Linux kernel bug AMD64 - affects skiplists
brong at fastmail.fm
Wed Jun 18 00:00:15 EDT 2008
I promised I'd have something to say about skiplists soon!
(hi Rudy - hope you had a good time off, leaving me here to
figure this out _all_by_myself_ ;) )
There's a bug in the linux kernel for amd64 builds only
that breaks some skiplist files.
Specifically, checkpointing a seen file with a long (greater
than page size) list of seen data will cause corruption where
it crosses the page break. The last 16-24 bytes will of the
page will be NULLed out.
You can read more about it in all its gory detail here:
Thanks Linus for the prompt (at least partial) fix.
If you are running one of those kernels now, I recommend you
either change the kernel version, or apply the patch Linus
posted. I was going to suggest a little "magic" patch, but
I've been unable to actually make it work in testing, so I
won't do it!
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