<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/core/dev_ioctl.c, branch v6.5</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net: dsa: replace NETDEV_PRE_CHANGE_HWTSTAMP notifier with a stub</title>
<updated>2023-04-09T14:35:49+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-06T11:42:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5a17818682cf43ad0fdd6035945f3b7a8c9dc5e9'/>
<id>5a17818682cf43ad0fdd6035945f3b7a8c9dc5e9</id>
<content type='text'>
There was a sort of rush surrounding commit 88c0a6b503b7 ("net: create a
netdev notifier for DSA to reject PTP on DSA master"), due to a desire
to convert DSA's attempt to deny TX timestamping on a DSA master to
something that doesn't block the kernel-wide API conversion from
ndo_eth_ioctl() to ndo_hwtstamp_set().

What was required was a mechanism that did not depend on ndo_eth_ioctl(),
and what was provided was a mechanism that did not depend on
ndo_eth_ioctl(), while at the same time introducing something that
wasn't absolutely necessary - a new netdev notifier.

There have been objections from Jakub Kicinski that using notifiers in
general when they are not absolutely necessary creates complications to
the control flow and difficulties to maintainers who look at the code.
So there is a desire to not use notifiers.

In addition to that, the notifier chain gets called even if there is no
DSA in the system and no one is interested in applying any restriction.

Take the model of udp_tunnel_nic_ops and introduce a stub mechanism,
through which net/core/dev_ioctl.c can call into DSA even when
CONFIG_NET_DSA=m.

Compared to the code that existed prior to the notifier conversion, aka
what was added in commits:
- 4cfab3566710 ("net: dsa: Add wrappers for overloaded ndo_ops")
- 3369afba1e46 ("net: Call into DSA netdevice_ops wrappers")

this is different because we are not overloading any struct
net_device_ops of the DSA master anymore, but rather, we are exposing a
rather specific functionality which is orthogonal to which API is used
to enable it - ndo_eth_ioctl() or ndo_hwtstamp_set().

Also, what is similar is that both approaches use function pointers to
get from built-in code to DSA.

There is no point in replicating the function pointers towards
__dsa_master_hwtstamp_validate() once for every CPU port (dev-&gt;dsa_ptr).
Instead, it is sufficient to introduce a singleton struct dsa_stubs,
built into the kernel, which contains a single function pointer to
__dsa_master_hwtstamp_validate().

I find this approach preferable to what we had originally, because
dev-&gt;dsa_ptr-&gt;netdev_ops-&gt;ndo_do_ioctl() used to require going through
struct dsa_port (dev-&gt;dsa_ptr), and so, this was incompatible with any
attempts to add any data encapsulation and hide DSA data structures from
the outside world.

Link: https://lore.kernel.org/netdev/20230403083019.120b72fd@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
There was a sort of rush surrounding commit 88c0a6b503b7 ("net: create a
netdev notifier for DSA to reject PTP on DSA master"), due to a desire
to convert DSA's attempt to deny TX timestamping on a DSA master to
something that doesn't block the kernel-wide API conversion from
ndo_eth_ioctl() to ndo_hwtstamp_set().

What was required was a mechanism that did not depend on ndo_eth_ioctl(),
and what was provided was a mechanism that did not depend on
ndo_eth_ioctl(), while at the same time introducing something that
wasn't absolutely necessary - a new netdev notifier.

There have been objections from Jakub Kicinski that using notifiers in
general when they are not absolutely necessary creates complications to
the control flow and difficulties to maintainers who look at the code.
So there is a desire to not use notifiers.

In addition to that, the notifier chain gets called even if there is no
DSA in the system and no one is interested in applying any restriction.

Take the model of udp_tunnel_nic_ops and introduce a stub mechanism,
through which net/core/dev_ioctl.c can call into DSA even when
CONFIG_NET_DSA=m.

Compared to the code that existed prior to the notifier conversion, aka
what was added in commits:
- 4cfab3566710 ("net: dsa: Add wrappers for overloaded ndo_ops")
- 3369afba1e46 ("net: Call into DSA netdevice_ops wrappers")

this is different because we are not overloading any struct
net_device_ops of the DSA master anymore, but rather, we are exposing a
rather specific functionality which is orthogonal to which API is used
to enable it - ndo_eth_ioctl() or ndo_hwtstamp_set().

Also, what is similar is that both approaches use function pointers to
get from built-in code to DSA.

There is no point in replicating the function pointers towards
__dsa_master_hwtstamp_validate() once for every CPU port (dev-&gt;dsa_ptr).
Instead, it is sufficient to introduce a singleton struct dsa_stubs,
built into the kernel, which contains a single function pointer to
__dsa_master_hwtstamp_validate().

