Robustness of Minix and sys_vircopy - Minix

This is a discussion on Robustness of Minix and sys_vircopy - Minix ; Friends, I would like to ask the following question (because I might be wrong). If any device driver has permission to use the `sys_vircopy' call, does not give it the authority to make harm to any process? That would mean ...

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Thread: Robustness of Minix and sys_vircopy

  1. Robustness of Minix and sys_vircopy

    Friends,

    I would like to ask the following question (because I might be wrong).

    If any device driver has permission to use the `sys_vircopy' call,
    does not give it the authority to make harm to any process? That would
    mean that any malicious (or simply faulty) device driver could bring
    the system down. Could not it?

    Might then the goal (robustness) be achieved this way?

    I also see robustness as something highly desirable. Couldn't the
    above problem with `sys_vircopy' prevent Minix to eventually evolve in
    a robust system?


  2. Re: Robustness of Minix and sys_vircopy

    In article <1170072169.106093.100700@s48g2000cws.googlegroups. com>,
    Matej Kosik wrote:
    >If any device driver has permission to use the `sys_vircopy' call,
    >does not give it the authority to make harm to any process? That would
    >mean that any malicious (or simply faulty) device driver could bring
    >the system down. Could not it?


    Yes.

    >I also see robustness as something highly desirable. Couldn't the
    >above problem with `sys_vircopy' prevent Minix to eventually evolve in
    >a robust system?


    That's why sys_vircopy has been replaced by a new 'safecopy' mechanism.


    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it had been hard done
    by. It was allowed to keep its horse, since horses were so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency

  3. Re: Robustness of Minix and sys_vircopy

    On Jan 29, 11:10 pm, phi...@ue.aioy.eu (Philip Homburg) wrote:

    > That's why sys_vircopy has been replaced by a new 'safecopy' mechanism.
    >


    Could you please elaborate on the 'improved' safecopy?

    does it work the same as sys_vircopy?

    is the same function call used?

    Is this part of the 3.1.2a release?

    Is it available as a download?

    Thanks

    Dave


  4. Re: Robustness of Minix and sys_vircopy

    In article <1170198175.076822.288780@l53g2000cwa.googlegroups. com>,
    dave373 wrote:
    >On Jan 29, 11:10 pm, phi...@ue.aioy.eu (Philip Homburg) wrote:
    >
    >> That's why sys_vircopy has been replaced by a new 'safecopy' mechanism.
    >>

    >
    >Could you please elaborate on the 'improved' safecopy?


    The basic idea is that a process exports part of its address space to the
    process that needs to copy.

    >does it work the same as sys_vircopy?
    >is the same function call used?


    No, it is a completely different interface.

    >Is this part of the 3.1.2a release?


    No.

    >Is it available as a download?


    It is in our SVN repository, which is publicly accessible. See



    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it had been hard done
    by. It was allowed to keep its horse, since horses were so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency

  5. Re: Robustness of Minix and sys_vircopy

    On Jan 31, 9:56 am, phi...@ue.aioy.eu (Philip Homburg) wrote:
    > In article <1170198175.076822.288...@l53g2000cwa.googlegroups. com>,
    >
    > dave373 wrote:
    > >On Jan 29, 11:10 pm, phi...@ue.aioy.eu (Philip Homburg) wrote:

    >
    > >> That's why sys_vircopy has been replaced by a new 'safecopy' mechanism.

    >
    > >Could you please elaborate on the 'improved' safecopy?

    >
    > The basic idea is that a process exports part of its address space to the
    > process that needs to copy.
    >
    > >does it work the same as sys_vircopy?
    > >is the same function call used?

    >
    > No, it is a completely different interface.
    >
    > >Is this part of the 3.1.2a release?

    >
    > No.
    >
    > >Is it available as a download?

    >
    > It is in our SVN repository, which is publicly accessible. See
    >
    >
    > --
    > That was it. Done. The faulty Monk was turned out into the desert where it
    > could believe what it liked, including the idea that it had been hard done
    > by. It was allowed to keep its horse, since horses were so cheap to make.
    > -- Douglas Adams in Dirk Gently's Holistic Detective Agency


    New system call was added in the new Minix version. Is it somewhere
    described?
    - how it shou,ld be used
    - how it solves the original problem
    - would the former `sys_vircopy' be removed later (so that people
    definitely should use `sys_safecopy' instead of `sys_vircopy' in their
    programs)
    ?

    Regards


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