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crypto: x86/curve25519 - support assemblers with no adx support

PATCH In review Jason A. Donenfeld 2 participants 2 messages Mar 1, 2020 – Mar 6, 2020

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x86 Crypto API
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Jason A. Donenfeld

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PATCH 1/1 crypto: x86/curve25519 - support assemblers with no adx support

Some older version of GAS do not support the ADX instructions, similarly to how they also don't support AVX and such. This commit adds the same build-time detection mechanisms we use for AVX and others for ADX, and then makes sure that the curve25519 library dispatcher calls the right functions.

Reported-by Willy Tarreau <[email protected]>
Signed-off-by Jason A. Donenfeld <[email protected]>

---
This patch is meant for 5.6-rcX.

 arch/x86/Makefile           | 5 +++--
 arch/x86/crypto/Makefile    | 7 ++++++-
 include/crypto/curve25519.h | 6 ++++--
 3 files changed, 13 insertions(+), 5 deletions(-)
arch/x86/Makefile +3 -2
index 94df0868804b..513a55562d75 100644
@@ -194,9 +194,10 @@ avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
 avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
 sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
 sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
+adx_instr := $(call as-instr,adox %r10$(comma)%r10,-DCONFIG_AS_ADX=1)
 
-KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
-KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
+KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr) $(adx_instr)
+KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr) $(adx_instr)
 
 KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
arch/x86/crypto/Makefile +6 -1
index b69e00bf20b8..8c2e9eadee8a 100644
@@ -11,6 +11,7 @@ avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\
 avx512_supported :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,yes,no)
 sha1_ni_supported :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,yes,no)
 sha256_ni_supported :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,yes,no)
+adx_supported := $(call as-instr,adox %r10$(comma)%r10,yes,no)
 
 obj-$(CONFIG_CRYPTO_GLUE_HELPER_X86) += glue_helper.o
 

@@ -39,7 +40,11 @@ obj-$(CONFIG_CRYPTO_AEGIS128_AESNI_SSE2) += aegis128-aesni.o
 
 obj-$(CONFIG_CRYPTO_NHPOLY1305_SSE2) += nhpoly1305-sse2.o
 obj-$(CONFIG_CRYPTO_NHPOLY1305_AVX2) += nhpoly1305-avx2.o
-obj-$(CONFIG_CRYPTO_CURVE25519_X86) += curve25519-x86_64.o
+
+# These modules require the assembler to support ADX.
+ifeq ($(adx_supported),yes)
+	obj-$(CONFIG_CRYPTO_CURVE25519_X86) += curve25519-x86_64.o
+endif
 
 # These modules require assembler to support AVX.
 ifeq ($(avx_supported),yes)
include/crypto/curve25519.h +4 -2
index 4e6dc840b159..9ecb3c1f0f15 100644
@@ -33,7 +33,8 @@ bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE],
 			     const u8 secret[CURVE25519_KEY_SIZE],
 			     const u8 basepoint[CURVE25519_KEY_SIZE])
 {
-	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
+	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519) &&
+	    (!IS_ENABLED(CONFIG_CRYPTO_CURVE25519_X86) || IS_ENABLED(CONFIG_AS_ADX)))
 		curve25519_arch(mypublic, secret, basepoint);
 	else
 		curve25519_generic(mypublic, secret, basepoint);

@@ -49,7 +50,8 @@ __must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],
 				    CURVE25519_KEY_SIZE)))
 		return false;
 
-	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
+	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519) &&
+	    (!IS_ENABLED(CONFIG_CRYPTO_CURVE25519_X86) || IS_ENABLED(CONFIG_AS_ADX)))
 		curve25519_base_arch(pub, secret);
 	else
 		curve25519_generic(pub, secret, curve25519_base_point);
Signature · 1 line
2.25.1
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#1 lore raw
Quoted 8 lines · Jason A. Donenfeld

Some older version of GAS do not support the ADX instructions, similarly to how they also don't support AVX and such. This commit adds the same build-time detection mechanisms we use for AVX and others for ADX, and then makes sure that the curve25519 library dispatcher calls the right functions.

Reported-by Willy Tarreau <[email protected]>
Signed-off-by Jason A. Donenfeld <[email protected]>
Quoted 7 lines

---
This patch is meant for 5.6-rcX.

 arch/x86/Makefile           | 5 +++--
 arch/x86/crypto/Makefile    | 7 ++++++-
 include/crypto/curve25519.h | 6 ++++--
 3 files changed, 13 insertions(+), 5 deletions(-)

Patch applied. Thanks.

Signature · 3 lines
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt