[v5,8/8] crypto, x86/sha: Eliminate casts on asm implementations
diff mbox series

Message ID 20191113182516.13545-9-keescook@chromium.org
State New
Headers show
Series
  • crypto: x86: Fix indirect function call casts
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Commit Message

Kees Cook Nov. 13, 2019, 6:25 p.m. UTC
In order to avoid CFI function prototype mismatches, this removes the
casts on assembly implementations of sha1/256/512 accelerators. The
safety checks from BUILD_BUG_ON() remain.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/crypto/sha1_ssse3_glue.c   | 61 ++++++++++++-----------------
 arch/x86/crypto/sha256_ssse3_glue.c | 31 +++++++--------
 arch/x86/crypto/sha512_ssse3_glue.c | 28 ++++++-------
 3 files changed, 50 insertions(+), 70 deletions(-)

Comments

Eric Biggers Nov. 13, 2019, 7:55 p.m. UTC | #1
On Wed, Nov 13, 2019 at 10:25:16AM -0800, Kees Cook wrote:
> In order to avoid CFI function prototype mismatches, this removes the
> casts on assembly implementations of sha1/256/512 accelerators. The
> safety checks from BUILD_BUG_ON() remain.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/x86/crypto/sha1_ssse3_glue.c   | 61 ++++++++++++-----------------
>  arch/x86/crypto/sha256_ssse3_glue.c | 31 +++++++--------
>  arch/x86/crypto/sha512_ssse3_glue.c | 28 ++++++-------
>  3 files changed, 50 insertions(+), 70 deletions(-)
> 
> diff --git a/arch/x86/crypto/sha1_ssse3_glue.c b/arch/x86/crypto/sha1_ssse3_glue.c
> index 639d4c2fd6a8..a151d899f37a 100644
> --- a/arch/x86/crypto/sha1_ssse3_glue.c
> +++ b/arch/x86/crypto/sha1_ssse3_glue.c
> @@ -27,11 +27,8 @@
>  #include <crypto/sha1_base.h>
>  #include <asm/simd.h>
>  
> -typedef void (sha1_transform_fn)(u32 *digest, const char *data,
> -				unsigned int rounds);
> -
>  static int sha1_update(struct shash_desc *desc, const u8 *data,
> -			     unsigned int len, sha1_transform_fn *sha1_xform)
> +			     unsigned int len, sha1_block_fn *sha1_xform)
>  {
>  	struct sha1_state *sctx = shash_desc_ctx(desc);
>  
> @@ -39,48 +36,44 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
>  	    (sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
>  		return crypto_sha1_update(desc, data, len);
>  
> -	/* make sure casting to sha1_block_fn() is safe */
> +	/* make sure sha1_block_fn() use in generic routines is safe */
>  	BUILD_BUG_ON(offsetof(struct sha1_state, state) != 0);

This update to the comment makes no sense, since sha1_block_fn() is obviously
safe in the helpers, and this says nothing about the assembly functions.
Instead this should say something like:

	/*
	 * Make sure that struct sha1_state begins directly with the 160-bit
	 * SHA1 internal state, as this is what the assembly functions expect.
	 */

Likewise for SHA-256 and SHA-512, except for those it would be a 256-bit and
512-bit internal state respectively.

> -asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
> -				     unsigned int rounds);
> +asmlinkage void sha1_transform_ssse3(struct sha1_state *digest,
> +				     u8 const *data, int rounds);

'u8 const' is unconventional.  Please use 'const u8' instead.

Also, this function prototype is also given in a comment in the corresponding
assembly file.  Can you please update that too, and also leave a comment in the
assembly file like "struct sha1_state is assumed to begin with u32 state[5]."?

Likewise for all the other SHA-1, and SHA-256, and SHA-512 assembly functions,
except it would be u32 state[8] for SHA-256 and u64 state[8] for SHA-512.

