diff mbox series

crypto: lib/Kconfig - fix chacha/poly1305 dependencies more more

Message ID 20250225164216.4807-1-arnd@kernel.org (mailing list archive)
State New
Headers show
Series crypto: lib/Kconfig - fix chacha/poly1305 dependencies more more | expand

Commit Message

Arnd Bergmann Feb. 25, 2025, 4:42 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

A recent change tries to fix Kconfig dependencies, but introduced
two problems in the process:

 - only arm, powerpc and x86 are changed, while mips, arm64 and s390
   are now broken

 - there are now configurations where the architecture enables its
   own helper functions as loadable modules, but they remain silently
   unused because CRYPTO_LIB_* falls back to the generic helpers

Address both by changing the logic again: the architecture functions
select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA, which may be a loadable
module or built-in, and this controls whether the library is
also built-in.

Fixes: 04f9ccc955c7 ("crypto: lib/Kconfig - Fix lib built-in failure when arch is modular")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
I did not quite understand what problem the 04f9ccc955c7 patch
actually tried to solve, so there is a chance that my version
undoes it. I tested this on randconfig builds across, arm,
arm64 and x86 and found no other dependency problems with these
libraries.
---
 arch/arm64/crypto/Kconfig |  4 ++--
 arch/mips/crypto/Kconfig  |  4 ++--
 arch/s390/crypto/Kconfig  |  2 +-
 lib/crypto/Kconfig        | 20 +++++++++++---------
 4 files changed, 16 insertions(+), 14 deletions(-)

Comments

Will Deacon Feb. 25, 2025, 9:33 p.m. UTC | #1 
On Tue, Feb 25, 2025 at 05:42:07PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> A recent change tries to fix Kconfig dependencies, but introduced
> two problems in the process:
> 
>  - only arm, powerpc and x86 are changed, while mips, arm64 and s390
>    are now broken
> 
>  - there are now configurations where the architecture enables its
>    own helper functions as loadable modules, but they remain silently
>    unused because CRYPTO_LIB_* falls back to the generic helpers
> 
> Address both by changing the logic again: the architecture functions
> select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA, which may be a loadable
> module or built-in, and this controls whether the library is
> also built-in.
> 
> Fixes: 04f9ccc955c7 ("crypto: lib/Kconfig - Fix lib built-in failure when arch is modular")

Which tree contains this change? I can't seem to resolve the SHA locally.

Will
Arnd Bergmann Feb. 25, 2025, 9:40 p.m. UTC | #2 
On Tue, Feb 25, 2025, at 22:33, Will Deacon wrote:
> On Tue, Feb 25, 2025 at 05:42:07PM +0100, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@arndb.de>
>> 
>> A recent change tries to fix Kconfig dependencies, but introduced
>> two problems in the process:
>> 
>>  - only arm, powerpc and x86 are changed, while mips, arm64 and s390
>>    are now broken
>> 
>>  - there are now configurations where the architecture enables its
>>    own helper functions as loadable modules, but they remain silently
>>    unused because CRYPTO_LIB_* falls back to the generic helpers
>> 
>> Address both by changing the logic again: the architecture functions
>> select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA, which may be a loadable
>> module or built-in, and this controls whether the library is
>> also built-in.
>> 
>> Fixes: 04f9ccc955c7 ("crypto: lib/Kconfig - Fix lib built-in failure when arch is modular")
>
> Which tree contains this change? I can't seem to resolve the SHA locally.

Sorry, that must have been an older commit ID. Today's linux-next
contains 56b8e4bb7622 ("crypto: lib/Kconfig - Fix lib built-in failure
when arch is modular")

which is in
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git

    Arnd
Arnd Bergmann Feb. 25, 2025, 9:50 p.m. UTC | #3 
On Tue, Feb 25, 2025, at 22:40, Arnd Bergmann wrote:
> On Tue, Feb 25, 2025, at 22:33, Will Deacon wrote:
>> On Tue, Feb 25, 2025 at 05:42:07PM +0100, Arnd Bergmann wrote:
>>> From: Arnd Bergmann <arnd@arndb.de>
>>> 
>>> A recent change tries to fix Kconfig dependencies, but introduced
>>> two problems in the process:
>>> 
>>>  - only arm, powerpc and x86 are changed, while mips, arm64 and s390
>>>    are now broken
>>> 
>>>  - there are now configurations where the architecture enables its
>>>    own helper functions as loadable modules, but they remain silently
>>>    unused because CRYPTO_LIB_* falls back to the generic helpers
>>> 
>>> Address both by changing the logic again: the architecture functions
>>> select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA, which may be a loadable
>>> module or built-in, and this controls whether the library is
>>> also built-in.
>>> 
>>> Fixes: 04f9ccc955c7 ("crypto: lib/Kconfig - Fix lib built-in failure when arch is modular")
>>
>> Which tree contains this change? I can't seem to resolve the SHA locally.
>
> Sorry, that must have been an older commit ID. Today's linux-next
> contains 56b8e4bb7622 ("crypto: lib/Kconfig - Fix lib built-in failure
> when arch is modular")
>
> which is in
> git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git

After looking at the original 0day report, I think the fix for
that problem would have been

--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -94,6 +94,7 @@ config WIREGUARD
        select CRYPTO_CHACHA_MIPS if CPU_MIPS32_R2
        select CRYPTO_POLY1305_MIPS if MIPS
        select CRYPTO_CHACHA_S390 if S390
+       select CRYPTO_CURVE25519_PPC64 if PPC64 && CPU_LITTLE_ENDIAN
        help
          WireGuard is a secure, fast, and easy to use replacement for IPSec
          that uses modern cryptography and clever networking tricks. It's

which makes powerpc behave the same way as the other architectures.
Ideally wireguard should not need to know about every architecture
specific algorithm that it might use though, and that requires
a different method of enabling those.

