This patch adds the helper crypto_clone_tfm. The purpose is to
allocate a tfm object with GFP_ATOMIC. As we cannot sleep, the
object has to be cloned from an existing tfm object.
This allows code paths that cannot otherwise allocate a crypto_tfm
object to do so. Once a new tfm has been obtained its key could
then be changed without impacting other users.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
crypto/api.c | 59 +++++++++++++++++++++++++++++++++++++++++++++---------
crypto/internal.h | 2 +
2 files changed, 52 insertions(+), 9 deletions(-)
diff --git a/crypto/api.c b/crypto/api.c
index f509d73fa682..d375e8cd770d 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -488,28 +488,44 @@ struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
}
EXPORT_SYMBOL_GPL(crypto_alloc_base);
-void *crypto_create_tfm_node(struct crypto_alg *alg,
- const struct crypto_type *frontend,
- int node)
+static void *crypto_alloc_tfmmem(struct crypto_alg *alg,
+ const struct crypto_type *frontend, int node,
+ gfp_t gfp)
{
- char *mem;
- struct crypto_tfm *tfm = NULL;
+ struct crypto_tfm *tfm;
unsigned int tfmsize;
unsigned int total;
- int err = -ENOMEM;
+ char *mem;
tfmsize = frontend->tfmsize;
total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
- mem = kzalloc_node(total, GFP_KERNEL, node);
+ mem = kzalloc_node(total, gfp, node);
if (mem == NULL)
- goto out_err;
+ return ERR_PTR(-ENOMEM);
tfm = (struct crypto_tfm *)(mem + tfmsize);
tfm->__crt_alg = alg;
tfm->node = node;
refcount_set(&tfm->refcnt, 1);
+ return mem;
+}
+
+void *crypto_create_tfm_node(struct crypto_alg *alg,
+ const struct crypto_type *frontend,
+ int node)
+{
+ struct crypto_tfm *tfm;
+ char *mem;
+ int err;
+
+ mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);
+ if (IS_ERR(mem))
+ goto out;
+
+ tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
+
err = frontend->init_tfm(tfm);
if (err)
goto out_free_tfm;
@@ -525,13 +541,38 @@ void *crypto_create_tfm_node(struct crypto_alg *alg,
if (err == -EAGAIN)
crypto_shoot_alg(alg);
kfree(mem);
-out_err:
mem = ERR_PTR(err);
out:
return mem;
}
EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
+void *crypto_clone_tfm(const struct crypto_type *frontend,
+ struct crypto_tfm *otfm)
+{
+ struct crypto_alg *alg = otfm->__crt_alg;
+ struct crypto_tfm *tfm;
+ char *mem;
+
+ mem = ERR_PTR(-ESTALE);
+ if (unlikely(!crypto_mod_get(alg)))
+ goto out;
+
+ mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);
+ if (IS_ERR(mem)) {
+ crypto_mod_put(alg);
+ goto out;
+ }
+
+ tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
+ tfm->crt_flags = otfm->crt_flags;
+ tfm->exit = otfm->exit;
+
+out:
+ return mem;
+}
+EXPORT_SYMBOL_GPL(crypto_clone_tfm);
+
struct crypto_alg *crypto_find_alg(const char *alg_name,
const struct crypto_type *frontend,
u32 type, u32 mask)
diff --git a/crypto/internal.h b/crypto/internal.h
index 5eee009ee494..8dd746b1130b 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -106,6 +106,8 @@ struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
u32 mask);
void *crypto_create_tfm_node(struct crypto_alg *alg,
const struct crypto_type *frontend, int node);
+void *crypto_clone_tfm(const struct crypto_type *frontend,
+ struct crypto_tfm *otfm);
static inline void *crypto_create_tfm(struct crypto_alg *alg,
const struct crypto_type *frontend)
