Re^3: 32 Bit Perl causing segmentation fault if data is big

-$ echo $? 139

139 - 128 = 11, which is SIGSEGV on my system (kill -l will identify). So we know it really was a segfault.

i am not aware of debugging perl core using GDB

Same way as any other program.

$ gdb --args perl -e'dump'
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gp
+l.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copy
+ing"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu"...
(no debugging symbols found)
(gdb) run
Starting program: /usr/bin/perl -edump
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
(no debugging symbols found)
(no debugging symbols found)
[New Thread 0xb7cfd8c0 (LWP 7206)]

Program received signal SIGABRT, Aborted.
[Switching to Thread 0xb7cfd8c0 (LWP 7206)]
0xb7eea424 in __kernel_vsyscall ()
(gdb) bt
#0  0xb7eea424 in __kernel_vsyscall ()
#1  0xb7d5b956 in kill () from /lib/i686/cmov/libc.so.6
#2  0x080a9e3b in Perl_my_unexec ()
#3  0x080ec065 in Perl_pp_goto ()
#4  0x080b1879 in Perl_runops_standard ()
#5  0x080ac6a0 in perl_run ()
#6  0x08063ddd in main ()
(gdb) q
The program is running.  Exit anyway? (y or n) y
[download]

not yet. but installing a new version in professional env is very difficult as i need to get sign off from lot of people.

You don't need to replace the system Perl. You can install it in a temporary directory somewhere.

Unzip Perl in a clean directory and run the following:

sh Configure -des -Doptimize="-g" -Dprefix=$HOME/tmp_perl
make
make test
make install
[download]

-Doptimize="-g" makes it a debug build, which isn't good for production, but good for finding problems inside of Perl itself.

-$ perl -v This is perl, v5.8.0 built for aix

Hum, I hear that 5.8.0 was a pretty bad version. 5.8.1 was better, and so much has been fixed since then.

#!/usr/local/perl-5.6.1/bin/perl

Wait, no, you're not using 5.8.0, you're using something even older!

And the 64-bit version appears to use 5.8.2. That could explain the difference. Or maybe not.

Comment on Re^3: 32 Bit Perl causing segmentation fault if data is big Select or Download Code

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Re^4: 32 Bit Perl causing segmentation fault if data is big by peacelover1976 (Initiate) on Mar 19, 2010 at 00:00 UTC
Thanks for the info. I tried GDB and please find the result below: $ gdb --args perl -e'dump' GNU gdb 6.6 Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and y +ou are welcome to change it and/or distribute copies of it under certain cond +itions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for det +ails. This GDB was configured as "powerpc-ibm-aix5.3.0.0"... (no debugging symbols found) (gdb) run Starting program: /usr/opt/perl5/bin/perl -edump Program received signal SIGABRT, Aborted. 0xd379c2cc in Perl_my_unexec () from /usr/opt/perl5/lib/5.8.2/aix-thre +ad-multi/CORE/libperl.a(libperl.o) (gdb) bt #0 0xd379c2cc in Perl_my_unexec () from /usr/opt/perl5/lib/5.8.2/aix- +thread-multi/CORE/libperl.a(libperl.o) #1 0xd3810294 in Perl_pp_goto () from /usr/opt/perl5/lib/5.8.2/aix-th +read-multi/CORE/libperl.a(libperl.o) #2 0xd3885ad8 in Perl_runops_standard () from /usr/opt/perl5/lib/5.8. +2/aix-thread-multi/CORE/libperl.a(libperl.o) #3 0xd3797b18 in S_run_body () from /usr/opt/perl5/lib/5.8.2/aix-thre +ad-multi/CORE/libperl.a(libperl.o) #4 0xd379efbc in perl_run () from /usr/opt/perl5/lib/5.8.2/aix-thread +-multi/CORE/libperl.a(libperl.o) #5 0x10000478 in main () (gdb) [download] i have no clue on the perl info from GDB (have used zillion times for C, C++ programs). Please help me on this. Thanks, Peacelover1976	[reply] [d/l]
Re^5: 32 Bit Perl causing segmentation fault if data is big by ikegami (Patriarch) on Mar 19, 2010 at 00:22 UTC
That was an example. You should run your own program under gdb, not my demo :) But forget that. Try your script with a newer version of Perl first. I intend to not hunt for a bug that's already been fixed. I ran your demo using Perl 5.10.0 on linux and I didn't have any problems.	[reply]