Re: ptrace single-stepping change breaks Wine

From: Davide Libenzi (davidel_at_xmailserver.org)
Date: 12/31/04

  • Next message: Park Lee: "Issue on ip_route_output_key() and ip_route_output_flow()" 
    Date:	Fri, 31 Dec 2004 07:16:00 -0800 (PST)
To: Andi Kleen <ak@muc.de>

    On Fri, 31 Dec 2004, Andi Kleen wrote:

    > > - you couldn't even debug signal handlers, because they were _really_
    > > hard to get into unless you knew where they were and put a breakpoint
    > > on them.
    >
    > Ok I see this as being a problem. But I bet it could be fixed
    > much simpler without doing all this complicated and likely-to-be-buggy
    > popf parsing you added.

    I don't think that the Wine problem resolution is due to the POPF
    instruction handling. Basically Linus patch does a nice cleanup plus POPF
    handling, so maybe the patch can be split.

    > > - you couldn't see the instruction after a system call.
    >
    > Are you sure?

    Yes, this was true with 2.4. Than it has been fixed some time ago. But
    handling that revealed a fragile handling of ptrace event delivery we had
    in do_syscall_trace(). Part of the Linus patch tries to solve the fact
    that on one side strace wants things to happen in a certain way, way that
    seem to break Wine. I think Linus cleanup of the ptrace event delivery can
    get strace, Wine and single-step-after-syscall right, w/out POPF handling.
    Then you guys can flame each other over the POPF handling ;)

    - Davide

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  • Next message: Park Lee: "Issue on ip_route_output_key() and ip_route_output_flow()"

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    • Re: ptrace single-stepping change breaks Wine
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