Segmentation Fault GTK+ application [duplicate] - c

Question

This question already has answers here:
Why do I get a segmentation fault in my GTK+ signal callback?
(2 answers)
Closed 5 years ago.
I'm making a GTK 3+ application using Glade.
Here is my structure in C :
# include <gtk/gtk.h>
# include <stdio.h>
# include <stdlib.h>
typedef struct s_gtk
{
GtkBuilder *interface;
GtkWidget *MainWindow;
GtkWidget *AddObject;
GtkWidget *DeleteObject;
GtkWidget *Launch;
GError *error;
gchar *filename;
} t_gtk;
My function for intializing gtk->AddObject, it is called in the main :
if ((gtk->interface = gtk_builder_new()) == NULL ||
(gtk->filename = g_build_filename("interface.glade", NULL)) == NULL)
{
g_error("%s", gtk->error->message);
g_error_free(gtk->error);
return (gtk->error->code);
}
gtk_builder_add_from_file(gtk->interface, gtk->filename, &gtk->error);
g_free(gtk->filename);
if (gtk->error)
{
g_printerr("%s\n", gtk->error->message);
g_error_free(gtk->error);
return (gtk->error->code);
}
gtk->MainWindow = GTK_WIDGET(gtk_builder_get_object
(gtk->interface, "MainWindow"));
gtk->AddObject = GTK_WIDGET(gtk_builder_get_object
(gtk->interface, "AddDialog"));
gtk_builder_connect_signals(gtk->interface, gtk);
return (0);
My handler for AddObject:
void on_AddObject_clicked(gpointer user_data)
{
t_gtk *gtk;
gint response;
gtk = (t_gtk *)user_data;
printf("I'm here\n");
response = gtk_dialog_run(GTK_DIALOG(gtk->AddObject));
printf("I'm here2\n");
if (response == 1)
{
printf("Add pressed!\n");
}
else
{
printf("Cancel pressed!\n");
}
gtk_widget_hide(gtk->AddObject);
}
And I get a Segfault here but I don't know why...:
response = gtk_dialog_run(GTK_DIALOG(gtk->AddObject));
Valgrind says it:
Invalid read of size 8
==7272== at 0x6B16620: g_type_check_instance_cast (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x401063: on_AddObject_clicked (in /home/vives_j/Documents/Epitech/Tests/main)
==7272== by 0x6AF3473: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D086: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D9DE: g_signal_emit (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x4F3CA1C: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0x4F3CA74: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0x6AF3473: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D086: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D9DE: g_signal_emit (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x4F3A9FF: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0xB795DBF: ffi_call_unix64 (in /usr/lib/x86_64-linux-gnu/libffi.so.6.0.2)
==7272== Address 0x400000003 is not stack'd, malloc'd or (recently) free'd
==7272==
==7272==
==7272== Process terminating with default action of signal 11 (SIGSEGV)
==7272== Access not within mapped region at address 0x400000003
==7272== at 0x6B16620: g_type_check_instance_cast (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x401063: on_AddObject_clicked (in /home/vives_j/Documents/Epitech/Tests/main)
==7272== by 0x6AF3473: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D086: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D9DE: g_signal_emit (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x4F3CA1C: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0x4F3CA74: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0x6AF3473: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D086: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x6B0D9DE: g_signal_emit (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.1)
==7272== by 0x4F3A9FF: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-3.so.0.1400.5)
==7272== by 0xB795DBF: ffi_call_unix64 (in /usr/lib/x86_64-linux-gnu/libffi.so.6.0.2)
==7272== If you believe this happened as a result of a stack
==7272== overflow in your program's main thread (unlikely but
==7272== possible), you can try to increase the size of the
==7272== main thread stack using the --main-stacksize= flag.
==7272== The main thread stack size used in this run was 8388608.
And I compile as (From make command):
gcc -Wextra -Wall -ansi -pedantic -I. -O3 -D REENTRANT -rdynamic -DGTK_DISABLE_DEPRECATED=1 -DGDK_DISABLE_DEPRECATED -DGDK_PIXBUF_DISABLE_DEPRECATED -DG_DISABLE_DEPRECATED -DGTK_MULTIHEAD_SAFE=1 -DGTK_MULTIDEVICE_SAFE=1 `pkg-config gmodule-export-2.0 --libs` `pkg-config gtk+-3.0 --cflags` -c -o main.o main.c
gcc main.o -o main `pkg-config gtk+-3.0 --libs` `pkg-config gmodule-export-2.0 --libs`
GDB results :
GNU gdb (Debian 7.7.1+dfsg-5) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.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 copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./main...done.
(gdb)
(gdb) run
Starting program: /home/vives_j/Documents/Epitech/Tests/main
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
(process:3752): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
[New Thread 0x7fffee33c700 (LWP 3756)]
[New Thread 0x7fffedb3b700 (LWP 3757)]
[New Thread 0x7fffecfe7700 (LWP 3759)]
I'm here
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff5f0f620 in g_type_check_instance_cast ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
