crypto: arm64/sha - avoid non-standard inline asm tricks

Message ID 20170426161132.11311-1-ard.biesheuvel@linaro.org
State Accepted
Commit f4857f4c2ee9aa4e2aacac1a845352b00197fb57
Headers show

Commit Message

Ard Biesheuvel April 26, 2017, 4:11 p.m.
Replace the inline asm which exports struct offsets as ELF symbols
with proper const variables exposing the same values. This works
around an issue with Clang which does not interpret the "i" (or "I")
constraints in the same way as GCC.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 arch/arm64/crypto/sha1-ce-core.S |  6 ++++--
 arch/arm64/crypto/sha1-ce-glue.c | 11 +++--------
 arch/arm64/crypto/sha2-ce-core.S |  6 ++++--
 arch/arm64/crypto/sha2-ce-glue.c | 13 +++++--------
 4 files changed, 16 insertions(+), 20 deletions(-)

-- 
2.9.3

Comments

Matthias Kaehlcke April 26, 2017, 5:34 p.m. | #1
El Wed, Apr 26, 2017 at 05:11:32PM +0100 Ard Biesheuvel ha dit:

> Replace the inline asm which exports struct offsets as ELF symbols

> with proper const variables exposing the same values. This works

> around an issue with Clang which does not interpret the "i" (or "I")

> constraints in the same way as GCC.

> 

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>


Tested-by: Matthias Kaehlcke <mka@chromium.org>


Thanks!

Matthias
Matthias Kaehlcke May 17, 2017, 6:10 p.m. | #2
El Wed, Apr 26, 2017 at 05:11:32PM +0100 Ard Biesheuvel ha dit:

> Replace the inline asm which exports struct offsets as ELF symbols

> with proper const variables exposing the same values. This works

> around an issue with Clang which does not interpret the "i" (or "I")

> constraints in the same way as GCC.

> 

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---

>  arch/arm64/crypto/sha1-ce-core.S |  6 ++++--

>  arch/arm64/crypto/sha1-ce-glue.c | 11 +++--------

>  arch/arm64/crypto/sha2-ce-core.S |  6 ++++--

>  arch/arm64/crypto/sha2-ce-glue.c | 13 +++++--------

>  4 files changed, 16 insertions(+), 20 deletions(-)


Herbert, do you plan to pick this up?

Thanks

Matthias
Herbert Xu May 18, 2017, 5:26 a.m. | #3
On Wed, Apr 26, 2017 at 05:11:32PM +0100, Ard Biesheuvel wrote:
> Replace the inline asm which exports struct offsets as ELF symbols

> with proper const variables exposing the same values. This works

> around an issue with Clang which does not interpret the "i" (or "I")

> constraints in the same way as GCC.

> 

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>


Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Patch

diff --git a/arch/arm64/crypto/sha1-ce-core.S b/arch/arm64/crypto/sha1-ce-core.S
index c98e7e849f06..8550408735a0 100644
--- a/arch/arm64/crypto/sha1-ce-core.S
+++ b/arch/arm64/crypto/sha1-ce-core.S
@@ -82,7 +82,8 @@  ENTRY(sha1_ce_transform)
 	ldr		dgb, [x0, #16]
 
 	/* load sha1_ce_state::finalize */
-	ldr		w4, [x0, #:lo12:sha1_ce_offsetof_finalize]
+	ldr_l		w4, sha1_ce_offsetof_finalize, x4
+	ldr		w4, [x0, x4]
 
 	/* load input */
 0:	ld1		{v8.4s-v11.4s}, [x1], #64
@@ -132,7 +133,8 @@  CPU_LE(	rev32		v11.16b, v11.16b	)
 	 * the padding is handled by the C code in that case.
 	 */
 	cbz		x4, 3f
-	ldr		x4, [x0, #:lo12:sha1_ce_offsetof_count]
+	ldr_l		w4, sha1_ce_offsetof_count, x4
+	ldr		x4, [x0, x4]
 	movi		v9.2d, #0
 	mov		x8, #0x80000000
 	movi		v10.2d, #0
diff --git a/arch/arm64/crypto/sha1-ce-glue.c b/arch/arm64/crypto/sha1-ce-glue.c
index aefda9868627..ea319c055f5d 100644
--- a/arch/arm64/crypto/sha1-ce-glue.c
+++ b/arch/arm64/crypto/sha1-ce-glue.c
@@ -17,9 +17,6 @@ 
 #include <linux/crypto.h>
 #include <linux/module.h>
 
