linux-kernel - [PATCH] crypto/async_pq: use __free_page() instead of put

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Message-Id: <1456738445-876239-1-git-send-email-arnd@arndb.de>
Date:	Mon, 29 Feb 2016 10:33:58 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>, linux-mm@...ck.org,
	Herbert Xu <herbert@...dor.apana.org.au>
Cc:	linux-arm-kernel@...ts.infradead.org,
	Michal Nazarewicz <mina86@...a86.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Arnd Bergmann <arnd@...db.de>,
	Dan Williams <dan.j.williams@...el.com>,
	"David S. Miller" <davem@...emloft.net>,
	NeilBrown <neilb@...e.com>,
	Markus Stockhausen <stockhausen@...logia.de>,
	Vinod Koul <vinod.koul@...el.com>,
	linux-crypto@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] crypto/async_pq: use __free_page() instead of put_page()

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@...db.de>
---
 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);
-- 
2.7.0