[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/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;
}