All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Suwan Kim <suwan.kim027@gmail.com>
Cc: kbuild@lists.01.org, kbuild-all@lists.01.org,
	linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org, shuah@kernel.org
Subject: Re: drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
Date: Thu, 24 Oct 2019 22:45:00 +0300	[thread overview]
Message-ID: <20191024194500.GD23523@kadam> (raw)
In-Reply-To: <20191023071120.GA3061@localhost.localdomain>

On Wed, Oct 23, 2019 at 04:11:20PM +0900, Suwan Kim wrote:
> On Tue, Oct 22, 2019 at 12:28:39PM +0300, Dan Carpenter wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   7d194c2100ad2a6dded545887d02754948ca5241
> > commit: ea44d190764b4422af4d1c29eaeb9e69e353b406 usbip: Implement SG support to vhci-hcd and stub driver
> > date:   7 weeks ago
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > New smatch warnings:
> > drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
> > 
> > Old smatch warnings:
> > drivers/usb/usbip/stub_rx.c:450 stub_recv_xbuff() error: uninitialized symbol 'ret'.
> > 
> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ea44d190764b4422af4d1c29eaeb9e69e353b406
> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > git remote update linus
> > git checkout ea44d190764b4422af4d1c29eaeb9e69e353b406
> > vim +/nents +505 drivers/usb/usbip/stub_rx.c
> > 
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  453  static void stub_recv_cmd_submit(struct stub_device *sdev,
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  454  				 struct usbip_header *pdu)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  455  {
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  456  	struct stub_priv *priv;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  457  	struct usbip_device *ud = &sdev->ud;
> > 2d8f4595d1f275 drivers/staging/usbip/stub_rx.c Max Vozeler        2011-01-12  458  	struct usb_device *udev = sdev->udev;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  459  	struct scatterlist *sgl = NULL, *sg;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  460  	void *buffer = NULL;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  461  	unsigned long long buf_len;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  462  	int nents;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  463  	int num_urbs = 1;
> > c6688ef9f29762 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  464  	int pipe = get_pipe(sdev, pdu);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  465  	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  466  	int support_sg = 1;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  467  	int np = 0;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  468  	int ret, i;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  469  
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  470  	if (pipe == -1)
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  471  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  472  
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  473  	priv = stub_priv_alloc(sdev, pdu);
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  474  	if (!priv)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  475  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  476  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  477  	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  478  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  479  	/* allocate urb transfer buffer, if needed */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  480  	if (buf_len) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  481  		if (use_sg) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  482  			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  483  			if (!sgl)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  484  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  485  		} else {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  486  			buffer = kzalloc(buf_len, GFP_KERNEL);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  487  			if (!buffer)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  488  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  489  		}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  490  	}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  491  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  492  	/* Check if the server's HCD supports SG */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  493  	if (use_sg && !udev->bus->sg_tablesize) {
> > 
> > Smatch thinks "use_sg" can be true when "buf_len" is zero.  It's hard
> > to tell if Smatch is right or wrong without more context...
> 
> This is a bit strange. The meaning of "use_sg" is that client will
> use scatter-gather and client's urb->num_sgs is not zero. And buffer
> length should not be zero.
> 
> usb_sg and buf_len are both client-dependent variables, so I think
> if they have wrong value in the server side, the client must have
> sent use_sg and buf_len with incorrect values.
> 
> Did this error occur when compiling?

Smatch is doing static analysis, yes.

> If then, Did Smatch also consider vhci tx side?

I'm not really sure...  I can't reproduce the warning because on my
system Smatch doesn't parse usbip_recv() correctly so it ends up
silencing that warning.  :/

regards,
dan carpenter


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: kbuild@lists.01.org
Subject: Re: drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
Date: Thu, 24 Oct 2019 22:45:00 +0300	[thread overview]
Message-ID: <20191024194500.GD23523@kadam> (raw)
In-Reply-To: <20191023071120.GA3061@localhost.localdomain>

[-- Attachment #1: Type: text/plain, Size: 6614 bytes --]

On Wed, Oct 23, 2019 at 04:11:20PM +0900, Suwan Kim wrote:
> On Tue, Oct 22, 2019 at 12:28:39PM +0300, Dan Carpenter wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   7d194c2100ad2a6dded545887d02754948ca5241
> > commit: ea44d190764b4422af4d1c29eaeb9e69e353b406 usbip: Implement SG support to vhci-hcd and stub driver
> > date:   7 weeks ago
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > New smatch warnings:
> > drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
> > 
> > Old smatch warnings:
> > drivers/usb/usbip/stub_rx.c:450 stub_recv_xbuff() error: uninitialized symbol 'ret'.
> > 
> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ea44d190764b4422af4d1c29eaeb9e69e353b406
> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > git remote update linus
> > git checkout ea44d190764b4422af4d1c29eaeb9e69e353b406
> > vim +/nents +505 drivers/usb/usbip/stub_rx.c
> > 
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  453  static void stub_recv_cmd_submit(struct stub_device *sdev,
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  454  				 struct usbip_header *pdu)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  455  {
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  456  	struct stub_priv *priv;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  457  	struct usbip_device *ud = &sdev->ud;
> > 2d8f4595d1f275 drivers/staging/usbip/stub_rx.c Max Vozeler        2011-01-12  458  	struct usb_device *udev = sdev->udev;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  459  	struct scatterlist *sgl = NULL, *sg;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  460  	void *buffer = NULL;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  461  	unsigned long long buf_len;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  462  	int nents;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  463  	int num_urbs = 1;
> > c6688ef9f29762 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  464  	int pipe = get_pipe(sdev, pdu);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  465  	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  466  	int support_sg = 1;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  467  	int np = 0;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  468  	int ret, i;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  469  
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  470  	if (pipe == -1)
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  471  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  472  
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  473  	priv = stub_priv_alloc(sdev, pdu);
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  474  	if (!priv)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  475  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  476  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  477  	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  478  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  479  	/* allocate urb transfer buffer, if needed */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  480  	if (buf_len) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  481  		if (use_sg) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  482  			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  483  			if (!sgl)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  484  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  485  		} else {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  486  			buffer = kzalloc(buf_len, GFP_KERNEL);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  487  			if (!buffer)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  488  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  489  		}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  490  	}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  491  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  492  	/* Check if the server's HCD supports SG */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  493  	if (use_sg && !udev->bus->sg_tablesize) {
> > 
> > Smatch thinks "use_sg" can be true when "buf_len" is zero.  It's hard
> > to tell if Smatch is right or wrong without more context...
> 
> This is a bit strange. The meaning of "use_sg" is that client will
> use scatter-gather and client's urb->num_sgs is not zero. And buffer
> length should not be zero.
> 
> usb_sg and buf_len are both client-dependent variables, so I think
> if they have wrong value in the server side, the client must have
> sent use_sg and buf_len with incorrect values.
> 
> Did this error occur when compiling?

Smatch is doing static analysis, yes.

> If then, Did Smatch also consider vhci tx side?

I'm not really sure...  I can't reproduce the warning because on my
system Smatch doesn't parse usbip_recv() correctly so it ends up
silencing that warning.  :/

regards,
dan carpenter

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: kbuild-all@lists.01.org
Subject: Re: drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
Date: Thu, 24 Oct 2019 22:45:00 +0300	[thread overview]
Message-ID: <20191024194500.GD23523@kadam> (raw)
In-Reply-To: <20191023071120.GA3061@localhost.localdomain>

[-- Attachment #1: Type: text/plain, Size: 6614 bytes --]

