crypto: caam - fix endless loop when DECO acquire fails

In case DECO0 cannot be acquired - i.e. run_descriptor_deco0() fails
with -ENODEV, caam_probe() enters an endless loop:

run_descriptor_deco0
	ret -ENODEV
	-> instantiate_rng
		-ENODEV, overwritten by -EAGAIN
		ret -EAGAIN
		-> caam_probe
			-EAGAIN results in endless loop

It turns out the error path in instantiate_rng() is incorrect,
the checks are done in the wrong order.

Cc: <stable@vger.kernel.org> # 3.13+
Fixes: 1005bccd7a ("crypto: caam - enable instantiation of all RNG4 state handles")
Reported-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Suggested-by: Auer Lukas <lukas.auer@aisec.fraunhofer.de>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Horia Geantă 2018-02-05 11:15:52 +02:00 committed by Herbert Xu
parent ba916b6a03
commit 225ece3e7d

View File

@ -228,12 +228,16 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask,
* without any error (HW optimizations for later
* CAAM eras), then try again.
*/
rdsta_val = rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_IFMASK;
if ((status && status != JRSTA_SSRC_JUMP_HALT_CC) ||
!(rdsta_val & (1 << sh_idx)))
ret = -EAGAIN;
if (ret)
break;
rdsta_val = rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_IFMASK;
if ((status && status != JRSTA_SSRC_JUMP_HALT_CC) ||
!(rdsta_val & (1 << sh_idx))) {
ret = -EAGAIN;
break;
}
dev_info(ctrldev, "Instantiated RNG4 SH%d\n", sh_idx);
/* Clear the contents before recreating the descriptor */
memset(desc, 0x00, CAAM_CMD_SZ * 7);