PaulHowarth/Blog/2010-06-25

Friday 25th June 2010

Fedora Project

Finally got round to debugging a segfault in gtorrentviewer (Bug #542502 and Bug #572806), which turned out to be straightforward as one of the bug reporters took the trouble to provide a reliable reproducer of the bug; in the end it was the simple matter of a GValue being declared as a local variable in a function and not initialized to zero before use, resulting in this stack trace:

[New Thread 23163]
Core was generated by `gtorrentviewer /storage/data/torrents-new/xxxx'.
Program terminated with signal 11, Segmentation fault.
#0  0x000000340cc28f9c in type_check_is_value_type_U (value=0x7fffdbacac80, 
    type=64) at gtype.c:3836
3836    gtype.c: No such file or directory.
        in gtype.c

...

Thread 1 (Thread 23160):
#0  0x000000340cc28f9c in type_check_is_value_type_U (value=0x7fffdbacac80, 
    type=64) at gtype.c:3836
        tflags = G_TYPE_FLAG_VALUE_ABSTRACT
        node = 0x2224010
#1  IA__g_type_check_value_holds (value=0x7fffdbacac80, type=64)
    at gtype.c:3878
No locals.
#2  0x000000340cc31219 in IA__g_value_set_string (value=0x7fffdbacac80, 
    v_string=0x22c4560 "http://tracker.openbittorrent.com/announce")
    at gvaluetypes.c:922
        __val = 0x7fffdbacac80
        __r = <value optimized out>
        _g_boolean_var_ = <value optimized out>
        new_val = 0x22c4560 "http://tracker.openbittorrent.com/announce"
        __PRETTY_FUNCTION__ = "IA__g_value_set_string"
#3  0x0000000000407aa6 in on_RefreshTrackerButton_clicked (
    mwin=<value optimized out>, user_data=<value optimized out>)
    at mainwindow.c:753
        iter = {stamp = -1347712751, user_data = 0x22e5830, user_data2 = 0x0, 
          user_data3 = 0x0}
        itemvalue = {g_type = 35799056, data = {{v_int = 214096389, v_uint = 
    214096389, v_long = 223552395781, v_ulong = 223552395781, v_int64 = 
    223552395781, v_uint64 = 223552395781, v_float = 3.00216485e-31, 
              v_double = 1.1044955880089772e-312, v_pointer = 0x340cc2da05}, {
              v_int = 36582800, v_uint = 36582800, v_long = 36582800, 
              v_ulong = 36582800, v_int64 = 36582800, v_uint64 = 36582800, 
              v_float = 1.27988727e-37, v_double = 1.8074304708681154e-316, 
              v_pointer = 0x22e3590 }
        }}
        err = 0x340cc1894c

The fix was as simple as this:

--- GTorrentViewer-0.2b/src/mainwindow.c.orig   2004-10-26 05:37:58.000000000 +0100
+++ GTorrentViewer-0.2b/src/mainwindow.c        2010-06-25 14:43:22.391786427 +0100
@@ -744,7 +744,7 @@
 {
   GtkListStore *list;
   GtkTreeIter iter;
-  GValue itemvalue;
+  GValue itemvalue = {0};
   gchar *tracker;
   GError *err;

Local Packages

Updated gtorrentviewer as per the Fedora package, fixing a crash when the "Refresh" button on the "Tracker Details" tab was pushed
Rebuilt libspf2 for perl 5.12.1 in Rawhide and added -fno-strict-aliasing compiler option
Updated perl-Number-Compare with patch from CPAN RT#58466 to fix "uninitialized value in comparison" warnings (raised as Bug #607982 in Fedora)
Updated perl-YAML-Tiny to 1.42:
- No functional changes
- Clarified documation regarding treatment of "bool" keywords
- YAML::Perl comparison tests were behaving incorrectly
- Author tests updated and moved into xt/
- Updated the versions of the other YAML parsers for testing
Completed the rebuild of Rawhide packages for perl 5.12.1: bw-whois, grepmail, perl-Array-Compare, perl-Carp-Clan, perl-Class-C3-XS, perl-Class-Factory-Util, perl-Class-Inspector, perl-Class-MOP, perl-Class-Singleton, perl-ConfigReader-Simple, perl-Convert-BinHex, perl-Convert-TNEF, perl-Convert-UUlib, perl-DBD-SQLite, perl-DBI, perl-DBM-Deep, perl-DateTime-Calendar-Mayan, perl-DateTime-Format-Builder, perl-DateTime-Format-MySQL, perl-DateTime-Format-Strptime, perl-DateTime, perl-Declare-Constraints-Simple, perl-Devel-GlobalDestruction, perl-Devel-StackTrace, perl-Devel-Symdump, perl-Digest-BubbleBabble, perl-Email-Address, perl-Error, perl-Expect, perl-ExtUtils-CBuilder, perl-File-Find-Rule-Perl, perl-File-Find-Rule, perl-File-Remove, perl-FileHandle-Fmode, perl-HTML-Lint, perl-HTML-SimpleLinkExtor, perl-HTTP-SimpleLinkChecker, perl-HTTP-Size, perl-Hook-LexWrap, perl-IO-Multiplex, perl-IO-Socket-INET6, perl-IO-Socket-SSL, perl-IO-Tty, perl-IO-stringy, perl-IPC-Run, perl-Jcode, perl-LMAP-CID2SPF, perl-Locale-US, perl-MIME-tools, perl-Mail-IMAPClient, perl-Mail-SPF-Query, perl-Mail-SPF-Test, perl-Mail-SPF, perl-Mail-SRS, perl-Mail-Sender, perl-Mail-Sendmail, perl-MailTools, perl-Module-Pluggable, perl-Module-Refresh, perl-Moose, perl-Net-CIDR-Lite, perl-Net-CIDR, perl-Net-DNS-Resolver-Programmable, perl-Net-DNS, perl-Net-IP, perl-Net-LibIDN, perl-Net-SMTP-SSL, perl-Net-SSLeay, perl-Net-Server, perl-NetAddr-IP, perl-Package-Constants, perl-Package-Stash, perl-Params-Coerce, perl-Params-Validate, perl-Parse-CPAN-Meta, perl-Pod-Escapes, perl-Pod-Simple, perl-Readonly-XS, perl-Readonly, perl-Regexp-Common, perl-SUPER, perl-Scope-Guard, perl-Sendmail-PMilter, perl-Socket6, perl-TimeDate, perl-version, and weblint++