On 07/01/2011 08:36 AM, Ingo Molnar wrote: > > So we could kill multiple birds with the same stone here: > > - remove various ugly uses of /dev/mem (including the rootkit usage), > with or without strict-devmem > > - extending it to above-4G for inspection purposes > > - allowing to kill /dev/mem access runtime similar to the > disable_modules lock-down killswitch, for the so inclined. > > Would you be interested in modifying your patch-set in such a > fashion? > There is another use that I have looked at, as well: for testing purposes, it would be extremely good to be able to dirty and/or flush an arbitrary physical cache line for testing purposes. This is very very similar to /dev/mem usage -- access to an arbitrary chunk of memory -- and a fully enabled /dev/mem can of course support this use (just mmap the page with the relevant cache line). However, it could also be a separate device which could have looser permissions than /dev/mem; or a set of ioctls on /dev/mem with a separate kill switch, because no data would ever be have modified or returned to user space. Either way, though, we found that it would share a lot of code with the /dev/mem implementation, and as such fixing up the underlying machinery is the sanest way to upstream this. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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