     Arnd
diff mbox series

Patch

diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 5636ab83f22a..3d90efdcf5a5 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -29,7 +29,7 @@  config CRYPTO_POLY1305_NEON
 	tristate "Hash functions: Poly1305 (NEON)"
 	depends on KERNEL_MODE_NEON
 	select CRYPTO_HASH
-	select CRYPTO_ARCH_HAVE_LIB_POLY1305
+	select CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
 	help
 	  Poly1305 authenticator algorithm (RFC7539)
 
@@ -190,7 +190,7 @@  config CRYPTO_CHACHA20_NEON
 	depends on KERNEL_MODE_NEON
 	select CRYPTO_SKCIPHER
 	select CRYPTO_LIB_CHACHA_GENERIC
-	select CRYPTO_ARCH_HAVE_LIB_CHACHA
+	select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
 	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..cbeb2f62eb79 100644
--- a/arch/mips/crypto/Kconfig
+++ b/arch/mips/crypto/Kconfig
@@ -5,7 +5,7 @@  menu "Accelerated Cryptographic Algorithms for CPU (mips)"
 config CRYPTO_POLY1305_MIPS
 	tristate "Hash functions: Poly1305"
 	depends on MIPS
-	select CRYPTO_ARCH_HAVE_LIB_POLY1305
+	select CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
 	help
 	  Poly1305 authenticator algorithm (RFC7539)
 
@@ -55,7 +55,7 @@  config CRYPTO_CHACHA_MIPS
 	tristate "Ciphers: ChaCha20, XChaCha20, XChaCha12 (MIPS32r2)"
 	depends on CPU_MIPS32_R2
 	select CRYPTO_SKCIPHER
-	select CRYPTO_ARCH_HAVE_LIB_CHACHA
+	select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
 	help
 	  Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
 	  stream cipher algorithms
diff --git a/arch/s390/crypto/Kconfig b/arch/s390/crypto/Kconfig
index b760232537f1..6f7495264943 100644
--- a/arch/s390/crypto/Kconfig
+++ b/arch/s390/crypto/Kconfig
@@ -112,7 +112,7 @@  config CRYPTO_CHACHA_S390
 	depends on S390
 	select CRYPTO_SKCIPHER
 	select CRYPTO_LIB_CHACHA_GENERIC
-	select CRYPTO_ARCH_HAVE_LIB_CHACHA
+	select CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
 	help
 	  Length-preserving cipher: ChaCha20 stream cipher (RFC 7539)
 
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index c542ef1d64d0..6b45bd634cd9 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -50,8 +50,6 @@  config CRYPTO_ARCH_HAVE_LIB_CHACHA
 
 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
@@ -65,7 +63,9 @@  config CRYPTO_LIB_CHACHA_GENERIC
 
 config CRYPTO_LIB_CHACHA
 	tristate "ChaCha library interface"
-	select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
+	select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA=n
+	select CRYPTO_ARCH_HAVE_LIB_CHACHA if CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA!=n
+	depends on CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA || !CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
 	help
 	  Enable the ChaCha library interface. This interface may be fulfilled
 	  by either the generic implementation or an arch-specific one, if one
@@ -80,8 +80,6 @@  config CRYPTO_ARCH_HAVE_LIB_CURVE25519
 
 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
@@ -94,7 +92,9 @@  config CRYPTO_LIB_CURVE25519_GENERIC
 
 config CRYPTO_LIB_CURVE25519
 	tristate "Curve25519 scalar multiplication library"
-	select CRYPTO_LIB_CURVE25519_GENERIC if CRYPTO_ARCH_HAVE_LIB_CURVE25519=n
+	select CRYPTO_LIB_CURVE25519_GENERIC if CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519=n
+	select CRYPTO_ARCH_HAVE_LIB_CURVE25519 if CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519!=n
+	depends on CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519 || !CRYPTO_ARCH_MAY_HAVE_LIB_CURVE25519
 	select CRYPTO_LIB_UTILS
 	help
 	  Enable the Curve25519 library interface. This interface may be
@@ -120,8 +120,6 @@  config CRYPTO_ARCH_HAVE_LIB_POLY1305
 
 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
@@ -134,7 +132,9 @@  config CRYPTO_LIB_POLY1305_GENERIC
 
 config CRYPTO_LIB_POLY1305
 	tristate "Poly1305 library interface"
-	select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
+	select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305=n
+	select CRYPTO_ARCH_HAVE_LIB_POLY1305 if CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305!=n
+	depends on CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
 	help
 	  Enable the Poly1305 library interface. This interface may be fulfilled
 	  by either the generic implementation or an arch-specific one, if one
@@ -143,6 +143,8 @@  config CRYPTO_LIB_POLY1305
 config CRYPTO_LIB_CHACHA20POLY1305
 	tristate "ChaCha20-Poly1305 AEAD support (8-byte nonce library version)"
 	depends on CRYPTO
+	depends on CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_MAY_HAVE_LIB_POLY1305
+	depends on CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA || !CRYPTO_ARCH_MAY_HAVE_LIB_CHACHA
 	select CRYPTO_LIB_CHACHA
 	select CRYPTO_LIB_POLY1305
 	select CRYPTO_ALGAPI