Messages in this thread | | | Date | Mon, 18 May 2009 08:48:50 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [GIT PULL] core kernel fixes |
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On Mon, 18 May 2009, Ingo Molnar wrote: > > Thomas Gleixner (1): > futex: futex mapping needs to be writable
I do not believe this is right.
Just a few lines later, we have:
* NOTE: When userspace waits on a MAP_SHARED mapping, even if * it's a read-only handle, it's expected that futexes attach to * the object not the particular process.
note how we are _supposed_ to be able to wait for something that is read-only. As such, asking for a writable page is bogus.
I'm not going to pull this. I can well imagine that there was a real bug, but this is _not_ the real fix.
The commentary is also TOTAL CRAP as far as I can tell. It starts out with:
commit 734b05b10e51d4ba38c8fc3ee02e846aab09eedf (futex: use fast_gup()) calls get_user_pages_fast() with the write argument set to 0. This went unnoticed [...]
and that is pure and utter SHIT. The fact is, the write argument was ALWAYS zero, and commit 734b05b10e51d4ba38c8fc3ee02e846aab09eedf has nothing to do with anything what-so-ever, and nothing went unnoticed anywhere.
The real bug was apparently just commit e4dc5b7a3 ("clean up").
I also have to object to the "Impact" line of that commit. That line is nonsensical and stupid. I hate to bring up this discussion again, but dammit, if those Impact lines are crap, then they are crap and should not be there!
The fact that they _look_ nicer and do not break up the story any more doesn't change that fact. If you cannot write sane and meaningful impact lines, then f*ck me with a spoon - JUST DON'T DO THEM!
I'm upset. Quite frankly, there are just _so_ many things wrong with that commit that I get angry when it is sent this late in the game.
Linus
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