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
This commit is contained in:
Peter Zijlstra 2020-03-10 18:07:44 +01:00
parent 7acfe53153
commit a92e92d1a7

View file

@ -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: