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
| ||
|
Message-ID: <20180425132352.cs22ak5jzwr2f4v4@pathway.suse.cz> Date: Wed, 25 Apr 2018 15:23:52 +0200 From: Petr Mladek <pmladek@...e.com> To: Sergey Senozhatsky <sergey.senozhatsky.work@...il.com> Cc: Steven Rostedt <rostedt@...dmis.org>, Andrew Morton <akpm@...ux-foundation.org>, Peter Zijlstra <peterz@...radead.org>, Tejun Heo <tj@...nel.org>, linux-kernel@...r.kernel.org, Sergey Senozhatsky <sergey.senozhatsky@...il.com> Subject: Re: [PATCHv2] printk: wake up klogd in vprintk_emit On Fri 2018-04-20 10:52:21, Sergey Senozhatsky wrote: > On (04/19/18 12:02), Petr Mladek wrote: > > On Thu 2018-04-19 10:42:50, Sergey Senozhatsky wrote: > > > We wake up klogd very late - only when current console_sem owner > > > is done pushing pending kernel messages to the serial/net consoles. > > > In some cases this results in lost syslog messages, because kernel > > > log buffer is a circular buffer and if we don't wakeup syslog long > > > enough there are chances that logbuf simply will wrap around. > > > > > > The patch moves the klog wake up call to vprintk_emit(), which is > > > the only legit way for a kernel message to appear in the logbuf, > > > right before we attempt to grab the console_sem (possibly spinning > > > on it waiting for the hand off) and call console drivers. > > > > The last two lines need an update. What about? > > Ah. Indeed! > > > "right after the attempt to handle consoles. As a result, klog > > will get waken either after flushing the new message to consoles > > or immediately when consoles are still busy with older messages." > > Looks good. Do you want me to resend the patch? JFYI, I have updated the commit message and pushed the patch into printk.git, for-4.18 branch. Best Regards, Petr
Powered by blists - more mailing lists