[lkml]   [2010]   [Jun]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 0/2] Yama: add PTRACE exception tracking
    Hi Christoph,

    On Wed, Jun 30, 2010 at 03:31:58AM -0400, Christoph Hellwig wrote:
    > Err, no. This is just a very clear sign that your ptrace restrictions
    > were completely wrong to start with and break applications left, right
    > and center. Just get rid of it instead of letting workarounds for your
    > bad design creep into the core kernel and applications.

    It's not my bad design; PTRACE is a terrible interface. In an effort
    to eliminate PTRACE, there are a few legitimate uses: direct debugging,
    and crash handlers. The crash handlers are an odd case because all
    they want is a backtrace and register details, but there's no way to do
    that on the fly without PTRACE, so that's how they've implemented it.
    In those cases, the crashing program knows who will attach to it, so
    there needs to be a safe way to declare that relationship instead of just
    giving up and saying "oh well, everything can PTRACE everything else".

    What is so objectionable about using a single PR_* value out of the
    2147483614 available?


    Kees Cook
    Ubuntu Security Team

     \ /
      Last update: 2010-06-30 17:47    [from the cache]
    ©2003-2014 Jasper Spaans. hosted at Digital Ocean