Re: proc_file_read() hack?

[Thomas Hood <jdthood@mail.com>]

On Wed, 2002-03-27 at 13:26, Todd Inglett wrote:
> I guess I don't understand the conflict.

There are three cases:
0)  start == 0
1)  0 < start < buffer
2)  start >= buffer

These exhaust all the possible values that can be returned
in *start.

You propose to change the code so that there are three cases:
0)  start == 0
1') 0 < start < PROC_BLOCK_SIZE
2'/3) start >= PROC_BLOCK_SIZE

However, we can't make the change you propose because it would
break functions that use case #1 with a *start value greater
than PROC_BLOCK_SIZE.

>... is there a chance that start >= PROC_BLOCK_SIZE (but start < page)
> in case #1?

Yes.

> If that is true I am wondering how it could possibly be correct
> since start will be used as a length which is greater than the
> size of the page.

start will be used as an offset, not as a length.

If you think the hack was a bad idea, I agree with you.
But we can't change it without auditing all the proc read
functions that use case #1.

--
Thomas Hood