Opened 13 years ago

Closed 10 years ago

Last modified 10 years ago

#7039 closed bug (fixed)

[Network stack] Panic: _mutex_lock (): double lock

Reported by: diver Owned by: axeld
Priority: normal Milestone: R1
Component: Network & Internet/Stack Version: R1/Development
Keywords: Cc:
Blocked By: Blocking:
Platform: All

Description

This is hrev39980, gcc4hybrid.

Running tcpdump in the first Terminal tab and ifconfig del /dev/net/... in another one crashes network stack.
Same thing with running tcpdump and disabling interface in Network preflet.

Attachments (2)

stack_crash.png​ (46.2 KB ) - added by diver 13 years ago.
0001-Change-the-monitor_lock-to-be-a-recursive_lock-fixin.patch​ (4.0 KB ) - added by jackburton 10 years ago.

Download all attachments as: .zip

Change History (10)

by diver, 13 years ago

Attachment: stack_crash.png​ added

comment:1 by diver, 13 years ago

Summary: [Network stack] crashes after ifconfig del + tcpdump → [Network stack] Panic: _mutex_lock (): double lock

comment:2 by diver, 10 years ago

Still here in hrev47314.

comment:3 by jackburton, 10 years ago

I'm trying under vbox but cannot reproduce. The virtual NIC is connected using "NAT".

Version 0, edited 10 years ago by jackburton (next)

comment:4 by diver, 10 years ago

Still crashes for me in hrev47724. NAT mode as well.

by jackburton, 10 years ago

Attachment: 0001-Change-the-monitor_lock-to-be-a-recursive_lock-fixin.patch​ added

comment:5 by jackburton, 10 years ago

patch: 0 → 1

comment:6 by jackburton, 10 years ago

The problem is that notify_device_monitor acquires the monitor lock (a mutex), then indirectly calls unregister_device_monitor, which acquires the lock again. I changed the mutex_to a recursive_lock, and the problem goes away. Please someone review the patch.

comment:7 by axeld, 10 years ago

Patch looks good. The only thing that is forbidden is to remove other handlers during notify.

comment:8 by jackburton, 10 years ago

Resolution: → fixed
Status: new → closed

Applied in hrev47876. Thank you Axel for the review!

Last edited 10 years ago by jackburton (previous) (diff)
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