[CRYPTO] api: Added spawns
Spawns lock a specific crypto algorithm in place. They can then be used
with crypto_spawn_tfm to allocate a tfm for that algorithm. When the base
algorithm of a spawn is deregistered, all its spawns will be automatically
removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/crypto/algapi.c b/crypto/algapi.c
index acea250..36c4f1bd 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -10,6 +10,7 @@
*
*/
+#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -73,27 +74,96 @@
return crypto_set_driver_name(alg);
}
-static int __crypto_register_alg(struct crypto_alg *alg)
+static void crypto_destroy_instance(struct crypto_alg *alg)
+{
+ struct crypto_instance *inst = (void *)alg;
+ struct crypto_template *tmpl = inst->tmpl;
+
+ tmpl->free(inst);
+ crypto_tmpl_put(tmpl);
+}
+
+static void crypto_remove_spawns(struct list_head *spawns,
+ struct list_head *list)
+{
+ struct crypto_spawn *spawn, *n;
+
+ list_for_each_entry_safe(spawn, n, spawns, list) {
+ struct crypto_instance *inst = spawn->inst;
+ struct crypto_template *tmpl = inst->tmpl;
+
+ list_del_init(&spawn->list);
+ spawn->alg = NULL;
+
+ if (crypto_is_dead(&inst->alg))
+ continue;
+
+ inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
+ if (!tmpl || !crypto_tmpl_get(tmpl))
+ continue;
+
+ crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
+ list_move(&inst->alg.cra_list, list);
+ hlist_del(&inst->list);
+ inst->alg.cra_destroy = crypto_destroy_instance;
+
+ if (!list_empty(&inst->alg.cra_users)) {
+ if (&n->list == spawns)
+ n = list_entry(inst->alg.cra_users.next,
+ typeof(*n), list);
+ __list_splice(&inst->alg.cra_users, spawns->prev);
+ }
+ }
+}
+
+static int __crypto_register_alg(struct crypto_alg *alg,
+ struct list_head *list)
{
struct crypto_alg *q;
- int ret = -EEXIST;
+ int ret = -EAGAIN;
+
+ if (crypto_is_dead(alg))
+ goto out;
+
+ INIT_LIST_HEAD(&alg->cra_users);
+
+ ret = -EEXIST;
atomic_set(&alg->cra_refcnt, 1);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg)
goto out;
- if (crypto_is_larval(q) &&
- (!strcmp(alg->cra_name, q->cra_name) ||
- !strcmp(alg->cra_driver_name, q->cra_name))) {
+
+ if (crypto_is_moribund(q))
+ continue;
+
+ if (crypto_is_larval(q)) {
struct crypto_larval *larval = (void *)q;
+ if (strcmp(alg->cra_name, q->cra_name) &&
+ strcmp(alg->cra_driver_name, q->cra_name))
+ continue;
+
+ if (larval->adult)
+ continue;
if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
continue;
if (!crypto_mod_get(alg))
continue;
+
larval->adult = alg;
complete(&larval->completion);
+ continue;
}
+
+ if (strcmp(alg->cra_name, q->cra_name))
+ continue;
+
+ if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
+ q->cra_priority > alg->cra_priority)
+ continue;
+
+ crypto_remove_spawns(&q->cra_users, list);
}
list_add(&alg->cra_list, &crypto_alg_list);
@@ -105,8 +175,20 @@
return ret;
}
+static void crypto_remove_final(struct list_head *list)
+{
+ struct crypto_alg *alg;
+ struct crypto_alg *n;
+
+ list_for_each_entry_safe(alg, n, list, cra_list) {
+ list_del_init(&alg->cra_list);
+ crypto_alg_put(alg);
+ }
+}
+
int crypto_register_alg(struct crypto_alg *alg)
{
+ LIST_HEAD(list);
int err;
err = crypto_check_alg(alg);
@@ -114,23 +196,35 @@
return err;
down_write(&crypto_alg_sem);
- err = __crypto_register_alg(alg);
+ err = __crypto_register_alg(alg, &list);
up_write(&crypto_alg_sem);
+ crypto_remove_final(&list);
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);
+static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
+{
+ if (unlikely(list_empty(&alg->cra_list)))
+ return -ENOENT;
+
+ alg->cra_flags |= CRYPTO_ALG_DEAD;
+
+ crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
+ list_del_init(&alg->cra_list);
+ crypto_remove_spawns(&alg->cra_users, list);
+
+ return 0;
+}
+
int crypto_unregister_alg(struct crypto_alg *alg)
{
- int ret = -ENOENT;
+ int ret;
+ LIST_HEAD(list);
down_write(&crypto_alg_sem);
- if (likely(!list_empty(&alg->cra_list))) {
- list_del_init(&alg->cra_list);
- ret = 0;
- }
- crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
+ ret = crypto_remove_alg(alg, &list);
up_write(&crypto_alg_sem);
if (ret)
@@ -140,6 +234,7 @@
if (alg->cra_destroy)
alg->cra_destroy(alg);
+ crypto_remove_final(&list);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
@@ -170,6 +265,7 @@
struct crypto_instance *inst;
struct hlist_node *p, *n;
struct hlist_head *list;
+ LIST_HEAD(users);
down_write(&crypto_alg_sem);
@@ -178,9 +274,8 @@
list = &tmpl->instances;
hlist_for_each_entry(inst, p, list, list) {
- BUG_ON(list_empty(&inst->alg.cra_list));
- list_del_init(&inst->alg.cra_list);
- crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
+ int err = crypto_remove_alg(&inst->alg, &users);
+ BUG_ON(err);
}
crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
@@ -191,6 +286,7 @@
BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
tmpl->free(inst);
}
+ crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);
@@ -222,6 +318,7 @@
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst)
{
+ LIST_HEAD(list);
int err = -EINVAL;
if (inst->alg.cra_destroy)
@@ -235,7 +332,7 @@
down_write(&crypto_alg_sem);
- err = __crypto_register_alg(&inst->alg);
+ err = __crypto_register_alg(&inst->alg, &list);
if (err)
goto unlock;
@@ -245,11 +342,67 @@
unlock:
up_write(&crypto_alg_sem);
+ crypto_remove_final(&list);
+
err:
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);
+int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
+ struct crypto_instance *inst)
+{
+ int err = -EAGAIN;
+
+ spawn->inst = inst;
+
+ down_write(&crypto_alg_sem);
+ if (!crypto_is_moribund(alg)) {
+ list_add(&spawn->list, &alg->cra_users);
+ spawn->alg = alg;
+ err = 0;
+ }
+ up_write(&crypto_alg_sem);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(crypto_init_spawn);
+
+void crypto_drop_spawn(struct crypto_spawn *spawn)
+{
+ down_write(&crypto_alg_sem);
+ list_del(&spawn->list);
+ up_write(&crypto_alg_sem);
+}
+EXPORT_SYMBOL_GPL(crypto_drop_spawn);
+
+struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn)
+{
+ struct crypto_alg *alg;
+ struct crypto_alg *alg2;
+ struct crypto_tfm *tfm;
+
+ down_read(&crypto_alg_sem);
+ alg = spawn->alg;
+ alg2 = alg;
+ if (alg2)
+ alg2 = crypto_mod_get(alg2);
+ up_read(&crypto_alg_sem);
+
+ if (!alg2) {
+ if (alg)
+ crypto_shoot_alg(alg);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ tfm = __crypto_alloc_tfm(alg, 0);
+ if (IS_ERR(tfm))
+ crypto_mod_put(alg);
+
+ return tfm;
+}
+EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
+
int crypto_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&crypto_chain, nb);
diff --git a/crypto/api.c b/crypto/api.c
index ddf6a76..7e5522c 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -15,11 +15,13 @@
*
*/
+#include <linux/err.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/param.h>
+#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"
@@ -38,12 +40,6 @@
return alg;
}
-static inline void crypto_alg_put(struct crypto_alg *alg)
-{
- if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
- alg->cra_destroy(alg);
-}
-
struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
{
return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
@@ -65,6 +61,9 @@
list_for_each_entry(q, &crypto_alg_list, cra_list) {
int exact, fuzzy;
+ if (crypto_is_moribund(q))
+ continue;
+
if ((q->cra_flags ^ type) & mask)
continue;
@@ -111,7 +110,7 @@
larval = kzalloc(sizeof(*larval), GFP_KERNEL);
if (!larval)
- return NULL;
+ return ERR_PTR(-ENOMEM);
larval->mask = mask;
larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
@@ -153,8 +152,11 @@
wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
alg = larval->adult;
- if (alg && !crypto_mod_get(alg))
- alg = NULL;
+ if (alg) {
+ if (!crypto_mod_get(alg))
+ alg = ERR_PTR(-EAGAIN);
+ } else
+ alg = ERR_PTR(-ENOENT);
crypto_mod_put(&larval->alg);
return alg;
@@ -165,9 +167,6 @@
{
struct crypto_alg *alg;
- if (!name)
- return NULL;
-
down_read(&crypto_alg_sem);
alg = __crypto_alg_lookup(name, type, mask);
up_read(&crypto_alg_sem);
@@ -181,7 +180,10 @@
struct crypto_alg *larval;
int ok;
- mask &= ~CRYPTO_ALG_LARVAL;
+ if (!name)
+ return ERR_PTR(-ENOENT);
+
+ mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
type &= mask;
alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
@@ -190,7 +192,7 @@
return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
larval = crypto_larval_alloc(name, type, mask);
- if (!larval || !crypto_is_larval(larval))
+ if (IS_ERR(larval) || !crypto_is_larval(larval))
return larval;
ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
@@ -203,7 +205,7 @@
alg = crypto_larval_wait(larval);
else {
crypto_mod_put(larval);
- alg = NULL;
+ alg = ERR_PTR(-ENOENT);
}
crypto_larval_kill(larval);
return alg;
@@ -298,31 +300,40 @@
return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
}
-struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
+void crypto_shoot_alg(struct crypto_alg *alg)
+{
+ down_write(&crypto_alg_sem);
+ alg->cra_flags |= CRYPTO_ALG_DYING;
+ up_write(&crypto_alg_sem);
+}
+EXPORT_SYMBOL_GPL(crypto_shoot_alg);
+
+struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags)
{
struct crypto_tfm *tfm = NULL;
- struct crypto_alg *alg;
unsigned int tfm_size;
-
- alg = crypto_alg_mod_lookup(name, 0, 0);
- if (alg == NULL)
- goto out;
+ int err = -ENOMEM;
tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
tfm = kzalloc(tfm_size, GFP_KERNEL);
if (tfm == NULL)
- goto out_put;
+ goto out;
tfm->__crt_alg = alg;
-
- if (crypto_init_flags(tfm, flags))
+
+ err = crypto_init_flags(tfm, flags);
+ if (err)
goto out_free_tfm;
- if (crypto_init_ops(tfm))
+ err = crypto_init_ops(tfm);
+ if (err)
goto out_free_tfm;
- if (alg->cra_init && alg->cra_init(tfm))
+ if (alg->cra_init && (err = alg->cra_init(tfm))) {
+ if (err == -EAGAIN)
+ crypto_shoot_alg(alg);
goto cra_init_failed;
+ }
goto out;
@@ -330,12 +341,36 @@
crypto_exit_ops(tfm);
out_free_tfm:
kfree(tfm);
- tfm = NULL;
-out_put:
- crypto_mod_put(alg);
+ tfm = ERR_PTR(err);
out:
return tfm;
}
+EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
+
+struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
+{
+ struct crypto_tfm *tfm = NULL;
+ int err;
+
+ do {
+ struct crypto_alg *alg;
+
+ alg = crypto_alg_mod_lookup(name, 0, 0);
+ err = PTR_ERR(alg);
+ if (IS_ERR(alg))
+ continue;
+
+ tfm = __crypto_alloc_tfm(alg, flags);
+ err = 0;
+ if (IS_ERR(tfm)) {
+ crypto_mod_put(alg);
+ err = PTR_ERR(tfm);
+ tfm = NULL;
+ }
+ } while (err == -EAGAIN && !signal_pending(current));
+
+ return tfm;
+}
void crypto_free_tfm(struct crypto_tfm *tfm)
{
@@ -361,7 +396,7 @@
int ret = 0;
struct crypto_alg *alg = crypto_alg_mod_lookup(name, 0, 0);
- if (alg) {
+ if (!IS_ERR(alg)) {
crypto_mod_put(alg);
ret = 1;
}
diff --git a/crypto/cryptomgr.c b/crypto/cryptomgr.c
index ae54942..9b5b156 100644
--- a/crypto/cryptomgr.c
+++ b/crypto/cryptomgr.c
@@ -17,6 +17,7 @@
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/rtnetlink.h>
+#include <linux/sched.h>
#include <linux/string.h>
#include <linux/workqueue.h>
@@ -44,21 +45,25 @@
struct cryptomgr_param *param = data;
struct crypto_template *tmpl;
struct crypto_instance *inst;
+ int err;
tmpl = crypto_lookup_template(param->template);
if (!tmpl)
goto err;
- inst = tmpl->alloc(¶m->alg, sizeof(param->alg));
- if (IS_ERR(inst))
- goto err;
- else if ((err = crypto_register_instance(tmpl, inst))) {
- tmpl->free(inst);
- goto err;
- }
+ do {
+ inst = tmpl->alloc(¶m->alg, sizeof(param->alg));
+ if (IS_ERR(inst))
+ err = PTR_ERR(inst);
+ else if ((err = crypto_register_instance(tmpl, inst)))
+ tmpl->free(inst);
+ } while (err == -EAGAIN && !signal_pending(current));
crypto_tmpl_put(tmpl);
+ if (err)
+ goto err;
+
out:
kfree(param);
return;
diff --git a/crypto/internal.h b/crypto/internal.h
index c08d93b..03c00b0 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -142,12 +142,21 @@
void crypto_larval_error(const char *name, u32 type, u32 mask);
+void crypto_shoot_alg(struct crypto_alg *alg);
+struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags);
+
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst);
int crypto_register_notifier(struct notifier_block *nb);
int crypto_unregister_notifier(struct notifier_block *nb);
+static inline void crypto_alg_put(struct crypto_alg *alg)
+{
+ if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
+ alg->cra_destroy(alg);
+}
+
static inline int crypto_tmpl_get(struct crypto_template *tmpl)
{
return try_module_get(tmpl->module);
@@ -163,6 +172,16 @@
return alg->cra_flags & CRYPTO_ALG_LARVAL;
}
+static inline int crypto_is_dead(struct crypto_alg *alg)
+{
+ return alg->cra_flags & CRYPTO_ALG_DEAD;
+}
+
+static inline int crypto_is_moribund(struct crypto_alg *alg)
+{
+ return alg->cra_flags & (CRYPTO_ALG_DEAD | CRYPTO_ALG_DYING);
+}
+
static inline int crypto_notify(unsigned long val, void *v)
{
return blocking_notifier_call_chain(&crypto_chain, val, v);
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index ffec530..b20f4bd 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -36,10 +36,21 @@
char name[CRYPTO_MAX_ALG_NAME];
};
+struct crypto_spawn {
+ struct list_head list;
+ struct crypto_alg *alg;
+ struct crypto_instance *inst;
+};
+
int crypto_register_template(struct crypto_template *tmpl);
void crypto_unregister_template(struct crypto_template *tmpl);
struct crypto_template *crypto_lookup_template(const char *name);
+int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
+ struct crypto_instance *inst);
+void crypto_drop_spawn(struct crypto_spawn *spawn);
+struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn);
+
static inline void *crypto_instance_ctx(struct crypto_instance *inst)
{
return inst->__ctx;
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 85f73c3..40a6330 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -35,6 +35,8 @@
#define CRYPTO_ALG_TYPE_COMPRESS 0x00000004
#define CRYPTO_ALG_LARVAL 0x00000010
+#define CRYPTO_ALG_DEAD 0x00000020
+#define CRYPTO_ALG_DYING 0x00000040
/*
* Transform masks and values (for crt_flags).
@@ -145,6 +147,8 @@
struct crypto_alg {
struct list_head cra_list;
+ struct list_head cra_users;
+
u32 cra_flags;
unsigned int cra_blocksize;
unsigned int cra_ctxsize;
