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author | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2014-04-14 12:00:36 -0300 |
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committer | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2014-04-14 12:00:36 -0300 |
commit | a803453c26535b1f07ff297732cb75ce51d5346d (patch) | |
tree | c204dd2fda16e95058e86a029b30389b5840db53 /crypto/ahash.c | |
parent | 46932cc3784fab58cedfed099127f243e7af9102 (diff) | |
parent | ce945bb935ddd4a72cc49c11e755dea2de7a81c9 (diff) | |
download | linux-crypto-a803453c26535b1f07ff297732cb75ce51d5346d.tar.gz linux-crypto-a803453c26535b1f07ff297732cb75ce51d5346d.zip |
Merge tag 'v3.15-rc1' into patchwork
Linux 3.15-rc1
* tag 'v3.15-rc1': (12180 commits)
Linux 3.15-rc1
mm: Initialize error in shmem_file_aio_read()
cifs: Use min_t() when comparing "size_t" and "unsigned long"
sym53c8xx_2: Set DID_REQUEUE return code when aborting squeue
powerpc: Don't try to set LPCR unless we're in hypervisor mode
futex: update documentation for ordering guarantees
ceph: fix pr_fmt() redefinition
vti: don't allow to add the same tunnel twice
gre: don't allow to add the same tunnel twice
drivers: net: xen-netfront: fix array initialization bug
missing bits of "splice: fix racy pipe->buffers uses"
cifs: fix the race in cifs_writev()
ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
pktgen: be friendly to LLTX devices
r8152: check RTL8152_UNPLUG
net: sun4i-emac: add promiscuous support
net/apne: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
blackfin: cleanup board files
bf609: clock: drop unused clock bit set/clear functions
Blackfin: bf537: rename "CONFIG_ADT75"
...
Diffstat (limited to '')
-rw-r--r-- | crypto/ahash.c | 147 |
1 files changed, 94 insertions, 53 deletions
diff --git a/crypto/ahash.c b/crypto/ahash.c index a92dc382..6e722339 100644 --- a/crypto/ahash.c +++ b/crypto/ahash.c @@ -190,6 +190,75 @@ static inline unsigned int ahash_align_buffer_size(unsigned len, return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); } +static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) +{ + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + unsigned long alignmask = crypto_ahash_alignmask(tfm); + unsigned int ds = crypto_ahash_digestsize(tfm); + struct ahash_request_priv *priv; + + priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), + (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? + GFP_KERNEL : GFP_ATOMIC); + if (!priv) + return -ENOMEM; + + /* + * WARNING: Voodoo programming below! + * + * The code below is obscure and hard to understand, thus explanation + * is necessary. See include/crypto/hash.h and include/linux/crypto.h + * to understand the layout of structures used here! + * + * The code here will replace portions of the ORIGINAL request with + * pointers to new code and buffers so the hashing operation can store + * the result in aligned buffer. We will call the modified request + * an ADJUSTED request. + * + * The newly mangled request will look as such: + * + * req { + * .result = ADJUSTED[new aligned buffer] + * .base.complete = ADJUSTED[pointer to completion function] + * .base.data = ADJUSTED[*req (pointer to self)] + * .priv = ADJUSTED[new priv] { + * .result = ORIGINAL(result) + * .complete = ORIGINAL(base.complete) + * .data = ORIGINAL(base.data) + * } + */ + + priv->result = req->result; + priv->complete = req->base.complete; + priv->data = req->base.data; + /* + * WARNING: We do not backup req->priv here! The req->priv + * is for internal use of the Crypto API and the + * user must _NOT_ _EVER_ depend on it's content! + */ + + req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); + req->base.complete = cplt; + req->base.data = req; + req->priv = priv; + + return 0; +} + +static void ahash_restore_req(struct ahash_request *req) +{ + struct ahash_request_priv *priv = req->priv; + + /* Restore the original crypto request. */ + req->result = priv->result; + req->base.complete = priv->complete; + req->base.data = priv->data; + req->priv = NULL; + + /* Free the req->priv.priv from the ADJUSTED request. */ + kzfree(priv); +} + static void ahash_op_unaligned_finish(struct ahash_request *req, int err) { struct ahash_request_priv *priv = req->priv; @@ -201,47 +270,37 @@ static void ahash_op_unaligned_finish(struct ahash_request *req, int err) memcpy(priv->result, req->result, crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); - kzfree(priv); + ahash_restore_req(req); } static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; - struct ahash_request_priv *priv = areq->priv; - crypto_completion_t complete = priv->complete; - void *data = priv->data; - ahash_op_unaligned_finish(areq, err); + /* + * Restore the original request, see ahash_op_unaligned() for what + * goes where. + * + * The "struct ahash_request *req" here is in fact the "req.base" + * from the ADJUSTED request from ahash_op_unaligned(), thus as it + * is a pointer to self, it is also the ADJUSTED "req" . + */ - areq->base.complete = complete; - areq->base.data = data; + /* First copy req->result into req->priv.result */ + ahash_op_unaligned_finish(areq, err); - complete(&areq->base, err); + /* Complete the ORIGINAL request. */ + areq->base.complete(&areq->base, err); } static int ahash_op_unaligned(struct ahash_request *req, int (*op)(struct ahash_request *)) { - struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); - unsigned long alignmask = crypto_ahash_alignmask(tfm); - unsigned int ds = crypto_ahash_digestsize(tfm); - struct ahash_request_priv *priv; int err; - priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), - (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? - GFP_KERNEL : GFP_ATOMIC); - if (!priv) - return -ENOMEM; - - priv->result = req->result; - priv->complete = req->base.complete; - priv->data = req->base.data; - - req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); - req->base.complete = ahash_op_unaligned_done; - req->base.data = req; - req->priv = priv; + err = ahash_save_req(req, ahash_op_unaligned_done); + if (err) + return err; err = op(req); ahash_op_unaligned_finish(req, err); @@ -290,19 +349,16 @@ static void ahash_def_finup_finish2(struct ahash_request *req, int err) memcpy(priv->result, req->result, crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); - kzfree(priv); + ahash_restore_req(req); } static void ahash_def_finup_done2(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; - struct ahash_request_priv *priv = areq->priv; - crypto_completion_t complete = priv->complete; - void *data = priv->data; ahash_def_finup_finish2(areq, err); - complete(data, err); + areq->base.complete(&areq->base, err); } static int ahash_def_finup_finish1(struct ahash_request *req, int err) @@ -322,38 +378,23 @@ out: static void ahash_def_finup_done1(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; - struct ahash_request_priv *priv = areq->priv; - crypto_completion_t complete = priv->complete; - void *data = priv->data; err = ahash_def_finup_finish1(areq, err); - complete(data, err); + areq->base.complete(&areq->base, err); } static int ahash_def_finup(struct ahash_request *req) { struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); - unsigned long alignmask = crypto_ahash_alignmask(tfm); - unsigned int ds = crypto_ahash_digestsize(tfm); - struct ahash_request_priv *priv; - - priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), - (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? - GFP_KERNEL : GFP_ATOMIC); - if (!priv) - return -ENOMEM; - - priv->result = req->result; - priv->complete = req->base.complete; - priv->data = req->base.data; + int err; - req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); - req->base.complete = ahash_def_finup_done1; - req->base.data = req; - req->priv = priv; + err = ahash_save_req(req, ahash_def_finup_done1); + if (err) + return err; - return ahash_def_finup_finish1(req, tfm->update(req)); + err = tfm->update(req); + return ahash_def_finup_finish1(req, err); } static int ahash_no_export(struct ahash_request *req, void *out) |