[debian-devel:14655] Re: Bug#117685: xpostit: reproducable segfaults

[Taketoshi Sano <kgh12351@xxxxxxxxxxx>]

佐野＠浜松です。

debian-x ML に流してみたけど、反応が無さそうなので
こっちでも聞いてみます。

xpostit を Debian に upload したんですが、
「新規メモ作成」→「消滅」を二回繰り返すと
Segmentation Fault で落ちるというバグレポートを
もらいました。

で、ちょっと調べてみたんですが、2.2 (potato) の 3.3.6 環境では
同じ操作をしても全然問題ありません。が、たしかに unstable/sid の
4.1.0 環境で試してみると、libxaw6/libxaw7 のどちらでコンパイル
しても落ちます。ただし落ちる場所はライブラリによって違うようです。

gdb で step 実行して追いかけてみると、xpostit のコード自体を
実行している時ではなく、ライブラリのコードを実行している時に
落ちているようなので、どうも X 関係のライブラリに問題の原因が
あるのではないかと疑っているのですが、ちょっとまだ正体を
突き止めるところまでいっていません。

なにかこの件に関して、ヒントになりそうな情報など
御存知でしたら教えてください。よろしくお願いします。

 on "Wed, 31 Oct 2001 14:38:58 +0900 (JST)",
 with "Bug#117685: xpostit: reproducable segfaults",