On Wed, Oct 23, 2019 at 04:11:20PM +0900, Suwan Kim wrote:
> On Tue, Oct 22, 2019 at 12:28:39PM +0300, Dan Carpenter wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   7d194c2100ad2a6dded545887d02754948ca5241
> > commit: ea44d190764b4422af4d1c29eaeb9e69e353b406 usbip: Implement SG support to vhci-hcd and stub driver
> > date:   7 weeks ago
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > New smatch warnings:
> > drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'.
> > 
> > Old smatch warnings:
> > drivers/usb/usbip/stub_rx.c:450 stub_recv_xbuff() error: uninitialized symbol 'ret'.
> > 
> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ea44d190764b4422af4d1c29eaeb9e69e353b406
> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > git remote update linus
> > git checkout ea44d190764b4422af4d1c29eaeb9e69e353b406
> > vim +/nents +505 drivers/usb/usbip/stub_rx.c
> > 
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  453  static void stub_recv_cmd_submit(struct stub_device *sdev,
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  454  				 struct usbip_header *pdu)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  455  {
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  456  	struct stub_priv *priv;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  457  	struct usbip_device *ud = &sdev->ud;
> > 2d8f4595d1f275 drivers/staging/usbip/stub_rx.c Max Vozeler        2011-01-12  458  	struct usb_device *udev = sdev->udev;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  459  	struct scatterlist *sgl = NULL, *sg;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  460  	void *buffer = NULL;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  461  	unsigned long long buf_len;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  462  	int nents;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  463  	int num_urbs = 1;
> > c6688ef9f29762 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  464  	int pipe = get_pipe(sdev, pdu);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  465  	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  466  	int support_sg = 1;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  467  	int np = 0;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  468  	int ret, i;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  469  
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  470  	if (pipe == -1)
> > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c     Shuah Khan         2017-12-07  471  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  472  
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  473  	priv = stub_priv_alloc(sdev, pdu);
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  474  	if (!priv)
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  475  		return;
> > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09  476  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  477  	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  478  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  479  	/* allocate urb transfer buffer, if needed */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  480  	if (buf_len) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  481  		if (use_sg) {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  482  			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  483  			if (!sgl)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  484  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  485  		} else {
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  486  			buffer = kzalloc(buf_len, GFP_KERNEL);
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  487  			if (!buffer)
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  488  				goto err_malloc;
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  489  		}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  490  	}
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  491  
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  492  	/* Check if the server's HCD supports SG */
> > ea44d190764b44 drivers/usb/usbip/stub_rx.c     Suwan Kim          2019-08-28  493  	if (use_sg && !udev->bus->sg_tablesize) {
> > 
> > Smatch thinks "use_sg" can be true when "buf_len" is zero.  It's hard
> > to tell if Smatch is right or wrong without more context...
> 
> This is a bit strange. The meaning of "use_sg" is that client will
> use scatter-gather and client's urb->num_sgs is not zero. And buffer
> length should not be zero.
> 
> usb_sg and buf_len are both client-dependent variables, so I think
> if they have wrong value in the server side, the client must have
> sent use_sg and buf_len with incorrect values.
> 
> Did this error occur when compiling?

Smatch is doing static analysis, yes.

> If then, Did Smatch also consider vhci tx side?

I'm not really sure...  I can't reproduce the warning because on my
system Smatch doesn't parse usbip_recv() correctly so it ends up
silencing that warning.  :/

regards,
dan carpenter

  reply	other threads:[~2019-10-24 19:45 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-22  9:28 drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents' Dan Carpenter
2019-10-22  9:28 ` Dan Carpenter
2019-10-22  9:28 ` Dan Carpenter
2019-10-23  7:11 ` Suwan Kim
2019-10-24 19:45   ` Dan Carpenter [this message]
2019-10-24 19:45     ` Dan Carpenter
2019-10-24 19:45     ` Dan Carpenter
2019-10-24 22:52     ` shuah
2019-10-24 22:52       ` shuah
2019-10-26  2:41       ` Suwan Kim
2019-10-30  8:19         ` Dan Carpenter
2019-10-30  8:19           ` Dan Carpenter
2019-10-30  8:19           ` Dan Carpenter
2019-10-26  3:40       ` Suwan Kim
2019-10-29 11:07         ` shuah
2019-10-29 11:07           ` shuah
2019-11-01 14:34           ` Suwan Kim
2019-11-04 17:07             ` shuah
2019-11-04 17:07               ` shuah
2019-11-11  2:45               ` Suwan Kim

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191024194500.GD23523@kadam \
    --to=dan.carpenter@oracle.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=kbuild-all@lists.01.org \
    --cc=kbuild@lists.01.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=shuah@kernel.org \
    --cc=suwan.kim027@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.