I find this approach preferable to what we had originally, because
dev-&gt;dsa_ptr-&gt;netdev_ops-&gt;ndo_do_ioctl() used to require going through
struct dsa_port (dev-&gt;dsa_ptr), and so, this was incompatible with any
attempts to add any data encapsulation and hide DSA data structures from
the outside world.

Link: https://lore.kernel.org/netdev/20230403083019.120b72fd@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: create a netdev notifier for DSA to reject PTP on DSA master</title>
<updated>2023-04-03T09:04:27+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=88c0a6b503b7f4fffb68a8d49c3987870c5b1d6b'/>
<id>88c0a6b503b7f4fffb68a8d49c3987870c5b1d6b</id>
<content type='text'>
The fact that PTP 2-step TX timestamping is broken on DSA switches if
the master also timestamps the same packets is documented by commit
f685e609a301 ("net: dsa: Deny PTP on master if switch supports it").
We attempt to help the users avoid shooting themselves in the foot by
making DSA reject the timestamping ioctls on an interface that is a DSA
master, and the switch tree beneath it contains switches which are aware
of PTP.

The only problem is that there isn't an established way of intercepting
ndo_eth_ioctl calls, so DSA creates avoidable burden upon the network
stack by creating a struct dsa_netdevice_ops with overlaid function
pointers that are manually checked from the relevant call sites. There
used to be 2 such dsa_netdevice_ops, but now, ndo_eth_ioctl is the only
one left.

There is an ongoing effort to migrate driver-visible hardware timestamping
control from the ndo_eth_ioctl() based API to a new ndo_hwtstamp_set()
model, but DSA actively prevents that migration, since dsa_master_ioctl()
is currently coded to manually call the master's legacy ndo_eth_ioctl(),
and so, whenever a network device driver would be converted to the new
API, DSA's restrictions would be circumvented, because any device could
be used as a DSA master.

The established way for unrelated modules to react on a net device event
is via netdevice notifiers. So we create a new notifier which gets
called whenever there is an attempt to change hardware timestamping
settings on a device.

Finally, there is another reason why a netdev notifier will be a good
idea, besides strictly DSA, and this has to do with PHY timestamping.

With ndo_eth_ioctl(), all MAC drivers must manually call
phy_has_hwtstamp() before deciding whether to act upon SIOCSHWTSTAMP,
otherwise they must pass this ioctl to the PHY driver via
phy_mii_ioctl().

With the new ndo_hwtstamp_set() API, it will be desirable to simply not
make any calls into the MAC device driver when timestamping should be
performed at the PHY level.

But there exist drivers, such as the lan966x switch, which need to
install packet traps for PTP regardless of whether they are the layer
that provides the hardware timestamps, or the PHY is. That would be
impossible to support with the new API.

The proposal there, too, is to introduce a netdev notifier which acts as
a better cue for switching drivers to add or remove PTP packet traps,
than ndo_hwtstamp_set(). The one introduced here "almost" works there as
well, except for the fact that packet traps should only be installed if
the PHY driver succeeded to enable hardware timestamping, whereas here,
we need to deny hardware timestamping on the DSA master before it
actually gets enabled. This is why this notifier is called "PRE_", and
the notifier that would get used for PHY timestamping and packet traps
would be called NETDEV_CHANGE_HWTSTAMP. This isn't a new concept, for
example NETDEV_CHANGEUPPER and NETDEV_PRECHANGEUPPER do the same thing.

In expectation of future netlink UAPI, we also pass a non-NULL extack
pointer to the netdev notifier, and we make DSA populate it with an
informative reason for the rejection. To avoid making it go to waste, we
make the ioctl-based dev_set_hwtstamp() create a fake extack and print
the message to the kernel log.

Link: https://lore.kernel.org/netdev/20230401191215.tvveoi3lkawgg6g4@skbuf/
Link: https://lore.kernel.org/netdev/20230310164451.ls7bbs6pdzs4m6pw@skbuf/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
The fact that PTP 2-step TX timestamping is broken on DSA switches if
the master also timestamps the same packets is documented by commit
f685e609a301 ("net: dsa: Deny PTP on master if switch supports it").
We attempt to help the users avoid shooting themselves in the foot by
making DSA reject the timestamping ioctls on an interface that is a DSA
master, and the switch tree beneath it contains switches which are aware
of PTP.

