Michal Suchánek <msucha...@suse.de> writes:
> On Mon, Mar 18, 2024 at 06:08:55PM +0100, Michal Suchánek wrote:
>> On Mon, Mar 18, 2024 at 10:50:49PM +1100, Michael Ellerman wrote:
>> > Michael Ellerman <m...@ellerman.id.au> writes:
>> > > Michal Suchánek <msucha...@suse.de> writes:
>> > >> 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 wireguard
>
> Attached.
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
<ja...@zx2c4.com>. 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.
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
<ja...@zx2c4.com>. All Rights Reserved.
cheers
