[v2 PATCH] crypto: lib/Kconfig - Hide arch options from user

Herbert Xu
2025-02-26T09:09:10Z

The ARCH_MAY_HAVE patch missed arm64, mips and s390. But it may
also lead to arch options being enabled but ineffective because
of modular/built-in conflicts.

As the primary user of all these options wireguard is selecting
the arch options anyway, make the same selections at the lib/crypto
option level and hide the arch options from the user.

Instead of selecting them centrally from lib/crypto, simply set
the default of each arch option as suggested by Eric Biggers.

Change the Crypto API generic algorithms to select the top-level
lib/crypto options instead of the generic one as otherwise there
is no way to enable the arch options (Eric Biggers). Introduce a
set of INTERNAL options to work around dependency cycles on the
CONFIG_CRYPTO symbol.

Fixes: 1047e21aecdf ("crypto: lib/Kconfig - Fix lib built-in failure when arch is modular")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Arnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/oe-kbuild-all/202502232152.JC84YDLp-lkp@intel.com/
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index 47d9cc59f254..0c19317a9ce0 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -3,10 +3,11 @@
menu "Accelerated Cryptographic Algorithms for CPU (arm)"

config CRYPTO_CURVE25519_NEON
- tristate "Public key crypto: Curve25519 (NEON)"
+ tristate
depends on KERNEL_MODE_NEON
- select CRYPTO_LIB_CURVE25519_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519
+ select CRYPTO_KPP
+ select CRYPTO_ARCH_HAVE_LIB_CURVE25519
+ default CRYPTO_LIB_CURVE25519_INTERNAL
help
Curve25519 algorithm

@@ -45,9 +46,10 @@ config CRYPTO_NHPOLY1305_NEON
- NEON (Advanced SIMD) extensions

config CRYPTO_POLY1305_ARM
- tristate "Hash functions: Poly1305 (NEON)"
+ tristate
select CRYPTO_HASH
- select CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
+ select CRYPTO_ARCH_HAVE_LIB_POLY1305
+ default CRYPTO_LIB_POLY1305_INTERNAL
help
Poly1305 authenticator algorithm (RFC7539)

@@ -212,9 +214,10 @@ config CRYPTO_AES_ARM_CE
- ARMv8 Crypto Extensions

config CRYPTO_CHACHA20_NEON
- tristate "Ciphers: ChaCha20, XChaCha20, XChaCha12 (NEON)"
+ tristate
select CRYPTO_SKCIPHER
- select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
+ select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
stream cipher algorithms
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 5636ab83f22a..1b14551cc301 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -26,10 +26,11 @@ config CRYPTO_NHPOLY1305_NEON
- NEON (Advanced SIMD) extensions

config CRYPTO_POLY1305_NEON
- tristate "Hash functions: Poly1305 (NEON)"
+ tristate
depends on KERNEL_MODE_NEON
select CRYPTO_HASH
select CRYPTO_ARCH_HAVE_LIB_POLY1305
+ default CRYPTO_LIB_POLY1305_INTERNAL
help
Poly1305 authenticator algorithm (RFC7539)

@@ -186,11 +187,11 @@ config CRYPTO_AES_ARM64_NEON_BLK
- NEON (Advanced SIMD) extensions

config CRYPTO_CHACHA20_NEON
- tristate "Ciphers: ChaCha (NEON)"
+ tristate
depends on KERNEL_MODE_NEON
select CRYPTO_SKCIPHER
- select CRYPTO_LIB_CHACHA_GENERIC
select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
stream cipher algorithms
diff --git a/arch/mips/crypto/Kconfig b/arch/mips/crypto/Kconfig
index 7decd40c4e20..545fc0e12422 100644
--- a/arch/mips/crypto/Kconfig
+++ b/arch/mips/crypto/Kconfig
@@ -3,9 +3,11 @@
menu "Accelerated Cryptographic Algorithms for CPU (mips)"

config CRYPTO_POLY1305_MIPS
- tristate "Hash functions: Poly1305"
+ tristate
depends on MIPS
+ select CRYPTO_HASH
select CRYPTO_ARCH_HAVE_LIB_POLY1305
+ default CRYPTO_LIB_POLY1305_INTERNAL
help
Poly1305 authenticator algorithm (RFC7539)

@@ -52,10 +54,11 @@ config CRYPTO_SHA512_OCTEON
Architecture: mips OCTEON using crypto instructions, when available

config CRYPTO_CHACHA_MIPS
- tristate "Ciphers: ChaCha20, XChaCha20, XChaCha12 (MIPS32r2)"
+ tristate
depends on CPU_MIPS32_R2
select CRYPTO_SKCIPHER
select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
stream cipher algorithms
diff --git a/arch/powerpc/crypto/Kconfig b/arch/powerpc/crypto/Kconfig
index e453cb0c82d2..5beed03869c9 100644
--- a/arch/powerpc/crypto/Kconfig
+++ b/arch/powerpc/crypto/Kconfig
@@ -3,10 +3,11 @@
menu "Accelerated Cryptographic Algorithms for CPU (powerpc)"

config CRYPTO_CURVE25519_PPC64
- tristate "Public key crypto: Curve25519 (PowerPC64)"
+ tristate
depends on PPC64 && CPU_LITTLE_ENDIAN
- select CRYPTO_LIB_CURVE25519_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519
+ select CRYPTO_KPP
+ select CRYPTO_ARCH_HAVE_LIB_CURVE25519
+ default CRYPTO_LIB_CURVE25519_INTERNAL
help
Curve25519 algorithm

@@ -91,11 +92,11 @@ config CRYPTO_AES_GCM_P10
later CPU. This module supports stitched acceleration for AES/GCM.

config CRYPTO_CHACHA20_P10
- tristate "Ciphers: ChaCha20, XChacha20, XChacha12 (P10 or later)"
+ tristate
depends on PPC64 && CPU_LITTLE_ENDIAN && VSX
select CRYPTO_SKCIPHER
- select CRYPTO_LIB_CHACHA_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
+ select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
stream cipher algorithms
diff --git a/arch/riscv/crypto/Kconfig b/arch/riscv/crypto/Kconfig
index ad58dad9a580..c67095a3d669 100644
--- a/arch/riscv/crypto/Kconfig
+++ b/arch/riscv/crypto/Kconfig
@@ -22,7 +22,6 @@ config CRYPTO_CHACHA_RISCV64
tristate "Ciphers: ChaCha"
depends on 64BIT && RISCV_ISA_V && TOOLCHAIN_HAS_VECTOR_CRYPTO
select CRYPTO_SKCIPHER
- select CRYPTO_LIB_CHACHA_GENERIC
help
Length-preserving ciphers: ChaCha20 stream cipher algorithm

diff --git a/arch/s390/crypto/Kconfig b/arch/s390/crypto/Kconfig
index b760232537f1..f6f82dab3594 100644
--- a/arch/s390/crypto/Kconfig
+++ b/arch/s390/crypto/Kconfig
@@ -108,11 +108,11 @@ config CRYPTO_DES_S390
As of z196 the CTR mode is hardware accelerated.

config CRYPTO_CHACHA_S390
- tristate "Ciphers: ChaCha20"
+ tristate
depends on S390
select CRYPTO_SKCIPHER
- select CRYPTO_LIB_CHACHA_GENERIC
select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving cipher: ChaCha20 stream cipher (RFC 7539)

diff --git a/arch/x86/crypto/Kconfig b/arch/x86/crypto/Kconfig
index c189dad0969b..d3128e99bac5 100644
--- a/arch/x86/crypto/Kconfig
+++ b/arch/x86/crypto/Kconfig
@@ -3,10 +3,11 @@
menu "Accelerated Cryptographic Algorithms for CPU (x86)"

config CRYPTO_CURVE25519_X86
- tristate "Public key crypto: Curve25519 (ADX)"
+ tristate
depends on X86 && 64BIT
- select CRYPTO_LIB_CURVE25519_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519
+ select CRYPTO_KPP
+ select CRYPTO_ARCH_HAVE_LIB_CURVE25519
+ default CRYPTO_LIB_CURVE25519_INTERNAL
help
Curve25519 algorithm

@@ -348,11 +349,11 @@ config CRYPTO_ARIA_GFNI_AVX512_X86_64
Processes 64 blocks in parallel.

config CRYPTO_CHACHA20_X86_64
- tristate "Ciphers: ChaCha20, XChaCha20, XChaCha12 (SSSE3/AVX2/AVX-512VL)"
+ tristate
depends on X86 && 64BIT
select CRYPTO_SKCIPHER
- select CRYPTO_LIB_CHACHA_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
+ select CRYPTO_ARCH_HAVE_LIB_CHACHA
+ default CRYPTO_LIB_CHACHA_INTERNAL
help
Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
stream cipher algorithms
@@ -417,10 +418,11 @@ config CRYPTO_POLYVAL_CLMUL_NI
- CLMUL-NI (carry-less multiplication new instructions)

config CRYPTO_POLY1305_X86_64
- tristate "Hash functions: Poly1305 (SSE2/AVX2)"
+ tristate
depends on X86 && 64BIT
- select CRYPTO_LIB_POLY1305_GENERIC
- select CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
+ select CRYPTO_HASH
+ select CRYPTO_ARCH_HAVE_LIB_POLY1305
+ default CRYPTO_LIB_POLY1305_INTERNAL
help
Poly1305 authenticator algorithm (RFC7539)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 74ae5f52b784..b7771d7bd3b3 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -317,7 +317,7 @@ config CRYPTO_ECRDSA
config CRYPTO_CURVE25519
tristate "Curve25519"
select CRYPTO_KPP
- select CRYPTO_LIB_CURVE25519_GENERIC
+ select CRYPTO_LIB_CURVE25519_INTERNAL
help
Curve25519 elliptic curve (RFC7748)

