[PATCH v2] crypto: rockchip/crypto - fix possible deadlock

[Herbert Xu]

On Sat, Nov 28, 2015 at 01:27:48PM +0100, Heiko Stübner wrote:
> Lockdep warns about a possible deadlock resulting from the use of regular
> spin_locks:
> 
> =================================
> [ INFO: inconsistent lock state ]
> 4.4.0-rc2+ #2724 Not tainted
> ---------------------------------
> inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> ksoftirqd/0/3 [HC0[0]:SC1[1]:HE1:SE0] takes:
> (&(&crypto_info->lock)->rlock){+.?...}, at: [<bf14a65c>] rk_crypto_tasklet_cb+0x24/0xb4 [rk_crypto]
> {SOFTIRQ-ON-W} state was registered at:
>   [<c007f4ac>] lock_acquire+0x178/0x218
>   [<c0759bac>] _raw_spin_lock+0x54/0x64
>   [<bf14af88>] rk_handle_req+0x7c/0xbc [rk_crypto]
>   [<bf14b040>] rk_des_ecb_encrypt+0x2c/0x30 [rk_crypto]
>   [<bf14b05c>] rk_aes_ecb_encrypt+0x18/0x1c [rk_crypto]
>   [<c028c820>] skcipher_encrypt_ablkcipher+0x64/0x68
>   [<c0290770>] __test_skcipher+0x2a8/0x8dc
>   [<c0292e94>] test_skcipher+0x38/0xc4
>   [<c0292fb0>] alg_test_skcipher+0x90/0xb0
>   [<c0292158>] alg_test+0x1e8/0x280
>   [<c028f6f4>] cryptomgr_test+0x34/0x54
>   [<c004bbe8>] kthread+0xf4/0x10c
>   [<c0010010>] ret_from_fork+0x14/0x24
> irq event stamp: 10672
> hardirqs last  enabled at (10672): [<c002fac8>] tasklet_action+0x48/0x104
> hardirqs last disabled at (10671): [<c002faa0>] tasklet_action+0x20/0x104
> softirqs last  enabled at (10658): [<c002ef84>] __do_softirq+0x358/0x49c
> softirqs last disabled at (10669): [<c002f108>] run_ksoftirqd+0x40/0x80
> 
> other info that might help us debug this:
> Possible unsafe locking scenario:
> 
>     CPU0
>     ----
>   lock(&(&crypto_info->lock)->rlock);
>   <Interrupt>
>     lock(&(&crypto_info->lock)->rlock);
> 
>  *** DEADLOCK ***
> 
> Fix this by moving to irq-disabling spinlocks.
> 
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> ---
> changes in v2:
> - don't use irqsave spinlock in the irq-handler itself

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt