Stephen Berman
2006-Dec-16 07:50 UTC
[Fontconfig] Did fontconfig cause these Emacs segfaults?
I''m currently running SUSE 10.1 and on this system I build CVS Emacs
with GTK support. Emacs was running fine until I installed the SUSE
10.1 rpm of wxGTK, then the next time I started Emacs it immediately
segfaulted (no other GTK application segfaulted). The backtrace
showed it crashing in libfontconfig; this is fontconfig-2.3.94-18.4.
Here are the first 11 frames of the backtrace:
Program received signal SIGSEGV, Segmentation fault.
0xb74b88fa in strcmp () from /lib/libc.so.6
(gdb) bt
#0 0xb74b88fa in strcmp () from /lib/libc.so.6
#1 0xb79c1b45 in FcObjectToPtr () from /usr/lib/libfontconfig.so.1
#2 0xb79c5741 in FcPatternAddWithBinding () from /usr/lib/libfontconfig.so.1
#3 0xb79c5df8 in FcPatternAdd () from /usr/lib/libfontconfig.so.1
#4 0xb79c5e84 in FcPatternBuild () from /usr/lib/libfontconfig.so.1
#5 0xb74150b8 in pango_fc_font_map_get_type ()
from /opt/gnome/lib/libpangoft2-1.0.so.0
#6 0xb7af0830 in pango_font_map_load_fontset ()
from /opt/gnome/lib/libpango-1.0.so.0
#7 0xb7aee84a in pango_context_get_font_description ()
from /opt/gnome/lib/libpango-1.0.so.0
#8 0xb7aeeb92 in pango_itemize_with_base_dir ()
from /opt/gnome/lib/libpango-1.0.so.0
#9 0xb7af6b0b in pango_layout_iter_get_char_extents ()
from /opt/gnome/lib/libpango-1.0.so.0
#10 0xb7af76dc in pango_layout_iter_get_char_extents ()
from /opt/gnome/lib/libpango-1.0.so.0
#11 0xb7cefedd in gtk_label_new () from /opt/gnome/lib/libgtk-x11-2.0.so.0
I had exchanges about this with the Emacs-GTK developer and with
wxwidget developers, and also posted to the openSUSE mailing list, but
didn''t get a solution.
Since the installed libfontconfig.so was stripped, I installed the
source rpm from SUSE 10.1, and compiled it with debugging enabled. In
the mean time I removed wxGTK and rebuilt the fontconfig cache several
times, and Emacs didn''t segfault every time any more. The last time
it sefaulted I got the following backtrace (first 15 frames):
Program received signal SIGSEGV, Segmentation fault.
0xb79c3e24 in FcPatternPosition (p=0xb68f9004, object=<value optimized
out>)
at fcint.h:828
828 return a - b;
(gdb) bt full
#0 0xb79c3e24 in FcPatternPosition (p=0xb68f9004,
object=<value optimized out>) at fcint.h:828
low = 0
high = 17
mid = 8
c = <value optimized out>
obj = 21
#1 0xb79c3e87 in FcPatternFindElt (p=0xb68f9004, object=0xb79d7491
"file")
at fcpat.c:725
i = -1219047104
#2 0xb79c5536 in FcPatternGet (p=0xb68f9004, object=0xb79d7491
"file", id=0,
v=0xbffe1330) at fcpat.c:1107
e = <value optimized out>
l = <value optimized out>
#3 0xb79c58ba in FcPatternGetString (p=0xb68f9004, object=0xb79d7491
"file",
id=0, s=0xbffe1398) at fcpat.c:1172
v = {
type = 140255896,
u = {
s = 0x85e92a8 "/usr/X11R6/lib/X11/fonts/misc/cu12.pcf.gz",
s_off = 140415656,
i = 140415656,
b = 140415656,
d = -1.8797073676043201,
m = 0x85e92a8,
c = 0x85e92a8,
c_off = 140415656,
f = 0x85e92a8,
p = 0x85e92a8,
l = 0x85e92a8,
l_off = 140415656
}
}
r = <value optimized out>
#4 0xb79b35da in FcConfigBuildFonts (config=0x85c2298) at fccfg.c:314
cfn = (FcChar8 *) 0x85e92a8
"/usr/X11R6/lib/X11/fonts/misc/cu12.pcf.gz"
fonts = (FcFontSet *) 0x85c5f38
cached_fonts = (FcFontSet *) 0x85cd988
cache = (FcGlobalCache *) 0x85c5ee0
list = <value optimized out>
oldDirs = (FcStrSet *) 0x85c7e30
dir = <value optimized out>
#5 0xb79bbf7f in FcInitLoadConfigAndFonts () at fcinit.c:85
config = (FcConfig *) 0x85c2298
#6 0xb79bc085 in FcInit () at fcinit.c:103
config = <value optimized out>
#7 0xb6a94d0b in XftInit () from /usr/X11R6/lib/libXft.so.2
No symbol table info available.
#8 0xb6d5a39a in qt_init_internal () from /usr/lib/qt3/lib/libqt-mt.so.3
No symbol table info available.
#9 0xb6d5b08b in qt_init () from /usr/lib/qt3/lib/libqt-mt.so.3
No symbol table info available.
#10 0xb6dc1ee3 in QApplication::QApplication ()
from /usr/lib/qt3/lib/libqt-mt.so.3
No symbol table info available.
#11 0xb72d2155 in createQApp ()
from /opt/gnome/lib/gtk-2.0/2.4.0/engines/libqtengine.so
No symbol table info available.
#12 0xb72c4e3f in theme_init ()
from /opt/gnome/lib/gtk-2.0/2.4.0/engines/libqtengine.so
No symbol table info available.
#13 0xb7da0a66 in gtk_theme_engine_get ()
from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#14 0xb7a7aeb8 in g_type_module_use () from /opt/gnome/lib/libgobject-2.0.so.0
No symbol table info available.
#15 0xb7da0899 in gtk_theme_engine_get ()
from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
The Emacs-GTK developer didn''t know why this segfault happened but
suggested that /usr/X11R6/lib/X11/fonts/misc/cu12.pcf.gz might be
broken and also speculated that the reason only Emacs among GTK apps
segfaulted was that Emacs lacks antialiasing fonts.
If anyone here has any insight from these backtraces, I would be
interested to hear it, even though Emacs hasn''t segfaulted for several
days now. I will soon be upgrading to SUSE 10.2, so that may take
care of this problem, but I wanted to make a last effort to find out
why it happened.
Thanks,
Steve Berman
Keith Packard
2006-Dec-16 12:33 UTC
[Fontconfig] Did fontconfig cause these Emacs segfaults?
On Fri, 2006-12-15 at 15:25 +0100, Stephen Berman wrote:> I''m currently running SUSE 10.1 and on this system I build CVS Emacs > with GTK support. Emacs was running fine until I installed the SUSE > 10.1 rpm of wxGTK, then the next time I started Emacs it immediately > segfaulted (no other GTK application segfaulted). The backtrace > showed it crashing in libfontconfig; this is fontconfig-2.3.94-18.4.Version 2.3.94 was never a released version of fontconfig; the .94 suffix indicates that it was the fourth release candidate for version 2.4. As to why SUSE decided to ship an unreleased version of fontconfig, I really cannot say. -- keith.packard@intel.com -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part Url : http://lists.freedesktop.org/archives/fontconfig/attachments/20061216/2989ce5f/attachment.pgp