@@ -615,7 +615,7 @@ config CRYPTO_ARC4

config CRYPTO_CHACHA20
tristate "ChaCha"
- select CRYPTO_LIB_CHACHA_GENERIC
+ select CRYPTO_LIB_CHACHA_INTERNAL
select CRYPTO_SKCIPHER
help
The ChaCha20, XChaCha20, and XChaCha12 stream cipher algorithms
@@ -936,7 +936,7 @@ config CRYPTO_POLYVAL
config CRYPTO_POLY1305
tristate "Poly1305"
select CRYPTO_HASH
- select CRYPTO_LIB_POLY1305_GENERIC
+ select CRYPTO_LIB_POLY1305_INTERNAL
help
Poly1305 authenticator algorithm (RFC7539)

diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index c542ef1d64d0..b09e78da959a 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -48,11 +48,6 @@ config CRYPTO_ARCH_HAVE_LIB_CHACHA
accelerated implementation of the ChaCha library interface,
either builtin or as a module.

-config CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
- tristate
- select CRYPTO_ARCH_HAVE_LIB_CHACHA if CRYPTO_LIB_CHACHA=m
- select CRYPTO_ARCH_HAVE_LIB_CHACHA if CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA=y
-
config CRYPTO_LIB_CHACHA_GENERIC
tristate
select CRYPTO_LIB_UTILS
@@ -63,9 +58,14 @@ config CRYPTO_LIB_CHACHA_GENERIC
implementation is enabled, this implementation serves the users
of CRYPTO_LIB_CHACHA.

+config CRYPTO_LIB_CHACHA_INTERNAL
+ tristate
+ select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
+
config CRYPTO_LIB_CHACHA
tristate "ChaCha library interface"
- select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
+ select CRYPTO
+ select CRYPTO_LIB_CHACHA_INTERNAL
help
Enable the ChaCha library interface. This interface may be fulfilled
by either the generic implementation or an arch-specific one, if one
@@ -78,13 +78,9 @@ config CRYPTO_ARCH_HAVE_LIB_CURVE25519
accelerated implementation of the Curve25519 library interface,
either builtin or as a module.

-config CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519
- tristate
- select CRYPTO_ARCH_HAVE_LIB_CURVE25519 if CRYPTO_LIB_CURVE25519=m
- select CRYPTO_ARCH_HAVE_LIB_CURVE25519 if CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519=y
-
config CRYPTO_LIB_CURVE25519_GENERIC
tristate
+ select CRYPTO_LIB_UTILS
help
This symbol can be depended upon by arch implementations of the
Curve25519 library interface that require the generic code as a
@@ -92,10 +88,14 @@ config CRYPTO_LIB_CURVE25519_GENERIC
implementation is enabled, this implementation serves the users
of CRYPTO_LIB_CURVE25519.

+config CRYPTO_LIB_CURVE25519_INTERNAL
+ tristate
+ select CRYPTO_LIB_CURVE25519_GENERIC if CRYPTO_ARCH_HAVE_LIB_CURVE25519=n
+
config CRYPTO_LIB_CURVE25519
tristate "Curve25519 scalar multiplication library"
- select CRYPTO_LIB_CURVE25519_GENERIC if CRYPTO_ARCH_HAVE_LIB_CURVE25519=n
- select CRYPTO_LIB_UTILS
+ select CRYPTO
+ select CRYPTO_LIB_CURVE25519_INTERNAL
help
Enable the Curve25519 library interface. This interface may be
fulfilled by either the generic implementation or an arch-specific
@@ -118,11 +118,6 @@ config CRYPTO_ARCH_HAVE_LIB_POLY1305
accelerated implementation of the Poly1305 library interface,
either builtin or as a module.

-config CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
- tristate
- select CRYPTO_ARCH_HAVE_LIB_POLY1305 if CRYPTO_LIB_POLY1305=m
- select CRYPTO_ARCH_HAVE_LIB_POLY1305 if CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305=y
-
config CRYPTO_LIB_POLY1305_GENERIC
tristate
help
@@ -132,9 +127,14 @@ config CRYPTO_LIB_POLY1305_GENERIC
implementation is enabled, this implementation serves the users
of CRYPTO_LIB_POLY1305.

+config CRYPTO_LIB_POLY1305_INTERNAL
+ tristate
+ select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
+
config CRYPTO_LIB_POLY1305
tristate "Poly1305 library interface"
- select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
+ select CRYPTO
+ select CRYPTO_LIB_POLY1305_INTERNAL
help
Enable the Poly1305 library interface. This interface may be fulfilled
by either the generic implementation or an arch-specific one, if one
@@ -142,9 +142,10 @@ config CRYPTO_LIB_POLY1305

config CRYPTO_LIB_CHACHA20POLY1305
tristate "ChaCha20-Poly1305 AEAD support (8-byte nonce library version)"
- depends on CRYPTO
+ select CRYPTO
select CRYPTO_LIB_CHACHA
select CRYPTO_LIB_POLY1305
+ select CRYPTO_LIB_UTILS
select CRYPTO_ALGAPI

config CRYPTO_LIB_SHA1
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt