* Thomas Gleixner <[EMAIL PROTECTED]> wrote:
> The __copy_to_user_inatomic() calls in file_read_actor() and
> pipe_read() are broken on original i386 machines, where WP-works-ok ==
> false, as __copy_to_user_inatomic() on such systems calls functions
> which might sleep and/or contain cond_resched() calls inside of a
> kmap_atomic() region.
>
> The original check for WP-works-ok was in access_ok(), but got moved
> during the 2.5 series to fix a race vs. swap.
>
> Return the number of bytes to copy in the case where we are in an
> atomic region, so the non atomic code pathes in file_read_actor() and
> pipe_read() are taken.
neat trick! (v2.6.21 must-have me thinks.)
> This could be optimized to avoid the kmap_atomicby moving the check
^---- add space
> for WP-works-ok into fault_in_pages_writeable(), but this is more
> intrusive and can be done later.
>
> Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
Acked-by: Ingo Molnar <[EMAIL PROTECTED]>
Ingo
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