On 02/29/2016 10:33 AM, Arnd Bergmann wrote: > 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. Hopefully that's true. If any such driver was leaking references to those pages, so the put_page() didn't actually result in freeing, the explicit __free_page should catch this via built-in checks. > Fixes: 0f80830dd044 ("mm/page_ref: add tracepoint to track down page reference manipulation") Since it's in mmotm which is quilt-based, the commit hash from -next is not stable. > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > --- > crypto/async_tx/async_pq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c > index c0748bbd4c08..08b3ac68952b 100644 > --- a/crypto/async_tx/async_pq.c > +++ b/crypto/async_tx/async_pq.c > @@ -444,7 +444,7 @@ static int __init async_pq_init(void) > > static void __exit async_pq_exit(void) > { > - put_page(pq_scribble_page); > + __free_page(pq_scribble_page); > } > > module_init(async_pq_init); > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html