Commit f6884295 authored by Harald Freudenberger's avatar Harald Freudenberger Committed by Heiko Carstens
Browse files

s390/pkey/crypto: Introduce xflags param for pkey in-kernel API 



Add a new parameter xflags to the in-kernel API function
pkey_key2protkey(). Currently there is only one flag supported:

* PKEY_XFLAG_NOMEMALLOC:
  If this flag is given in the xflags parameter, the pkey
  implementation is not allowed to allocate memory but instead should
  fall back to use preallocated memory or simple fail with -ENOMEM.
  This flag is for protected key derive within a cipher or similar
  which must not allocate memory which would cause io operations - see
  also the CRYPTO_ALG_ALLOCATES_MEMORY flag in crypto.h.

The one and only user of this in-kernel API - the skcipher
implementations PAES in paes_s390.c set this flag upon request
to derive a protected key from the given raw key material.

Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: default avatarHolger Dengler <dengler@linux.ibm.com>
Link: https://lore.kernel.org/r/20250424133619.16495-26-freude@linux.ibm.com


Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent e5a7f7e0

arch/s390/crypto/paes_s390.c

+3 −3
Original line number Diff line number Diff line
@@ -182,14 +182,14 @@ static inline int __paes_keyblob2pkey(const u8 *key, unsigned int keylen, 
{

	int i, rc = -EIO;



	/* try three times in case of busy card */

	/* try three times in case of busy card or no mem */

	for (i = 0; rc && i < 3; i++) {

		if (rc == -EBUSY && in_task()) {

		if ((rc == -EBUSY || rc == -ENOMEM) && in_task()) {

			if (msleep_interruptible(1000))

				return -EINTR;

		}

		rc = pkey_key2protkey(key, keylen, pk->protkey, &pk->len,

				      &pk->type);

				      &pk->type, PKEY_XFLAG_NOMEMALLOC);

	}



	return rc;

arch/s390/include/asm/pkey.h

+4 −1
Original line number Diff line number Diff line
@@ -20,10 +20,13 @@ 
 * @param key pointer to a buffer containing the key blob

 * @param keylen size of the key blob in bytes

 * @param protkey pointer to buffer receiving the protected key

 * @param xflags additional execution flags (see PKEY_XFLAG_* definitions below)

 *	  As of now the only supported flag is PKEY_XFLAG_NOMEMALLOC.

 * @return 0 on success, negative errno value on failure

 */

int pkey_key2protkey(const u8 *key, u32 keylen,

		     u8 *protkey, u32 *protkeylen, u32 *protkeytype);

		     u8 *protkey, u32 *protkeylen, u32 *protkeytype,

		     u32 xflags);



/*

 * If this flag is given in the xflags parameter, the pkey implementation

drivers/s390/crypto/pkey_api.c

+1 −2
Original line number Diff line number Diff line
@@ -53,10 +53,9 @@ static int key2protkey(const struct pkey_apqn *apqns, size_t nr_apqns, 
 * In-Kernel function: Transform a key blob (of any type) into a protected key

 */

int pkey_key2protkey(const u8 *key, u32 keylen,

		     u8 *protkey, u32 *protkeylen, u32 *protkeytype)

		     u8 *protkey, u32 *protkeylen, u32 *protkeytype, u32 xflags)

{

	int rc;

	const u32 xflags = 0;



	rc = key2protkey(NULL, 0, key, keylen,

			 protkey, protkeylen, protkeytype, xflags);