brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

netlink: use 48 byte ctx instead of 6 signed longs for callback 

People are inclined to stuff random things into cb->args[n] because it
looks like an array of integers. Sometimes people even put u64s in there
with comments noting that a certain member takes up two slots. The
horror! Really this should mirror the usage of skb->cb, which are just
48 opaque bytes suitable for casting a struct. Then people can create
their usual casting macros for accessing strongly typed members of a
struct.

As a plus, this also gives us the same amount of space on 32bit and 64bit.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason A. Donenfeld 2019-06-28 16:40:21 +02:00 committed by David S. Miller
parent 53962bcea9
commit 362b87f5b1
1 changed files with 8 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/linux/netlink.h
View File

@ -192,7 +192,14 @@ struct netlink_callback {
bool strict_check;
u16 answer_flags;
unsigned int prev_seq, seq;
long args[6];
union {
u8 ctx[48];
/* args is deprecated. Cast a struct over ctx instead
* for proper type safety.
*/
long args[6];
};
};
struct netlink_notify {