Commit 9bc3dd24 authored by Corentin Labbe's avatar Corentin Labbe Committed by Herbert Xu
Browse files

crypto: sun4i-ss - fix kmap usage 



With the recent kmap change, some tests which were conditional on
CONFIG_DEBUG_HIGHMEM now are enabled by default.
This permit to detect a problem in sun4i-ss usage of kmap.

sun4i-ss uses two kmap via sg_miter (one for input, one for output), but
using two kmap at the same time is hard:
"the ordering has to be correct and with sg_miter that's probably hard to get
right." (quoting Tlgx)

So the easiest solution is to never have two sg_miter/kmap open at the same time.
After each use of sg_miter, I store the current index, for being able to
resume sg_miter to the right place.

Fixes: 6298e948 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Signed-off-by: default avatarCorentin Labbe <clabbe@baylibre.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 4ec8977b

drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c

+65 −44
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq) 
	unsigned int ileft = areq->cryptlen;

	unsigned int oleft = areq->cryptlen;

	unsigned int todo;

	unsigned long pi = 0, po = 0; /* progress for in and out */

	bool miter_err;

	struct sg_mapping_iter mi, mo;

	unsigned int oi, oo; /* offset for in and out */

	unsigned long flags;
@@ -63,23 +65,23 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq) 
	}

	writel(mode, ss->base + SS_CTL);



	sg_miter_start(&mi, areq->src, sg_nents(areq->src),

		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);

	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),

		       SG_MITER_TO_SG | SG_MITER_ATOMIC);

	sg_miter_next(&mi);

	sg_miter_next(&mo);

	if (!mi.addr || !mo.addr) {

		dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

		err = -EINVAL;

		goto release_ss;

	}



	ileft = areq->cryptlen / 4;

	oleft = areq->cryptlen / 4;

	oi = 0;

	oo = 0;

	do {

		if (ileft) {

			sg_miter_start(&mi, areq->src, sg_nents(areq->src),

					SG_MITER_FROM_SG | SG_MITER_ATOMIC);

			if (pi)

				sg_miter_skip(&mi, pi);

			miter_err = sg_miter_next(&mi);

			if (!miter_err || !mi.addr) {

				dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

				err = -EINVAL;

				goto release_ss;

			}

			todo = min(rx_cnt, ileft);

			todo = min_t(size_t, todo, (mi.length - oi) / 4);

			if (todo) {
@@ -88,14 +90,26 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq) 
				oi += todo * 4;

			}

			if (oi == mi.length) {

			sg_miter_next(&mi);

				pi += mi.length;

				oi = 0;

			}

			sg_miter_stop(&mi);

		}



		spaces = readl(ss->base + SS_FCSR);

		rx_cnt = SS_RXFIFO_SPACES(spaces);

		tx_cnt = SS_TXFIFO_SPACES(spaces);



		sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),

			       SG_MITER_TO_SG | SG_MITER_ATOMIC);

		if (po)

			sg_miter_skip(&mo, po);

		miter_err = sg_miter_next(&mo);

		if (!miter_err || !mo.addr) {

			dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

			err = -EINVAL;

			goto release_ss;

		}

		todo = min(tx_cnt, oleft);

		todo = min_t(size_t, todo, (mo.length - oo) / 4);

		if (todo) {
@@ -104,9 +118,10 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq) 
			oo += todo * 4;

		}

		if (oo == mo.length) {

			sg_miter_next(&mo);

			oo = 0;

			po += mo.length;

		}

		sg_miter_stop(&mo);

	} while (oleft);



	if (areq->iv) {
@@ -120,8 +135,6 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq) 
	}



release_ss:

	sg_miter_stop(&mi);

	sg_miter_stop(&mo);

	writel(0, ss->base + SS_CTL);

	spin_unlock_irqrestore(&ss->slock, flags);

	return err;
@@ -174,6 +187,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 
	unsigned int todo;

	void *backup_iv = NULL;

	struct sg_mapping_iter mi, mo;

	unsigned long pi = 0, po = 0; /* progress for in and out */

	bool miter_err;

	unsigned int oi, oo;	/* offset for in and out */

	unsigned int ob = 0;	/* offset in buf */

	unsigned int obo = 0;	/* offset in bufo*/
@@ -234,17 +249,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 
	}

	writel(mode, ss->base + SS_CTL);



	sg_miter_start(&mi, areq->src, sg_nents(areq->src),

		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);

	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),

		       SG_MITER_TO_SG | SG_MITER_ATOMIC);

	sg_miter_next(&mi);

	sg_miter_next(&mo);

	if (!mi.addr || !mo.addr) {

		dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

		err = -EINVAL;

		goto release_ss;

	}

	ileft = areq->cryptlen;

	oleft = areq->cryptlen;

	oi = 0;
@@ -252,6 +256,16 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 


	while (oleft) {

		if (ileft) {

			sg_miter_start(&mi, areq->src, sg_nents(areq->src),

				       SG_MITER_FROM_SG | SG_MITER_ATOMIC);

			if (pi)

				sg_miter_skip(&mi, pi);

			miter_err = sg_miter_next(&mi);

			if (!miter_err || !mi.addr) {

				dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

				err = -EINVAL;

				goto release_ss;

			}

			/*

			 * todo is the number of consecutive 4byte word that we

			 * can read from current SG
@@ -284,31 +298,38 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 
				}

			}

			if (oi == mi.length) {

				sg_miter_next(&mi);

				pi += mi.length;

				oi = 0;

			}

			sg_miter_stop(&mi);

		}



		spaces = readl(ss->base + SS_FCSR);

		rx_cnt = SS_RXFIFO_SPACES(spaces);

		tx_cnt = SS_TXFIFO_SPACES(spaces);

		dev_dbg(ss->dev,

			"%x %u/%zu %u/%u cnt=%u %u/%zu %u/%u cnt=%u %u\n",

			mode,

			oi, mi.length, ileft, areq->cryptlen, rx_cnt,

			oo, mo.length, oleft, areq->cryptlen, tx_cnt, ob);



		if (!tx_cnt)

			continue;

		sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),

			       SG_MITER_TO_SG | SG_MITER_ATOMIC);

		if (po)

			sg_miter_skip(&mo, po);

		miter_err = sg_miter_next(&mo);

		if (!miter_err || !mo.addr) {

			dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");

			err = -EINVAL;

			goto release_ss;

		}

		/* todo in 4bytes word */

		todo = min(tx_cnt, oleft / 4);

		todo = min_t(size_t, todo, (mo.length - oo) / 4);



		if (todo) {

			readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);

			oleft -= todo * 4;

			oo += todo * 4;

			if (oo == mo.length) {

				sg_miter_next(&mo);

				po += mo.length;

				oo = 0;

			}

		} else {
@@ -333,12 +354,14 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 
				obo += todo;

				oo += todo;

				if (oo == mo.length) {

					po += mo.length;

					sg_miter_next(&mo);

					oo = 0;

				}

			} while (obo < obl);

			/* bufo must be fully used here */

		}

		sg_miter_stop(&mo);

	}

	if (areq->iv) {

		if (mode & SS_DECRYPTION) {
@@ -351,8 +374,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq) 
	}



release_ss:

	sg_miter_stop(&mi);

	sg_miter_stop(&mo);

	writel(0, ss->base + SS_CTL);

	spin_unlock_irqrestore(&ss->slock, flags);