[PATCH] powerpc/crypto/chacha-p10: Fix failure on non Power10
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2024-03-28 13:03:10
The chacha-p10-crypto module provides optimised chacha routines for Power10. It also selects CRYPTO_ARCH_HAVE_LIB_CHACHA which says it provides chacha_crypt_arch() to generic code. Notably the module needs to provide chacha_crypt_arch() regardless of whether it is loaded on Power10 or an older CPU. The implementation of chacha_crypt_arch() already has a fallback to chacha_crypt_generic(), however the module as a whole fails to load on pre-Power10, because of the use of module_cpu_feature_match(). This breaks for example loading wireguard: jostaberry-1:~ # modprobe -v wireguard insmod /lib/modules/6.8.0-lp155.8.g7e0e887-default/kernel/arch/powerpc/crypto/chacha-p10-crypto.ko.zst modprobe: ERROR: could not insert 'wireguard': No such device Fix it by removing module_cpu_feature_match(), and instead check the CPU feature manually. If the CPU feature is not found, the module still loads successfully, but doesn't register the Power10 specific algorithms. That allows chacha_crypt_generic() to remain available for use, fixing the problem. [root@fedora ~]# modprobe -v wireguard insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/net/ipv4/udp_tunnel.ko insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/net/ipv6/ip6_udp_tunnel.ko insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/lib/crypto/libchacha.ko insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/arch/powerpc/crypto/chacha-p10-crypto.ko insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/lib/crypto/libchacha20poly1305.ko insmod /lib/modules/6.8.0-00001-g786a790c4d79/kernel/drivers/net/wireguard/wireguard.ko [ 18.910452][ T721] wireguard: allowedips self-tests: pass [ 18.914999][ T721] wireguard: nonce counter self-tests: pass [ 19.029066][ T721] wireguard: ratelimiter self-tests: pass [ 19.029257][ T721] wireguard: WireGuard 1.0.0 loaded. See www.wireguard.com for information. [ 19.029361][ T721] wireguard: Copyright (C) 2015-2019 Jason A. Donenfeld [off-list ref]. All Rights Reserved. Reported-by: Michal Suchánek <redacted> Closes: https://lore.kernel.org/all/20240315122005.GG20665@kitsune.suse.cz/ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/crypto/chacha-p10-glue.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/crypto/chacha-p10-glue.c b/arch/powerpc/crypto/chacha-p10-glue.c
index 74fb86b0d209..7c728755852e 100644
--- a/arch/powerpc/crypto/chacha-p10-glue.c
+++ b/arch/powerpc/crypto/chacha-p10-glue.c@@ -197,6 +197,9 @@ static struct skcipher_alg algs[] = { static int __init chacha_p10_init(void) { + if (!cpu_has_feature(CPU_FTR_ARCH_31)) + return 0; + static_branch_enable(&have_p10); return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
@@ -204,10 +207,13 @@ static int __init chacha_p10_init(void) static void __exit chacha_p10_exit(void) { + if (!static_branch_likely(&have_p10)) + return; + crypto_unregister_skciphers(algs, ARRAY_SIZE(algs)); } -module_cpu_feature_match(PPC_MODULE_FEATURE_P10, chacha_p10_init); +module_init(chacha_p10_init); module_exit(chacha_p10_exit); MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (P10 accelerated)");
--
2.44.0