commit c849163b80c05f4567b1adef5db7f377460f88cd
author Marcelo Cerri <mhcerri@linux.vnet.ibm.com> Mon Aug 12 18:49:37 2013 -0300
committer Herbert Xu <herbert@gondor.apana.org.au> Wed Aug 14 20:42:04 2013 +1000
tree b7e3e40e463ed921040c1049212e40132103c536
parent f22d08111a1d23f7432ee8d9c2dd637deb6963bd

crypto: nx - fix concurrency issue

The NX driver uses the transformation context to store several fields
containing data related to the state of the operations in progress.
Since a single tfm can be used by different kernel threads at the same
time, we need to protect the data stored into the context.

This patch makes use of spin locks to protect the data where a race
condition can happen.

Reviewed-by: Fionnuala Gunter <fin@linux.vnet.ibm.com>
Reviewed-by: Joy Latten <jmlatten@linux.vnet.ibm.com>
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/nx/nx-sha256.c

diff --git a/drivers/crypto/nx/nx-sha256.c b/drivers/crypto/nx/nx-sha256.c
index 254b01a..6547a71 100644
--- a/drivers/crypto/nx/nx-sha256.c
+++ b/drivers/crypto/nx/nx-sha256.c
@@ -57,8 +57,11 @@
 	struct nx_sg *in_sg;
 	u64 to_process, leftover, total;
 	u32 max_sg_len;
+	unsigned long irq_flags;
 	int rc = 0;
 
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
+
 	/* 2 cases for total data len:
 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
@@ -136,6 +139,7 @@
 		memcpy(sctx->buf, data, leftover);
 	sctx->count = leftover;
 out:
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return rc;
 }
 
@@ -146,8 +150,11 @@
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	struct nx_sg *in_sg, *out_sg;
 	u32 max_sg_len;
+	unsigned long irq_flags;
 	int rc;
 
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
+
 	max_sg_len = min_t(u32, nx_driver.of.max_sg_len, nx_ctx->ap->sglen);
 
 	if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
@@ -186,6 +193,7 @@
 		     &(nx_ctx->stats->sha256_bytes));
 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
 out:
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return rc;
 }
 
@@ -195,6 +203,9 @@
 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	struct sha256_state *octx = out;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
 	octx->count = sctx->count +
 		      (csbcpb->cpb.sha256.message_bit_length / 8);
@@ -217,6 +228,7 @@
 		octx->state[7] = SHA256_H7;
 	}
 
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return 0;
 }
 
@@ -226,6 +238,9 @@
 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	const struct sha256_state *ictx = in;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
 	memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf));
 
@@ -240,6 +255,7 @@
 		NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 	}
 
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return 0;
 }