我一直在开发一个名为RoboJournal的程序已有一段时间了。有人最近给我发了一个错误报告，解释了在启用拼写检查功能的同时显示编辑器窗口表单时整个程序是如何崩溃的。但是，在程序设置中禁用拼写检查时，一切正常。这个bug似乎只影响Qt（4.8.3）的特定版本，因为我已经在4.7.4和4.8.4上测试了应用程序，一切正常。我之前从未注意到这个错误，因为我没有在4.8.3上开发应用程序。这个错误是我还没有为Debian打包应用程序的主要原因;我计划在下一个版本中包含该修复程序。
每当遇到崩溃的bug时，我通常会通过调试器（gdb）运行代码，设置断点，并逐行检查，直到找到问题为止。但是，这次我不能这样做，因为这个bug只会影响发布版本;我尝试针对Qt 4.8.3调试库构建应用程序，但令我惊讶的是一切正常！显然，崩溃与Qt特定版本上的发布库有关，但我不知道它是什么。当遇到问题的唯一方法是发布版本时，如何正确调试应用程序？当我通过gdb运行它时，我尝试在发布版本上设置断点，但这不起作用。
幸运的是，这个错误似乎已经在Qt 4.8.4中得到修复（而且更新，但我还没有在Qt 5上测试过这个），但我还是要找出那些使用4.8的人的解决方法。 3。 （我不能指望用户推出他们自己的Qt，我不知道什么时候Debian人会用新版本更新他们的回购）任何想法？
这是崩溃的gdb输出。据我所知，这个bug与libc.so.6有关：
buffer overflow detected ***: /usr/local/bin/robojournal terminated
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x5c)[0x7ffff44fb82c]
/lib/x86_64-linux-gnu/libc.so.6(+0x109700)[0x7ffff44fa700]
/usr/local/bin/robojournal[0x49982f]
/usr/local/bin/robojournal[0x49a374]
/usr/local/bin/robojournal[0x49b192]
/usr/local/bin/robojournal[0x49b6da]
/usr/local/bin/robojournal[0x4a947d]
/usr/local/bin/robojournal[0x432e17]
/usr/local/bin/robojournal[0x43529f]
/usr/local/bin/robojournal[0x421afb]
/usr/local/bin/robojournal[0x4ace7b]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN11QMetaObject8activateEP7QObjectPKS_iPPv+0x483)[0x7ffff5075123]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN15QAbstractButton7clickedEb+0x32)[0x7ffff5bee422]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x589d2e)[0x7ffff5941d2e]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x58a560)[0x7ffff5942560]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN15QAbstractButton17mouseReleaseEventEP11QMouseEvent+0x8c)[0x7ffff59427cc]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN11QToolButton17mouseReleaseEventEP11QMouseEvent+0xa)[0x7ffff59fc99a]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN7QWidget5eventEP6QEvent+0x7e0)[0x7ffff55d3850]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent+0xac)[0x7ffff5583e9c]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN12QApplication6notifyEP7QObjectP6QEvent+0x99b)[0x7ffff5588b6b]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN16QCoreApplication14notifyInternalEP7QObjectP6QEvent+0x8e)[0x7ffff505f56e]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN19QApplicationPrivate14sendMouseEventEP7QWidgetP11QMouseEventS1_S1_PS1_R8QPointerIS0_Eb+0x143)[0x7ffff5584cd3]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x24a554)[0x7ffff5602554]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(_ZN12QApplication15x11ProcessEventEP7_XEvent+0xd6f)[0x7ffff560144f]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x270fa2)[0x7ffff5628fa2]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x135)[0x7ffff296cab5]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x47de8)[0x7ffff296cde8]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_iteration+0x34)[0x7ffff296cea4]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x66)[0x7ffff508dbf6]
/usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x270c1e)[0x7ffff5628c1e]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN10QEventLoop13processEventsE6QFlagsINS_17ProcessEventsFlagEE+0x2f)[0x7ffff505e2bf]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0x138)[0x7ffff505e548]
/usr/lib/x86_64-linux-gnu/libQtCore.so.4(_ZN16QCoreApplication4execEv+0x88)[0x7ffff5063708]
/usr/local/bin/robojournal[0x412f34]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7ffff441276d]
/usr/local/bin/robojournal[0x413cc1]
======= Memory map: ========
00400000-005b0000 r-xp 00000000 08:01 48248 /usr/local/bin/robojournal
007af000-007b0000 r--p 001af000 08:01 48248 /usr/local/bin/robojournal
007b0000-007b5000 rw-p 001b0000 08:01 48248 /usr/local/bin/robojournal
007b5000-00eb3000 rw-p 00000000 00:00 0 [heap]
7fffdc000000-7fffdc021000 rw-p 00000000 00:00 0
7fffdc021000-7fffe0000000 ---p 00000000 00:00 0
7fffe16a0000-7fffe16a1000 ---p 00000000 00:00 0
7fffe16a1000-7fffe1ea1000 rw-p 00000000 00:00 0
7fffe1ea1000-7fffe215d000 r-xp 00000000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe215d000-7fffe235c000 ---p 002bc000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe235c000-7fffe2362000 r--p 002bb000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe2362000-7fffe23e0000 rw-p 002c1000 08:01 130 /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18.0.0
