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author | Milton Miller <miltonm@us.ibm.com> | 2021-03-29 10:20:39 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-14 08:42:08 +0200 |
commit | dfe7805e6aa6f54f7b01c3f11c23af938ad9bd7b (patch) | |
tree | 529ac231c67974ca3fed581dff0cb51314c96b5c /net/qrtr/qrtr.c | |
parent | ae4a8d10ac8b059776bab82ac2540322adbf9843 (diff) |
net/ncsi: Avoid channel_monitor hrtimer deadlock
[ Upstream commit 03cb4d05b4ea9a3491674ca40952adb708d549fa ]
Calling ncsi_stop_channel_monitor from channel_monitor is a guaranteed
deadlock on SMP because stop calls del_timer_sync on the timer that
invoked channel_monitor as its timer function.
Recognise the inherent race of marking the monitor disabled before
deleting the timer by just returning if enable was cleared. After
a timeout (the default case -- reset to START when response received)
just mark the monitor.enabled false.
If the channel has an entry on the channel_queue list, or if the
state is not ACTIVE or INACTIVE, then warn and mark the timer stopped
and don't restart, as the locking is broken somehow.
Fixes: 0795fb2021f0 ("net/ncsi: Stop monitor if channel times out or is inactive")
Signed-off-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/qrtr/qrtr.c')
0 files changed, 0 insertions, 0 deletions