- Eric
Kees Cook Nov. 21, 2019, 11:14 p.m. UTC | #2
On Wed, Nov 13, 2019 at 11:55:30AM -0800, Eric Biggers wrote:
> On Wed, Nov 13, 2019 at 10:25:16AM -0800, Kees Cook wrote:
> > In order to avoid CFI function prototype mismatches, this removes the
> > casts on assembly implementations of sha1/256/512 accelerators. The
> > safety checks from BUILD_BUG_ON() remain.
> > 
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  arch/x86/crypto/sha1_ssse3_glue.c   | 61 ++++++++++++-----------------
> >  arch/x86/crypto/sha256_ssse3_glue.c | 31 +++++++--------
> >  arch/x86/crypto/sha512_ssse3_glue.c | 28 ++++++-------
> >  3 files changed, 50 insertions(+), 70 deletions(-)
> > 
> > diff --git a/arch/x86/crypto/sha1_ssse3_glue.c b/arch/x86/crypto/sha1_ssse3_glue.c
> > index 639d4c2fd6a8..a151d899f37a 100644
> > --- a/arch/x86/crypto/sha1_ssse3_glue.c
> > +++ b/arch/x86/crypto/sha1_ssse3_glue.c
> > @@ -27,11 +27,8 @@
> >  #include <crypto/sha1_base.h>
> >  #include <asm/simd.h>
> >  
> > -typedef void (sha1_transform_fn)(u32 *digest, const char *data,
> > -				unsigned int rounds);
> > -
> >  static int sha1_update(struct shash_desc *desc, const u8 *data,
> > -			     unsigned int len, sha1_transform_fn *sha1_xform)
> > +			     unsigned int len, sha1_block_fn *sha1_xform)
> >  {
> >  	struct sha1_state *sctx = shash_desc_ctx(desc);
> >  
> > @@ -39,48 +36,44 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
> >  	    (sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
> >  		return crypto_sha1_update(desc, data, len);
> >  
> > -	/* make sure casting to sha1_block_fn() is safe */
> > +	/* make sure sha1_block_fn() use in generic routines is safe */
> >  	BUILD_BUG_ON(offsetof(struct sha1_state, state) != 0);
> 
> This update to the comment makes no sense, since sha1_block_fn() is obviously
> safe in the helpers, and this says nothing about the assembly functions.
> Instead this should say something like:
> 
> 	/*
> 	 * Make sure that struct sha1_state begins directly with the 160-bit
> 	 * SHA1 internal state, as this is what the assembly functions expect.
> 	 */
> 
> Likewise for SHA-256 and SHA-512, except for those it would be a 256-bit and
> 512-bit internal state respectively.

Thanks! Agreed, that is much clearer.

> > -asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
> > -				     unsigned int rounds);
> > +asmlinkage void sha1_transform_ssse3(struct sha1_state *digest,
> > +				     u8 const *data, int rounds);
> 
> 'u8 const' is unconventional.  Please use 'const u8' instead.

Yeah, I noticed that but decided to disrupt less. Fixed now.

> Also, this function prototype is also given in a comment in the corresponding
> assembly file.  Can you please update that too, and also leave a comment in the
> assembly file like "struct sha1_state is assumed to begin with u32 state[5]."?
> 
> Likewise for all the other SHA-1, and SHA-256, and SHA-512 assembly functions,
> except it would be u32 state[8] for SHA-256 and u64 state[8] for SHA-512.

I love how each uses an entirely different comment style. :) Updated!

Patch
diff mbox series

diff --git a/arch/x86/crypto/sha1_ssse3_glue.c b/arch/x86/crypto/sha1_ssse3_glue.c
index 639d4c2fd6a8..a151d899f37a 100644
--- a/arch/x86/crypto/sha1_ssse3_glue.c
+++ b/arch/x86/crypto/sha1_ssse3_glue.c
@@ -27,11 +27,8 @@ 
 #include <crypto/sha1_base.h>
 #include <asm/simd.h>
 
-typedef void (sha1_transform_fn)(u32 *digest, const char *data,
-				unsigned int rounds);
-
 static int sha1_update(struct shash_desc *desc, const u8 *data,
-			     unsigned int len, sha1_transform_fn *sha1_xform)
+			     unsigned int len, sha1_block_fn *sha1_xform)
 {
 	struct sha1_state *sctx = shash_desc_ctx(desc);
 
@@ -39,48 +36,44 @@  static int sha1_update(struct shash_desc *desc, const u8 *data,
 	    (sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
 		return crypto_sha1_update(desc, data, len);
 
