lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 6 Jun 2018 20:08:48 +0530 From: Tejaswi Tanikella <tejaswit@...eaurora.org> To: David Miller <davem@...emloft.net> Cc: netdev@...r.kernel.org, f.fainelli@...il.com, andrew@...n.ch, edumazet@...gle.com Subject: Re: [PATCH net] ipv4: igmp: hold wakelock to prevent delayed reports On Mon, Jun 04, 2018 at 11:06:40AM -0400, David Miller wrote: > From: Tejaswi Tanikella <tejaswit@...eaurora.org> > Date: Fri, 1 Jun 2018 19:35:41 +0530 > > > On receiving a IGMPv2/v3 query, based on max_delay set in the header a > > timer is started to send out a response after a random time within > > max_delay. If the system then moves into suspend state, Report is > > delayed until system wakes up. > > > > In one reported scenario, on arm64 devices, max_delay was set to 10s, > > Reports were consistantly delayed if the timer is scheduled after 5 plus > > seconds. > > > > Hold wakelock while starting the timer to prevent moving into suspend > > state. > > > > Signed-off-by: Tejaswi Tanikella <tejaswit@...eaurora.org> > > As Florian stated, this won't be the only networking facility to hit > a problem like this. So, if we go down this route, we probably want > to generically solve this. > > But I have a deeper concern. > > Do we really want every timer based querying mechanism to prevent a > system from being able to suspend? > > We get to the point where external entities can generate traffic which > can prevent a remote system from entering suspend state. Like you suggested maybe aquiring a wakelock will unnecessarily stop the system from suspending. Would using alarmtimer be better? It seems similar to a hrtimer but can wake the system up from suspend. This should allow the system to suspend till the timer expires. But might cause repeated wake-ups and suspends.
Powered by blists - more mailing lists