s390/crypto: fix possible sleep during spinlock aquired

This patch fixes a complain about possible sleep during spinlock aquired "BUG: sleeping function called from invalid context at include/crypto/algapi.h:426" for the ctr(aes) and ctr(des) s390 specific ciphers. Instead of using a spinlock this patch introduces a mutex which is save to be held in sleeping context. Please note a deadlock is not possible as mutex_trylock() is used. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reported-by: Julian Wiedmann <jwi@linux.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
mariobalanica · May 29, 2019 · 1c2c702 · 1c2c702
1 parent bef9f0b
commit 1c2c702
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Showing 2 changed files with 8 additions and 7 deletions.
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
@@ -27,14 +27,14 @@
 #include <linux/module.h>
 #include <linux/cpufeature.h>
 #include <linux/init.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/fips.h>
 #include <linux/string.h>
 #include <crypto/xts.h>
 #include <asm/cpacf.h>
 
 static u8 *ctrblk;
-static DEFINE_SPINLOCK(ctrblk_lock);
+static DEFINE_MUTEX(ctrblk_lock);
 
 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
 		    kma_functions;
@@ -698,7 +698,7 @@ static int ctr_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
 	unsigned int n, nbytes;
 	int ret, locked;
 
-	locked = spin_trylock(&ctrblk_lock);
+	locked = mutex_trylock(&ctrblk_lock);
 
 	ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE);
 	while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
@@ -716,7 +716,7 @@ static int ctr_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
 		ret = blkcipher_walk_done(desc, walk, nbytes - n);
 	}
 	if (locked)
-		spin_unlock(&ctrblk_lock);
+		mutex_unlock(&ctrblk_lock);
 	/*
 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
 	 */

diff --git a/arch/s390/crypto/des_s390.c b/arch/s390/crypto/des_s390.c
@@ -14,14 +14,15 @@
 #include <linux/cpufeature.h>
 #include <linux/crypto.h>
 #include <linux/fips.h>
+#include <linux/mutex.h>
 #include <crypto/algapi.h>
 #include <crypto/des.h>
 #include <asm/cpacf.h>
 
 #define DES3_KEY_SIZE	(3 * DES_KEY_SIZE)
 
 static u8 *ctrblk;
-static DEFINE_SPINLOCK(ctrblk_lock);
+static DEFINE_MUTEX(ctrblk_lock);
 
 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
 
@@ -374,7 +375,7 @@ static int ctr_desall_crypt(struct blkcipher_desc *desc, unsigned long fc,
 	unsigned int n, nbytes;
 	int ret, locked;
 
-	locked = spin_trylock(&ctrblk_lock);
+	locked = mutex_trylock(&ctrblk_lock);
 
 	ret = blkcipher_walk_virt_block(desc, walk, DES_BLOCK_SIZE);
 	while ((nbytes = walk->nbytes) >= DES_BLOCK_SIZE) {
@@ -391,7 +392,7 @@ static int ctr_desall_crypt(struct blkcipher_desc *desc, unsigned long fc,
 		ret = blkcipher_walk_done(desc, walk, nbytes - n);
 	}
 	if (locked)
-		spin_unlock(&ctrblk_lock);
+		mutex_unlock(&ctrblk_lock);
 	/* final block may be < DES_BLOCK_SIZE, copy only nbytes */
 	if (nbytes) {
 		cpacf_kmctr(fc, ctx->key, buf, walk->src.virt.addr,