From: Borislav Petkov <b...@suse.de> Hi all,
sorry for spamming so quickly again and not waiting for a week before resubmitting but I believe the stuff is ready for 4.8. So here's v4 with all the minor review comments addressed. Changelog: ---------- v3: here's v3 integrating Ingo's comments. The thing is called printk.devkmsg= or printk_devkmsg now, depending on cmdline option or sysctl. v2: here's v2 with the requested sysctl option kernel.printk_kmsg and locking of the setting when printk.kmsg= is supplied on the command line. Patch 1 is unchanged. Patch 2 has grown the sysctl addition. v1: Rostedt is busy so I took Linus' old patch and Steven's last v2 and split and extended them with the comments people had on the last thread: https://lkml.kernel.org/r/20160425145606.59832...@gandalf.local.home I hope, at least. So it is ratelimiting by default, with "on" and "off" cmdline options. I called the option somewhat a bit shorter too: "printk.kmsg" The current use cases of this and of which I'm aware are: * debug the kernel and thus shut up all interfering input from userspace, i.e. boot with "printk.kmsg=off" * debug userspace (and by that I mean systemd) by booting with "printk.kmsg=on" so that the ratelimiting is disabled and the kernel log gets all the spew. Thoughts? Please queue, thanks. Borislav Petkov (2): ratelimit: Extend to print suppressed messages on release printk: Add kernel parameter to control writes to /dev/kmsg Documentation/kernel-parameters.txt | 6 +++ Documentation/sysctl/kernel.txt | 14 ++++++ include/linux/printk.h | 7 +++ include/linux/ratelimit.h | 38 +++++++++++++--- kernel/printk/printk.c | 86 +++++++++++++++++++++++++++++++++---- kernel/sysctl.c | 9 ++++ lib/ratelimit.c | 10 +++-- 7 files changed, 153 insertions(+), 17 deletions(-) -- 2.7.3
