Re: veryfiing a memory address

Richard B. Johnson (root@analogic.com)
Tue, 7 Jan 1997 09:41:43 -0500 (EST)


On Sat, 4 Jan 1997, Peter J. Braam wrote:

> Happy new year!
>
> Is there a way to verify if one can read/write an address in memory, other
> than handling the segfault that would happen if it failed?
>
> Under Mach one has a system call "vm_region" which returns such
> information on a region.
>
> We have "mprotect" which verifies, but also sets a flag. It would be great
> if mprotect could be used as a checker without changing the flags on the
> region.
>
> For example we could do this by letting "mprot" change nothing but just
> verify if the prot argument is negative.
>
> Maybe something else is in place already?
>
> - Peter -
> braam@cs.cmu.edu
>

Intel has VERR and VERW which will verify a segment for reading or writing.
Page 26-278 of the Intel rag, ISBN 1-55512-159-4.

Cheers,
Dick Johnson
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Richard B. Johnson
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