crypto: api - Add crypto_stack_request_init and initialise flags fully

Add a helper to initialise crypto stack requests and use it for
ahash and acomp.  Make sure that the flags field is initialised
fully in the helper to silence false-positive warnings from the
compiler.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202504250751.mdy28Ibr-lkp@intel.com/
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: herbertx

include/crypto/acompress.h

@@ -547,8 +547,7 @@ static inline struct acomp_req *acomp_request_on_stack_init(
 {
 	struct acomp_req *req = (void *)buf;
 
-	acomp_request_set_tfm(req, tfm);
-	req->base.flags = CRYPTO_TFM_REQ_ON_STACK;
+	crypto_stack_request_init(&req->base, crypto_acomp_tfm(tfm));
 	return req;
 }
 

include/crypto/hash.h

@@ -1029,8 +1029,7 @@ static inline struct ahash_request *ahash_request_on_stack_init(
 {
 	struct ahash_request *req = (void *)buf;
 
-	ahash_request_set_tfm(req, tfm);
-	req->base.flags = CRYPTO_TFM_REQ_ON_STACK;
+	crypto_stack_request_init(&req->base, crypto_ahash_tfm(tfm));
 	return req;
 }
 

include/crypto/internal/acompress.h

@@ -231,8 +231,8 @@ static inline struct acomp_req *acomp_fbreq_on_stack_init(
 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(old);
 	struct acomp_req *req = (void *)buf;
 
-	acomp_request_set_tfm(req, crypto_acomp_fb(tfm));
-	req->base.flags = CRYPTO_TFM_REQ_ON_STACK;
+	crypto_stack_request_init(&req->base,
+				  crypto_acomp_tfm(crypto_acomp_fb(tfm)));
 	acomp_request_set_callback(req, acomp_request_flags(old), NULL, NULL);
 	req->base.flags &= ~CRYPTO_ACOMP_REQ_PRIVATE;
 	req->base.flags |= old->base.flags & CRYPTO_ACOMP_REQ_PRIVATE;

include/crypto/internal/hash.h

@@ -283,8 +283,8 @@ static inline struct ahash_request *ahash_fbreq_on_stack_init(
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(old);
 	struct ahash_request *req = (void *)buf;
 
-	ahash_request_set_tfm(req, crypto_ahash_fb(tfm));
-	req->base.flags = CRYPTO_TFM_REQ_ON_STACK;
+	crypto_stack_request_init(&req->base,
+				  crypto_ahash_tfm(crypto_ahash_fb(tfm)));
 	ahash_request_set_callback(req, ahash_request_flags(old), NULL, NULL);
 	req->base.flags &= ~CRYPTO_AHASH_REQ_PRIVATE;
 	req->base.flags |= old->base.flags & CRYPTO_AHASH_REQ_PRIVATE;

include/linux/crypto.h

@@ -514,5 +514,13 @@ static inline void crypto_request_set_tfm(struct crypto_async_request *req,
 struct crypto_async_request *crypto_request_clone(
 	struct crypto_async_request *req, size_t total, gfp_t gfp);
 
+static inline void crypto_stack_request_init(struct crypto_async_request *req,
+					     struct crypto_tfm *tfm)
+{
+	req->flags = 0;
+	crypto_request_set_tfm(req, tfm);
+	req->flags |= CRYPTO_TFM_REQ_ON_STACK;
+}
+
 #endif	/* _LINUX_CRYPTO_H */