Created attachment 403623 [details] GDB backtrace Description: When trying to print certain pointers in a Qt/C++ application, gdb hangs indefinitely with 100% CPU usage. strace shows an infinite loop of the same lseek call. A backtrace of gdb attached to the stuck gdb is attached. Version: GNU gdb (GDB) Fedora (7.0.1-36.fc12) x86_64 How reproducible: Every time. Steps to Reproduce: 1. Run gdb on our large Qt/C++ application 2. Try and print a QString Actual results: Infinite loop of "lseek(11, 20354560, SEEK_SET) = 20354560" in strace, 100% cpu usage. Expected results: Printing of QString variable. Additional info: Arails bug #3485 Also saw this while attaching gdb to the stuck gdb process. Relevant? Is there a way to disable "itertoolsmodule"? Reading symbols from /usr/lib64/python2.6/lib-dynload/itertoolsmodule.so...Reading symbols from /usr/lib/debug/usr/lib64/python2.6/lib-dynload/itertoolsmodule.so.debug...done. done. Loaded symbols for /usr/lib64/python2.6/lib-dynload/itertoolsmodule.so lookup_partial_symbol (pst=0x222b2d0, name=0x7fffe4533ef0 "oaCommon::srcName", global=1, domain=VAR_DOMAIN) at ../../gdb/symtab.c:1735 1735 if (length == 0)
I just found that with LD_BIND_NOW=1 set, gdb works as expected.
Tried to attach to twinkle and printed various QString's but I do not see a problem. (gdb) frame #1 0x0000003d3033c931 in QKeySequence::decodeString (str=...) at kernel/qkeysequence.cpp:441 441 } else if ( accel[0] == 'F' && (fnum = accel.mid(1).toInt()) && (fnum >= 1) && (fnum <= 35) ) { (gdb) p accel $12 = {static null = {static null = <same as static member of an already seen type>, d = 0x0, static shared_null = 0x0}, d = 0xd5fe10, static shared_null = 0x0} (gdb) p &accel $13 = (QString *) 0x7fffffffa1d0 But found one C++ namespaces performance backport has been forgotten so hopefully it gets fixed by it.
gdb-7.0.1-38.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/gdb-7.0.1-38.fc12
patch 38 and above seem to be working. Thanks!
gdb-7.0.1-49.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/gdb-7.0.1-49.fc12