[incr Tcl] / Bugs / #251 protect-2.5 segfaults

Don Porter - 2014-02-20

The bug-240 branch (updated to trunk) is effective
in stopping the segfault, but see comments in bug 240
about questions raised by it.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2014-02-20

Copying over the key comment that summarizes
the current status:

Branch bug-240 has stopped the test suite segfaults,
but now suffers from failing test:

==== tinfo-10.1 type info types FAILED
==== Contents of test case:

type dog {
}

type cat {
}

lsort [dog info types]

---- Result was:
bar cat confused-dog dog dogbase foo tail tail1 tail2 wag
---- Result should have been (exact matching):
cat dog
==== tinfo-10.1 FAILED

when run in -singleproc 1 mode. Might just be a test error,
or might be something more serious. The other issue is with
all this Preserve-ing and refcounting to stop segfaults from
accessing freed memory, there's a real risk that memory leaks
have been introduced.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Arnulf Wiedemann - 2014-09-13

Description has changed:

Diff:

--- old +++ new @@ -1,4 +1,3 @@ - The is Bug 240 restarted. The segfault appears to happen more frequently now, but still not every time.

status: open --> pending

assigned_to: Arnulf Wiedemann
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Arnulf Wiedemann - 2014-09-13

I have tested with Tcl trunk and Itcl trunk and there was no problem on my machine.
Can you please check again.
Thanks.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2014-09-14

It appears the fix requires both Itcl trunk and Tcl trunk,
so the bug points to some combo of bugs in Itcl and TclOO.

Testing the Itcl trunk with Tcl 8.6.1 still delivers frequent
segfaults.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2014-09-14

....and so I go looking for the checkin that
solved the matter, and the failure goes away, even
in the scenario where I just saw it.

I suppose closing this until it can be reliably
reproduced is reasonable. Wish I had greater confidence
we knew what was wrong and why it is fixed (if it is
indeed fixed). I cannot chase it now.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
- Arnulf Wiedemann - 2014-09-15
  
  It could have to do with the fix for fossil bug ticket
  2cd667f270b68ef66d668338e09d144e20405e23
  because there was a crash, when checking protection (private method).
  Because of a lot of payed work I cannot look for that closer now.
  
  Arnulf
  
  Last edit: Arnulf Wiedemann 2014-09-20
  
  If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2014-09-22

Using current trunk for both Tcl and Itcl with repeated
runs of

make test TESTFLAGS="-singleproc 1"

I will see a segfault in protection.test

Based on history, my guess is this is the protect-2.5
problem still unfixed, but I cannot reproduce with
a -verbose option to be sure.

Sorry not to have a more reliable reproduction yet. Might
be able to produce one in a few weeks.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Here's the stack trace of the crash

