[PATCH v2] usb: Use memdup_user to reuse the code

[PATCH v2] usb: Use memdup_user to reuse the code

[Pathak, Rahul (R.)]

From: Rahul Pathak <rpathak@visteon.com>

Fixing coccicheck warning which recommends to use memdup_user instead
to reimplement its code, using memdup_user simplifies the code

./drivers/usb/core/devio.c:1398:11-18: WARNING opportunity for memdup_user

Changes after v1: setting isopkt=NULL for proper kfree() call

Signed-off-by: Rahul Pathak <rpathak@visteon.com>
---
 drivers/usb/core/devio.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 38ae877c..844407c 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1395,11 +1395,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
 		number_of_packets = uurb->number_of_packets;
 		isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) *
 				   number_of_packets;
-		isopkt = kmalloc(isofrmlen, GFP_KERNEL);
-		if (!isopkt)
-			return -ENOMEM;
-		if (copy_from_user(isopkt, iso_frame_desc, isofrmlen)) {
-			ret = -EFAULT;
+		isopkt = memdup_user(iso_frame_desc, isofrmlen);
+		if (IS_ERR(isopkt)) {
+			ret = PTR_ERR(isopkt);
+			isopkt = NULL;
 			goto error;
 		}
 		for (totlen = u = 0; u < number_of_packets; u++) {
-- 
1.9.1

Re: [PATCH v2] usb: Use memdup_user to reuse the code

[Alan Stern]

On Tue, 8 Dec 2015, Pathak, Rahul (R.) wrote:

> From: Rahul Pathak <rpathak@visteon.com>
> 
> Fixing coccicheck warning which recommends to use memdup_user instead
> to reimplement its code, using memdup_user simplifies the code
> 
> ./drivers/usb/core/devio.c:1398:11-18: WARNING opportunity for memdup_user
> 
> Changes after v1: setting isopkt=NULL for proper kfree() call

This line belongs below the "---" tear line, so that it doesn't show up 
in the final commit changelog.  People reading the final commit won't 
care about earlier versions of the patch.

> Signed-off-by: Rahul Pathak <rpathak@visteon.com>
> ---
>  drivers/usb/core/devio.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index 38ae877c..844407c 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -1395,11 +1395,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
>  		number_of_packets = uurb->number_of_packets;
>  		isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) *
>  				   number_of_packets;
> -		isopkt = kmalloc(isofrmlen, GFP_KERNEL);
> -		if (!isopkt)
> -			return -ENOMEM;
> -		if (copy_from_user(isopkt, iso_frame_desc, isofrmlen)) {
> -			ret = -EFAULT;
> +		isopkt = memdup_user(iso_frame_desc, isofrmlen);
> +		if (IS_ERR(isopkt)) {
> +			ret = PTR_ERR(isopkt);
> +			isopkt = NULL;
>  			goto error;
>  		}
>  		for (totlen = u = 0; u < number_of_packets; u++) {

Aside from that,

Acked-by: Alan Stern <stern@rowland.harvard.edu>

Alan Stern

Re: [PATCH v2] usb: Use memdup_user to reuse the code

[Pathak, Rahul (R.)]

Hello Alan,

Should I resend  this patch version  with the tear line correction?

Regards
Rahul Pathak


________________________________________
From: Alan Stern <stern@rowland.harvard.edu>
Sent: Tuesday, December 8, 2015 8:53 PM
To: Pathak, Rahul (R.)
Cc: gregkh@linuxfoundation.org; kborer@gmail.com; dan.carpenter@oracle.com; chasemetzger15@gmail.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] usb: Use memdup_user to reuse the code

On Tue, 8 Dec 2015, Pathak, Rahul (R.) wrote:

> From: Rahul Pathak <rpathak@visteon.com>
>
> Fixing coccicheck warning which recommends to use memdup_user instead
> to reimplement its code, using memdup_user simplifies the code
>
> ./drivers/usb/core/devio.c:1398:11-18: WARNING opportunity for memdup_user
>
> Changes after v1: setting isopkt=NULL for proper kfree() call

This line belongs below the "---" tear line, so that it doesn't show up
in the final commit changelog.  People reading the final commit won't
care about earlier versions of the patch.

> Signed-off-by: Rahul Pathak <rpathak@visteon.com>
> ---
>  drivers/usb/core/devio.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index 38ae877c..844407c 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -1395,11 +1395,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
>               number_of_packets = uurb->number_of_packets;
>               isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) *
>                                  number_of_packets;
> -             isopkt = kmalloc(isofrmlen, GFP_KERNEL);
> -             if (!isopkt)
> -                     return -ENOMEM;
> -             if (copy_from_user(isopkt, iso_frame_desc, isofrmlen)) {
> -                     ret = -EFAULT;
> +             isopkt = memdup_user(iso_frame_desc, isofrmlen);
> +             if (IS_ERR(isopkt)) {
> +                     ret = PTR_ERR(isopkt);
> +                     isopkt = NULL;
>                       goto error;
>               }
>               for (totlen = u = 0; u < number_of_packets; u++) {

Aside from that,

Acked-by: Alan Stern <stern@rowland.harvard.edu>

Alan Stern

Re: [PATCH v2] usb: Use memdup_user to reuse the code

[gregkh]

On Wed, Dec 09, 2015 at 08:02:53AM +0000, Pathak, Rahul (R.) wrote:
> Hello Alan,
> 
> Should I resend  this patch version  with the tear line correction?

Why wouldn't you?

Re: [PATCH v2] usb: Use memdup_user to reuse the code

[gregkh]

On Wed, Dec 09, 2015 at 08:02:53AM +0000, Pathak, Rahul (R.) wrote:
> Hello Alan,
> 
> Should I resend  this patch version  with the tear line correction?

Yes please.

Re: [PATCH v2] usb: Use memdup_user to reuse the code

[rahul pathak]

Hello Greg,

I have already resent the patch yesterday in new mail.

 -- Sending this mail again because previous mail was blocked as spam.

Regards
Rahul

On Fri, Dec 11, 2015 at 10:01 PM, gregkh@linuxfoundation.org
<gregkh@linuxfoundation.org> wrote:
> On Wed, Dec 09, 2015 at 08:02:53AM +0000, Pathak, Rahul (R.) wrote:
>> Hello Alan,
>>
>> Should I resend  this patch version  with the tear line correction?
>
> Yes please.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html