Re: [PATCH v1] arch/x86/kernel: check the return value of insn_decode_kernel()

[Steven Rostedt]

On Fri,  2 Sep 2022 00:47:06 -0700
Li Zhong <floridsleeves@xxxxxxxxx> wrote:

> @@ -20,9 +20,10 @@
>  int arch_jump_entry_size(struct jump_entry *entry)
>  {
>  	struct insn insn = {};
> +	int ret;
>  
> -	insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
> -	BUG_ON(insn.length != 2 && insn.length != 5);
> +	ret = insn_decode_kernel(&insn, (void *)jump_entry_code(entry));

It's highly unlikely that length will be 2 or 5 if ret is not zero (as it
is initialized to zero going into this function).

> +	BUG_ON(ret < 0 || insn.length != 2 && insn.length != 5);

In any case, you need parenthesis around the && condition.

-- Steve


>  
>  	return insn.length;