---- protect-2.5 start

Program received signal SIGSEGV, Segmentation fault.
0x00002aaaae523bc5 in ItclMapMethodNameProc ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
(gdb) bt
#0  0x00002aaaae523bc5 in ItclMapMethodNameProc ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
#1  0x0000000000598cc6 in TclOOObjectCmdCore (oPtr=0xbf9000, interp=0x824680,
    objc=2, objv=0xcc83e0, flags=1, startCls=0x0)
    at /home/dgp/fossil/tcl-only/generic/tclOO.c:2514
#2  0x0000000000598bdf in TclOOInvokeObject (interp=0x824680, object=0xbf9000,
    startCls=0x0, publicPrivate=1, objc=2, objv=0xcc83e0)
    at /home/dgp/fossil/tcl-only/generic/tclOO.c:2454
#3  0x0000000000414e43 in TclNRRunCallbacks (interp=0x824680, result=0,
    rootPtr=0xb2ed70) at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4392
#4  0x00002aaaae523146 in ItclObjectCmd ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
#5  0x00002aaaae520561 in CallItclObjectCmd ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
#6  0x0000000000414e43 in TclNRRunCallbacks (interp=0x824680, result=0,
    rootPtr=0xb2ed70) at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4392
#7  0x00002aaaae520918 in Itcl_EvalMemberCode ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
#8  0x00002aaaae52101b in NRExecMethod ()
   from /home/dgp/x86_64/linuxoldld/lib/itcl4.0.0/libitcl4.0.0.so
#9  0x0000000000414dbc in Dispatch (data=0xc12268, interp=0x824680, result=0)
    at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4359
#10 0x0000000000414e43 in TclNRRunCallbacks (interp=0x824680, result=0,
    rootPtr=0xb2ed70) at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4392
#11 0x000000000041a916 in Tcl_NRCallObjProc (interp=0x824680,
    objProc=0x2aaaae520f80 <NRExecMethod>, clientData=0xbf9500, objc=1,
    objv=0xcc8370) at /home/dgp/fossil/tcl-only/generic/tclBasic.c:8075
#12 0x0000000000414dbc in Dispatch (data=0xc11938, interp=0x824680, result=0)
    at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4359
#13 0x0000000000414e43 in TclNRRunCallbacks (interp=0x824680, result=0,
    rootPtr=0x0) at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4392
#14 0x0000000000414569 in Tcl_EvalObjv (interp=0x824680, objc=1,
    objv=0x831f80, flags=2097168)
    at /home/dgp/fossil/tcl-only/generic/tclBasic.c:4123
#15 0x0000000000416d67 in TclEvalEx (interp=0x824680,
    script=0x885120 "# all.tcl --\n#\n# This file contains a top-level script to run all of the Tcl\n# tests.  Execute it by invoking \"source all.test\" when running tcltest\n# in this directory.\n#\n# Copyright (c) 1998-2000 by"...,
    numBytes=348, flags=0, line=13, clNextOuter=0x0,
    outerScript=0x885120 "# all.tcl --\n#\n# This file contains a top-level script to run all of the Tcl\n# tests.  Execute it by invoking \"source all.test\" when running tcltest\n# in this directory.\n#\n# Copyright (c) 1998-2000 by"...)
    at /home/dgp/fossil/tcl-only/generic/tclBasic.c:5261
#16 0x000000000052ec04 in Tcl_FSEvalFileEx (interp=0x824680, pathPtr=0x867440,
    encodingName=0x0) at /home/dgp/fossil/tcl-only/generic/tclIOUtil.c:1815
#17 0x00000000005377c0 in Tcl_MainEx (argc=-1, argv=0x7fffffffdd18,
    appInitProc=0x40f189 <Tcl_AppInit>, interp=0x824680)
    at /home/dgp/fossil/tcl-only/generic/tclMain.c:417
#18 0x000000000040f182 in main (argc=6, argv=0x7fffffffdce8)
    at /home/dgp/fossil/tcl-only/unix/tclAppInit.c:84

Last edit: Don Porter 2014-10-01

Don Porter - 2015-01-09

The bug-240 branch with

make test TESTFLAGS="'-singleproc 1 -file type[fi]*.test -match "mymethod-1.1 tinfo-10.1"'

produces

==== tinfo-10.1 type info types FAILED
==== Contents of test case:

type dog { } type cat { } lsort [dog info types]

---- Result was:
bar cat dog foo
---- Result should have been (exact matching):
cat dog
==== tinfo-10.1 FAILED

which seems to indicate that this branch fails to actually
delete the types foo and bar in the -cleanup of test mymethod-1.1.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2015-01-13

Restoring a commented-out release stops the
test suite failure and the segfaults do not come back.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2015-01-13

Merging bug fix branch to go out in Itcl 4.0.3.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Don Porter - 2015-01-13

status: pending --> closed-fixed

assigned_to: Arnulf Wiedemann --> Don Porter
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

protect-2.5 segfaults

Group

Searches

Help

#251 protect-2.5 segfaults

Discussion