The only problem is that there isn't an established way of intercepting
ndo_eth_ioctl calls, so DSA creates avoidable burden upon the network
stack by creating a struct dsa_netdevice_ops with overlaid function
pointers that are manually checked from the relevant call sites. There
used to be 2 such dsa_netdevice_ops, but now, ndo_eth_ioctl is the only
one left.

There is an ongoing effort to migrate driver-visible hardware timestamping
control from the ndo_eth_ioctl() based API to a new ndo_hwtstamp_set()
model, but DSA actively prevents that migration, since dsa_master_ioctl()
is currently coded to manually call the master's legacy ndo_eth_ioctl(),
and so, whenever a network device driver would be converted to the new
API, DSA's restrictions would be circumvented, because any device could
be used as a DSA master.

The established way for unrelated modules to react on a net device event
is via netdevice notifiers. So we create a new notifier which gets
called whenever there is an attempt to change hardware timestamping
settings on a device.

Finally, there is another reason why a netdev notifier will be a good
idea, besides strictly DSA, and this has to do with PHY timestamping.

With ndo_eth_ioctl(), all MAC drivers must manually call
phy_has_hwtstamp() before deciding whether to act upon SIOCSHWTSTAMP,
otherwise they must pass this ioctl to the PHY driver via
phy_mii_ioctl().

With the new ndo_hwtstamp_set() API, it will be desirable to simply not
make any calls into the MAC device driver when timestamping should be
performed at the PHY level.

But there exist drivers, such as the lan966x switch, which need to
install packet traps for PTP regardless of whether they are the layer
that provides the hardware timestamps, or the PHY is. That would be
impossible to support with the new API.

The proposal there, too, is to introduce a netdev notifier which acts as
a better cue for switching drivers to add or remove PTP packet traps,
than ndo_hwtstamp_set(). The one introduced here "almost" works there as
well, except for the fact that packet traps should only be installed if
the PHY driver succeeded to enable hardware timestamping, whereas here,
we need to deny hardware timestamping on the DSA master before it
actually gets enabled. This is why this notifier is called "PRE_", and
the notifier that would get used for PHY timestamping and packet traps
would be called NETDEV_CHANGE_HWTSTAMP. This isn't a new concept, for
example NETDEV_CHANGEUPPER and NETDEV_PRECHANGEUPPER do the same thing.

In expectation of future netlink UAPI, we also pass a non-NULL extack
pointer to the netdev notifier, and we make DSA populate it with an
informative reason for the rejection. To avoid making it go to waste, we
make the ioctl-based dev_set_hwtstamp() create a fake extack and print
the message to the kernel log.

Link: https://lore.kernel.org/netdev/20230401191215.tvveoi3lkawgg6g4@skbuf/
Link: https://lore.kernel.org/netdev/20230310164451.ls7bbs6pdzs4m6pw@skbuf/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: add struct kernel_hwtstamp_config and make net_hwtstamp_validate() use it</title>
<updated>2023-04-03T09:04:27+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c4bffeaa8d50b7279c5a76597efa4b06e709df63'/>
<id>c4bffeaa8d50b7279c5a76597efa4b06e709df63</id>
<content type='text'>
Jakub Kicinski suggested that we may want to add new UAPI for
controlling hardware timestamping through netlink in the future, and in
that case, we will be limited to the struct hwtstamp_config that is
currently passed in fixed binary format through the SIOCGHWTSTAMP and
SIOCSHWTSTAMP ioctls. It would be good if new kernel code already
started operating on an extensible kernel variant of that structure,
similar in concept to struct kernel_ethtool_coalesce vs struct
ethtool_coalesce.

Since struct hwtstamp_config is in include/uapi/linux/net_tstamp.h, here
we introduce include/linux/net_tstamp.h which shadows that other header,
but also includes it, so that existing includers of this header work as
before. In addition to that, we add the definition for the kernel-only
structure, and a helper which translates all fields by manual copying.
I am doing a manual copy in order to not force the alignment (or type)
of the fields of struct kernel_hwtstamp_config to be the same as of
struct hwtstamp_config, even though now, they are the same.

Link: https://lore.kernel.org/netdev/20230330223519.36ce7d23@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
Jakub Kicinski suggested that we may want to add new UAPI for
controlling hardware timestamping through netlink in the future, and in
that case, we will be limited to the struct hwtstamp_config that is
currently passed in fixed binary format through the SIOCGHWTSTAMP and
SIOCSHWTSTAMP ioctls. It would be good if new kernel code already
started operating on an extensible kernel variant of that structure,
similar in concept to struct kernel_ethtool_coalesce vs struct
ethtool_coalesce.

