# Re: \[PATCH v6 1/9\] kernel: Support TIF\_SYSCALL\_INTERCEPT flag

- From: peterz@infradead.org
- Date: 2020-09-11 09:32:36 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2020/09/6101761
- Thread: https://ratatoskr.run/linux-api/2020/09/6094737/t.md

```text
On Fri, Sep 04, 2020 at 04:31:39PM -0400, Gabriel Krisman Bertazi wrote:
> +static inline void __set_tsk_syscall_intercept(struct task_struct *tsk,
> +					   unsigned int type)
> +{
> +	tsk->syscall_intercept |= type;
> +
> +	if (tsk->syscall_intercept)
> +		set_tsk_thread_flag(tsk, TIF_SYSCALL_INTERCEPT);
> +}

Did the above want to be:

	unsigned int old = tsk->syscall_intercept;
	tsk->syscall_intercept |= type;
	if (!old)
		set_tsk_thread_flag(tsk, TIF_SYSCALL_INTERCEPT)

?

> +static inline void __clear_tsk_syscall_intercept(struct task_struct *tsk,
> +					     unsigned int type)
> +{
> +	tsk->syscall_intercept &= ~type;
> +
> +	if (tsk->syscall_intercept == 0)
> +		clear_tsk_thread_flag(tsk, TIF_SYSCALL_INTERCEPT);
> +}
```