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>

arch/arm/crypto/chacha-glue.c

@@ -286,11 +286,13 @@ static struct skcipher_alg neon_algs[] = {
 
 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 int __init chacha_simd_mod_init(void)
 			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);

arch/arm/crypto/curve25519-glue.c

@@ -108,14 +108,15 @@ static int __init mod_init(void)
 {
 	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);
 }
 

arch/arm/crypto/poly1305-glue.c

@@ -249,16 +249,19 @@ static int __init arm_poly1305_mod_init(void)
 	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;

arch/arm64/crypto/chacha-neon-glue.c

@@ -211,12 +211,13 @@ static int __init chacha_simd_mod_init(void)
 
 	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));
 }
 

arch/arm64/crypto/poly1305-glue.c

@@ -220,12 +220,13 @@ static int __init neon_poly1305_mod_init(void)
 
 	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);
 }
 

arch/mips/crypto/chacha-glue.c

@@ -128,12 +128,14 @@ static struct skcipher_alg algs[] = {
 
 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);

arch/mips/crypto/poly1305-glue.c

@@ -187,12 +187,14 @@ static struct shash_alg mips_poly1305_alg = {
 
 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);

arch/x86/crypto/blake2s-glue.c

@@ -210,12 +210,14 @@ static int __init blake2s_mod_init(void)
 			      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));
 }
 

arch/x86/crypto/chacha_glue.c

@@ -299,12 +299,13 @@ static int __init chacha_simd_mod_init(void)
 		    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));
 }
 

arch/x86/crypto/curve25519-x86_64.c

@@ -2457,13 +2457,14 @@ static int __init curve25519_mod_init(void)
 		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);
 }
 

arch/x86/crypto/poly1305_glue.c

@@ -224,12 +224,13 @@ static int __init poly1305_simd_mod_init(void)
 	    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);