crypto: arch - conditionalize crypto api in arch glue for lib code

For glue code that's used by Zinc, the actual Crypto API functions might
not necessarily exist, and don't need to exist either. Before this
patch, there are valid build configurations that lead to a unbuildable
kernel. This fixes it to conditionalize those symbols on the existence
of the proper config entry.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c
index 3f0c057..6ebbb2b 100644
--- a/arch/arm/crypto/chacha-glue.c
+++ b/arch/arm/crypto/chacha-glue.c
@@ -286,11 +286,13 @@
 
 static int __init chacha_simd_mod_init(void)
 {
-	int err;
+	int err = 0;
 
-	err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
-	if (err)
-		return err;
+	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
+		err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+		if (err)
+			return err;
+	}
 
 	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
 		int i;
@@ -310,18 +312,22 @@
 			static_branch_enable(&use_neon);
 		}
 
-		err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
-		if (err)
-			crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+		if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
+			err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
+			if (err)
+				crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+		}
 	}
 	return err;
 }
 
 static void __exit chacha_simd_mod_fini(void)
 {
-	crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
-	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
-		crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
+	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
+		crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+		if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
+			crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
+	}
 }
 
 module_init(chacha_simd_mod_init);
diff --git a/arch/arm/crypto/curve25519-glue.c b/arch/arm/crypto/curve25519-glue.c
index 2e9e12d..f3f42cf 100644
--- a/arch/arm/crypto/curve25519-glue.c
+++ b/arch/arm/crypto/curve25519-glue.c
@@ -108,14 +108,15 @@
 {
 	if (elf_hwcap & HWCAP_NEON) {
 		static_branch_enable(&have_neon);
-		return crypto_register_kpp(&curve25519_alg);
+		return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
+			crypto_register_kpp(&curve25519_alg) : 0;
 	}
 	return 0;
 }
 
 static void __exit mod_exit(void)
 {
-	if (elf_hwcap & HWCAP_NEON)
+	if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && elf_hwcap & HWCAP_NEON)
 		crypto_unregister_kpp(&curve25519_alg);
 }
 
diff --git a/arch/arm/crypto/poly1305-glue.c b/arch/arm/crypto/poly1305-glue.c
index 74a725a..abe3f2d 100644
--- a/arch/arm/crypto/poly1305-glue.c
+++ b/arch/arm/crypto/poly1305-glue.c
@@ -249,16 +249,19 @@
 	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
 	    (elf_hwcap & HWCAP_NEON))
 		static_branch_enable(&have_neon);
-	else
+	else if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
 		/* register only the first entry */
 		return crypto_register_shash(&arm_poly1305_algs[0]);
 
-	return crypto_register_shashes(arm_poly1305_algs,
-				       ARRAY_SIZE(arm_poly1305_algs));
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
+		crypto_register_shashes(arm_poly1305_algs,
+					ARRAY_SIZE(arm_poly1305_algs)) : 0;
 }
 
 static void __exit arm_poly1305_mod_exit(void)
 {
+	if (!IS_REACHABLE(CONFIG_CRYPTO_HASH))
+		return;
 	if (!static_branch_likely(&have_neon)) {
 		crypto_unregister_shash(&arm_poly1305_algs[0]);
 		return;
diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c
index b08029d..c1f9660 100644
--- a/arch/arm64/crypto/chacha-neon-glue.c
+++ b/arch/arm64/crypto/chacha-neon-glue.c
@@ -211,12 +211,13 @@
 
 	static_branch_enable(&have_neon);
 
-	return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
+	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
+		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
 }
 
 static void __exit chacha_simd_mod_fini(void)
 {
-	if (cpu_have_named_feature(ASIMD))
+	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && cpu_have_named_feature(ASIMD))
 		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
 }
 
diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c
index dd843d0..83a2338 100644
--- a/arch/arm64/crypto/poly1305-glue.c
+++ b/arch/arm64/crypto/poly1305-glue.c
@@ -220,12 +220,13 @@
 
 	static_branch_enable(&have_neon);
 
