[PATCH v2 11/20] s390/zcrypt/pkey: Rework ep11 findcard() implementation and callers

Harald Freudenberger
2025-03-04T17:21:30Z

Rework the memory usage of the ep11 findcard() implementation:
- findcard does not allocate memory for the list of apqns
any more.
- the callers are now responsible to provide an array of
apqns to store the matching apqns into.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
drivers/s390/crypto/pkey_ep11.c | 19 ++++++++-----------
drivers/s390/crypto/zcrypt_ep11misc.c | 18 ++++--------------
drivers/s390/crypto/zcrypt_ep11misc.h | 12 +++++-------
3 files changed, 17 insertions(+), 32 deletions(-)

diff --git a/drivers/s390/crypto/pkey_ep11.c b/drivers/s390/crypto/pkey_ep11.c
index 5b033ca3e828..b970f0be84be 100644
--- a/drivers/s390/crypto/pkey_ep11.c
+++ b/drivers/s390/crypto/pkey_ep11.c
@@ -73,7 +73,7 @@ static int ep11_apqns4key(const u8 *key, u32 keylen, u32 flags,
struct pkey_apqn *apqns, size_t *nr_apqns)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
- u32 _nr_apqns, *_apqns = NULL;
+ u32 _apqns[MAXAPQNSINLIST], _nr_apqns = ARRAY_SIZE(_apqns);
int rc;

if (!flags)
@@ -98,7 +98,7 @@ static int ep11_apqns4key(const u8 *key, u32 keylen, u32 flags,
minhwtype = ZCRYPT_CEX7;
api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
}
- rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
+ rc = ep11_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
minhwtype, api, kb->wkvp);
if (rc)
goto out;
@@ -115,7 +115,7 @@ static int ep11_apqns4key(const u8 *key, u32 keylen, u32 flags,
minhwtype = ZCRYPT_CEX7;
api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
}
- rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
+ rc = ep11_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
minhwtype, api, kb->wkvp);
if (rc)
goto out;
@@ -135,7 +135,6 @@ static int ep11_apqns4key(const u8 *key, u32 keylen, u32 flags,
*nr_apqns = _nr_apqns;

out:
- kfree(_apqns);
pr_debug("rc=%d\n", rc);
return rc;
}
@@ -144,7 +143,7 @@ static int ep11_apqns4type(enum pkey_key_type ktype,
u8 cur_mkvp[32], u8 alt_mkvp[32], u32 flags,
struct pkey_apqn *apqns, size_t *nr_apqns)
{
- u32 _nr_apqns, *_apqns = NULL;
+ u32 _apqns[MAXAPQNSINLIST], _nr_apqns = ARRAY_SIZE(_apqns);
int rc;

zcrypt_wait_api_operational();
@@ -158,7 +157,7 @@ static int ep11_apqns4type(enum pkey_key_type ktype,
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
wkvp = cur_mkvp;
api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
- rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
+ rc = ep11_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
ZCRYPT_CEX7, api, wkvp);
if (rc)
goto out;
@@ -178,7 +177,6 @@ static int ep11_apqns4type(enum pkey_key_type ktype,
*nr_apqns = _nr_apqns;

out:
- kfree(_apqns);
pr_debug("rc=%d\n", rc);
return rc;
}
@@ -423,7 +421,7 @@ static int ep11_verifykey(const u8 *key, u32 keylen,
u32 *keytype, u32 *keybitsize, u32 *flags)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
- u32 nr_apqns, *apqns = NULL;
+ u32 apqns[MAXAPQNSINLIST], nr_apqns = ARRAY_SIZE(apqns);
int rc;

if (keylen < sizeof(*hdr))
@@ -443,7 +441,7 @@ static int ep11_verifykey(const u8 *key, u32 keylen,
*keybitsize = kb->head.bitlen;

api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
- rc = ep11_findcard2(&apqns, &nr_apqns, *card, *dom,
+ rc = ep11_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX7, api,
ep11_kb_wkvp(key, keylen));
if (rc)
@@ -467,7 +465,7 @@ static int ep11_verifykey(const u8 *key, u32 keylen,
*keybitsize = kh->bitlen;

