* [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
@ 2021-04-09 22:11 ` Nathan Chancellor
0 siblings, 0 replies; 8+ messages in thread
From: Nathan Chancellor @ 2021-04-09 22:11 UTC (permalink / raw)
To: Herbert Xu, David S. Miller
Cc: Russell King, Nick Desaulniers, Ard Biesheuvel,
Jason A. Donenfeld, linux-crypto, linux-arm-kernel, linux-kernel,
clang-built-linux, Nathan Chancellor, stable, Arnd Bergmann,
Jessica Clarke
Debian's clang carries a patch that makes the default FPU mode
'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON
instructions on hardware that does not support them:
https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch
https://bugs.debian.org/841474
https://bugs.debian.org/842142
https://bugs.debian.org/914268
This results in the following build error when clang's integrated
assembler is used because the '.arch' directive overrides the '.fpu'
directive:
arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON
vmov.i32 q0, #1
^
arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON
vshr.u64 q1, q0, #7
^
arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON
vshr.u64 q0, q0, #8
^
arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON
vmov.i32 d4, #19
^
Shuffle the order of the '.arch' and '.fpu' directives so that the code
builds regardless of the default FPU mode. This has been tested against
both clang with and without Debian's patch and GCC.
Cc: stable@vger.kernel.org
Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118
Reported-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Jessica Clarke <jrtc27@jrtc27.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
arch/arm/crypto/curve25519-core.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/crypto/curve25519-core.S b/arch/arm/crypto/curve25519-core.S
index be18af52e7dc..b697fa5d059a 100644
--- a/arch/arm/crypto/curve25519-core.S
+++ b/arch/arm/crypto/curve25519-core.S
@@ -10,8 +10,8 @@
#include <linux/linkage.h>
.text
-.fpu neon
.arch armv7-a
+.fpu neon
.align 4
ENTRY(curve25519_neon)
base-commit: e49d033bddf5b565044e2abe4241353959bc9120
--
2.31.1.189.g2e36527f23
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
2021-04-09 22:11 ` Nathan Chancellor
@ 2021-04-09 22:14 ` Jason A. Donenfeld
-1 siblings, 0 replies; 8+ messages in thread
From: Jason A. Donenfeld @ 2021-04-09 22:14 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Herbert Xu, David S. Miller, Russell King, Nick Desaulniers,
Ard Biesheuvel, Linux Crypto Mailing List, linux-arm-kernel, LKML,
clang-built-linux, stable, Arnd Bergmann, Jessica Clarke
Seems reasonable to me.
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
@ 2021-04-09 22:14 ` Jason A. Donenfeld
0 siblings, 0 replies; 8+ messages in thread
From: Jason A. Donenfeld @ 2021-04-09 22:14 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Herbert Xu, David S. Miller, Russell King, Nick Desaulniers,
Ard Biesheuvel, Linux Crypto Mailing List, linux-arm-kernel, LKML,
clang-built-linux, stable, Arnd Bergmann, Jessica Clarke
Seems reasonable to me.
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
2021-04-09 22:11 ` Nathan Chancellor
@ 2021-04-09 23:36 ` Nick Desaulniers
-1 siblings, 0 replies; 8+ messages in thread
From: Nick Desaulniers @ 2021-04-09 23:36 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Herbert Xu, David S. Miller, Russell King, Ard Biesheuvel,
Jason A. Donenfeld,
open list:HARDWARE RANDOM NUMBER GENERATOR CORE, Linux ARM, LKML,
clang-built-linux, # 3.4.x, Arnd Bergmann, Jessica Clarke
On Fri, Apr 9, 2021 at 3:12 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> Debian's clang carries a patch that makes the default FPU mode
> 'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON
> instructions on hardware that does not support them:
>
> https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch
> https://bugs.debian.org/841474
> https://bugs.debian.org/842142
> https://bugs.debian.org/914268
Another good link would be the one from Jessica describing more
precisely what the ARM targets for Debian are:
https://wiki.debian.org/ArchitectureSpecificsMemo#armel
>
> This results in the following build error when clang's integrated
> assembler is used because the '.arch' directive overrides the '.fpu'
> directive:
>
> arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON
> vmov.i32 q0, #1
> ^
> arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON
> vshr.u64 q1, q0, #7
> ^
> arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON
> vshr.u64 q0, q0, #8
> ^
> arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON
> vmov.i32 d4, #19
> ^
>
> Shuffle the order of the '.arch' and '.fpu' directives so that the code
> builds regardless of the default FPU mode. This has been tested against
> both clang with and without Debian's patch and GCC.
>
> Cc: stable@vger.kernel.org
> Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
> Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Jessica Clarke <jrtc27@jrtc27.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Great work tracking down that Debian was carrying patches! Thank you!
