From: Johan Hovold <johan@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Johan Hovold <johan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] USB: serial: mos7720: Fix error code in mos7720_write()
Date: Thu, 28 Jan 2021 09:56:00 +0000 [thread overview]
Message-ID: <YBKKMK9UfRjB52sW@hovoldconsulting.com> (raw)
In-Reply-To: <YBKFW60qMJbtjvum@mwanda>
On Thu, Jan 28, 2021 at 12:35:23PM +0300, Dan Carpenter wrote:
> This code should return -ENOMEM if the kmalloc() fails but instead
> it returns success.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> The first error path is probably wrong as well?
>
> drivers/usb/serial/mos7720.c
> 1077 /* try to find a free urb in the list */
> 1078 urb = NULL;
> 1079
> 1080 for (i = 0; i < NUM_URBS; ++i) {
> 1081 if (mos7720_port->write_urb_pool[i] &&
> 1082 mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
> 1083 urb = mos7720_port->write_urb_pool[i];
> 1084 dev_dbg(&port->dev, "URB:%d\n", i);
> 1085 break;
> 1086 }
> 1087 }
> 1088
> 1089 if (urb = NULL) {
> 1090 dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
> 1091 goto exit;
>
> Should return -ENODEV?
No, this bit is correct (modulo the missing locking and reliance on the
URB status). When there are no free URBs we want the tty layer to
retry later.
> 1092 }
>
> drivers/usb/serial/mos7720.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
> index ed347a6d50ba..aa55169796a3 100644
> --- a/drivers/usb/serial/mos7720.c
> +++ b/drivers/usb/serial/mos7720.c
> @@ -1094,8 +1094,10 @@ static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
> if (urb->transfer_buffer = NULL) {
> urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
> GFP_ATOMIC);
> - if (!urb->transfer_buffer)
> + if (!urb->transfer_buffer) {
> + bytes_sent = -ENOMEM;
> goto exit;
> + }
> }
> transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
Now applied, thanks.
Johan
WARNING: multiple messages have this Message-ID (diff)
From: Johan Hovold <johan@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Johan Hovold <johan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] USB: serial: mos7720: Fix error code in mos7720_write()
Date: Thu, 28 Jan 2021 10:56:00 +0100 [thread overview]
Message-ID: <YBKKMK9UfRjB52sW@hovoldconsulting.com> (raw)
In-Reply-To: <YBKFW60qMJbtjvum@mwanda>
On Thu, Jan 28, 2021 at 12:35:23PM +0300, Dan Carpenter wrote:
> This code should return -ENOMEM if the kmalloc() fails but instead
> it returns success.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> The first error path is probably wrong as well?
>
> drivers/usb/serial/mos7720.c
> 1077 /* try to find a free urb in the list */
> 1078 urb = NULL;
> 1079
> 1080 for (i = 0; i < NUM_URBS; ++i) {
> 1081 if (mos7720_port->write_urb_pool[i] &&
> 1082 mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
> 1083 urb = mos7720_port->write_urb_pool[i];
> 1084 dev_dbg(&port->dev, "URB:%d\n", i);
> 1085 break;
> 1086 }
> 1087 }
> 1088
> 1089 if (urb == NULL) {
> 1090 dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
> 1091 goto exit;
>
> Should return -ENODEV?
No, this bit is correct (modulo the missing locking and reliance on the
URB status). When there are no free URBs we want the tty layer to
retry later.
> 1092 }
>
> drivers/usb/serial/mos7720.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
> index ed347a6d50ba..aa55169796a3 100644
> --- a/drivers/usb/serial/mos7720.c
> +++ b/drivers/usb/serial/mos7720.c
> @@ -1094,8 +1094,10 @@ static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
> if (urb->transfer_buffer == NULL) {
> urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
> GFP_ATOMIC);
> - if (!urb->transfer_buffer)
> + if (!urb->transfer_buffer) {
> + bytes_sent = -ENOMEM;
> goto exit;
> + }
> }
> transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
Now applied, thanks.
Johan
next prev parent reply other threads:[~2021-01-28 9:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-28 9:35 [PATCH] USB: serial: mos7720: Fix error code in mos7720_write() Dan Carpenter
2021-01-28 9:35 ` Dan Carpenter
2021-01-28 9:56 ` Johan Hovold [this message]
2021-01-28 9:56 ` Johan Hovold
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