Re: [PATCH v2 10/10] objtool: Support multiple stack_op per instruction

From: Josh Poimboeuf
Date: Thu Apr 02 2020 - 13:54:35 EST


On Fri, Mar 27, 2020 at 03:28:47PM +0000, Julien Thierry wrote:
> @@ -127,6 +129,10 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
> if (insn.sib.nbytes)
> sib = insn.sib.bytes[0];
>
> + op = calloc(1, sizeof(*op));
> + if (!op)
> + return -1;
> +

Why not malloc()?

> +static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
> +{
> + struct stack_op *op;
> +
> + list_for_each_entry(op, &insn->stack_ops, list) {
> + int res;
> +
> + res = update_insn_state(insn, state, op);
> + if (res)
> + return res;

This should probably be like:

if (update_insn_state(insn, state, op))
return 1;

That way the error codes are converted to non-fatal warnings like before
(which I admit is confusing...)

> @@ -2205,29 +2244,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
> return 0;
>
> case INSN_STACK:
> - if (update_insn_state(insn, &state))
> + if (handle_insn_ops(insn, &state))
> return 1;

How about "handle_stack_ops"?

--
Josh