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 <w@1wt.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 94df086..513a555 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -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)
 

diff --git a/arch/x86/crypto/Makefile b/arch/x86/crypto/Makefile
index b69e00b..8c2e9ea 100644 (file)
--- a/arch/x86/crypto/Makefile
+++ b/arch/x86/crypto/Makefile
@@ -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)

diff --git a/include/crypto/curve25519.h b/include/crypto/curve25519.h
index 4e6dc84..9ecb3c1 100644 (file)
--- a/include/crypto/curve25519.h
+++ b/include/crypto/curve25519.h
@@ -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);