lkml.org 
[lkml]   [1999]   [Dec]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: CLONE_PTRACE implementation incomplete
    Hi!

    > > IIRC, Linus has already claimed once that he doesn't very much like the
    > > whole reparenting mess introduced for debugging. He said that instead of
    > > fixing some other bugs in this code, ptrace should be fixed so the ppid of
    > > a process isn't changed just because it's being debugged. (Actually, he
    > > proposed that the connection between debugger and debuggee shouldn't be
    > > made using the p_pptr field, but through another specific field; I believe
    > > this is even quite easy to achieve, as it's very similar to the CLONE_WAIT
    > > flag's implementation...)
    > >
    > > So, if this is fixed, CLONE_PTRACE can truly become standalone (it will
    > > just copy the new p_dbptr field)...
    > >
    > > Any takers? (I can only start on this when I have my new comp, which will
    > > take a few more weeks...)
    >
    >
    > I've thought about doing something like this. I'd really, really, really like
    > to have some way to trace processes without the Heisenberg effect. Because of
    > the reparenting games it plays, ptrace messes up the semantics of the
    > interaction between a traced process and its parent. These alterations
    > greatly limit the usefulness of ptrace. In a proper solution, any changes
    > should be absolutely minimal (e.g., if a process watched itself carefully, it
    > might notice that system calls run slower while it's being traced).

    BTW do you know that with current strace, task can actually do _other_
    syscalls than you see with ptrace() interface?
    Pavel
    --
    I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
    Panos Katsaloulis describing me w.r.t. patents me at discuss@linmodems.org

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:55    [W:0.022 / U:60.084 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site