-#define ASM_EXPORT(sym, val) \
-	asm(".globl " #sym "; .set " #sym ", %0" :: "I"(val));
-
 MODULE_DESCRIPTION("SHA1 secure hash using ARMv8 Crypto Extensions");
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");
@@ -32,6 +29,9 @@  struct sha1_ce_state {
 asmlinkage void sha1_ce_transform(struct sha1_ce_state *sst, u8 const *src,
 				  int blocks);
 
+const u32 sha1_ce_offsetof_count = offsetof(struct sha1_ce_state, sst.count);
+const u32 sha1_ce_offsetof_finalize = offsetof(struct sha1_ce_state, finalize);
+
 static int sha1_ce_update(struct shash_desc *desc, const u8 *data,
 			  unsigned int len)
 {
@@ -52,11 +52,6 @@  static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
 	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
 	bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
 
-	ASM_EXPORT(sha1_ce_offsetof_count,
-		   offsetof(struct sha1_ce_state, sst.count));
-	ASM_EXPORT(sha1_ce_offsetof_finalize,
-		   offsetof(struct sha1_ce_state, finalize));
-
 	/*
 	 * Allow the asm code to perform the finalization if there is no
 	 * partial data and the input is a round multiple of the block size.
diff --git a/arch/arm64/crypto/sha2-ce-core.S b/arch/arm64/crypto/sha2-ce-core.S
index 01cfee066837..679c6c002f4f 100644
--- a/arch/arm64/crypto/sha2-ce-core.S
+++ b/arch/arm64/crypto/sha2-ce-core.S
@@ -88,7 +88,8 @@  ENTRY(sha2_ce_transform)
 	ld1		{dgav.4s, dgbv.4s}, [x0]
 
 	/* load sha256_ce_state::finalize */
-	ldr		w4, [x0, #:lo12:sha256_ce_offsetof_finalize]
+	ldr_l		w4, sha256_ce_offsetof_finalize, x4
+	ldr		w4, [x0, x4]
 
 	/* load input */
 0:	ld1		{v16.4s-v19.4s}, [x1], #64
@@ -136,7 +137,8 @@  CPU_LE(	rev32		v19.16b, v19.16b	)
 	 * the padding is handled by the C code in that case.
 	 */
 	cbz		x4, 3f
-	ldr		x4, [x0, #:lo12:sha256_ce_offsetof_count]
+	ldr_l		w4, sha256_ce_offsetof_count, x4
+	ldr		x4, [x0, x4]
 	movi		v17.2d, #0
 	mov		x8, #0x80000000
 	movi		v18.2d, #0
diff --git a/arch/arm64/crypto/sha2-ce-glue.c b/arch/arm64/crypto/sha2-ce-glue.c
index 7cd587564a41..0ed9486f75dd 100644
--- a/arch/arm64/crypto/sha2-ce-glue.c
+++ b/arch/arm64/crypto/sha2-ce-glue.c
@@ -17,9 +17,6 @@ 
 #include <linux/crypto.h>
 #include <linux/module.h>
 
-#define ASM_EXPORT(sym, val) \
-	asm(".globl " #sym "; .set " #sym ", %0" :: "I"(val));
-
 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");
@@ -32,6 +29,11 @@  struct sha256_ce_state {
 asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
 				  int blocks);
 
+const u32 sha256_ce_offsetof_count = offsetof(struct sha256_ce_state,
+					      sst.count);
+const u32 sha256_ce_offsetof_finalize = offsetof(struct sha256_ce_state,
+						 finalize);
+
 static int sha256_ce_update(struct shash_desc *desc, const u8 *data,
 			    unsigned int len)
 {
@@ -52,11 +54,6 @@  static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
 	bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE);
 
-	ASM_EXPORT(sha256_ce_offsetof_count,
-		   offsetof(struct sha256_ce_state, sst.count));
-	ASM_EXPORT(sha256_ce_offsetof_finalize,
-		   offsetof(struct sha256_ce_state, finalize));
-
 	/*
 	 * Allow the asm code to perform the finalization if there is no
 	 * partial data and the input is a round multiple of the block size.