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| author | Arnd Bergmann <arnd@arndb.de> | 2021-07-27 16:44:47 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-27 22:11:43 +0300 |
| commit | b9067f5dc4a07c8e24e01a1b277c6722d91be39e (patch) | |
| tree | 0f52e398f8c7fa30060d3f3029485a76f1d21921 /Documentation/networking | |
| parent | 2fba2eae30d3401716d56467007d6938c0d580ed (diff) | |
| download | linux-b9067f5dc4a07c8e24e01a1b277c6722d91be39e.tar.xz | |
net: split out SIOCDEVPRIVATE handling from dev_ioctl
SIOCDEVPRIVATE ioctl commands are mainly used in really old
drivers, and they have a number of problems:
- They hide behind the normal .ndo_do_ioctl function that
is also used for other things in modern drivers, so it's
hard to spot a driver that actually uses one of these
- Since drivers use a number different calling conventions,
it is impossible to support compat mode for them in
a generic way.
- With all drivers using the same 16 commands codes, there
is no way to introspect the data being passed through
things like strace.
Add a new net_device_ops callback pointer, to address the
first two of these. Separating them from .ndo_do_ioctl
makes it easy to grep for drivers with a .ndo_siocdevprivate
callback, and the unwieldy name hopefully makes it easier
to spot in code review.
By passing the ifreq structure and the ifr_data pointer
separately, it is no longer necessary to overload these,
and the driver can use either one for a given command.
Cc: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/netdevices.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index 17bdcb746dcf..02f1faac839a 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -222,6 +222,13 @@ ndo_do_ioctl: Synchronization: rtnl_lock() semaphore. Context: process +ndo_siocdevprivate: + Synchronization: rtnl_lock() semaphore. + Context: process + + This is used to implement SIOCDEVPRIVATE ioctl helpers. + These should not be added to new drivers, so don't use. + ndo_get_stats: Synchronization: rtnl_lock() semaphore, dev_base_lock rwlock, or RCU. Context: atomic (can't sleep under rwlock or RCU) |