> Thank you for reporting.
> 
> I send the copy of this mail to debian-x list,
> expecting to get attention from someone with
> enough knowledge and skill in Xaw library.
> 
> In <E15yf7i-0003AT-00@xxxxxxxxxxxxx>,
>  on "Tue, 30 Oct 2001 20:04:33 +0000",
>  with "Bug#117685: xpostit: reproducable segfaults",
>   James Troup <james@xxxxxxxxxx> wrote:
> 
> james> Package: xpostit
> james> Version: 3.3.1-7
> james> Severity: normal
> james> 
> james> I can reproducably segfault xpostit by starting it up, right clicking,
> james> creating a 1.5x2 note, clicking on destroy, clicking on confirm, then
> james> right clicking again, and finally selecting 'create a 1.5x2 note'.
> james> Unfortunately (?), recompiling it from source makes the segfault go
> james> away, so I can't provide a useful backtrace.
> james> 
> james> -- System Information
> james> Debian Release: testing/unstable
> james> Architecture: i386
> james> Kernel: Linux plato 2.2.19 #1 Mon Sep 17 17:52:54 BST 2001 i686
> james> Locale: LANG=C, LC_CTYPE=C
> james> 
> james> Versions of packages xpostit depends on:
> james> ii  libc6                         2.2.4-4    GNU C Library: Shared libraries an
> james> ii  libxaw7                       4.1.0-9    X Athena widget set library
> james> ii  xlibs                         4.1.0-9    X Window System client libraries
> 
> checked, and reproducable here in sid/unstable.
> I have installed same version of packages
> (libc6_2.2.4-4, libxaw7(-dev)_4.1.0-9, xlibs_4.1.0-9),
> but recompiled binary is still affected by this problem.
> 
> And, interestingly, this problem would not happen
> in my potato XFree86 3.3.6 environment.  So I doubt 
> this is caused by some inconsistency in libXaw in 
> XFree86 4.1.0.
> 
> Here is the script from gdb output with the binary built with -ggdb:
> (gdb) run
> Starting program: /usr/local/src/package-build/xpostit/build/xpostit-3.3.1/./xpostit 
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x4005a5ce in _XawTextZapSelection () from /usr/X11R6/lib/libXaw.so.7
> (gdb) where
> #0  0x4005a5ce in _XawTextZapSelection () from /usr/X11R6/lib/libXaw.so.7
> #1  0x4005a557 in _XawTextZapSelection () from /usr/X11R6/lib/libXaw.so.7
> #2  0x400c1593 in _XtMatchAtom () from /usr/X11R6/lib/libXt.so.6
> #3  0x400c1a0c in _XtMatchAtom () from /usr/X11R6/lib/libXt.so.6
> #4  0x400c1f24 in _XtTranslateEvent () from /usr/X11R6/lib/libXt.so.6
> #5  0x4009f5a2 in XtDispatchEventToWidget () from /usr/X11R6/lib/libXt.so.6
> #6  0x400a077c in _XtSendFocusEvent () from /usr/X11R6/lib/libXt.so.6
> #7  0x400a7afc in _XtHandleFocus () from /usr/X11R6/lib/libXt.so.6
> #8  0x4009f53f in XtDispatchEventToWidget () from /usr/X11R6/lib/libXt.so.6
> #9  0x4009fd6e in _XtOnGrabList () from /usr/X11R6/lib/libXt.so.6
> #10 0x400a0108 in XtDispatchEvent () from /usr/X11R6/lib/libXt.so.6
> #11 0x400a0519 in XtAppMainLoop () from /usr/X11R6/lib/libXt.so.6
> #12 0x0804cb7a in main (argc=1, argv=0xbffffa04) at xpostit.c:228
> #13 0x4020566f in __libc_start_main () from /lib/libc.so.6
> (gdb) 
> 
> When I use Xaw6 with libxaw6-dev installed, then
> the script of gdb is changed:
> (gdb) run
> Starting program: /usr/local/src/package-build/xpostit/build/xpostit-3.3.1/./xpostit 
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x400428ff in XawTextSourceRead () from /usr/X11R6/lib/libXaw.so.6
> (gdb) where
> #0  0x400428ff in XawTextSourceRead () from /usr/X11R6/lib/libXaw.so.6
> #1  0x40033ea7 in _XawMultiSaveAsFile () from /usr/X11R6/lib/libXaw.so.6
> #2  0x40042477 in XawTextSinkFindDistance () from /usr/X11R6/lib/libXaw.so.6
> #3  0x4003dd2f in _XawTextGetSTRING () from /usr/X11R6/lib/libXaw.so.6
> #4  0x4003d849 in XawSimpleMenuClearActiveEntry ()
>    from /usr/X11R6/lib/libXaw.so.6
> #5  0x40040fe3 in _XawTextPrepareToUpdate () from /usr/X11R6/lib/libXaw.so.6
> #6  0x40042c6c in _XawTextMBToWC () from /usr/X11R6/lib/libXaw.so.6
> #7  0x40045a7a in _XawTextZapSelection () from /usr/X11R6/lib/libXaw.so.6
> #8  0x400a8593 in _XtMatchAtom () from /usr/X11R6/lib/libXt.so.6
> #9  0x400a8a0c in _XtMatchAtom () from /usr/X11R6/lib/libXt.so.6
> #10 0x400a8f24 in _XtTranslateEvent () from /usr/X11R6/lib/libXt.so.6
> #11 0x400865a2 in XtDispatchEventToWidget () from /usr/X11R6/lib/libXt.so.6
> #12 0x4008777c in _XtSendFocusEvent () from /usr/X11R6/lib/libXt.so.6
> #13 0x4008eb0b in _XtHandleFocus () from /usr/X11R6/lib/libXt.so.6
> #14 0x4008653f in XtDispatchEventToWidget () from /usr/X11R6/lib/libXt.so.6
> #15 0x40086d6e in _XtOnGrabList () from /usr/X11R6/lib/libXt.so.6
> #16 0x40087108 in XtDispatchEvent () from /usr/X11R6/lib/libXt.so.6
> #17 0x40087519 in XtAppMainLoop () from /usr/X11R6/lib/libXt.so.6
> #18 0x0804cb7a in main (argc=1, argv=0xbffffa04) at xpostit.c:228
> #19 0x401ec66f in __libc_start_main () from /lib/libc.so.6
> (gdb)
> 
> I've not confirmed where the problem lies, but the segV
> does not occur in the code of xpostit when I checked
> the execution by "step" command in gdb.
> 
> Can you give me some hints ?  If you know something,
> please let me know.
> 
> TIA.
> -- 
> Taketoshi Sano: <sano@debian.org>,<sano@debian.or.jp>,<kgh12351@xxxxxxxxxxx>

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    <kgh12351@xxxxxxxxxxx> : Taketoshi Sano (佐野　武俊)