Re: flush_page_to_ram() question in kernel/ptrace.c

From: David S. Miller (davem@redhat.com)
Date: Thu Mar 08 2001 - 16:08:45 EST


Manfred Spraul writes:
> > memcpy(buf, maddr + (addr & ~PAGE_MASK), len);
> > flush_page_to_ram(page);
> ^^^^^^^^^^^^^^^^^^^^^^
> Is this flush required?
>
> The memcpy read from the mapping, it didn't write.

You have to kick it out of the cache so that future reads on the
kernel side don't get stale data with caching setups that allow
illegal aliases to form.

Later,
David S. Miller
davem@redhat.com

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This archive was generated by hypermail 2b29 : Thu Mar 15 2001 - 21:00:09 EST