linux/net/ax25
Francois Romieu df1c941468 net: avoid overflow when rose /proc displays timer information.
rose /proc code does not serialize timer accesses.

Initial report by Bernard F6BVP Pidoux exhibits overflow amounting
to 116 ticks on its HZ=250 system.

Full timer access serialization would imho be overkill as rose /proc
does not enforce consistency between displayed ROSE_STATE_XYZ and
timer values during changes of state.

The patch may also fix similar behavior in ax25 /proc, ax25 ioctl
and netrom /proc as they all exhibit the same timer serialization
policy. This point has not been reported though.

The sole remaining use of ax25_display_timer - ax25 rtt valuation -
may also perform marginally better but I have not analyzed it too
deeply.

Cc: Thomas DL9SAU Osterried <thomas@osterried.de>
Link: https://lore.kernel.org/all/d5e93cc7-a91f-13d3-49a1-b50c11f0f811@free.fr/
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Tested-by: Bernard Pidoux <f6bvp@free.fr>
Link: https://lore.kernel.org/r/Yuk9vq7t7VhmnOXu@electric-eye.fr.zoreil.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-05 19:00:02 -07:00
..
af_ax25.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-08-03 09:04:55 +02:00
ax25_addr.c
ax25_dev.c ax25: use GFP_KERNEL in ax25_dev_device_up() 2022-06-17 20:34:13 -07:00
ax25_ds_in.c
ax25_ds_subr.c
ax25_ds_timer.c
ax25_iface.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_in.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_ip.c ax25: use skb_expand_head 2021-08-03 11:21:39 +01:00
ax25_out.c ax25: constify dev_addr passing 2021-10-13 09:40:45 -07:00
ax25_route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-03 17:36:16 -08:00
ax25_std_in.c
ax25_std_subr.c
ax25_std_timer.c
ax25_subr.c ax25: Fix ax25 session cleanup problems 2022-06-02 10:37:57 +02:00
ax25_timer.c net: avoid overflow when rose /proc displays timer information. 2022-08-05 19:00:02 -07:00
ax25_uid.c
Kconfig
Makefile
sysctl_net_ax25.c