-	/* make sure casting to sha1_block_fn() is safe */
+	/* make sure sha1_block_fn() use in generic routines is safe */
 	BUILD_BUG_ON(offsetof(struct sha1_state, state) != 0);
 
 	kernel_fpu_begin();
-	sha1_base_do_update(desc, data, len,
-			    (sha1_block_fn *)sha1_xform);
+	sha1_base_do_update(desc, data, len, sha1_xform);
 	kernel_fpu_end();
 
 	return 0;
 }
 
 static int sha1_finup(struct shash_desc *desc, const u8 *data,
-		      unsigned int len, u8 *out, sha1_transform_fn *sha1_xform)
+		      unsigned int len, u8 *out, sha1_block_fn *sha1_xform)
 {
 	if (!crypto_simd_usable())
 		return crypto_sha1_finup(desc, data, len, out);
 
 	kernel_fpu_begin();
 	if (len)
-		sha1_base_do_update(desc, data, len,
-				    (sha1_block_fn *)sha1_xform);
-	sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_xform);
+		sha1_base_do_update(desc, data, len, sha1_xform);
+	sha1_base_do_finalize(desc, sha1_xform);
 	kernel_fpu_end();
 
 	return sha1_base_finish(desc, out);
 }
 
-asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
-				     unsigned int rounds);
+asmlinkage void sha1_transform_ssse3(struct sha1_state *digest,
+				     u8 const *data, int rounds);
 
 static int sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
 			     unsigned int len)
 {
-	return sha1_update(desc, data, len,
-			(sha1_transform_fn *) sha1_transform_ssse3);
+	return sha1_update(desc, data, len, sha1_transform_ssse3);
 }
 
 static int sha1_ssse3_finup(struct shash_desc *desc, const u8 *data,
 			      unsigned int len, u8 *out)
 {
-	return sha1_finup(desc, data, len, out,
-			(sha1_transform_fn *) sha1_transform_ssse3);
+	return sha1_finup(desc, data, len, out, sha1_transform_ssse3);
 }
 
 /* Add padding and return the message digest. */
@@ -119,21 +112,19 @@  static void unregister_sha1_ssse3(void)
 }
 
 #ifdef CONFIG_AS_AVX
-asmlinkage void sha1_transform_avx(u32 *digest, const char *data,
-				   unsigned int rounds);
+asmlinkage void sha1_transform_avx(struct sha1_state *digest,
+				   u8 const *data, int rounds);
 
 static int sha1_avx_update(struct shash_desc *desc, const u8 *data,
 			     unsigned int len)
 {
-	return sha1_update(desc, data, len,
-			(sha1_transform_fn *) sha1_transform_avx);
+	return sha1_update(desc, data, len, sha1_transform_avx);
 }
 
 static int sha1_avx_finup(struct shash_desc *desc, const u8 *data,
 			      unsigned int len, u8 *out)
 {
-	return sha1_finup(desc, data, len, out,
-			(sha1_transform_fn *) sha1_transform_avx);
+	return sha1_finup(desc, data, len, out, sha1_transform_avx);
 }
 
 static int sha1_avx_final(struct shash_desc *desc, u8 *out)
@@ -190,8 +181,8 @@  static inline void unregister_sha1_avx(void) { }
 #if defined(CONFIG_AS_AVX2) && (CONFIG_AS_AVX)
 #define SHA1_AVX2_BLOCK_OPTSIZE	4	/* optimal 4*64 bytes of SHA1 blocks */
 
-asmlinkage void sha1_transform_avx2(u32 *digest, const char *data,
-				    unsigned int rounds);
+asmlinkage void sha1_transform_avx2(struct sha1_state *digest,
+				    u8 const *data, int rounds);
 
 static bool avx2_usable(void)
 {
@@ -203,8 +194,8 @@  static bool avx2_usable(void)
 	return false;
 }
 
-static void sha1_apply_transform_avx2(u32 *digest, const char *data,
-				unsigned int rounds)
+static void sha1_apply_transform_avx2(struct sha1_state *digest,
+				      u8 const *data, int rounds)
 {
 	/* Select the optimal transform based on data block size */
 	if (rounds >= SHA1_AVX2_BLOCK_OPTSIZE)
@@ -216,15 +207,13 @@  static void sha1_apply_transform_avx2(u32 *digest, const char *data,
 static int sha1_avx2_update(struct shash_desc *desc, const u8 *data,
 			     unsigned int len)
 {
-	return sha1_update(desc, data, len,
-		(sha1_transform_fn *) sha1_apply_transform_avx2);
+	return sha1_update(desc, data, len, sha1_apply_transform_avx2);
 }
 
 static int sha1_avx2_finup(struct shash_desc *desc, const u8 *data,
 			      unsigned int len, u8 *out)
 {
-	return sha1_finup(desc, data, len, out,
-		(sha1_transform_fn *) sha1_apply_transform_avx2);
+	return sha1_finup(desc, data, len, out, sha1_apply_transform_avx2);
 }
 
 static int sha1_avx2_final(struct shash_desc *desc, u8 *out)
@@ -267,21 +256,19 @@  static inline void unregister_sha1_avx2(void) { }
 #endif
 