I've run this through the same 3 assemblers.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> arch/arm/crypto/curve25519-core.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/crypto/curve25519-core.S b/arch/arm/crypto/curve25519-core.S
> index be18af52e7dc..b697fa5d059a 100644
> --- a/arch/arm/crypto/curve25519-core.S
> +++ b/arch/arm/crypto/curve25519-core.S
> @@ -10,8 +10,8 @@
> #include <linux/linkage.h>
>
> .text
> -.fpu neon
> .arch armv7-a
> +.fpu neon
> .align 4
>
> ENTRY(curve25519_neon)
>
> base-commit: e49d033bddf5b565044e2abe4241353959bc9120
> --
> 2.31.1.189.g2e36527f23
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
@ 2021-04-09 23:36 ` Nick Desaulniers
0 siblings, 0 replies; 8+ messages in thread
From: Nick Desaulniers @ 2021-04-09 23:36 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Herbert Xu, David S. Miller, Russell King, Ard Biesheuvel,
Jason A. Donenfeld,
open list:HARDWARE RANDOM NUMBER GENERATOR CORE, Linux ARM, LKML,
clang-built-linux, # 3.4.x, Arnd Bergmann, Jessica Clarke
On Fri, Apr 9, 2021 at 3:12 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> Debian's clang carries a patch that makes the default FPU mode
> 'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON
> instructions on hardware that does not support them:
>
> https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch
> https://bugs.debian.org/841474
> https://bugs.debian.org/842142
> https://bugs.debian.org/914268
Another good link would be the one from Jessica describing more
precisely what the ARM targets for Debian are:
https://wiki.debian.org/ArchitectureSpecificsMemo#armel
>
> This results in the following build error when clang's integrated
> assembler is used because the '.arch' directive overrides the '.fpu'
> directive:
>
> arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON
> vmov.i32 q0, #1
> ^
> arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON
> vshr.u64 q1, q0, #7
> ^
> arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON
> vshr.u64 q0, q0, #8
> ^
> arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON
> vmov.i32 d4, #19
> ^
>
> Shuffle the order of the '.arch' and '.fpu' directives so that the code
> builds regardless of the default FPU mode. This has been tested against
> both clang with and without Debian's patch and GCC.
>
> Cc: stable@vger.kernel.org
> Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
> Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Jessica Clarke <jrtc27@jrtc27.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Great work tracking down that Debian was carrying patches! Thank you!
I've run this through the same 3 assemblers.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> arch/arm/crypto/curve25519-core.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/crypto/curve25519-core.S b/arch/arm/crypto/curve25519-core.S
> index be18af52e7dc..b697fa5d059a 100644
> --- a/arch/arm/crypto/curve25519-core.S
> +++ b/arch/arm/crypto/curve25519-core.S
> @@ -10,8 +10,8 @@
> #include <linux/linkage.h>
>
> .text
> -.fpu neon
> .arch armv7-a
> +.fpu neon
> .align 4
>
> ENTRY(curve25519_neon)
>
> base-commit: e49d033bddf5b565044e2abe4241353959bc9120
> --
> 2.31.1.189.g2e36527f23
>
--
Thanks,
~Nick Desaulniers
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
2021-04-09 22:11 ` Nathan Chancellor
@ 2021-04-16 11:32 ` Herbert Xu
-1 siblings, 0 replies; 8+ messages in thread
From: Herbert Xu @ 2021-04-16 11:32 UTC (permalink / raw)
To: Nathan Chancellor
Cc: David S. Miller, Russell King, Nick Desaulniers, Ard Biesheuvel,
Jason A. Donenfeld, linux-crypto, linux-arm-kernel, linux-kernel,
clang-built-linux, stable, Arnd Bergmann, Jessica Clarke
On Fri, Apr 09, 2021 at 03:11:55PM -0700, Nathan Chancellor wrote:
> Debian's clang carries a patch that makes the default FPU mode
> 'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON
> instructions on hardware that does not support them:
>
> https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch
> https://bugs.debian.org/841474
> https://bugs.debian.org/842142
> https://bugs.debian.org/914268
>
> This results in the following build error when clang's integrated
> assembler is used because the '.arch' directive overrides the '.fpu'
> directive:
>
> arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON
> vmov.i32 q0, #1
> ^
> arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON
> vshr.u64 q1, q0, #7
> ^
> arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON
> vshr.u64 q0, q0, #8
> ^
> arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON
> vmov.i32 d4, #19
> ^
>
> Shuffle the order of the '.arch' and '.fpu' directives so that the code
> builds regardless of the default FPU mode. This has been tested against
> both clang with and without Debian's patch and GCC.
>
> Cc: stable@vger.kernel.org
> Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
> Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Jessica Clarke <jrtc27@jrtc27.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
> arch/arm/crypto/curve25519-core.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
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
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch'
@ 2021-04-16 11:32 ` Herbert Xu
0 siblings, 0 replies; 8+ messages in thread
From: Herbert Xu @ 2021-04-16 11:32 UTC (permalink / raw)
To: Nathan Chancellor
Cc: David S. Miller, Russell King, Nick Desaulniers, Ard Biesheuvel,
Jason A. Donenfeld, linux-crypto, linux-arm-kernel, linux-kernel,
clang-built-linux, stable, Arnd Bergmann, Jessica Clarke
On Fri, Apr 09, 2021 at 03:11:55PM -0700, Nathan Chancellor wrote:
> Debian's clang carries a patch that makes the default FPU mode
> 'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON
> instructions on hardware that does not support them:
>
> https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch
> https://bugs.debian.org/841474
> https://bugs.debian.org/842142
> https://bugs.debian.org/914268
>
> This results in the following build error when clang's integrated
> assembler is used because the '.arch' directive overrides the '.fpu'
> directive:
>
> arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON
> vmov.i32 q0, #1
> ^
> arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON
> vshr.u64 q1, q0, #7
> ^
> arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON
> vshr.u64 q0, q0, #8
> ^
> arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON
> vmov.i32 d4, #19
> ^
>
> Shuffle the order of the '.arch' and '.fpu' directives so that the code
> builds regardless of the default FPU mode. This has been tested against
> both clang with and without Debian's patch and GCC.
>
> Cc: stable@vger.kernel.org
> Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
> Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Jessica Clarke <jrtc27@jrtc27.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
> arch/arm/crypto/curve25519-core.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread