X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=security%2Fkeys%2Fuser_defined.c;h=8e71895b97a7eaa90c4aee3088794d5b827a7cd6;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=8d65b3a281297e60e09bccb4724092b31406dd7a;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 8d65b3a28..8e71895b9 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -15,18 +15,10 @@ #include #include #include +#include #include #include "internal.h" -static int user_instantiate(struct key *key, const void *data, size_t datalen); -static int user_duplicate(struct key *key, const struct key *source); -static int user_update(struct key *key, const void *data, size_t datalen); -static int user_match(const struct key *key, const void *criterion); -static void user_destroy(struct key *key); -static void user_describe(const struct key *user, struct seq_file *m); -static long user_read(const struct key *key, - char __user *buffer, size_t buflen); - /* * user defined keys take an arbitrary string as the description and an * arbitrary blob of data as the payload @@ -34,7 +26,6 @@ static long user_read(const struct key *key, struct key_type key_type_user = { .name = "user", .instantiate = user_instantiate, - .duplicate = user_duplicate, .update = user_update, .match = user_match, .destroy = user_destroy, @@ -42,12 +33,15 @@ struct key_type key_type_user = { .read = user_read, }; +EXPORT_SYMBOL_GPL(key_type_user); + /*****************************************************************************/ /* * instantiate a user defined key */ -static int user_instantiate(struct key *key, const void *data, size_t datalen) +int user_instantiate(struct key *key, const void *data, size_t datalen) { + struct user_key_payload *upayload; int ret; ret = -EINVAL; @@ -58,109 +52,112 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen) if (ret < 0) goto error; - /* attach the data */ ret = -ENOMEM; - key->payload.data = kmalloc(datalen, GFP_KERNEL); - if (!key->payload.data) + upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + if (!upayload) goto error; - memcpy(key->payload.data, data, datalen); + /* attach the data */ + upayload->datalen = datalen; + memcpy(upayload->data, data, datalen); + rcu_assign_pointer(key->payload.data, upayload); ret = 0; - error: +error: return ret; } /* end user_instantiate() */ +EXPORT_SYMBOL_GPL(user_instantiate); /*****************************************************************************/ /* - * duplicate a user defined key + * dispose of the old data from an updated user defined key */ -static int user_duplicate(struct key *key, const struct key *source) +static void user_update_rcu_disposal(struct rcu_head *rcu) { - int ret; - - /* just copy the payload */ - ret = -ENOMEM; - key->payload.data = kmalloc(source->datalen, GFP_KERNEL); + struct user_key_payload *upayload; - if (key->payload.data) { - key->datalen = source->datalen; - memcpy(key->payload.data, source->payload.data, source->datalen); - ret = 0; - } + upayload = container_of(rcu, struct user_key_payload, rcu); - return ret; + kfree(upayload); -} /* end user_duplicate() */ +} /* end user_update_rcu_disposal() */ /*****************************************************************************/ /* * update a user defined key + * - the key's semaphore is write-locked */ -static int user_update(struct key *key, const void *data, size_t datalen) +int user_update(struct key *key, const void *data, size_t datalen) { - void *new, *zap; + struct user_key_payload *upayload, *zap; int ret; ret = -EINVAL; if (datalen <= 0 || datalen > 32767 || !data) goto error; - /* copy the data */ + /* construct a replacement payload */ ret = -ENOMEM; - new = kmalloc(datalen, GFP_KERNEL); - if (!new) + upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + if (!upayload) goto error; - memcpy(new, data, datalen); + upayload->datalen = datalen; + memcpy(upayload->data, data, datalen); /* check the quota and attach the new data */ - zap = new; - write_lock(&key->lock); + zap = upayload; ret = key_payload_reserve(key, datalen); if (ret == 0) { /* attach the new data, displacing the old */ zap = key->payload.data; - key->payload.data = new; + rcu_assign_pointer(key->payload.data, upayload); key->expiry = 0; } - write_unlock(&key->lock); - kfree(zap); + call_rcu(&zap->rcu, user_update_rcu_disposal); - error: +error: return ret; } /* end user_update() */ +EXPORT_SYMBOL_GPL(user_update); + /*****************************************************************************/ /* * match users on their name */ -static int user_match(const struct key *key, const void *description) +int user_match(const struct key *key, const void *description) { return strcmp(key->description, description) == 0; } /* end user_match() */ +EXPORT_SYMBOL_GPL(user_match); + /*****************************************************************************/ /* * dispose of the data dangling from the corpse of a user */ -static void user_destroy(struct key *key) +void user_destroy(struct key *key) { - kfree(key->payload.data); + struct user_key_payload *upayload = key->payload.data; + + kfree(upayload); } /* end user_destroy() */ +EXPORT_SYMBOL_GPL(user_destroy); + /*****************************************************************************/ /* - * describe the user + * describe the user key */ -static void user_describe(const struct key *key, struct seq_file *m) +void user_describe(const struct key *key, struct seq_file *m) { seq_puts(m, key->description); @@ -168,24 +165,32 @@ static void user_describe(const struct key *key, struct seq_file *m) } /* end user_describe() */ +EXPORT_SYMBOL_GPL(user_describe); + /*****************************************************************************/ /* * read the key data + * - the key's semaphore is read-locked */ -static long user_read(const struct key *key, - char __user *buffer, size_t buflen) +long user_read(const struct key *key, char __user *buffer, size_t buflen) { - long ret = key->datalen; + struct user_key_payload *upayload; + long ret; + + upayload = rcu_dereference(key->payload.data); + ret = upayload->datalen; /* we can return the data as is */ if (buffer && buflen > 0) { - if (buflen > key->datalen) - buflen = key->datalen; + if (buflen > upayload->datalen) + buflen = upayload->datalen; - if (copy_to_user(buffer, key->payload.data, buflen) != 0) + if (copy_to_user(buffer, upayload->data, buflen) != 0) ret = -EFAULT; } return ret; } /* end user_read() */ + +EXPORT_SYMBOL_GPL(user_read);