[PATCH] s390/pkey: Use memdup_user() rather than duplicating its implementation

Markus Elfring
2019-11-06T10:22:13Z

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 6 Nov 2019 11:11:42 +0100

Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

Generated by: scripts/coccinelle/api/memdup_user.cocci

Delete local variables which became unnecessary with this refactoring
in two function implementations.

Fixes: f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d ("s390/pkey: add CCA AES cipher key support")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/s390/crypto/pkey_api.c | 32 ++++++--------------------------
1 file changed, 6 insertions(+), 26 deletions(-)

diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c
index 9de3d46b3253..8c0f12686cba 100644
--- a/drivers/s390/crypto/pkey_api.c
+++ b/drivers/s390/crypto/pkey_api.c
@@ -715,36 +715,16 @@ static int pkey_apqns4keytype(enum pkey_key_type ktype,

static void *_copy_key_from_user(void __user *ukey, size_t keylen)
{
- void *kkey;
-
- if (!ukey || keylen < MINKEYBLOBSIZE || keylen > KEYBLOBBUFSIZE)
- return ERR_PTR(-EINVAL);
- kkey = kmalloc(keylen, GFP_KERNEL);
- if (!kkey)
- return ERR_PTR(-ENOMEM);
- if (copy_from_user(kkey, ukey, keylen)) {
- kfree(kkey);
- return ERR_PTR(-EFAULT);
- }
-
- return kkey;
+ return !ukey || keylen < MINKEYBLOBSIZE || keylen > KEYBLOBBUFSIZE
+ ? ERR_PTR(-EINVAL)
+ : memdup_user(ukey, keylen);
}

static void *_copy_apqns_from_user(void __user *uapqns, size_t nr_apqns)
{
- void *kapqns = NULL;
- size_t nbytes;
-
- if (uapqns && nr_apqns > 0) {
- nbytes = nr_apqns * sizeof(struct pkey_apqn);
- kapqns = kmalloc(nbytes, GFP_KERNEL);
- if (!kapqns)
- return ERR_PTR(-ENOMEM);
- if (copy_from_user(kapqns, uapqns, nbytes))
- return ERR_PTR(-EFAULT);
- }
-
- return kapqns;
+ return uapqns && nr_apqns > 0
+ ? memdup_user(uapqns, nr_apqns * sizeof(struct pkey_apqn))
+ : NULL;
}

static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd,
--
2.24.0