[Bug 48407] New: OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

Bug ID: 48407
           Summary: OllyDbg 2.x segfaults the process after attaching to
                    it
           Product: Wine
           Version: 5.0-rc3
          Hardware: x86
               URL: http://www.ollydbg.de/odbg201.zip
                OS: Linux
            Status: NEW
          Keywords: regression
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
   Regression SHA1: 4ee629a3bafb1408a4e567908fef949837a39f10
      Distribution: ---

Since commit 4ee629a3bafb1408a4e567908fef949837a39f10, OllyDbg will hang after
attaching to a process while the process itself will crash, and the message
`Segmentation fault' is printed in the terminal where the process is launched
from (not OllyDbg).

How to reproduce after downloading OllyDbg (link provided in report) using a
32-bit prefix:

1) Launch a simple window app, such as `winemine'
2) From another terminal, launch OllyDbg in same prefix.

Optionally: To speed up the attaching in OllyDbg, go to
Options->Options->Analysis. In `Automatic Module Analysis' set it to `Off'.

3) In OllyDbg, go to File->Attach and select the process (winemine). Wait a few
seconds until modules are processed, then the process will segfault and OllyDbg
will hang.

I tried to debug this to no avail, it's very unfamiliar territory for me, so
it's a bit over my head.

Reverting that commit on current wine git is not easy and I don't know how to
do it, since the break_process and related functions have been removed from the
wineserver at some point. So unfortunately I don't know where to start to fix
this regression.

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

--- Comment #1 from Jacek Caban  ---
Created attachment 66185
  --> https://bugs.winehq.org/attachment.cgi?id=66185
hack

The problem is that OllyDbg tries to set PAGE_GUARD protection on whole ntdll
code. This can't work with current design because we need to be able to execute
signals to handle it and signal handlers themselves are protected. The
unrecoverable page fault happens in this case on return from mprotect to ntdll.

The attached hack works around the problem. I didn't look why it worked before
(my guess is that the problematic protection change is part of the initial
breakpoint exception and before the patch, simulated breakpoint was not
considered as this "special iniial" one; that would match the difference the
patch made for VS). The path forward is to move ntdll to PE lib + native lib
hybrid. I imagine that page guard related signal handling will not reach PE
part in this case.

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

--- Comment #2 from Gabriel Ivăncescu  ---
Thanks for looking into the bug. Indeed, the hack solves the problem (for now).
Just wondering, would this hack be suitable for wine-staging meanwhile?

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

--- Comment #3 from Jacek Caban  ---
It doesn't seem like a good candidate for staging to me. This hack is not
something that could be improved while being staged. We need a very different
approach for Wine.

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

Jacek Caban  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
      Fixed by SHA1|                            |c96ef78b6d6d9184d8ec4cd1892
                   |                            |4a3049d388583

--- Comment #4 from Jacek Caban  ---
This is fixed in current git. Commit c96ef78b6d6d9184d8ec4cd18924a3049d388583
seems like the most likely fix (not verified).

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

Nikolay Sivov  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|-unknown                    |ntdll

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

--- Comment #5 from Gabriel Ivăncescu  ---
I confirm this is fixed. Thanks.

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

Alexandre Julliard  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #6 from Alexandre Julliard  ---
Closing bugs fixed in 5.17.

[Bug 48407] OllyDbg 2.x segfaults the process after attaching to it

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48407

Anastasius Focht  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|http://www.ollydbg.de/odbg2 |https://web.archive.org/web
                   |01.zip                      |/20140209193012/http://olly
                   |                            |dbg.de/odbg201.zip
           Keywords|                            |download
                 CC|                            |[e-mail]