On Monday, February 1, 2016 4:18 PM, Herbert Xu wrote:
>
> On Wed, Jan 27, 2016 at 05:08:35PM +0800, Rui Wang wrote:
>>
>> +static int sha1_mb_async_import(struct ahash_request *req, const void
>> +*in) {
>> + struct ahash_request *mcryptd_req = ahash_request_ctx(req);
>> + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
>> + struct sha1_mb_ctx *ctx = crypto_ahash_ctx(tfm);
>> + struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
>> + struct crypto_shash *child = mcryptd_ahash_child(mcryptd_tfm);
>> + struct mcryptd_hash_request_ctx *rctx;
>> + struct shash_desc *desc;
>> + int err;
>> +
>> + memcpy(mcryptd_req, req, sizeof(*req));
>> + ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
>> + rctx = ahash_request_ctx(mcryptd_req);
>> + desc = &rctx->desc;
>> + desc->tfm = child;
>> + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
>> +
>> + err = crypto_shash_init(desc);
>> + if (err)
>> + return err;
>
> What is this desc for?
Hi Herbert,
Yeah I just realized that the call to crypto_shash_init() isn't necessary
here. What it does is overwritten by crypto_ahash_import(). But this desc
still needs to be initialized here because it's newly allocated by
ahash_request_alloc(). We eventually calls the shash version of import()
which needs desc as an argument. The real context to be imported is then
derived from shash_desc_ctx(desc).
desc is a sub-field of struct mcryptd_hash_request_ctx, which is again a
sub-field of the bigger blob allocated by ahash_request_alloc(). The entire
blob's size is set in sha1_mb_async_init_tfm(). So a better version is as
follows:
(just removed the call to crypto_shash_init())
>From 4bcb73adbef99aada94c49f352063619aa24d43d Mon Sep 17 00:00:00 2001
From: Rui Wang <rui.y.wang@xxxxxxxxx>
Date: Mon, 14 Dec 2015 17:22:13 +0800
Subject: [PATCH v2 1/4] crypto x86/sha1_mb: Fix load failure
modprobe sha1_mb fails with the following message:
modprobe: ERROR: could not insert 'sha1_mb': No such device
It is because it needs to set its statesize and implement its
import() and export() interface.
v2: remove redundant call to crypto_shash_init()
Signed-off-by: Rui Wang <rui.y.wang@xxxxxxxxx>
---
arch/x86/crypto/sha-mb/sha1_mb.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/arch/x86/crypto/sha-mb/sha1_mb.c b/arch/x86/crypto/sha-mb/sha1_mb.c
index a841e97..a8a0224 100644
--- a/arch/x86/crypto/sha-mb/sha1_mb.c
+++ b/arch/x86/crypto/sha-mb/sha1_mb.c
@@ -762,6 +762,38 @@ static int sha1_mb_async_digest(struct ahash_request *req)
return crypto_ahash_digest(mcryptd_req);
}
+static int sha1_mb_async_export(struct ahash_request *req, void *out)
+{
+ struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct sha1_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+ memcpy(mcryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+ return crypto_ahash_export(mcryptd_req, out);
+}
+
+static int sha1_mb_async_import(struct ahash_request *req, const void *in)
+{
+ struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct sha1_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+ struct crypto_shash *child = mcryptd_ahash_child(mcryptd_tfm);
+ struct mcryptd_hash_request_ctx *rctx;
+ struct shash_desc *desc;
+
+ memcpy(mcryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+ rctx = ahash_request_ctx(mcryptd_req);
+ desc = &rctx->desc;
+ desc->tfm = child;
+ desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ return crypto_ahash_import(mcryptd_req, in);
+}
+
static int sha1_mb_async_init_tfm(struct crypto_tfm *tfm)
{
struct mcryptd_ahash *mcryptd_tfm;
@@ -796,8 +828,11 @@ static struct ahash_alg sha1_mb_async_alg = {
.final = sha1_mb_async_final,
.finup = sha1_mb_async_finup,
.digest = sha1_mb_async_digest,
+ .export = sha1_mb_async_export,
+ .import = sha1_mb_async_import,
.halg = {
.digestsize = SHA1_DIGEST_SIZE,
+ .statesize = sizeof(struct sha1_hash_ctx),
.base = {
.cra_name = "sha1",
.cra_driver_name = "sha1_mb",
--
1.8.3.1
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