Re: [RFC PATCH v1 04/10] net: qrtr: Report sender endpoint in aux data

[Denis Kenzior <denkenz@gmail.com>]

On 10/18/24 7:22 PM, Kuniyuki Iwashima wrote:
> From: Denis Kenzior <denkenz@gmail.com>
> Date: Fri, 18 Oct 2024 13:18:22 -0500
>> @@ -1234,6 +1247,78 @@ static int qrtr_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
>>   	return rc;
>>   }
>>   
>> +static int qrtr_setsockopt(struct socket *sock, int level, int optname,
>> +			   sockptr_t optval, unsigned int optlen)
>> +{
>> +	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
>> +	struct sock *sk = sock->sk;
>> +	unsigned int val = 0;
>> +	int rc = 0;
>> +
>> +	if (level != SOL_QRTR)
>> +		return -ENOPROTOOPT;
>> +
>> +	if (optlen >= sizeof(val) &&
>> +	    copy_from_sockptr(&val, optval, sizeof(val)))
>> +		return -EFAULT;
>> +
>> +	lock_sock(sk);
> 
> This seems unnecessary to me.
> 
> sk_setsockopt(), do_ip_setsockopt(), and do_ipv6_setsockopt() do not
> hold lock_sock() for assign_bit().

Indeed, thanks for spotting that.  I'll fix this in the next version.  I'll also 
drop lock_sock/release_sock in qrtr_sock_set_report_endpoint (patch 9).

> 
> Also, QRTR_BIND_ENDPOINT in a later patch will not need lock_sock()
> neither.  The value is u32, so you can use WRITE_ONCE() here and
> READ_ONCE() in getsockopt().
> 

Makes sense, I'll fix this as well.

> 
>> +
>> +	switch (optname) {
>> +	case QRTR_REPORT_ENDPOINT:
>> +		assign_bit(QRTR_F_REPORT_ENDPOINT, &ipc->flags, val);
>> +		break;
>> +	default:
>> +		rc = -ENOPROTOOPT;
>> +	}
>> +
>> +	release_sock(sk);
>> +
>> +	return rc;
>> +}
>> +
>> +static int qrtr_getsockopt(struct socket *sock, int level, int optname,
>> +			   char __user *optval, int __user *optlen)
>> +{
>> +	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
>> +	struct sock *sk = sock->sk;
>> +	unsigned int val;
>> +	int len;
>> +	int rc = 0;
>> +
>> +	if (level != SOL_QRTR)
>> +		return -ENOPROTOOPT;
>> +
>> +	if (get_user(len, optlen))
>> +		return -EFAULT;
>> +
>> +	if (len < sizeof(val))
>> +		return -EINVAL;
>> +
>> +	lock_sock(sk);
> 
> Same remark.
> 
> 
>> +
>> +	switch (optname) {
>> +	case QRTR_REPORT_ENDPOINT:
>> +		val = test_bit(QRTR_F_REPORT_ENDPOINT, &ipc->flags);
>> +		break;
>> +	default:
>> +		rc = -ENOPROTOOPT;
>> +	}
>> +
>> +	release_sock(sk);
>> +
>> +	if (rc)
>> +		return rc;
>> +
>> +	len = sizeof(int);
>> +
>> +	if (put_user(len, optlen) ||
>> +	    copy_to_user(optval, &val, len))
>> +		rc = -EFAULT;
>> +
>> +	return rc;
>> +}
>> +
>>   static int qrtr_release(struct socket *sock)
>>   {
>>   	struct sock *sk = sock->sk;