From: Harald Freudenberger Date: Thu, 24 Apr 2025 13:36:00 +0000 (+0200) Subject: s390/zcrypt: Introduce cprb mempool for cca misc functions X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9bdb5f7e8369b1456c60c998b524062d1f412d06;p=users%2Fdwmw2%2Flinux.git s390/zcrypt: Introduce cprb mempool for cca misc functions Introduce a new module parameter "zcrypt_mempool_threshold" for the zcrypt module. This parameter controls the minimal amount of mempool items which are pre-allocated for urgent requests/replies and will be used with the support for the new xflag ZCRYPT_XFLAG_NOMEMALLOC. The default value of 5 shall provide enough memory items to support up to 5 requests (and their associated reply) in parallel. The minimum value is 1 and is checked in zcrypt module init(). If the mempool is depleted upon one cca misc functions is called with the named xflag set, the function will fail with -ENOMEM and the caller is responsible for taking further actions. For CCA each mempool item is 16KB, as a CCA CPRB needs to hold the request and the reply. The pool items only support requests/replies with a limit of about 8KB. So by default the CCA mempool consumes 5 * 16KB = 80KB This is only part of an rework to support a new xflag ZCRYPT_XFLAG_NOMEMALLOC but not yet complete. Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Link: https://lore.kernel.org/r/20250424133619.16495-7-freude@linux.ibm.com Signed-off-by: Heiko Carstens --- diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 3a75c3b6c0044..57d819966dad3 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -50,6 +50,10 @@ MODULE_DESCRIPTION("Cryptographic Coprocessor interface, " \ "Copyright IBM Corp. 2001, 2012"); MODULE_LICENSE("GPL"); +unsigned int zcrypt_mempool_threshold = 5; +module_param_named(mempool_threshold, zcrypt_mempool_threshold, uint, 0440); +MODULE_PARM_DESC(mempool_threshold, "CCA and EP11 request/reply mempool minimal items (min: 1)"); + /* * zcrypt tracepoint functions */ @@ -2144,13 +2148,23 @@ int __init zcrypt_api_init(void) { int rc; + /* make sure the mempool threshold is >= 1 */ + if (zcrypt_mempool_threshold < 1) { + rc = -EINVAL; + goto out; + } + rc = zcrypt_debug_init(); if (rc) goto out; rc = zcdn_init(); if (rc) - goto out; + goto out_zcdn_init_failed; + + rc = zcrypt_ccamisc_init(); + if (rc) + goto out_ccamisc_init_failed; /* Register the request sprayer. */ rc = misc_register(&zcrypt_misc_device); @@ -2163,7 +2177,10 @@ int __init zcrypt_api_init(void) return 0; out_misc_register_failed: + zcrypt_ccamisc_exit(); +out_ccamisc_init_failed: zcdn_exit(); +out_zcdn_init_failed: zcrypt_debug_exit(); out: return rc; diff --git a/drivers/s390/crypto/zcrypt_api.h b/drivers/s390/crypto/zcrypt_api.h index 44f1583295451..14ed3e4e8e565 100644 --- a/drivers/s390/crypto/zcrypt_api.h +++ b/drivers/s390/crypto/zcrypt_api.h @@ -139,6 +139,8 @@ extern atomic_t zcrypt_rescan_req; extern spinlock_t zcrypt_list_lock; extern struct list_head zcrypt_card_list; +extern unsigned int zcrypt_mempool_threshold; + #define for_each_zcrypt_card(_zc) \ list_for_each_entry(_zc, &zcrypt_card_list, list) diff --git a/drivers/s390/crypto/zcrypt_ccamisc.c b/drivers/s390/crypto/zcrypt_ccamisc.c index 521baaea06ffe..d51ab5a0c58fa 100644 --- a/drivers/s390/crypto/zcrypt_ccamisc.c +++ b/drivers/s390/crypto/zcrypt_ccamisc.c @@ -11,6 +11,7 @@ #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include +#include #include #include #include @@ -40,6 +41,16 @@ struct cca_info_list_entry { static LIST_HEAD(cca_info_list); static DEFINE_SPINLOCK(cca_info_list_lock); +/* + * Cprb memory pool held for urgent cases where no memory + * can be allocated via kmalloc. This pool is only used + * when alloc_and_prep_cprbmem() is called with the xflag + * ZCRYPT_XFLAG_NOMEMALLOC. The cprb memory needs to hold + * space for request AND reply! + */ +#define CPRB_MEMPOOL_ITEM_SIZE (16 * 1024) +static mempool_t *cprb_mempool; + /* * Simple check if the token is a valid CCA secure AES data key * token. If keybitsize is given, the bitsize of the key is @@ -219,19 +230,27 @@ EXPORT_SYMBOL(cca_check_sececckeytoken); static int alloc_and_prep_cprbmem(size_t paramblen, u8 **p_cprb_mem, struct CPRBX **p_req_cprb, - struct CPRBX **p_rep_cprb) + struct CPRBX **p_rep_cprb, + u32 xflags) { - u8 *cprbmem; + u8 *cprbmem = NULL; size_t cprbplusparamblen = sizeof(struct CPRBX) + paramblen; + size_t len = 2 * cprbplusparamblen; struct CPRBX *preqcblk, *prepcblk; /* * allocate consecutive memory for request CPRB, request param * block, reply CPRB and reply param block */ - cprbmem = kcalloc(2, cprbplusparamblen, GFP_KERNEL); + if (xflags & ZCRYPT_XFLAG_NOMEMALLOC) { + if (len <= CPRB_MEMPOOL_ITEM_SIZE) + cprbmem = mempool_alloc_preallocated(cprb_mempool); + } else { + cprbmem = kmalloc(len, GFP_KERNEL); + } if (!cprbmem) return -ENOMEM; + memset(cprbmem, 0, len); preqcblk = (struct CPRBX *)cprbmem; prepcblk = (struct CPRBX *)(cprbmem + cprbplusparamblen); @@ -261,11 +280,15 @@ static int alloc_and_prep_cprbmem(size_t paramblen, * with zeros before freeing (useful if there was some * clear key material in there). */ -static void free_cprbmem(void *mem, size_t paramblen, int scrub) +static void free_cprbmem(void *mem, size_t paramblen, bool scrub, u32 xflags) { - if (scrub) + if (mem && scrub) memzero_explicit(mem, 2 * (sizeof(struct CPRBX) + paramblen)); - kfree(mem); + + if (xflags & ZCRYPT_XFLAG_NOMEMALLOC) + mempool_free(mem, cprb_mempool); + else + kfree(mem); } /* @@ -330,9 +353,11 @@ int cca_genseckey(u16 cardnr, u16 domain, } keyblock; } lv3; } __packed * prepparm; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -379,7 +404,7 @@ int cca_genseckey(u16 cardnr, u16 domain, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, errno %d\n", __func__, (int)cardnr, (int)domain, rc); @@ -424,7 +449,7 @@ int cca_genseckey(u16 cardnr, u16 domain, memcpy(seckey, prepparm->lv3.keyblock.tok, SECKEYBLOBSIZE); out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, false, xflags); return rc; } EXPORT_SYMBOL(cca_genseckey); @@ -471,9 +496,11 @@ int cca_clr2seckey(u16 cardnr, u16 domain, u32 keybitsize, } keyblock; } lv3; } __packed * prepparm; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -517,7 +544,7 @@ int cca_clr2seckey(u16 cardnr, u16 domain, u32 keybitsize, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -563,7 +590,7 @@ int cca_clr2seckey(u16 cardnr, u16 domain, u32 keybitsize, memcpy(seckey, prepparm->lv3.keyblock.tok, SECKEYBLOBSIZE); out: - free_cprbmem(mem, PARMBSIZE, 1); + free_cprbmem(mem, PARMBSIZE, true, xflags); return rc; } EXPORT_SYMBOL(cca_clr2seckey); @@ -617,9 +644,11 @@ int cca_sec2protkey(u16 cardnr, u16 domain, } ckb; } lv3; } __packed * prepparm; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -644,7 +673,7 @@ int cca_sec2protkey(u16 cardnr, u16 domain, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -712,7 +741,7 @@ int cca_sec2protkey(u16 cardnr, u16 domain, *protkeylen = prepparm->lv3.ckb.len; out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, true, xflags); return rc; } EXPORT_SYMBOL(cca_sec2protkey); @@ -811,9 +840,11 @@ int cca_gencipherkey(u16 cardnr, u16 domain, u32 keybitsize, u32 keygenflags, } kb; } __packed * prepparm; struct cipherkeytoken *t; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -872,7 +903,7 @@ int cca_gencipherkey(u16 cardnr, u16 domain, u32 keybitsize, u32 keygenflags, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -923,7 +954,7 @@ int cca_gencipherkey(u16 cardnr, u16 domain, u32 keybitsize, u32 keygenflags, *keybufsize = t->len; out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, false, xflags); return rc; } EXPORT_SYMBOL(cca_gencipherkey); @@ -987,9 +1018,11 @@ static int _ip_cprb_helper(u16 cardnr, u16 domain, } __packed * prepparm; struct cipherkeytoken *t; int complete = strncmp(rule_array_2, "COMPLETE", 8) ? 