[asterisk-bugs] [Asterisk 0019112]: [patch] Deadlock ao2_callback / ast_write / handle_incoming

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=19112 
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Reported By:                irroot
Assigned To:                
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Project:                    Asterisk
Issue ID:                   19112
Category:                   Channels/chan_sip/General
Reproducibility:            random
Severity:                   minor
Priority:                   normal
Status:                     confirmed
Asterisk Version:           1.8.4-rc2 
JIRA:                       SWP-3327 
Regression:                 No 
Reviewboard Link:           https://reviewboard.asterisk.org/r/1171 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2011-04-13 03:10 CDT
Last Modified:              2011-05-19 06:55 CDT
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Summary:                    [patch] Deadlock ao2_callback / ast_write /
handle_incoming
Description: 

Channel walk is contending a lock on a channel held by ast_write while
sip_write is contending a private lock held by handle incoming that is
contending the channel lock held by the write ...

now if i was holding the channel lock in handle_incoming before i locked
private this would not happen ...
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Relationships       ID      Summary
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related to          0019107 Deadlock between rtp_engine.c (ast_rtp_...
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 (0135147) one47 (reporter) - 2011-05-19 06:55
 https://issues.asterisk.org/view.php?id=19112#c135147 
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The patch is probably a reasonable response, but is fixing "innocent"
functions, which are getting the locks in the correct order, and therefore
should be safe.

Since this issue was raised, https://reviewboard.asterisk.org/r/1182/
looks as if it may fix the root cause, and this is already applied to 1.8
trunk AFAIK.

This has prompted me to provide a 1.6 equivalent patch, which I will raise
separately. 

Issue History 
Date Modified    Username       Field                    Change               
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2011-05-19 06:55 one47          Note Added: 0135147                          
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