Re: [PATCH 10 of 20] ipath - core driver, part 3 of 4

Linus Torvalds
2005-12-30T18:46:11Z

All your user page lookup/pinning code is terminally broken.

You can't do it that way. You have serveral major conceptual bugs, like
keeping track of pages without incrementing their page count, and just
expecting that they are magically "pinned" even you do nothing at all to
pin them. The process exits or does an munmap, and the page will be used
for something else, and you'll just corrupt totally random memory.

Similarly, you do page_address() on the page, which just can't work on
highmem pages.

Crap like this must not be merged. Drivers aren't supposed to play VM
tricks in the first place - even if they were to get it right (which they
never do). Don't do it.

Linus