Re: Another VM race? (was: page_launder() bug)

Rik van Riel
2001-05-13T23:05:24Z

On Sun, 13 May 2001, Mikulas Patocka wrote:

> CPU 0 CPU 1
> is executing the code marked is executing try_to_free_buffers on
> above with ^^^^^^^: the same page (it can be, because CPU 0
> did not lock the page)
>
> (page->buffers &&
>
> page->buffers = NULL
>
> MAJOR(page->buffers->b_dev) ==
> RAMDISK_MAJOR)) ===> Oops, NULL pointer dereference!
>
>
>
> Maybe compiler CSE optimization will eliminate the double load of
> page->buffers, but we must not rely on it. If the compiler doesn't
> optimize it, it can produce random oopses.

You're right, this should be fixed. Do you happen to have a
patch ? ;)

regards,

Rik
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