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authorArnd Bergmann <arnd@arndb.de>2021-07-27 15:44:47 +0200
committerDavid S. Miller <davem@davemloft.net>2021-07-27 20:11:43 +0100
commitb9067f5dc4a07c8e24e01a1b277c6722d91be39e (patch)
tree0f52e398f8c7fa30060d3f3029485a76f1d21921 /Documentation/networking
parent2fba2eae30d3401716d56467007d6938c0d580ed (diff)
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.rst7
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)