7fffe23e0000-7fffe23e5000 rw-p 00000000 00:00 0
7fffe23e5000-7fffe23f5000 r-xp 00000000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe23f5000-7fffe25f5000 ---p 00010000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe25f5000-7fffe25f6000 r--p 00010000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe25f6000-7fffe25f7000 rw-p 00011000 08:01 4894 /usr/lib/x86_64-linux-gnu/qt4/plugins/sqldrivers/libqsqlmysql.so
7fffe2648000-7fffe264c000 r-xp 00000000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe264c000-7fffe284c000 ---p 00004000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284c000-7fffe284d000 r--p 00004000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284d000-7fffe284e000 rw-p 00005000 08:01 10234 /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so
7fffe284e000-7fffe286a000 r--s 00000000 08:01 40509 /usr/share/mime/mime.cache
7fffe286b000-7fffe28cb000 rw-s 00000000 00:04 4620315 /SYSV00000000 (deleted)
7fffe28cb000-7fffe2afe000 rw-s 00000000 00:04 4587546 /SYSV00000000 (deleted)
7fffe2afe000-7fffe2ba3000 r--p 00000000 08:01 277820 /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Bold.ttf
7fffe2ba3000-7fffe2bae000 r-xp 00000000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2bae000-7fffe2dad000 ---p 0000b000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2dad000-7fffe2dae000 r--p 0000a000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2dae000-7fffe2db1000 rw-p 0000b000 08:01 9203 /usr/lib/x86_64-linux-gnu/libjbig.so.0.0.0
7fffe2db1000-7fffe2e1e000 r-xp 00000000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe2e1e000-7fffe301e000 ---p 0006d000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe301e000-7fffe301f000 r--p 0006d000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe301f000-7fffe3022000 rw-p 0006e000 08:01 9499 /usr/lib/x86_64-linux-gnu/libtiff.so.5.1.0
7fffe3022000-7fffe3029000 r-xp 00000000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3029000-7fffe3228000 ---p 00007000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3228000-7fffe3229000 r--p 00006000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe3229000-7fffe322a000 rw-p 00007000 08:01 10954 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtiff.so
7fffe322a000-7fffe322f000 r-xp 00000000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe322f000-7fffe342e000 ---p 00005000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe342e000-7fffe342f000 r--p 00004000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe342f000-7fffe3430000 rw-p 00005000 08:01 10953 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqtga.so
7fffe3430000-7fffe3484000 r-xp 00000000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3484000-7fffe3683000 ---p 00054000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3683000-7fffe3685000 r--p 00053000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3685000-7fffe3686000 rw-p 00055000 08:01 8631 /usr/lib/x86_64-linux-gnu/libQtSvg.so.4.8.3
7fffe3686000-7fffe368b000 r-xp 00000000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe368b000-7fffe388a000 ---p 00005000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388a000-7fffe388b000 r--p 00004000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388b000-7fffe388c000 rw-p 00005000 08:01 10952 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqsvg.so
7fffe388c000-7fffe38c1000 r-xp 00000000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe38c1000-7fffe3ac0000 ---p 00035000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac0000-7fffe3ac1000 r--p 00034000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac1000-7fffe3ac2000 rw-p 00035000 08:01 9225 /usr/lib/x86_64-linux-gnu/liblcms.so.1.0.19
7fffe3ac2000-7fffe3ac5000 rw-p 00000000 00:00 0
7fffe3ac5000-7fffe3b4f000 r-xp 00000000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3b4f000-7fffe3d4f000 ---p 0008a000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d4f000-7fffe3d52000 r--p 0008a000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d52000-7fffe3d54000 rw-p 0008d000 08:01 9259 /usr/lib/x86_64-linux-gnu/libmng.so.1.1.0.10
