Re: Linux 2.5.69

[William Lee Irwin III <wli@holomorphy.com>]

On Mon, May 05, 2003 at 08:56:41AM -0700, Linus Torvalds wrote:
> They actually started in 2.5.60 if it's the same bug.
> And yes, you'd get random crashes, panics, lockups and even reboots. The 
> problem was that the pmd/pgd's were put in the slab cache in between 
> 2.5.59 and 2.5.60, and that was simply wrong because the AGP code changes 
> the cacheability of the kernel pages when it maps stuff into the AGP 
> aperture. That in turn will change the page tables but it won't update the 
> cached entries in the pmd slab caches. 
> So what happens is that once you exit X, and the page tables are put back
> together without the cacheability changes, and you start a new program,
> that program may get a page table with partly bogus kernel page table
> entries.
> That, in turn, when it happens will cause _major_ memory corruption, and
> your machine is toast, often in very interesting ways because the internal
> kernel data structures got corrupted. It can also cause random SIGSEGV's
> etc.
> But it only happens with AGP, and a lot of people either don't use it or 
> run only one X session.

Any chance one of you could try out the fixed slabification patches?
Message-ID: <20030505105213.GO8931@holomorphy.com>

-- wli