Re: Cannot load wireguard module
From: Michal Suchánek <hidden>
Date: 2024-03-20 16:05:24
Also in:
netdev
On Wed, Mar 20, 2024 at 11:41:32PM +1100, Michael Ellerman wrote:
Michal Suchánek [off-list ref] writes:quoted
On Mon, Mar 18, 2024 at 06:08:55PM +0100, Michal Suchánek wrote:quoted
On Mon, Mar 18, 2024 at 10:50:49PM +1100, Michael Ellerman wrote:quoted
Michael Ellerman [off-list ref] writes:quoted
Michal Suchánek [off-list ref] writes:quoted
Hello, I cannot load the wireguard module. Loading the module provides no diagnostic other than 'No such device'. Please provide maningful diagnostics for loading software-only driver, clearly there is no particular device needed.Presumably it's just bubbling up an -ENODEV from somewhere. Can you get a trace of it? Something like: # trace-cmd record -p function_graph -F modprobe wireguardAttached.Sorry :/, you need to also trace children of modprobe, with -c. But, I was able to reproduce the same issue here. On a P9, a kernel with CONFIG_CRYPTO_CHACHA20_P10=n everything works: $ modprobe -v wireguard insmod /lib/modules/6.8.0/kernel/net/ipv4/udp_tunnel.ko insmod /lib/modules/6.8.0/kernel/net/ipv6/ip6_udp_tunnel.ko insmod /lib/modules/6.8.0/kernel/lib/crypto/libchacha.ko insmod /lib/modules/6.8.0/kernel/lib/crypto/libchacha20poly1305.ko insmod /lib/modules/6.8.0/kernel/drivers/net/wireguard/wireguard.ko [ 19.180564][ T692] wireguard: allowedips self-tests: pass [ 19.185080][ T692] wireguard: nonce counter self-tests: pass [ 19.310438][ T692] wireguard: ratelimiter self-tests: pass [ 19.310639][ T692] wireguard: WireGuard 1.0.0 loaded. See www.wireguard.com for information. [ 19.310746][ T692] wireguard: Copyright (C) 2015-2019 Jason A. Donenfeld [off-list ref]. All Rights Reserved. If I build CONFIG_CRYPTO_CHACHA20_P10 as a module then it breaks: $ modprobe -v wireguard insmod /lib/modules/6.8.0/kernel/net/ipv4/udp_tunnel.ko insmod /lib/modules/6.8.0/kernel/net/ipv6/ip6_udp_tunnel.ko insmod /lib/modules/6.8.0/kernel/lib/crypto/libchacha.ko insmod /lib/modules/6.8.0/kernel/arch/powerpc/crypto/chacha-p10-crypto.ko modprobe: ERROR: could not insert 'wireguard': No such device The ENODEV is coming from module_cpu_feature_match(), which blocks the driver from loading on non-p10. Looking at other arches (arm64 at least) it seems like the driver should instead be loading but disabling the p10 path. Which then allows chacha_crypt_arch() to exist, and it has a fallback to use chacha_crypt_generic(). I don't see how module_cpu_feature_match() can co-exist with the driver also providing a fallback. Hopefully someone who knows crypto better than me can explain it.
Maybe it doesn't. ppc64le is the only platform that needs the fallback, on other platforms that have hardware-specific chacha implementation it seems to be using pretty common feature so the fallback is rarely if ever needed in practice. Thanks Michal
quoted hunk ↗ jump to hunk
This diff fixes it for me:diff --git a/arch/powerpc/crypto/chacha-p10-glue.c b/arch/powerpc/crypto/chacha-p10-glue.c index 74fb86b0d209..9d2c30b0904c 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(PPC_FEATURE2_ARCH_3_1)) + return 0; + static_branch_enable(&have_p10); return crypto_register_skciphers(algs, ARRAY_SIZE(algs));@@ -207,7 +210,7 @@ static void __exit chacha_p10_exit(void) 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)");Giving me: $ modprobe -v wireguard insmod /lib/modules/6.8.0-dirty/kernel/net/ipv4/udp_tunnel.ko insmod /lib/modules/6.8.0-dirty/kernel/net/ipv6/ip6_udp_tunnel.ko insmod /lib/modules/6.8.0-dirty/kernel/lib/crypto/libchacha.ko insmod /lib/modules/6.8.0-dirty/kernel/arch/powerpc/crypto/chacha-p10-crypto.ko insmod /lib/modules/6.8.0-dirty/kernel/lib/crypto/libchacha20poly1305.ko insmod /lib/modules/6.8.0-dirty/kernel/drivers/net/wireguard/wireguard.ko [ 19.657941][ T718] wireguard: allowedips self-tests: pass [ 19.662501][ T718] wireguard: nonce counter self-tests: pass [ 19.782933][ T718] wireguard: ratelimiter self-tests: pass [ 19.783114][ T718] wireguard: WireGuard 1.0.0 loaded. See www.wireguard.com for information. [ 19.783223][ T718] wireguard: Copyright (C) 2015-2019 Jason A. Donenfeld [off-list ref]. All Rights Reserved. cheers