ||
+ insn->jump_dest->func->pfunc == func)) {
ret = validate_branch(file, insn->jump_dest,
state);
if (ret) {
@@ -1945,11 +1975,6 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
BT_FUNC("(branch)", insn);
return ret;
}
-
- } else if (func && has_modified_stack_frame(&state)) {
- WARN_FUNC("sibling call from callable instruction with modified stack frame",
- sec, insn->offset);
- return 1;
}
if (insn->type == INSN_JUMP_UNCONDITIONAL)
@@ -1958,11 +1983,10 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_JUMP_DYNAMIC:
- if (func && list_empty(&insn->alts) &&
- has_modified_stack_frame(&state)) {
- WARN_FUNC("sibling call from callable instruction with modified stack frame",
- sec, insn->offset);
- return 1;
+ if (func && list_empty(&insn->alts)) {
+ ret = validate_sibling_call(insn, &state);
+ if (ret)
+ return ret;
}
return 0;