-	return crypto_register_shash(&neon_poly1305_alg);
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
+		crypto_register_shash(&neon_poly1305_alg) : 0;
 }
 
 static void __exit neon_poly1305_mod_exit(void)
 {
-	if (cpu_have_named_feature(ASIMD))
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH) && cpu_have_named_feature(ASIMD))
 		crypto_unregister_shash(&neon_poly1305_alg);
 }
 
diff --git a/arch/mips/crypto/chacha-glue.c b/arch/mips/crypto/chacha-glue.c
index 779e399..d1fd23e 100644
--- a/arch/mips/crypto/chacha-glue.c
+++ b/arch/mips/crypto/chacha-glue.c
@@ -128,12 +128,14 @@
 
 static int __init chacha_simd_mod_init(void)
 {
-	return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
+	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
+		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
 }
 
 static void __exit chacha_simd_mod_fini(void)
 {
-	crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
+	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
+		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
 }
 
 module_init(chacha_simd_mod_init);
diff --git a/arch/mips/crypto/poly1305-glue.c b/arch/mips/crypto/poly1305-glue.c
index b759b6c..b37d29c 100644
--- a/arch/mips/crypto/poly1305-glue.c
+++ b/arch/mips/crypto/poly1305-glue.c
@@ -187,12 +187,14 @@
 
 static int __init mips_poly1305_mod_init(void)
 {
-	return crypto_register_shash(&mips_poly1305_alg);
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
+		crypto_register_shash(&mips_poly1305_alg) : 0;
 }
 
 static void __exit mips_poly1305_mod_exit(void)
 {
-	crypto_unregister_shash(&mips_poly1305_alg);
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
+		crypto_unregister_shash(&mips_poly1305_alg);
 }
 
 module_init(mips_poly1305_mod_init);
diff --git a/arch/x86/crypto/blake2s-glue.c b/arch/x86/crypto/blake2s-glue.c
index 4a37ba7..1d9ff8a 100644
--- a/arch/x86/crypto/blake2s-glue.c
+++ b/arch/x86/crypto/blake2s-glue.c
@@ -210,12 +210,14 @@
 			      XFEATURE_MASK_AVX512, NULL))
 		static_branch_enable(&blake2s_use_avx512);
 
-	return crypto_register_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
+		crypto_register_shashes(blake2s_algs,
+					ARRAY_SIZE(blake2s_algs)) : 0;
 }
 
 static void __exit blake2s_mod_exit(void)
 {
-	if (boot_cpu_has(X86_FEATURE_SSSE3))
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH) && boot_cpu_has(X86_FEATURE_SSSE3))
 		crypto_unregister_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
 }
 
diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
index a94e30b..68a7495 100644
--- a/arch/x86/crypto/chacha_glue.c
+++ b/arch/x86/crypto/chacha_glue.c
@@ -299,12 +299,13 @@
 		    boot_cpu_has(X86_FEATURE_AVX512BW)) /* kmovq */
 			static_branch_enable(&chacha_use_avx512vl);
 	}
-	return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
+	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
+		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
 }
 
 static void __exit chacha_simd_mod_fini(void)
 {
-	if (boot_cpu_has(X86_FEATURE_SSSE3))
+	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && boot_cpu_has(X86_FEATURE_SSSE3))
 		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
 }
 
diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c
index a52a3fb..eec7d2d 100644
--- a/arch/x86/crypto/curve25519-x86_64.c
+++ b/arch/x86/crypto/curve25519-x86_64.c
@@ -2457,13 +2457,14 @@
 		static_branch_enable(&curve25519_use_adx);
 	else
 		return 0;
-	return crypto_register_kpp(&curve25519_alg);
+	return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
+		crypto_register_kpp(&curve25519_alg) : 0;
 }
 
 static void __exit curve25519_mod_exit(void)
 {
-	if (boot_cpu_has(X86_FEATURE_BMI2) ||
-	    boot_cpu_has(X86_FEATURE_ADX))
+	if (IS_REACHABLE(CONFIG_CRYPTO_KPP) &&
+	    (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX)))
 		crypto_unregister_kpp(&curve25519_alg);
 }
 
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
index 370cd88..0cc4537 100644
--- a/arch/x86/crypto/poly1305_glue.c
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -224,12 +224,13 @@
 	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
 		static_branch_enable(&poly1305_use_avx2);
 
-	return crypto_register_shash(&alg);
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0;
 }
 
 static void __exit poly1305_simd_mod_exit(void)
 {
-	crypto_unregister_shash(&alg);
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
+		crypto_unregister_shash(&alg);
 }
 
 module_init(poly1305_simd_mod_init);