Hi Jon, On Fri, Jul 01, 2022 at 02:22:38PM -0600, Jonathan Corbet wrote: > So please forgive the noise from the peanut gallery Yuh oh, I sure hope this isn't newsworthy for LWN. This has already consumed me for two days... > myself wondering...do you really need a knob for this? The kernel > itself can observe how often (and for how long) the system is suspended, > and might well be able to do the right thing without explicit input from > user space. If it works it would eliminate a potential configuration > problem and also perhaps respond correctly to changing workloads. > > For example, rather than testing a knob, avoid resetting keys on resume > if the suspend time is less than (say) 30s? > > Educate me on what I'm missing here, please :) What you're missing is that wireguard needs to do this before going to sleep, not when waking up, because one of the objectives is forward secrecy. See https://git.zx2c4.com/wireguard-linux/tree/drivers/net/wireguard/device.c#n63 if (IS_ENABLED(CONFIG_PM_AUTOSLEEP) || IS_ENABLED(CONFIG_ANDROID)) return 0; if (action != PM_HIBERNATION_PREPARE && action != PM_SUSPEND_PREPARE) return 0; [...] wg_noise_handshake_clear(&peer->handshake); wg_noise_keypairs_clear(&peer->keypairs); Somebody asked the same question on wgml here - https://lore.kernel.org/wireguard/CAHmME9p2OYSTX2C5M0faKtw2N8jiyohvRqnAPKa=e7BWynF7fQ@xxxxxxxxxxxxxx/T/ - and then eventually suggested that I should wake up computers from sleep to clear that memory. No way jose. Anyway, this matter has been resolved in this thread here: https://lore.kernel.org/lkml/20220630191230.235306-1-kaleshsingh@xxxxxxxxxx/T/ And this Android change: https://android-review.googlesource.com/c/kernel/common/+/2142693/1 Resulting in these two commits landing in Greg's tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git/commit/?id=261e224d6a5c43e2bb8a07b7662f9b4ec425cfec https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git/commit/?id=1045a06724f322ed61f1ffb994427c7bdbe64647 So hopefully this thread can come to an end and I can get back to work. Jason
