[PATCH v2] crypto: arm64/aes-blk - fix and move skcipher_walk_done out of kernel_neon_begin,_end

From: Jia He
Date: Fri Jun 08 2018 - 03:42:04 EST


In a arm64 server(QDF2400),I met a similar might-sleep warning as [1]:
[ 7.019116] BUG: sleeping function called from invalid context at
./include/crypto/algapi.h:416
[ 7.027863] in_atomic(): 1, irqs_disabled(): 0, pid: 410, name:
cryptomgr_test
[ 7.035106] 1 lock held by cryptomgr_test/410:
[ 7.039549] #0: (ptrval) (&drbg->drbg_mutex){+.+.}, at:
drbg_instantiate+0x34/0x398
[ 7.048038] CPU: 9 PID: 410 Comm: cryptomgr_test Not tainted
4.17.0-rc6+ #27
[ 7.068228] dump_backtrace+0x0/0x1c0
[ 7.071890] show_stack+0x24/0x30
[ 7.075208] dump_stack+0xb0/0xec
[ 7.078523] ___might_sleep+0x160/0x238
[ 7.082360] skcipher_walk_done+0x118/0x2c8
[ 7.086545] ctr_encrypt+0x98/0x130
[ 7.090035] simd_skcipher_encrypt+0x68/0xc0
[ 7.094304] drbg_kcapi_sym_ctr+0xd4/0x1f8
[ 7.098400] drbg_ctr_update+0x98/0x330
[ 7.102236] drbg_seed+0x1b8/0x2f0
[ 7.105637] drbg_instantiate+0x2ac/0x398
[ 7.109646] drbg_kcapi_seed+0xbc/0x188
[ 7.113482] crypto_rng_reset+0x4c/0xb0
[ 7.117319] alg_test_drbg+0xec/0x330
[ 7.120981] alg_test.part.6+0x1c8/0x3c8
[ 7.124903] alg_test+0x58/0xa0
[ 7.128044] cryptomgr_test+0x50/0x58
[ 7.131708] kthread+0x134/0x138
[ 7.134936] ret_from_fork+0x10/0x1c

Seems there is a bug in Ard Biesheuvel's commit.
Fixes: 683381747270 ("crypto: arm64/aes-blk - move kernel mode neon
en/disable into loop")

[1] https://www.spinics.net/lists/linux-crypto/msg33103.html

Signed-off-by: jia.he@xxxxxxxxxxxxxxxx
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 4.17
---
v2: cc stable
---
arch/arm64/crypto/aes-glue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index 253188f..e3e5095 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -223,8 +223,8 @@ static int ctr_encrypt(struct skcipher_request *req)
kernel_neon_begin();
aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
(u8 *)ctx->key_enc, rounds, blocks, walk.iv);
- err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
kernel_neon_end();
+ err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
if (walk.nbytes) {
u8 __aligned(8) tail[AES_BLOCK_SIZE];
--
1.8.3.1