6.6-stable review patch. If anyone has any objections, please let me know.
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From: Michael Ellerman mpe@ellerman.id.au
[ Upstream commit 69630926011c1f7170a465b7b5c228deb66e9372 ]
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 Jason@zx2c4.com. All Rights Reserved.
Reported-by: Michal Suchánek msuchanek@suse.de Closes: https://lore.kernel.org/all/20240315122005.GG20665@kitsune.suse.cz/ Acked-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240328130200.3041687-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin sashal@kernel.org --- 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 74fb86b0d2097..7c728755852e1 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)");