Re: Buffer corruption (2.1.81)

Bill Hawes (whawes@star.net)
Mon, 26 Jan 1998 10:46:03 -0500


Chris Evans wrote:

> Hmmm, locate the dentry list in a read-only segment, remarking it as r/w
> whenever we need to manipulate its contents? Slow but thorough. Same for
> buffers?
>
> Patches like this and the memory leak tester should be (relatively hidden)
> config options.

Being able to protect selected lists would be very nice. The problem is that the
dentry and buffer lists are among the most active in the kernel, so I suspect
the overhead of making it r/w for legal operations would be prohibitive. If the
detection patch slowed the system down too much, people wouldn't be willing to
run the patch for extended periods.

The buffer corruption problem is rare enough (fortunately!) that it might take
quite a while to catch ...

It would be really nice if memory protection could be extended to only allow
write access from a certain range of addresses. Then each data structure could
be protected so that only its controlling subsystem could change it.

Regards,
Bill