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authorHerbert Xu <herbert@gondor.apana.org.au>2009-02-26 14:06:31 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2009-02-26 14:06:31 +0800
commita760a6656e6f00bb0144a42a048cf0266646e22c (patch)
tree51fffed59af5edcdd550f4517a775cba02a3d21c
parentbb402f16ecf9bcdb944b8fa730f0e43cae519673 (diff)
downloadlinux-linaro-stable-a760a6656e6f00bb0144a42a048cf0266646e22c.tar.gz
crypto: api - Fix module load deadlock with fallback algorithms
With the mandatory algorithm testing at registration, we have now created a deadlock with algorithms requiring fallbacks. This can happen if the module containing the algorithm requiring fallback is loaded first, without the fallback module being loaded first. The system will then try to test the new algorithm, find that it needs to load a fallback, and then try to load that. As both algorithms share the same module alias, it can attempt to load the original algorithm again and block indefinitely. As algorithms requiring fallbacks are a special case, we can fix this by giving them a different module alias than the rest. Then it's just a matter of using the right aliases according to what algorithms we're trying to find. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--arch/s390/crypto/aes_s390.c2
-rw-r--r--crypto/api.c15
-rw-r--r--drivers/crypto/padlock-aes.c2
-rw-r--r--drivers/crypto/padlock-sha.c4
4 files changed, 17 insertions, 6 deletions
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index c42cd898f68b..6118890c946d 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -556,7 +556,7 @@ static void __exit aes_s390_fini(void)
module_init(aes_s390_init);
module_exit(aes_s390_fini);
-MODULE_ALIAS("aes");
+MODULE_ALIAS("aes-all");
MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
MODULE_LICENSE("GPL");
diff --git a/crypto/api.c b/crypto/api.c
index efe77df6863f..38a2bc02a98c 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -215,8 +215,19 @@ struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
type &= mask;
- alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
- name);
+ alg = crypto_alg_lookup(name, type, mask);
+ if (!alg) {
+ char tmp[CRYPTO_MAX_ALG_NAME];
+
+ request_module(name);
+
+ if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask) &&
+ snprintf(tmp, sizeof(tmp), "%s-all", name) < sizeof(tmp))
+ request_module(tmp);
+
+ alg = crypto_alg_lookup(name, type, mask);
+ }
+
if (alg)
return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c
index 856b3cc25583..3f0fdd18255d 100644
--- a/drivers/crypto/padlock-aes.c
+++ b/drivers/crypto/padlock-aes.c
@@ -489,4 +489,4 @@ MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");
-MODULE_ALIAS("aes");
+MODULE_ALIAS("aes-all");
diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
index a7fbadebf623..a2c8e8514b63 100644
--- a/drivers/crypto/padlock-sha.c
+++ b/drivers/crypto/padlock-sha.c
@@ -304,7 +304,7 @@ MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");
-MODULE_ALIAS("sha1");
-MODULE_ALIAS("sha256");
+MODULE_ALIAS("sha1-all");
+MODULE_ALIAS("sha256-all");
MODULE_ALIAS("sha1-padlock");
MODULE_ALIAS("sha256-padlock");