Re: How to develop a random number generation device

On Fri, 14 Sep 2007 11:47:32 -0700, John Larkin wrote:
On Fri, 14 Sep 2007 04:13:48 +0100, Nobody <nobody@xxxxxxxxxxx> wrote:
On Thu, 13 Sep 2007 19:06:18 -0400, krw wrote:

Nothing the OS does can prevent machine code from overrunning a buffer.

Absolute nonsense. Perhaps buffer overruns can't be prevented using
C++, but they *can* be prevented.

Not by the *OS*.

Sure it can. Not in Windows and not with C++, perhaps. An OS can
surely make it impossible to write safe code and a real OS is
required to make safe code possible.

That doesn't address the issue, which was whether the OS can
prevent buffer overruns.

I can't prevent them, but it could and should trap them and abort the
offending task, with no possibility of subsequent damage.

Under a decent OS, bad code should only hurt itself.

Actually, with the *nix permissions system, that's pretty much
how it works anyway. The user can only write to subdirectories where
he has write permission, which saves disk files; as far as allocating
memory, it seems like you'd need either a hardware memory manager, or
check every freaking instruction - hey, maybe that's why they need 3 GHz
processors to add 2 + 2 these days! ;-)

Cheers!
Rich

.

Relevant Pages

  • Re: How to develop a random number generation device
    ... question of whether the OS can prevent buffer overruns. ... to write safe code" or "a real OS is required to make safe code possible". ... I'm not talking about process isolation. ...
    (sci.electronics.design)
  • Re: How to develop a random number generation device
    ... required to make safe code possible. ... question of whether the OS can prevent buffer overruns. ... One CPU would do nothing but manage the ... high-performance CPUs would be assigned to user tasks. ...
    (sci.electronics.design)
  • Re: How to develop a random number generation device
    ... Perhaps buffer overruns can't be ... required to make safe code possible. ... A buffer overrun is where a process trashes its own memory. ... The links to extended explanatory data seem to be good as well. ...
    (sci.electronics.design)
  • Re: How to develop a random number generation device
    ... question of whether the OS can prevent buffer overruns. ... to write safe code" or "a real OS is required to make safe code possible". ... Requiring the use of a higher-level ... language simply means that a programmer has to make some effort to get ...
    (sci.electronics.design)
  • Re: How to develop a random number generation device
    ... question of whether the OS can prevent buffer overruns. ... to write safe code" or "a real OS is required to make safe code possible". ... Requiring the use of a higher-level ... language simply means that a programmer has to make some effort to get ...
    (sci.electronics.design)
Loading