0 : 1; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -1038,7 +1071,7 @@ static int _ip_cprb_helper(u16 cardnr, u16 domain, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -1077,7 +1110,7 @@ static int _ip_cprb_helper(u16 cardnr, u16 domain, *key_token_size = t->len; out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, false, xflags); return rc; } @@ -1217,9 +1250,11 @@ int cca_cipher2protkey(u16 cardnr, u16 domain, const u8 *ckey, } kb; } __packed * prepparm; int keytoklen = ((struct cipherkeytoken *)ckey)->len; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -1249,7 +1284,7 @@ int cca_cipher2protkey(u16 cardnr, u16 domain, const u8 *ckey, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -1323,7 +1358,7 @@ int cca_cipher2protkey(u16 cardnr, u16 domain, const u8 *ckey, *protkeylen = prepparm->vud.ckb.keylen; out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, true, xflags); return rc; } EXPORT_SYMBOL(cca_cipher2protkey); @@ -1380,9 +1415,11 @@ int cca_ecc2protkey(u16 cardnr, u16 domain, const u8 *key, /* followed by a key block */ } __packed * prepparm; int keylen = ((struct eccprivkeytoken *)key)->len; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -1412,7 +1449,7 @@ int cca_ecc2protkey(u16 cardnr, u16 domain, const u8 *key, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -1470,7 +1507,7 @@ int cca_ecc2protkey(u16 cardnr, u16 domain, const u8 *key, *protkeytype = PKEY_KEYTYPE_ECC; out: - free_cprbmem(mem, PARMBSIZE, 0); + free_cprbmem(mem, PARMBSIZE, true, xflags); return rc; } EXPORT_SYMBOL(cca_ecc2protkey); @@ -1503,9 +1540,11 @@ int cca_query_crypto_facility(u16 cardnr, u16 domain, u8 subfunc_code[2]; u8 lvdata[]; } __packed * prepparm; + const u32 xflags = 0; /* get already prepared memory for 2 cprbs with param block each */ - rc = alloc_and_prep_cprbmem(parmbsize, &mem, &preqcblk, &prepcblk); + rc = alloc_and_prep_cprbmem(parmbsize, &mem, + &preqcblk, &prepcblk, xflags); if (rc) return rc; @@ -1526,7 +1565,7 @@ int cca_query_crypto_facility(u16 cardnr, u16 domain, prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk); /* forward xcrb with request CPRB and reply CPRB to zcrypt dd */ - rc = zcrypt_send_cprb(&xcrb, 0); + rc = zcrypt_send_cprb(&xcrb, xflags); if (rc) { ZCRYPT_DBF_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n", __func__, (int)cardnr, (int)domain, rc); @@ -1573,7 +1612,7 @@ int cca_query_crypto_facility(u16 cardnr, u16 domain, } out: - free_cprbmem(mem, parmbsize, 0); + free_cprbmem(mem, parmbsize, false, xflags); return rc; } EXPORT_SYMBOL(cca_query_crypto_facility); @@ -1959,7 +1998,19 @@ int cca_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain, } EXPORT_SYMBOL(cca_findcard2); -void __exit zcrypt_ccamisc_exit(void) +int __init zcrypt_ccamisc_init(void) +{ + /* Pre-allocate a small memory pool for cca cprbs. */ + cprb_mempool = mempool_create_kmalloc_pool(zcrypt_mempool_threshold, + CPRB_MEMPOOL_ITEM_SIZE); + if (!cprb_mempool) + return -ENOMEM; + + return 0; +} + +void zcrypt_ccamisc_exit(void) { mkvp_cache_free(); + mempool_destroy(cprb_mempool); } diff --git a/drivers/s390/crypto/zcrypt_ccamisc.h b/drivers/s390/crypto/zcrypt_ccamisc.h index 26bdca702523d..273edf2bb0366 100644 --- a/drivers/s390/crypto/zcrypt_ccamisc.h +++ b/drivers/s390/crypto/zcrypt_ccamisc.h @@ -272,6 +272,7 @@ struct cca_info { */ int cca_get_info(u16 card, u16 dom, struct cca_info *ci, int verify); +int zcrypt_ccamisc_init(void); void zcrypt_ccamisc_exit(void); #endif /* _ZCRYPT_CCAMISC_H_ */