forwarded 358518 http://rt.perl.org/rt3/Ticket/Display.html?id=61912 thanks
I have managed to isolate a test-case for this and submitted it upstream. The report I submitted upstream is as follows: ----------------------------------------------------------------- This bug report is based on a report submitted to the Debian Bug Tracking System by Eduard Bloch - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=358518 The SDBM_File module doesn't seem to be thread-safe. If a file is tied before a thread is created, the pointer to the DBM object is shared between threads. Each thread then attempts to free it, causing a crash. The following script reproduces the problem for me: ================================== #!/usr/bin/perl use strict; use Fcntl; use SDBM_File; use threads; use threads::shared; my %dbtest; tie(%dbtest, 'SDBM_File', "test.db", O_RDWR|O_CREAT, 0666); for (1 .. 2) { my $thr = threads->new(\&testThread, $_); $thr->detach(); } sleep 4; sub testThread { my $n = shift; print "thread #" . $n . " started\n"; } ================================== Running it using debugperl/gdb: ================================== Starting program: /usr/bin/debugperl sdbm_test.pl [Thread debugging using libthread_db enabled] [New Thread 0xb7d868c0 (LWP 17290)] [New Thread 0xb7c2eb90 (LWP 17295)] [New Thread 0xb742db90 (LWP 17308)] [Thread 0xb742db90 (LWP 17308) exited] [New Thread 0xb742db90 (LWP 17313)] *** glibc detected *** /usr/bin/debugperl: double free or corruption (!prev): 0x08a5b4e8 *** ======= Backtrace: ========= /lib/i686/cmov/libc.so.6[0xb7e276b4] /lib/i686/cmov/libc.so.6(cfree+0x96)[0xb7e298b6] /usr/lib/perl/5.10/auto/SDBM_File/SDBM_File.so(sdbm_close+0x3b)[0xb7c3f79b] /usr/lib/perl/5.10/auto/SDBM_File/SDBM_File.so(XS_SDBM_File_DESTROY+0xcf)[0xb7c3e5df] /usr/bin/debugperl(Perl_pp_entersub+0xae1)[0x80e0bd1] /usr/bin/debugperl(Perl_call_sv+0x720)[0x80d5c50] /usr/bin/debugperl(Perl_sv_clear+0x1d4)[0x81065d4] /usr/bin/debugperl(Perl_sv_free2+0x69)[0x8107289] /usr/bin/debugperl[0x80eefc1] /usr/bin/debugperl(Perl_sv_clean_objs+0x29)[0x80ef039] /usr/bin/debugperl(perl_destruct+0x3f0)[0x80dadf0] /usr/lib/perl/5.10/auto/threads/threads.so[0xb7f651ab] /usr/lib/perl/5.10/auto/threads/threads.so[0xb7f653ab] /usr/lib/perl/5.10/auto/threads/threads.so[0xb7f68c0b] /lib/i686/cmov/libpthread.so.0[0xb7f1a4c0] /lib/i686/cmov/libc.so.6(clone+0x5e)[0xb7e9961e] ======= Memory map: ======== 08048000-0828a000 r-xp 00000000 fe:01 527887 /usr/bin/debugperl 0828a000-0828c000 rw-p 00242000 fe:01 527887 /usr/bin/debugperl 086d8000-08f33000 rw-p 086d8000 00:00 0 [heap] b6b00000-b6b21000 rw-p b6b00000 00:00 0 b6b21000-b6c00000 ---p b6b21000 00:00 0 b6c0d000-b6c19000 r-xp 00000000 fe:01 762863 /lib/libgcc_s.so.1 b6c19000-b6c1a000 rw-p 0000b000 fe:01 762863 /lib/libgcc_s.so.1 b6c2d000-b6c2e000 ---p b6c2d000 00:00 0 b6c2e000-b742e000 rw-p b6c2e000 00:00 0 b742e000-b742f000 ---p b742e000 00:00 0 b742f000-b7c2f000 rw-p b742f000 00:00 0 b7c2f000-b7c33000 r-xp 00000000 fe:01 557739 /usr/lib/perl/5.10.0/auto/Socket/Socket.so b7c33000-b7c34000 rw-p 00004000 fe:01 557739 /usr/lib/perl/5.10.0/auto/Socket/Socket.so b7c34000-b7c38000 r-xp 00000000 fe:01 557729 /usr/lib/perl/5.10.0/auto/IO/IO.so b7c38000-b7c39000 rw-p 00003000 fe:01 557729 /usr/lib/perl/5.10.0/auto/IO/IO.so b7c39000-b7c41000 r-xp 00000000 fe:01 17403 /usr/lib/perl/5.10.0/auto/SDBM_File/SDBM_File.so b7c41000-b7c42000 rw-p 00007000 fe:01 17403 /usr/lib/perl/5.10.0/auto/SDBM_File/SDBM_File.so b7c42000-b7c4b000 r-xp 00000000 fe:01 607618 /usr/lib/perl/5.10.0/auto/threads/shared/shared.so b7c4b000-b7c4c000 rw-p 00009000 fe:01 607618 /usr/lib/perl/5.10.0/auto/threads/shared/shared.so b7c4c000-b7d86000 r--p 00000000 fe:01 551711 /usr/lib/locale/locale-archive b7d86000-b7d87000 rw-p b7d86000 00:00 0 b7d87000-b7d90000 r-xp 00000000 fe:01 762957 /lib/i686/cmov/libcrypt-2.7.so b7d90000-b7d92000 rw-p 00008000 fe:01 762957 /lib/i686/cmov/libcrypt-2.7.so b7d92000-b7db9000 rw-p b7d92000 00:00 0 b7db9000-b7f0e000 r-xp 00000000 fe:01 762955 /lib/i686/cmov/libc-2.7.so b7f0e000-b7f0f000 r--p 00155000 fe:01 762955 /lib/i686/cmov/libc-2.7.so b7f0f000-b7f11000 rw-p 00156000 fe:01 762955 /lib/i686/cmov/libc-2.7.so b7f11000-b7f14000 rw-p b7f11000 00:00 0 b7f14000-b7f29000 r-xp 00000000 fe:01 763043 /lib/i686/cmov/libpthread-2.7.so b7f29000-b7f2b000 rw-p 00014000 fe:01 763043 /lib/i686/cmov/libpthread-2.7.so b7f2b000-b7f2e000 rw-p b7f2b000 00:00 0 b7f2e000-b7f52000 r-xp 00000000 fe:01 763006 /lib/i686/cmov/libm-2.7.so b7f52000-b7f54000 rw-p 00023000 fe:01 763006 /lib/i686/cmov/libm-2.7.so b7f54000-b7f56000 r-xp 00000000 fe:01 762998 /lib/i686/cmov/libdl-2.7.so b7f56000-b7f58000 rw-p 00001000 fe:01 762998 /lib/i686/cmov/libdl-2.7.so b7f58000-b7f5b000 r-xp 00000000 fe:01 557730 /usr/lib/perl/5.10.0/auto/Cwd/Cwd.so b7f5b000-b7f5c000 rw-p 00002000 fe:01 557730 /usr/lib/perl/5.10.0/auto/Cwd/Cwd.so b7f5c000-b7f5f000 r-xp 00000000 fe:01 557734 /usr/lib/perl/5.10.0/auto/Fcntl/Fcntl.so b7f5f000-b7f60000 rw-p 00002000 fe:01 557734 /usr/lib/perl/5.10.0/auto/Fcntl/Fcntl.so b7f60000-b7f6a000 r-xp 00000000 fe:01 607619 /usr/lib/perl/5.10.0/auto/threads/threads.so b7f6a000-b7f6b000 rw-p 00009000 fe:01 607619 /usr/lib/perl/5.10.0/auto/threads/threads.so b7f6b000-b7f6d000 rw-p b7f6b000 00:00 0 b7f6d000-b7f6e000 r-xp b7f6d000 00:00 0 [vdso] b7f6e000-b7f88000 r-xp 00000000 fe:01 763488 /lib/ld-2.7.so b7f88000-b7f8a000 rw-p 0001a000 fe:01 763488 /lib/ld-2.7.so bf974000-bf989000 rw-p bffeb000 00:00 0 [stack] Program received signal SIGABRT, Aborted. [Switching to Thread 0xb742db90 (LWP 17313)] 0xb7f6d424 in __kernel_vsyscall () (gdb) bt #0 0xb7f6d424 in __kernel_vsyscall () #1 0xb7de4640 in raise () from /lib/i686/cmov/libc.so.6 #2 0xb7de6018 in abort () from /lib/i686/cmov/libc.so.6 #3 0xb7e213dd in ?? () from /lib/i686/cmov/libc.so.6 #4 0x00000006 in ?? () #5 0xb742c914 in ?? () #6 0x00000400 in ?? () #7 0xb7ef75c8 in ?? () from /lib/i686/cmov/libc.so.6 #8 0x00000017 in ?? () #9 0xbf9887bd in ?? () #10 0x00000012 in ?? () #11 0xb7ef75e1 in ?? () from /lib/i686/cmov/libc.so.6 #12 0x00000002 in ?? () #13 0xb7ef76c0 in ?? () from /lib/i686/cmov/libc.so.6 #14 0x00000021 in ?? () #15 0xb7ef75e5 in ?? () from /lib/i686/cmov/libc.so.6 #16 0x00000004 in ?? () #17 0xb742ce43 in ?? () #18 0x00000008 in ?? () #19 0xb7ef75eb in ?? () from /lib/i686/cmov/libc.so.6 #20 0x00000005 in ?? () #21 0x08cc6dd8 in ?? () #22 0x00000000 in ?? () ================================== If I set a breakpoint in sdbm_close, I can see that it is called twice from different threads with the same DB pointer. -- Chris Butler <[email protected]> GnuPG Key ID: 1024D/D097A261 -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