api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
- rc = ep11_findcard2(&apqns, &nr_apqns, *card, *dom,
+ rc = ep11_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX7, api,
ep11_kb_wkvp(key, keylen));
if (rc)
@@ -484,7 +482,6 @@ static int ep11_verifykey(const u8 *key, u32 keylen,
}

out:
- kfree(apqns);
pr_debug("rc=%d\n", rc);
return rc;
}
diff --git a/drivers/s390/crypto/zcrypt_ep11misc.c b/drivers/s390/crypto/zcrypt_ep11misc.c
index 04153b476168..6005ef79c001 100644
--- a/drivers/s390/crypto/zcrypt_ep11misc.c
+++ b/drivers/s390/crypto/zcrypt_ep11misc.c
@@ -1614,14 +1614,14 @@ int ep11_kblob2protkey(u16 card, u16 dom,
}
EXPORT_SYMBOL(ep11_kblob2protkey);

-int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
+int ep11_findcard2(u32 *apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
int minhwtype, int minapi, const u8 *wkvp)
{
struct zcrypt_device_status_ext *device_status;
- u32 *_apqns = NULL, _nr_apqns = 0;
int i, card, dom, rc;
struct ep11_domain_info edi;
struct ep11_card_info eci;
+ u32 _nr_apqns = 0;

/* occupy the device status memory */
mutex_lock(&dev_status_mem_mutex);
@@ -1635,13 +1635,6 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
if (rc)
goto out;

- /* allocate 1k space for up to 256 apqns */
- _apqns = kmalloc_array(256, sizeof(u32), GFP_KERNEL);
- if (!_apqns) {
- rc = -ENOMEM;
- goto out;
- }
-
/* walk through all the crypto apqnss */
for (i = 0; i < ZCRYPT_DEV_STATUS_ENTRIES; i++) {
card = AP_QID_CARD(device_status[i].qid);
@@ -1678,17 +1671,14 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
continue;
}
/* apqn passed all filtering criterons, add to the array */
- if (_nr_apqns < 256)
- _apqns[_nr_apqns++] = (((u16)card) << 16) | ((u16)dom);
+ if (_nr_apqns < *nr_apqns)
+ apqns[_nr_apqns++] = (((u16)card) << 16) | ((u16)dom);
}

/* nothing found ? */
if (!_nr_apqns) {
- kfree(_apqns);
rc = -ENODEV;
} else {
- /* no re-allocation, simple return the _apqns array */
- *apqns = _apqns;
*nr_apqns = _nr_apqns;
rc = 0;
}
diff --git a/drivers/s390/crypto/zcrypt_ep11misc.h b/drivers/s390/crypto/zcrypt_ep11misc.h
index a4b98eca8431..cbd615547bc2 100644
--- a/drivers/s390/crypto/zcrypt_ep11misc.h
+++ b/drivers/s390/crypto/zcrypt_ep11misc.h
@@ -136,14 +136,12 @@ int ep11_clr2keyblob(u16 cardnr, u16 domain, u32 keybitsize, u32 keygenflags,
* key for this domain. When a wkvp is given there will always be a re-fetch
* of the domain info for the potential apqn - so this triggers an request
* reply to each apqn eligible.
- * The array of apqn entries is allocated with kmalloc and returned in *apqns;
- * the number of apqns stored into the list is returned in *nr_apqns. One apqn
- * entry is simple a 32 bit value with 16 bit cardnr and 16 bit domain nr and
- * may be casted to struct pkey_apqn. The return value is either 0 for success
- * or a negative errno value. If no apqn meeting the criteria is found,
- * -ENODEV is returned.
+ * The caller should set *nr_apqns to the nr of elements available in *apqns.
+ * On return *nr_apqns is then updated with the nr of apqns filled into *apqns.
+ * The return value is either 0 for success or a negative errno value.
+ * If no apqn meeting the criteria is found, -ENODEV is returned.
*/
-int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
+int ep11_findcard2(u32 *apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
int minhwtype, int minapi, const u8 *wkvp);

/*
--
2.43.0