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]> Signed-off-by: Herbert Xu <[email protected]>
teawater · Mar 5, 2020 · 1579f1b · 1579f1b
1 parent c9cc051
commit 1579f1b
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Showing 3 changed files with 13 additions and 5 deletions.
diff --git 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
@@ -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
@@ -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);