Messages in this thread | | | From | Michal Hocko <> | Subject | Re: Should mmap MAP_LOCKED fail if mm_poppulate fails? | Date | Tue, 28 Apr 2015 14:11:48 +0200 |
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Hi, it seems that the initial email got lost (or ignored). I would like to revive it again. I've cooked up a potential fix to this issue which will follow as a reply to this email.
The first patch is dumb and straightforward. It should be safe as is and also good without the follow up 2 patches which try to handle potential allocation failures in the do_munmap path more gracefully. As we still do not fail small allocations even the first patch could be simplified a bit and the retry loop replaced by a BUG_ON right away. But I felt this would better be done robust.
An obvious alternative would be patching the man pages to mention the subtle difference between mlock and MAP_LOCKED semantic. I have checked debian code search and it shown some applications relying on MAP_LOCKED but I have no idea whether they really require the mlock all-or-nothing fault in semantic.
Any thoughts, ideas?
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