Bug 539506 - [4.7] wait4 blocks on non-existing pid
Summary: [4.7] wait4 blocks on non-existing pid
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel
Version: 4.7
Hardware: All
OS: Linux
urgent
urgent
Target Milestone: rc
: ---
Assignee: Oleg Nesterov
QA Contact: Petr Beňas
URL:
Whiteboard:
Depends On:
Blocks: 532951 555869 567321
TreeView+ depends on / blocked
 
Reported: 2009-11-20 12:25 UTC by Andreas Schwab
Modified: 2015-01-04 22:59 UTC (History)
18 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
If a process was using ptrace() to trace a multi-threaded process, and that multi-threaded process dumped its core, the process performing the trace could hang in wait4(). This issue could be triggered by running "strace -f" on a multi-threaded process that was dumping its core, resulting in the strace command hanging.
Clone Of: 532951
: 567321 (view as bug list)
Environment:
Last Closed: 2011-02-16 15:45:41 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2011:0263 0 normal SHIPPED_LIVE Important: Red Hat Enterprise Linux 4.9 kernel security and bug fix update 2011-02-16 15:14:55 UTC

Comment 1 Andreas Schwab 2009-11-20 12:27:30 UTC
 2221 pts/3    S+     0:00      |   \_ ./strace -o trace -f /root/thread3
 2222 pts/3    Dl+    0:00      |       \_ /root/thread3
 2223 pts/3    Z+     0:00      |           \_ [thread3] <defunct>
# strace -p 2221
Process 2221 attached - interrupt to quit
wait4(2420,  <unfinished ...>
Process 2221 detached
# ps 2420
  PID TTY      STAT   TIME COMMAND

Comment 2 Chris Ward 2009-11-30 10:49:14 UTC
This issue is blocking the release of a 4.8.z kernel. What is the recommended course of action?

Ron, using an imported RHTS from RHTS it was discovered that the 4.8.z kernel exhibits what appears to be a regression. I'm not certain though of what nvr it was re-introduced.

Comment 3 Michal Nowak 2009-11-30 11:08:45 UTC
This bug blocks strace 4.8.z erratum RHBA-2009:9039.

This bug is not a regression, it always used to be like this but: without this fix we won't reliably fix bug 532951 (RHBA-2009:9039).

Comment 4 Vitaly Mayatskikh 2009-12-14 12:21:07 UTC
Posted to RHKL today. I agree with Michal, this is not a regression.

Comment 5 RHEL Program Management 2010-01-05 14:50:23 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 6 Linda Wang 2010-01-08 05:02:51 UTC
There are heavy discussion about Vitaly's patch on rkml, and since
Vitaly is on pto 'til 1/13, Oleg has kind enough to take over
the discussion and preparing a new patch for this issue.

He was able to get help to test out his new patch, but given the 
complexity of the code paths, during testing, new issue
was revealed. Therefore he is currently looking into the new issue.

Therefore, move the bug back to ASSI state.

Comment 14 Vivek Goyal 2010-01-19 21:06:43 UTC
Committed in 89.19.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/

Comment 31 Petr Beňas 2010-11-19 11:35:43 UTC
Reproduced in 89.18.EL and verified in 89.19.EL.

Comment 33 Douglas Silas 2011-01-30 22:56:08 UTC
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
If a process was using ptrace() to trace a multi-threaded process, and that multi-threaded process dumped its core, the process performing the trace could hang in wait4(). This issue could be triggered by running "strace -f" on a multi-threaded process that was dumping its core, resulting in the strace command hanging.

Comment 34 errata-xmlrpc 2011-02-16 15:45:41 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0263.html


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