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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 /crypto
parentbb402f16ecf9bcdb944b8fa730f0e43cae519673 (diff)
downloadlinux-linaro-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>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/api.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/crypto/api.c b/crypto/api.c
index efe77df6863..38a2bc02a98 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;