 #ifdef CONFIG_AS_SHA1_NI
-asmlinkage void sha1_ni_transform(u32 *digest, const char *data,
-				   unsigned int rounds);
+asmlinkage void sha1_ni_transform(struct sha1_state *digest, u8 const *data,
+				  int rounds);
 
 static int sha1_ni_update(struct shash_desc *desc, const u8 *data,
 			     unsigned int len)
 {
-	return sha1_update(desc, data, len,
-		(sha1_transform_fn *) sha1_ni_transform);
+	return sha1_update(desc, data, len, sha1_ni_transform);
 }
 
 static int sha1_ni_finup(struct shash_desc *desc, const u8 *data,
 			      unsigned int len, u8 *out)
 {
-	return sha1_finup(desc, data, len, out,
-		(sha1_transform_fn *) sha1_ni_transform);
+	return sha1_finup(desc, data, len, out, sha1_ni_transform);
 }
 
 static int sha1_ni_final(struct shash_desc *desc, u8 *out)
diff --git a/arch/x86/crypto/sha256_ssse3_glue.c b/arch/x86/crypto/sha256_ssse3_glue.c
index f9aff31fe59e..960f56100a6c 100644
--- a/arch/x86/crypto/sha256_ssse3_glue.c
+++ b/arch/x86/crypto/sha256_ssse3_glue.c
@@ -41,12 +41,11 @@ 
 #include <linux/string.h>
 #include <asm/simd.h>
 
-asmlinkage void sha256_transform_ssse3(u32 *digest, const char *data,
-				       u64 rounds);
-typedef void (sha256_transform_fn)(u32 *digest, const char *data, u64 rounds);
+asmlinkage void sha256_transform_ssse3(struct sha256_state *digest,
+				       u8 const *data, int rounds);
 
 static int _sha256_update(struct shash_desc *desc, const u8 *data,
-			  unsigned int len, sha256_transform_fn *sha256_xform)
+			  unsigned int len, sha256_block_fn *sha256_xform)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);
 
@@ -54,28 +53,26 @@  static int _sha256_update(struct shash_desc *desc, const u8 *data,
 	    (sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
 		return crypto_sha256_update(desc, data, len);
 
-	/* make sure casting to sha256_block_fn() is safe */
+	/* make sure sha256_block_fn() use in generic routines is safe */
 	BUILD_BUG_ON(offsetof(struct sha256_state, state) != 0);
 
 	kernel_fpu_begin();
-	sha256_base_do_update(desc, data, len,
-			      (sha256_block_fn *)sha256_xform);
+	sha256_base_do_update(desc, data, len, sha256_xform);
 	kernel_fpu_end();
 
 	return 0;
 }
 
 static int sha256_finup(struct shash_desc *desc, const u8 *data,
-	      unsigned int len, u8 *out, sha256_transform_fn *sha256_xform)
+	      unsigned int len, u8 *out, sha256_block_fn *sha256_xform)
 {
 	if (!crypto_simd_usable())
 		return crypto_sha256_finup(desc, data, len, out);
 
 	kernel_fpu_begin();
 	if (len)
-		sha256_base_do_update(desc, data, len,
-				      (sha256_block_fn *)sha256_xform);
-	sha256_base_do_finalize(desc, (sha256_block_fn *)sha256_xform);
+		sha256_base_do_update(desc, data, len, sha256_xform);
+	sha256_base_do_finalize(desc, sha256_xform);
 	kernel_fpu_end();
 
 	return sha256_base_finish(desc, out);
@@ -145,8 +142,8 @@  static void unregister_sha256_ssse3(void)
 }
 
 #ifdef CONFIG_AS_AVX
-asmlinkage void sha256_transform_avx(u32 *digest, const char *data,
-				     u64 rounds);
+asmlinkage void sha256_transform_avx(struct sha256_state *digest,
+				     u8 const *data, int blocks);
 
 static int sha256_avx_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
@@ -227,8 +224,8 @@  static inline void unregister_sha256_avx(void) { }
 #endif
 
