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| author |   Xie He <xie.he.0141@gmail.com> | 2021-01-25 20:09:39 -0800 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2021-01-26 17:53:45 -0800 |
| commit | b491e6a7391e3ecdebdd7a097550195cc878924a (patch) | |
| tree | 6417a2500f7b50d5d54b8acfb0b8af48551a1cdc /include | |
| parent | team: protect features update by RCU to avoid deadlock (diff) | |
| download | linux-dev-b491e6a7391e3ecdebdd7a097550195cc878924a.tar.xz linux-dev-b491e6a7391e3ecdebdd7a097550195cc878924a.zip | |
net: lapb: Add locking to the lapb module
In the lapb module, the timers may run concurrently with other code in
this module, and there is currently no locking to prevent the code from
racing on "struct lapb_cb". This patch adds locking to prevent racing.
1. Add "spinlock_t lock" to "struct lapb_cb"; Add "spin_lock_bh" and
"spin_unlock_bh" to APIs, timer functions and notifier functions.
2. Add "bool t1timer_stop, t2timer_stop" to "struct lapb_cb" to make us
able to ask running timers to abort; Modify "lapb_stop_t1timer" and
"lapb_stop_t2timer" to make them able to abort running timers;
Modify "lapb_t2timer_expiry" and "lapb_t1timer_expiry" to make them
abort after they are stopped by "lapb_stop_t1timer", "lapb_stop_t2timer",
and "lapb_start_t1timer", "lapb_start_t2timer".
3. Let lapb_unregister wait for other API functions and running timers
to stop.
4. The lapb_device_event function calls lapb_disconnect_request. In
order to avoid trying to hold the lock twice, add a new function named
"__lapb_disconnect_request" which assumes the lock is held, and make
it called by lapb_disconnect_request and lapb_device_event.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Link: https://lore.kernel.org/r/20210126040939.69995-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/lapb.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/lapb.h b/include/net/lapb.h index ccc3d1f020b0..eee73442a1ba 100644 --- a/include/net/lapb.h +++ b/include/net/lapb.h @@ -92,6 +92,7 @@ struct lapb_cb { unsigned short n2, n2count; unsigned short t1, t2; struct timer_list t1timer, t2timer; + bool t1timer_stop, t2timer_stop; /* Internal control information */ struct sk_buff_head write_queue; @@ -103,6 +104,7 @@ struct lapb_cb { struct lapb_frame frmr_data; unsigned char frmr_type; + spinlock_t lock; refcount_t refcnt; }; |