objtool: Introduce validate_return()

Trivial 'cleanup' to save one indentation level and match
validate_call().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200324160923.963996225@infradead.org

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6b6178e..da17b5a 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1975,6 +1975,41 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st
        return validate_call(insn, state);
 }
 
+static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
+{
+       if (state->uaccess && !func_uaccess_safe(func)) {
+               WARN_FUNC("return with UACCESS enabled",
+                         insn->sec, insn->offset);
+               return 1;
+       }
+
+       if (!state->uaccess && func_uaccess_safe(func)) {
+               WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function",
+                         insn->sec, insn->offset);
+               return 1;
+       }
+
+       if (state->df) {
+               WARN_FUNC("return with DF set",
+                         insn->sec, insn->offset);
+               return 1;
+       }
+
+       if (func && has_modified_stack_frame(state)) {
+               WARN_FUNC("return with modified stack frame",
+                         insn->sec, insn->offset);
+               return 1;
+       }
+
+       if (state->bp_scratch) {
+               WARN("%s uses BP as a scratch register",
+                    func->name);
+               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
@@ -2090,34 +2125,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
                switch (insn->type) {
 
                case INSN_RETURN:
-                       if (state.uaccess && !func_uaccess_safe(func)) {
-                               WARN_FUNC("return with UACCESS enabled", sec, insn->offset);
-                               return 1;
-                       }
-
-                       if (!state.uaccess && func_uaccess_safe(func)) {
-                               WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", sec, insn->offset);
-                               return 1;
-                       }
-
-                       if (state.df) {
-                               WARN_FUNC("return with DF set", sec, insn->offset);
-                               return 1;
-                       }
-
-                       if (func && has_modified_stack_frame(&state)) {
-                               WARN_FUNC("return with modified stack frame",
-                                         sec, insn->offset);
-                               return 1;
-                       }
-
-                       if (state.bp_scratch) {
-                               WARN("%s uses BP as a scratch register",
-                                    func->name);
-                               return 1;
-                       }
-
-                       return 0;
+                       return validate_return(func, insn, &state);
 
                case INSN_CALL:
                case INSN_CALL_DYNAMIC: