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* [PATCH] staging: gdm724x: Fix DMA from stack
@ 2021-02-09 14:54 ameynarkhede03
  2021-02-09 17:22 ` kernel test robot
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: ameynarkhede03 @ 2021-02-09 14:54 UTC (permalink / raw)
  To: gregkh; +Cc: devel, linux-kernel, Amey Narkhede

From: Amey Narkhede <ameynarkhede03@gmail.com>

Stack allocated buffers cannot be used for DMA
on all architectures so allocate usbdev buffer
using kmalloc().

Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/staging/gdm724x/gdm_usb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
index dc4da66c3..50dc463d4 100644
--- a/drivers/staging/gdm724x/gdm_usb.c
+++ b/drivers/staging/gdm724x/gdm_usb.c
@@ -56,7 +56,7 @@ static int gdm_usb_recv(void *priv_dev,

 static int request_mac_address(struct lte_udev *udev)
 {
-	u8 buf[16] = {0,};
+	u8 *buf;
 	struct hci_packet *hci = (struct hci_packet *)buf;
 	struct usb_device *usbdev = udev->usbdev;
 	int actual;
@@ -66,6 +66,10 @@ static int request_mac_address(struct lte_udev *udev)
 	hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1);
 	hci->data[0] = MAC_ADDRESS;

+	buf = kmalloc(16, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
 	ret = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 2), buf, 5,
 			   &actual, 1000);

--
2.30.0

^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] staging: gdm724x: Fix DMA from stack
  2021-02-09 14:54 [PATCH] staging: gdm724x: Fix DMA from stack ameynarkhede03
@ 2021-02-09 17:22 ` kernel test robot
  2021-02-09 17:40 ` Greg KH
  2021-02-09 18:19 ` Dan Carpenter
  2 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2021-02-09 17:22 UTC (permalink / raw)
  To: ameynarkhede03, gregkh; +Cc: kbuild-all, devel, Amey Narkhede, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 4848 bytes --]

Hi,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on staging/staging-testing]

url:    https://github.com/0day-ci/linux/commits/ameynarkhede03-gmail-com/staging-gdm724x-Fix-DMA-from-stack/20210209-225530
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git 06b0c0dce88e2aa2f01343db0f26d214d7f264a0
config: m68k-allmodconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/d793f4f05736924fc2207a0f8c338115523930da
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review ameynarkhede03-gmail-com/staging-gdm724x-Fix-DMA-from-stack/20210209-225530
        git checkout d793f4f05736924fc2207a0f8c338115523930da
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/kernel.h:10,
                    from include/linux/list.h:9,
                    from include/linux/module.h:12,
                    from drivers/staging/gdm724x/gdm_usb.c:6:
   include/linux/scatterlist.h: In function 'sg_set_buf':
   arch/m68k/include/asm/page_mm.h:174:49: warning: ordered comparison of pointer with null pointer [-Wextra]
     174 | #define virt_addr_valid(kaddr) ((void *)(kaddr) >= (void *)PAGE_OFFSET && (void *)(kaddr) < high_memory)
         |                                                 ^~
   include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
      78 | # define unlikely(x) __builtin_expect(!!(x), 0)
         |                                          ^
   include/linux/scatterlist.h:137:2: note: in expansion of macro 'BUG_ON'
     137 |  BUG_ON(!virt_addr_valid(buf));
         |  ^~~~~~
   include/linux/scatterlist.h:137:10: note: in expansion of macro 'virt_addr_valid'
     137 |  BUG_ON(!virt_addr_valid(buf));
         |          ^~~~~~~~~~~~~~~
   drivers/staging/gdm724x/gdm_usb.c: In function 'request_mac_address':
>> drivers/staging/gdm724x/gdm_usb.c:60:21: warning: 'buf' is used uninitialized in this function [-Wuninitialized]
      60 |  struct hci_packet *hci = (struct hci_packet *)buf;
         |                     ^~~


vim +/buf +60 drivers/staging/gdm724x/gdm_usb.c

61e12104764512 Won Kang       2013-07-25  50  
61e12104764512 Won Kang       2013-07-25  51  static int gdm_usb_recv(void *priv_dev,
35db0350c5ef0d Aybuke Ozdemir 2014-03-14  52  			int (*cb)(void *cb_data,
35db0350c5ef0d Aybuke Ozdemir 2014-03-14  53  				  void *data, int len, int context),
61e12104764512 Won Kang       2013-07-25  54  			void *cb_data,
61e12104764512 Won Kang       2013-07-25  55  			int context);
61e12104764512 Won Kang       2013-07-25  56  
61e12104764512 Won Kang       2013-07-25  57  static int request_mac_address(struct lte_udev *udev)
61e12104764512 Won Kang       2013-07-25  58  {
d793f4f0573692 Amey Narkhede  2021-02-09  59  	u8 *buf;
61e12104764512 Won Kang       2013-07-25 @60  	struct hci_packet *hci = (struct hci_packet *)buf;
61e12104764512 Won Kang       2013-07-25  61  	struct usb_device *usbdev = udev->usbdev;
61e12104764512 Won Kang       2013-07-25  62  	int actual;
61e12104764512 Won Kang       2013-07-25  63  	int ret = -1;
61e12104764512 Won Kang       2013-07-25  64  
1b5e56ece3f501 Quytelda Kahja 2018-02-22  65  	hci->cmd_evt = gdm_cpu_to_dev16(udev->gdm_ed, LTE_GET_INFORMATION);
1b5e56ece3f501 Quytelda Kahja 2018-02-22  66  	hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1);
61e12104764512 Won Kang       2013-07-25  67  	hci->data[0] = MAC_ADDRESS;
61e12104764512 Won Kang       2013-07-25  68  
d793f4f0573692 Amey Narkhede  2021-02-09  69  	buf = kmalloc(16, GFP_KERNEL);
d793f4f0573692 Amey Narkhede  2021-02-09  70  	if (!buf)
d793f4f0573692 Amey Narkhede  2021-02-09  71  		return -ENOMEM;
d793f4f0573692 Amey Narkhede  2021-02-09  72  
61e12104764512 Won Kang       2013-07-25  73  	ret = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 2), buf, 5,
61e12104764512 Won Kang       2013-07-25  74  			   &actual, 1000);
61e12104764512 Won Kang       2013-07-25  75  
61e12104764512 Won Kang       2013-07-25  76  	udev->request_mac_addr = 1;
61e12104764512 Won Kang       2013-07-25  77  
61e12104764512 Won Kang       2013-07-25  78  	return ret;
61e12104764512 Won Kang       2013-07-25  79  }
61e12104764512 Won Kang       2013-07-25  80  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] staging: gdm724x: Fix DMA from stack
  2021-02-09 14:54 [PATCH] staging: gdm724x: Fix DMA from stack ameynarkhede03
  2021-02-09 17:22 ` kernel test robot
@ 2021-02-09 17:40 ` Greg KH
  2021-02-09 19:35   ` Amey Narkhede
  2021-02-09 18:19 ` Dan Carpenter
  2 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2021-02-09 17:40 UTC (permalink / raw)
  To: ameynarkhede03; +Cc: devel, linux-kernel

On Tue, Feb 09, 2021 at 08:24:15PM +0530, ameynarkhede03@gmail.com wrote:
> From: Amey Narkhede <ameynarkhede03@gmail.com>
> 
> Stack allocated buffers cannot be used for DMA
> on all architectures so allocate usbdev buffer
> using kmalloc().
> 
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  drivers/staging/gdm724x/gdm_usb.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
> index dc4da66c3..50dc463d4 100644
> --- a/drivers/staging/gdm724x/gdm_usb.c
> +++ b/drivers/staging/gdm724x/gdm_usb.c
> @@ -56,7 +56,7 @@ static int gdm_usb_recv(void *priv_dev,
> 
>  static int request_mac_address(struct lte_udev *udev)
>  {
> -	u8 buf[16] = {0,};
> +	u8 *buf;
>  	struct hci_packet *hci = (struct hci_packet *)buf;
>  	struct usb_device *usbdev = udev->usbdev;
>  	int actual;
> @@ -66,6 +66,10 @@ static int request_mac_address(struct lte_udev *udev)
>  	hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1);
>  	hci->data[0] = MAC_ADDRESS;
> 
> +	buf = kmalloc(16, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +

This is great, but you just added a build warning, which implies that
the patch is incorrect.

You also have a memory leak here, which is not acceptable :(

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] staging: gdm724x: Fix DMA from stack
  2021-02-09 14:54 [PATCH] staging: gdm724x: Fix DMA from stack ameynarkhede03
  2021-02-09 17:22 ` kernel test robot
  2021-02-09 17:40 ` Greg KH
@ 2021-02-09 18:19 ` Dan Carpenter
  2 siblings, 0 replies; 5+ messages in thread
From: Dan Carpenter @ 2021-02-09 18:19 UTC (permalink / raw)
  To: ameynarkhede03; +Cc: gregkh, devel, linux-kernel

On Tue, Feb 09, 2021 at 08:24:15PM +0530, ameynarkhede03@gmail.com wrote:
> From: Amey Narkhede <ameynarkhede03@gmail.com>
> 
> Stack allocated buffers cannot be used for DMA
> on all architectures so allocate usbdev buffer
> using kmalloc().
> 
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  drivers/staging/gdm724x/gdm_usb.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
> index dc4da66c3..50dc463d4 100644
> --- a/drivers/staging/gdm724x/gdm_usb.c
> +++ b/drivers/staging/gdm724x/gdm_usb.c
> @@ -56,7 +56,7 @@ static int gdm_usb_recv(void *priv_dev,
> 
>  static int request_mac_address(struct lte_udev *udev)
>  {
> -	u8 buf[16] = {0,};
> +	u8 *buf;
>  	struct hci_packet *hci = (struct hci_packet *)buf;
>  	struct usb_device *usbdev = udev->usbdev;
>  	int actual;
> @@ -66,6 +66,10 @@ static int request_mac_address(struct lte_udev *udev)
>  	hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1);
>  	hci->data[0] = MAC_ADDRESS;
> 
> +	buf = kmalloc(16, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
>  	ret = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 2), buf, 5,
>  			   &actual, 1000);


You need to add a kfree() as well.

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] staging: gdm724x: Fix DMA from stack
  2021-02-09 17:40 ` Greg KH
@ 2021-02-09 19:35   ` Amey Narkhede
  0 siblings, 0 replies; 5+ messages in thread
From: Amey Narkhede @ 2021-02-09 19:35 UTC (permalink / raw)
  To: Greg KH; +Cc: devel, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 1454 bytes --]

On 21/02/09 06:40PM, Greg KH wrote:
> On Tue, Feb 09, 2021 at 08:24:15PM +0530, ameynarkhede03@gmail.com wrote:
> > From: Amey Narkhede <ameynarkhede03@gmail.com>
> >
> > Stack allocated buffers cannot be used for DMA
> > on all architectures so allocate usbdev buffer
> > using kmalloc().
> >
> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> > ---
> >  drivers/staging/gdm724x/gdm_usb.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
> > index dc4da66c3..50dc463d4 100644
> > --- a/drivers/staging/gdm724x/gdm_usb.c
> > +++ b/drivers/staging/gdm724x/gdm_usb.c
> > @@ -56,7 +56,7 @@ static int gdm_usb_recv(void *priv_dev,
> >
> >  static int request_mac_address(struct lte_udev *udev)
> >  {
> > -	u8 buf[16] = {0,};
> > +	u8 *buf;
> >  	struct hci_packet *hci = (struct hci_packet *)buf;
> >  	struct usb_device *usbdev = udev->usbdev;
> >  	int actual;
> > @@ -66,6 +66,10 @@ static int request_mac_address(struct lte_udev *udev)
> >  	hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1);
> >  	hci->data[0] = MAC_ADDRESS;
> >
> > +	buf = kmalloc(16, GFP_KERNEL);
> > +	if (!buf)
> > +		return -ENOMEM;
> > +
>
> This is great, but you just added a build warning, which implies that
> the patch is incorrect.
>
> You also have a memory leak here, which is not acceptable :(
>
> thanks,
>
> greg k-h
Apologoes. I'll send v2.

Thanks,
Amey

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^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-02-09 23:18 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-09 14:54 [PATCH] staging: gdm724x: Fix DMA from stack ameynarkhede03
2021-02-09 17:22 ` kernel test robot
2021-02-09 17:40 ` Greg KH
2021-02-09 19:35   ` Amey Narkhede
2021-02-09 18:19 ` Dan Carpenter

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