7fffe3d54000-7fffe3d59000 r-xp 00000000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3d59000-7fffe3f59000 ---p 00005000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f59000-7fffe3f5a000 r--p 00005000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f5a000-7fffe3f5b000 rw-p 00006000 08:01 10951 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqmng.so
7fffe3f5b000-7fffe3f9a000 r-xp 00000000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe3f9a000-7fffe419a000 ---p 0003f000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419a000-7fffe419b000 r--p 0003f000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419b000-7fffe419c000 rw-p 00040000 08:01 9207 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
7fffe419c000-7fffe41ac000 rw-p 00000000 00:00 0
7fffe41c2000-7fffe41c9000 r-xp 00000000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe41c9000-7fffe43c8000 ---p 00007000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43c8000-7fffe43c9000 r--p 00006000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43c9000-7fffe43ca000 rw-p 00007000 08:01 10950 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqjpeg.so
7fffe43ca000-7fffe43d1000 r-xp 00000000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe43d1000-7fffe45d0000 ---p 00007000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d0000-7fffe45d1000 r--p 00006000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d1000-7fffe45d2000 rw-p 00007000 08:01 10949 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqico.so
7fffe45d2000-7fffe45d9000 r-xp 00000000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe45d9000-7fffe47d8000 ---p 00007000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47d8000-7fffe47d9000 r--p 00006000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47d9000-7fffe47da000 rw-p 00007000 08:01 10948 /usr/lib/x86_64-linux-gnu/qt4/plugins/imageformats/libqgif.so
7fffe47da000-7fffe47dc000 r-xp 00000000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe47dc000-7fffe49db000 ---p 00002000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49db000-7fffe49dc000 r--p 00001000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49dc000-7fffe49dd000 rw-p 00002000 08:01 10901 /usr/lib/x86_64-linux-gnu/pango/1.6.0/modules/pango-basic-fc.so
7fffe49dd000-7fffe49e6000 r-xp 00000000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe49e6000-7fffe4be6000 ---p 00009000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be6000-7fffe4be7000 r--p 00009000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be7000-7fffe4be8000 rw-p 0000a000 08:01 10648 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libpixmap.so
7fffe4be8000-7fffe4c17000 r-xp 00000000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4c17000-7fffe4e17000 ---p 0002f000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e17000-7fffe4e18000 r--p 0002f000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e18000-7fffe4e19000 rw-p 00030000 08:01 10647 /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/libmurrine.so
7fffe4e19000-7fffe4e25000 r-xp 00000000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe4e25000-7fffe5024000 ---p 0000c000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe5024000-7fffe5025000 r--p 0000b000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
7fffe5025000-7fffe5026000 rw-p 0000c000 08:01 5140 /lib/x86_64-linux-gnu/libnss_files-2.15.so
Program received signal SIGABRT, Aborted.
0x00007ffff4427425 in raise () from /lib/x86_64-linux-gnu/libc.so.6
答案 0 :(得分：0)
处理分段错误的最简单方法是分析保存到内核生成的coredump中的堆栈跟踪。大多数发行版都禁用了coredump save，因此可以启用它
ulimit -c unlimited
Proc文件系统有几个文件来配置corudump生产。最重要的是core pattern /proc/sys/kernel/core_pattern，它指定了coredump名称和可选的后处理命令。
当进程收到分段错误信号时，内核会将其状态保存在coredump文件中，以后可以使用dgb进行检查：
gdb -c core ./binary_which_produced_the_core
bt
这将打印出在发生分段错误时程序正在执行的操作的回溯。
另外，为了使回溯更具信息性，您必须安装带有调试符号的包。在您的情况下，您将需要libc，Qt，glib和您自己的二进制符号。使用Qt，glib和libc，这就像
一样简单sudo apt-get install libc6-dbg libqt4-dbg libglib2.0-0-dbg
如果您的构建工具是qmake，那么使用Qt二进制文件会更复杂。
CONFIG += debug
将启用调试符号，但是，它还将启用代码中的断言和其他检查，使其行为不同。 如果构建工具是cmake或autotools而不是生成调试符号变得微不足道。