2016-03-01 3:04 GMT+09:00 Dan Williams [off-list ref]:

On Mon, Feb 29, 2016 at 1:33 AM, Arnd Bergmann [off-list ref] wrote:

quoted

The addition of tracepoints to the page reference tracking had an
unfortunate side-effect in at least one driver that calls put_page
from its exit function, resulting in a link error:

`.exit.text' referenced in section `__jump_table' of crypto/built-in.o: defined in discarded section `.exit.text' of crypto/built-in.o

From a cursory look at that this driver, it seems that it may be
doing the wrong thing here anyway, as the page gets allocated
using 'alloc_page()', and should be freed using '__free_page()'
rather than 'put_page()'.

With this patch, I no longer get any other build errors from the
page_ref patch, so hopefully we can assume that it's always wrong
to call any of those functions from __exit code, and that no other
driver does it.

Fixes: 0f80830dd044 ("mm/page_ref: add tracepoint to track down page reference manipulation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Dan Williams <redacted>

Vinod, will you take this one?

Problematic patch ("mm/page_ref: ~~~") is not yet merged one. It is on mmotm
and this fix should go together with it or before it. I think that
handling this fix by
Andrew is easier to all.

Thanks.