<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/usb/gadget/function/f_phonet.c, branch v5.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>usb: gadget: Use fallthrough pseudo-keyword</title>
<updated>2020-07-10T06:55:18+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2020-07-07T17:15:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a74005ab91856276ca5e424a239ebe73347079d8'/>
<id>a74005ab91856276ca5e424a239ebe73347079d8</id>
<content type='text'>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget: f_phonet: Replace zero-length array with flexible-array member</title>
<updated>2020-02-14T16:38:16+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2020-02-11T23:23:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b57a368efde6b2980606169cdcaa1c4101adffe0'/>
<id>b57a368efde6b2980606169cdcaa1c4101adffe0</id>
<content type='text'>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Link: https://lore.kernel.org/r/20200211232303.GA21495@embeddedor
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Link: https://lore.kernel.org/r/20200211232303.GA21495@embeddedor
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget: f_phonet: fix pn_net_xmit()'s return type</title>
<updated>2018-04-25T09:46:53+00:00</updated>
<author>
<name>Luc Van Oostenryck</name>
<email>luc.vanoostenryck@gmail.com</email>
</author>
<published>2018-04-24T13:18:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=064b40754291f95121bbdb05645a3a110d0ae346'/>
<id>064b40754291f95121bbdb05645a3a110d0ae346</id>
<content type='text'>
The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.

Signed-off-by: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Signed-off-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.

Signed-off-by: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Signed-off-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs</title>
<updated>2017-11-14T22:44:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-14T22:44:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=abc36be236358162202e86ad88616ff95a755101'/>
<id>abc36be236358162202e86ad88616ff95a755101</id>
<content type='text'>
Pull configfs updates from Christoph Hellwig:
 "A couple of configfs cleanups:

   - proper use of the bool type (Thomas Meyer)

   - constification of struct config_item_type (Bhumika Goyal)"

* tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs:
  RDMA/cma: make config_item_type const
  stm class: make config_item_type const
  ACPI: configfs: make config_item_type const
  nvmet: make config_item_type const
  usb: gadget: configfs: make config_item_type const
  PCI: endpoint: make config_item_type const
  iio: make function argument and some structures const
  usb: gadget: make config_item_type structures const
  dlm: make config_item_type const
  netconsole: make config_item_type const
  nullb: make config_item_type const
  ocfs2/cluster: make config_item_type const
  target: make config_item_type const
  configfs: make ci_type field, some pointers and function arguments const
  configfs: make config_item_type const
  configfs: Fix bool initialization/comparison
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull configfs updates from Christoph Hellwig:
 "A couple of configfs cleanups:

   - proper use of the bool type (Thomas Meyer)

   - constification of struct config_item_type (Bhumika Goyal)"

* tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs:
  RDMA/cma: make config_item_type const
  stm class: make config_item_type const
  ACPI: configfs: make config_item_type const
  nvmet: make config_item_type const
  usb: gadget: configfs: make config_item_type const
  PCI: endpoint: make config_item_type const
  iio: make function argument and some structures const
  usb: gadget: make config_item_type structures const
  dlm: make config_item_type const
  netconsole: make config_item_type const
  nullb: make config_item_type const
  ocfs2/cluster: make config_item_type const
  target: make config_item_type const
  configfs: make ci_type field, some pointers and function arguments const
  configfs: make config_item_type const
  configfs: Fix bool initialization/comparison
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: gadget: function: Remove redundant license text</title>
<updated>2017-11-07T14:45:02+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-06T14:37:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=24ceb9c669bc18c7de3ae38863ffed8b68ceae9b'/>
<id>24ceb9c669bc18c7de3ae38863ffed8b68ceae9b</id>
<content type='text'>
Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Cc: Johan Hovold &lt;johan@kernel.org&gt;
Cc: Jerry Zhang &lt;zhangjerry@google.com&gt;
Cc: John Keeping &lt;john@metanate.com&gt;
Cc: Krzysztof Opasiak &lt;k.opasiak@samsung.com&gt;
Cc: Abdulhadi Mohamed &lt;abdulahhadi2@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Cc: Janusz Dziedzic &lt;januszx.dziedzic@linux.intel.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Acked-by: Michal Nazarewicz &lt;mina86@mina86.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Acked-by: Vincent Pelletier &lt;plr.vincent@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Cc: Johan Hovold &lt;johan@kernel.org&gt;
Cc: Jerry Zhang &lt;zhangjerry@google.com&gt;
Cc: John Keeping &lt;john@metanate.com&gt;
Cc: Krzysztof Opasiak &lt;k.opasiak@samsung.com&gt;
Cc: Abdulhadi Mohamed &lt;abdulahhadi2@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Cc: Janusz Dziedzic &lt;januszx.dziedzic@linux.intel.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Acked-by: Michal Nazarewicz &lt;mina86@mina86.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Acked-by: Vincent Pelletier &lt;plr.vincent@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: add SPDX identifiers to all remaining files in drivers/usb/</title>
<updated>2017-11-04T10:48:02+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-03T10:28:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5fd54ace4721fc5ce2bb5aef6318fcf17f421460'/>
<id>5fd54ace4721fc5ce2bb5aef6318fcf17f421460</id>
<content type='text'>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Acked-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Acked-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget: f_phonet: mark expected switch fall-throughs</title>
<updated>2017-11-01T15:51:09+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>garsilva@embeddedor.com</email>
</author>
<published>2017-10-24T19:52:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0f8838a8a0738d74afecf6d198c083e259ee389e'/>
<id>0f8838a8a0738d74afecf6d198c083e259ee389e</id>
<content type='text'>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 115004
Addresses-Coverity-ID: 115005
Signed-off-by: Gustavo A. R. Silva &lt;garsilva@embeddedor.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 115004
Addresses-Coverity-ID: 115005
Signed-off-by: Gustavo A. R. Silva &lt;garsilva@embeddedor.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget: make config_item_type structures const</title>
<updated>2017-10-19T14:15:23+00:00</updated>
<author>
<name>Bhumika Goyal</name>
<email>bhumirks@gmail.com</email>
</author>
<published>2017-10-16T15:18:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=973639023444320d4fb5c17af58996463b3392d9'/>
<id>973639023444320d4fb5c17af58996463b3392d9</id>
<content type='text'>
Make these structures const as they are only passed to the const
argument of the functions config_{group/item}_init_type_name.

Signed-off-by: Bhumika Goyal &lt;bhumirks@gmail.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make these structures const as they are only passed to the const
argument of the functions config_{group/item}_init_type_name.

Signed-off-by: Bhumika Goyal &lt;bhumirks@gmail.com&gt;
Acked-by: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>networking: introduce and use skb_put_data()</title>
<updated>2017-06-16T15:48:37+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2017-06-16T12:29:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=59ae1d127ac0ae404baf414c434ba2651b793f46'/>
<id>59ae1d127ac0ae404baf414c434ba2651b793f46</id>
<content type='text'>
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Fix inconsistent teardown and release of private netdev state.</title>
<updated>2017-06-07T19:53:24+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2017-05-08T16:52:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cf124db566e6b036b8bcbe8decbed740bdfac8c6'/>
<id>cf124db566e6b036b8bcbe8decbed740bdfac8c6</id>
<content type='text'>
Network devices can allocate reasources and private memory using
netdev_ops-&gt;ndo_init().  However, the release of these resources
can occur in one of two different places.

Either netdev_ops-&gt;ndo_uninit() or netdev-&gt;destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops-&gt;ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev-&gt;destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev-&gt;destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops-&gt;ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops-&gt;ndo_uninit().  But
it is not able to invoke netdev-&gt;destructor().

This is because netdev-&gt;destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev-&gt;destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev-&gt;destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev-&gt;priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev-&gt;destructor(), except for
free_netdev().

netdev-&gt;needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops-&gt;ndo_init() succeeds, by invoking both ndo_ops-&gt;ndo_uninit()
and netdev-&gt;priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev-&gt;priv_destructor() and optionally call free_netdev().

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Network devices can allocate reasources and private memory using
netdev_ops-&gt;ndo_init().  However, the release of these resources
can occur in one of two different places.

Either netdev_ops-&gt;ndo_uninit() or netdev-&gt;destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops-&gt;ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev-&gt;destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev-&gt;destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops-&gt;ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops-&gt;ndo_uninit().  But
it is not able to invoke netdev-&gt;destructor().

This is because netdev-&gt;destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev-&gt;destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev-&gt;destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev-&gt;priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev-&gt;destructor(), except for
free_netdev().

netdev-&gt;needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops-&gt;ndo_init() succeeds, by invoking both ndo_ops-&gt;ndo_uninit()
and netdev-&gt;priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev-&gt;priv_destructor() and optionally call free_netdev().

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
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