Since struct hwtstamp_config is in include/uapi/linux/net_tstamp.h, here
we introduce include/linux/net_tstamp.h which shadows that other header,
but also includes it, so that existing includers of this header work as
before. In addition to that, we add the definition for the kernel-only
structure, and a helper which translates all fields by manual copying.
I am doing a manual copy in order to not force the alignment (or type)
of the fields of struct kernel_hwtstamp_config to be the same as of
struct hwtstamp_config, even though now, they are the same.

Link: https://lore.kernel.org/netdev/20230330223519.36ce7d23@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: move copy_from_user() out of net_hwtstamp_validate()</title>
<updated>2023-04-03T09:04:26+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5d5fd8f2552f6b9c50d3937c77b6783f99fbe83'/>
<id>d5d5fd8f2552f6b9c50d3937c77b6783f99fbe83</id>
<content type='text'>
The kernel will want to start using the more meaningful struct
hwtstamp_config pointer in more places, so move the copy_from_user() at
the beginning of dev_set_hwtstamp() in order to get to that, and pass
this argument to net_hwtstamp_validate().

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
The kernel will want to start using the more meaningful struct
hwtstamp_config pointer in more places, so move the copy_from_user() at
the beginning of dev_set_hwtstamp() in order to get to that, and pass
this argument to net_hwtstamp_validate().

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: promote SIOCSHWTSTAMP and SIOCGHWTSTAMP ioctls to dedicated handlers</title>
<updated>2023-04-03T09:04:26+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4ee58e1e56800b589afe31c34547e2bc0c59f586'/>
<id>4ee58e1e56800b589afe31c34547e2bc0c59f586</id>
<content type='text'>
DSA does not want to intercept all ioctls handled by dev_eth_ioctl(),
only SIOCSHWTSTAMP. This can be seen from commit f685e609a301 ("net:
dsa: Deny PTP on master if switch supports it"). However, the way in
which the dsa_ndo_eth_ioctl() is called would suggest otherwise.

Split the handling of SIOCSHWTSTAMP and SIOCGHWTSTAMP ioctls into
separate case statements of dev_ifsioc(), and make each one call its own
sub-function. This also removes the dsa_ndo_eth_ioctl() call from
dev_eth_ioctl(), which from now on exclusively handles PHY ioctls.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
DSA does not want to intercept all ioctls handled by dev_eth_ioctl(),
only SIOCSHWTSTAMP. This can be seen from commit f685e609a301 ("net:
dsa: Deny PTP on master if switch supports it"). However, the way in
which the dsa_ndo_eth_ioctl() is called would suggest otherwise.

Split the handling of SIOCSHWTSTAMP and SIOCGHWTSTAMP ioctls into
separate case statements of dev_ifsioc(), and make each one call its own
sub-function. This also removes the dsa_ndo_eth_ioctl() call from
dev_eth_ioctl(), which from now on exclusively handles PHY ioctls.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: simplify handling of dsa_ndo_eth_ioctl() return code</title>
<updated>2023-04-03T09:04:26+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1193db2a55b6b04f296f03affdfa80c16ecc3814'/>
<id>1193db2a55b6b04f296f03affdfa80c16ecc3814</id>
<content type='text'>
In the expression "x == 0 || x != -95", the term "x == 0" does not
change the expression's logical value, because 0 != -95, and so,
if x is 0, the expression would still be true by virtue of the second
term. If x is non-zero, the expression depends on the truth value of
the second term anyway. As such, the first term is redundant and can
be deleted.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
In the expression "x == 0 || x != -95", the term "x == 0" does not
change the expression's logical value, because 0 != -95, and so,
if x is 0, the expression would still be true by virtue of the second
term. If x is non-zero, the expression depends on the truth value of
the second term anyway. As such, the first term is redundant and can
be deleted.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: don't abuse "default" case for unknown ioctl in dev_ifsioc()</title>
<updated>2023-04-03T09:04:26+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-02T12:37:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00d521b39307c3232bdc685c2e9fd82ed973ac24'/>
<id>00d521b39307c3232bdc685c2e9fd82ed973ac24</id>
<content type='text'>
The "switch (cmd)" block from dev_ifsioc() gained a bit too much
unnecessary manual handling of "cmd" in the "default" case, starting
with the private ioctls.

Clean that up by using the "ellipsis" gcc extension, adding separate
cases for the rest of the ioctls, and letting the default case only
return -EINVAL.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.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>
The "switch (cmd)" block from dev_ifsioc() gained a bit too much
unnecessary manual handling of "cmd" in the "default" case, starting
with the private ioctls.

