tcl8.4 segfaults while running binutils testsuite

[James Troup]

tcl8.4 8.4.7-1 segfaults while running the binutils testsuite on hoary/i386.
This is both a regression from 8.4.6-1 and Ubuntu-specific, Debian's 8.4.7-1
doesn't appear to have this problem.

[James Troup (elmo)]

hya

[Matthias Klose (doko)]

unreproducible with current hoary

[James Troup (elmo)]

(In reply to comment #2)
> unreproducible with current hoary

no, it's not.

[James Troup (elmo)]

It takes several runs to reproduce sometimes and gdb isn't very helpful.

(gdb) run ./www/c_interface.tcl >c_interface.html
Starting program: /home/james/scratch/tcl8.4/tcl8.4-8.4.7/unix/tclsh
./www/c_interface.tcl >c_interface.html
[Thread debugging using libthread_db enabled]
[New Thread 1076113536 (LWP 14342)]
[New Thread 1084509104 (LWP 14343)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1076113536 (LWP 14342)]
0x4000c410 in _dl_fini () from /lib/ld-linux.so.2
(gdb) bt
#0 0x4000c410 in _dl_fini () from /lib/ld-linux.so.2
#1 0x4013490f in exit () from /lib/tls/i686/cmov/libc.so.6
#2 0x40069b44 in Tcl_Exit () from /usr/lib/libtcl8.4.so.0
#3 0x4004a3b5 in Tcl_ExitObjCmd () from /usr/lib/libtcl8.4.so.0
#4 0x40044604 in TclEvalObjvInternal () from /usr/lib/libtcl8.4.so.0
#5 0x400451b4 in Tcl_EvalEx () from /usr/lib/libtcl8.4.so.0
#6 0x4004563b in Tcl_Eval () from /usr/lib/libtcl8.4.so.0
#7 0x4008eafe in Tcl_Main () from /usr/lib/libtcl8.4.so.0
#8 0x08048733 in main (argc=134512916, argv=0x8048114) at ../unix/tclAppInit.c:90
(gdb)

[James Troup (elmo)]

Deinstalling libc6-i686 doesn't change anything, but disabling TLS
(LD_ASSUME_KERNEL=2.4.21) seems to 'fix' it.

[James Troup (elmo)]

So:

 o Debian's 8.4.7-1 does also have this problem.
 o 8.4.6-1 (Ubuntu or Debian) doesn't.
 o 8.4.8, recently released upstream, still does.

The problematic change appears to be this:

        * unix/tclUnixNotfy.c (NotifierThreadProc): Accepted Joe
          Mistachkin's patch for [Tcl SF Bug 990500], properly closing the
          notifier thread when its exits.

cf.
http://sourceforge.net/tracker/?group_id=10894&atid=110894&func=detail&aid=990500

If I revert that patch, I can longer reproduce the segfault, even with 10,000
iterations.

[Matthias Klose (doko)]

binutils-2.15-5ubuntu1 built on all architectures.

[James Troup (elmo)]

(In reply to comment #7)
> binutils-2.15-5ubuntu1 built on all architectures.