[dm-devel] [PATCH] dm-crypt: Fix per-bio data alignment

[Milan Broz]

The commit
  298a9fa08a1577211d42a75e8fc073baef61e0d9
  dm crypt: use per-bio data
causes OOPS on 32bit i686 architecture

  BUG: unable to handle kernel paging request at 20000000
  IP: [<e0fe2433>] clone_endio+0x13/0xe0 [dm_mod]
  ...

 [<c1257b61>] bio_endio+0x61/0x90
 [<e142476c>] crypt_dec_pending+0x8c/0xd0 [dm_crypt]
 [<e142666f>] kcryptd_crypt+0x4bf/0x4f0 [dm_crypt]

This patch fixes the issue by aligning per-bio alocated structure size.

Reported-by: Krzysztof Kolasa <kkolasa at winsoft.pl>
Signed-off-by: Milan Broz <gmazyland at gmail.com>
---
 drivers/md/dm-crypt.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 2785007..33f26a2 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1735,9 +1735,10 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad;
 	}
 
-	cc->per_bio_data_size = ti->per_bio_data_size =
-				sizeof(struct dm_crypt_io) + cc->dmreq_start +
-				sizeof(struct dm_crypt_request) + cc->iv_size;
+	cc->per_bio_data_size = ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
+				      sizeof(struct dm_crypt_request) + cc->iv_size,
+				      ARCH_KMALLOC_MINALIGN);
+	ti->per_bio_data_size = cc->per_bio_data_size;
 
 	cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
 	if (!cc->page_pool) {
-- 
2.1.0