Clean that up by using the "ellipsis" gcc extension, adding separate
cases for the rest of the ioctls, and letting the default case only
return -EINVAL.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dev_ioctl: fix a W=1 warning</title>
<updated>2023-03-27T08:32:21+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2023-03-24T22:11:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e5b42483ccce50d5b957f474fd332afd4ef0c27b'/>
<id>e5b42483ccce50d5b957f474fd332afd4ef0c27b</id>
<content type='text'>
This fixes the following warning when compiled with GCC 12.2.0 and W=1.

net/core/dev_ioctl.c:475: warning: Function parameter or member 'data'
not described in 'dev_ioctl'

Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.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>
This fixes the following warning when compiled with GCC 12.2.0 and W=1.

net/core/dev_ioctl.c:475: warning: Function parameter or member 'data'
not described in 'dev_ioctl'

Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dev: Convert sa_data to flexible array in struct sockaddr</title>
<updated>2022-10-25T18:44:20+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-10-18T09:56:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b5f0de6df6dce8d641ef58ef7012f3304dffb9a1'/>
<id>b5f0de6df6dce8d641ef58ef7012f3304dffb9a1</id>
<content type='text'>
One of the worst offenders of "fake flexible arrays" is struct sockaddr,
as it is the classic example of why GCC and Clang have been traditionally
forced to treat all trailing arrays as fake flexible arrays: in the
distant misty past, sa_data became too small, and code started just
treating it as a flexible array, even though it was fixed-size. The
special case by the compiler is specifically that sizeof(sa-&gt;sa_data)
and FORTIFY_SOURCE (which uses __builtin_object_size(sa-&gt;sa_data, 1))
do not agree (14 and -1 respectively), which makes FORTIFY_SOURCE treat
it as a flexible array.

However, the coming -fstrict-flex-arrays compiler flag will remove
these special cases so that FORTIFY_SOURCE can gain coverage over all
the trailing arrays in the kernel that are _not_ supposed to be treated
as a flexible array. To deal with this change, convert sa_data to a true
flexible array. To keep the structure size the same, move sa_data into
a union with a newly introduced sa_data_min with the original size. The
result is that FORTIFY_SOURCE can continue to have no idea how large
sa_data may actually be, but anything using sizeof(sa-&gt;sa_data) must
switch to sizeof(sa-&gt;sa_data_min).

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: Dylan Yudaken &lt;dylany@fb.com&gt;
Cc: Yajun Deng &lt;yajun.deng@linux.dev&gt;
Cc: Petr Machata &lt;petrm@nvidia.com&gt;
Cc: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221018095503.never.671-kees@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
One of the worst offenders of "fake flexible arrays" is struct sockaddr,
as it is the classic example of why GCC and Clang have been traditionally
forced to treat all trailing arrays as fake flexible arrays: in the
distant misty past, sa_data became too small, and code started just
treating it as a flexible array, even though it was fixed-size. The
special case by the compiler is specifically that sizeof(sa-&gt;sa_data)
and FORTIFY_SOURCE (which uses __builtin_object_size(sa-&gt;sa_data, 1))
do not agree (14 and -1 respectively), which makes FORTIFY_SOURCE treat
it as a flexible array.

However, the coming -fstrict-flex-arrays compiler flag will remove
these special cases so that FORTIFY_SOURCE can gain coverage over all
the trailing arrays in the kernel that are _not_ supposed to be treated
as a flexible array. To deal with this change, convert sa_data to a true
flexible array. To keep the structure size the same, move sa_data into
a union with a newly introduced sa_data_min with the original size. The
result is that FORTIFY_SOURCE can continue to have no idea how large
sa_data may actually be, but anything using sizeof(sa-&gt;sa_data) must
switch to sizeof(sa-&gt;sa_data_min).

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: Dylan Yudaken &lt;dylany@fb.com&gt;
Cc: Yajun Deng &lt;yajun.deng@linux.dev&gt;
Cc: Petr Machata &lt;petrm@nvidia.com&gt;
Cc: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221018095503.never.671-kees@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: rename reference+tracking helpers</title>
<updated>2022-06-10T04:52:55+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-06-08T04:39:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d62607c3fe45911b2331fac073355a8c914bbde2'/>
<id>d62607c3fe45911b2331fac073355a8c914bbde2</id>
<content type='text'>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
 dev_hold_track()    -&gt; netdev_hold()
 dev_put_track()     -&gt; netdev_put()
 dev_replace_track() -&gt; netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
 dev_hold_track()    -&gt; netdev_hold()
 dev_put_track()     -&gt; netdev_put()
 dev_replace_track() -&gt; netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