 #if defined(CONFIG_AS_AVX2) && defined(CONFIG_AS_AVX)
-asmlinkage void sha256_transform_rorx(u32 *digest, const char *data,
-				      u64 rounds);
+asmlinkage void sha256_transform_rorx(struct sha256_state *digest,
+				      u8 const *data, int rounds);
 
 static int sha256_avx2_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
@@ -307,8 +304,8 @@  static inline void unregister_sha256_avx2(void) { }
 #endif
 
 #ifdef CONFIG_AS_SHA256_NI
-asmlinkage void sha256_ni_transform(u32 *digest, const char *data,
-				   u64 rounds); /*unsigned int rounds);*/
+asmlinkage void sha256_ni_transform(struct sha256_state *digest,
+				    u8 const *data, int rounds);
 
 static int sha256_ni_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
diff --git a/arch/x86/crypto/sha512_ssse3_glue.c b/arch/x86/crypto/sha512_ssse3_glue.c
index 458356a3f124..09349d93f562 100644
--- a/arch/x86/crypto/sha512_ssse3_glue.c
+++ b/arch/x86/crypto/sha512_ssse3_glue.c
@@ -39,13 +39,11 @@ 
 #include <crypto/sha512_base.h>
 #include <asm/simd.h>
 
-asmlinkage void sha512_transform_ssse3(u64 *digest, const char *data,
-				       u64 rounds);
-
-typedef void (sha512_transform_fn)(u64 *digest, const char *data, u64 rounds);
+asmlinkage void sha512_transform_ssse3(struct sha512_state *digest,
+				       u8 const *data, int rounds);
 
 static int sha512_update(struct shash_desc *desc, const u8 *data,
-		       unsigned int len, sha512_transform_fn *sha512_xform)
+		       unsigned int len, sha512_block_fn *sha512_xform)
 {
 	struct sha512_state *sctx = shash_desc_ctx(desc);
 
@@ -53,28 +51,26 @@  static int sha512_update(struct shash_desc *desc, const u8 *data,
 	    (sctx->count[0] % SHA512_BLOCK_SIZE) + len < SHA512_BLOCK_SIZE)
 		return crypto_sha512_update(desc, data, len);
 
-	/* make sure casting to sha512_block_fn() is safe */
+	/* make sure sha512_block_fn() use in generic routines is safe */
 	BUILD_BUG_ON(offsetof(struct sha512_state, state) != 0);
 
 	kernel_fpu_begin();
-	sha512_base_do_update(desc, data, len,
-			      (sha512_block_fn *)sha512_xform);
+	sha512_base_do_update(desc, data, len, sha512_xform);
 	kernel_fpu_end();
 
 	return 0;
 }
 
 static int sha512_finup(struct shash_desc *desc, const u8 *data,
-	      unsigned int len, u8 *out, sha512_transform_fn *sha512_xform)
+	      unsigned int len, u8 *out, sha512_block_fn *sha512_xform)
 {
 	if (!crypto_simd_usable())
 		return crypto_sha512_finup(desc, data, len, out);
 
 	kernel_fpu_begin();
 	if (len)
-		sha512_base_do_update(desc, data, len,
-				      (sha512_block_fn *)sha512_xform);
-	sha512_base_do_finalize(desc, (sha512_block_fn *)sha512_xform);
+		sha512_base_do_update(desc, data, len, sha512_xform);
+	sha512_base_do_finalize(desc, sha512_xform);
 	kernel_fpu_end();
 
 	return sha512_base_finish(desc, out);
@@ -144,8 +140,8 @@  static void unregister_sha512_ssse3(void)
 }
 
 #ifdef CONFIG_AS_AVX
-asmlinkage void sha512_transform_avx(u64 *digest, const char *data,
-				     u64 rounds);
+asmlinkage void sha512_transform_avx(struct sha512_state *digest,
+				     u8 const *data, int rounds);
 static bool avx_usable(void)
 {
 	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
@@ -225,8 +221,8 @@  static inline void unregister_sha512_avx(void) { }
 #endif
 
 #if defined(CONFIG_AS_AVX2) && defined(CONFIG_AS_AVX)
-asmlinkage void sha512_transform_rorx(u64 *digest, const char *data,
-				      u64 rounds);
+asmlinkage void sha512_transform_rorx(struct sha512_state *digest,
+				      u8 const *data, int rounds);
 
 static int sha512_avx2_update(struct shash_desc *desc, const u8 *data,
 		       unsigned int len)