(gdb) backtrac
#0 0x00007ffff5f0f620 in g_type_check_instance_cast ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#1 0x0000000000401034 in on_AddObject_clicked (user_data=0x8d0350)
at main.c:57
#2 0x00007ffff5eec474 in ?? ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#3 0x00007ffff5f06087 in g_signal_emit_valist ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#4 0x00007ffff5f069df in g_signal_emit ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#5 0x00007ffff762ca1d in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#6 0x00007ffff762ca75 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#7 0x00007ffff5eec474 in ?? ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#8 0x00007ffff5f06087 in g_signal_emit_valist ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#9 0x00007ffff5f069df in g_signal_emit ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007ffff762aa00 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#11 0x00007ffff127edc0 in ffi_call_unix64 ()
from /usr/lib/x86_64-linux-gnu/libffi.so.6
#12 0x00007ffff127e828 in ffi_call ()
from /usr/lib/x86_64-linux-gnu/libffi.so.6
---Type <return> to continue, or q <return> to quit---
#13 0x00007ffff5eecebc in g_cclosure_marshal_generic_va ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007ffff5eec474 in ?? ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x00007ffff5f06087 in g_signal_emit_valist ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#16 0x00007ffff5f069df in g_signal_emit ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#17 0x00007ffff76cf191 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00007ffff5eef233 in g_cclosure_marshal_VOID__BOXEDv ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#19 0x00007ffff5eec474 in ?? ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007ffff5f06087 in g_signal_emit_valist ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x00007ffff5f069df in g_signal_emit ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#22 0x00007ffff76cc94e in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#23 0x00007ffff76cdd9b in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#24 0x00007ffff76d05e0 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#25 0x00007ffff76a3e7b in gtk_event_controller_handle_event ()
from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#26 0x00007ffff783f41d in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
---Type <return> to continue, or q <return> to quit---
#27 0x00007ffff771241e in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#28 0x00007ffff5eec474 in ?? ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#29 0x00007ffff5f05b30 in g_signal_emit_valist ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#30 0x00007ffff5f069df in g_signal_emit ()
from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#31 0x00007ffff7842de4 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#32 0x00007ffff770fd2e in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#33 0x00007ffff771193e in gtk_main_do_event ()
from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#34 0x00007ffff72b8b12 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#35 0x00007ffff5c16c5d in g_main_context_dispatch ()
from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#36 0x00007ffff5c16f48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#37 0x00007ffff5c17272 in g_main_loop_run ()
from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#38 0x00007ffff7710bf5 in gtk_main ()
from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#39 0x0000000000401275 in main (ac=1, av=0x7fffffffdcf8) at main.c:115
(gdb) quit
The line 57 is the line I posted previously where it crashed.
Glade file :
http://pastebin.com/JrHza6iW
I think I have a clue. Because, when I took this example code from a tutorial :
http://pastebin.com/WpJ6kWQB
and compiled it with (and their builder file):
gcc -o dialog1 dialog1.c $(pkg-config --cflags --libs gtk+-2.0 \
* gmodule-export-2.0)
It works, but if I change gtk+-2.0 by 3.0, it crashes at the same thing.
Thank you in advance !!

Answer 1

I found the problem.
In my handler function, we need to pass in parameter the type of the widget we clicked. Here, it's a GtkButton, so I added it in my parameters that I receive :
void on_AddObject_clicked(GtkButton *button, gpointer user_data)
{
t_gtk *gtk;
gint response;
gtk = (t_gtk *)user_data;
(void) button;
printf("I'm here\n");
response = gtk_dialog_run(GTK_DIALOG(gtk->AddObject));
printf("I'm here2\n");
if (response == 1)
{
printf("Add pressed!\n");
}
else
{
printf("Cancel pressed!\n");
}
gtk_widget_hide(gtk->AddObject);
}
I think GTK needs it in background. So it's resolved.
Thank you anyway for your help ! :)

Answer 2

Valgrind won't help you much here. Delete the .o and executable, recompile adding -g and -O0 to the compile commands.
Then run gdb, and, when the segmentation fault occurs, do a backtrace. You should be able to follow that to where the problem is. (post the backtrace here)
Did you see any message during the run? Even warnings?