On Wed, Mar 08, 2017 at 11:14:20PM +0200, Krzysztof Kozlowski wrote:
> Running TCRYPT with LRW compiled causes spinlock recursion:
> testing speed of async lrw(aes) (lrw(ecb-aes-s5p)) encryption
> tcrypt: test 0 (256 bit key, 16 byte blocks): 19007 operations in 1
> seconds (304112 bytes)
> tcrypt: test 1 (256 bit key, 64 byte blocks): 15753 operations in 1
> seconds (1008192 bytes)
> tcrypt: test 2 (256 bit key, 256 byte blocks): 14293 operations in 1
> seconds (3659008 bytes)
> tcrypt: test 3 (256 bit key, 1024 byte blocks): 11906 operations in 1
> seconds (12191744 bytes)
> tcrypt: test 4 (256 bit key, 8192 byte blocks):
> BUG: spinlock recursion on CPU#1, irq/84-10830000/89
> lock: 0xeea99a68, .magic: dead4ead, .owner: irq/84-10830000/89,
> .owner_cpu: 1
> CPU: 1 PID: 89 Comm: irq/84-10830000 Not tainted
> 4.11.0-rc1-00001-g897ca6d0800d #559
> Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
> [<c010e1ec>] (unwind_backtrace) from [<c010ae1c>] (show_stack+0x10/0x14)
> [<c010ae1c>] (show_stack) from [<c03449c0>] (dump_stack+0x78/0x8c)
> [<c03449c0>] (dump_stack) from [<c015de68>] (do_raw_spin_lock+0x11c/0x120)
> [<c015de68>] (do_raw_spin_lock) from [<c0720110>]
> [<c0720110>] (_raw_spin_lock_irqsave) from [<c0572ca0>]
> [<c0572ca0>] (s5p_aes_crypt) from [<bf1d8aa4>] (do_encrypt+0x78/0xb0
> [<bf1d8aa4>] (do_encrypt [lrw]) from [<bf1d8b00>] (encrypt_done+0x24/0x54
> [<bf1d8b00>] (encrypt_done [lrw]) from [<c05732a0>]
> [<c05732a0>] (s5p_aes_complete) from [<c0573440>]
> [<c0573440>] (s5p_aes_interrupt) from [<c01667c4>]
> [<c01667c4>] (irq_thread_fn) from [<c0166a98>] (irq_thread+0x12c/0x1e0)
> [<c0166a98>] (irq_thread) from [<c0136a28>] (kthread+0x108/0x138)
> [<c0136a28>] (kthread) from [<c0107778>] (ret_from_fork+0x14/0x3c)
> Interrupt handling routine was calling req->base.complete() under
> spinlock. In most cases this wasn't fatal but when combined with some
> of the cipher modes (like LRW) this caused recursion - starting the new
> encryption (s5p_aes_crypt()) while still holding the spinlock from
> previous round (s5p_aes_complete()).
> Beside that, the s5p_aes_interrupt() error handling path could execute
> two completions in case of error for RX and TX blocks.
> Rewrite the interrupt handling routine and the completion by:
> 1. Splitting the operations on scatterlist copies from
> s5p_aes_complete() into separate s5p_sg_done(). This still should be
> done under lock.
> The s5p_aes_complete() now only calls req->base.complete() and it has
> to be called outside of lock.
> 2. Moving the s5p_aes_complete() out of spinlock critical sections.
> In interrupt service routine s5p_aes_interrupts(), it appeared in few
> places, including error paths inside other functions called from ISR.
> This code was not so obvious to read so simplify it by putting the
> s5p_aes_complete() only within ISR level.
> Reported-by: Nathan Royce <nroycea+ker...@gmail.com>
> Cc: <sta...@vger.kernel.org> # v4.10.x: 07de4bc88c crypto: s5p-sss - Fix
> Cc: <sta...@vger.kernel.org> # v4.10.x
> Signed-off-by: Krzysztof Kozlowski <k...@kernel.org>
Patch applied. Thanks.
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt