search for: livepatch

...Wed, Jan 25, 2023 at 12:34:26PM +0100, Petr Mladek wrote: > > On Tue 2023-01-24 11:21:39, Seth Forshee wrote: > > > On Tue, Jan 24, 2023 at 03:17:43PM +0100, Petr Mladek wrote: > > > > On Fri 2023-01-20 16:12:22, Seth Forshee (DigitalOcean) wrote: > > > > > Livepatch relies on stack checking of sleeping tasks to switch kthreads, > > > > > so a busy kthread can block a livepatch transition indefinitely. We've > > > > > seen this happen fairly often with busy vhost kthreads. > > > > > > > > > --- a/dri...

...07174628.2086373-1-song at kernel.org/ > > > > Interesting thread. I had thought about something along the lines of the > > original patch, but there are some ideas in there that I hadn't > > considered. > > Here's another idea, have we considered this? Have livepatch set > TIF_NEED_RESCHED on all kthreads to force them into schedule(), and then > have the scheduler call klp_try_switch_task() if TIF_PATCH_PENDING is > set. > > Not sure how scheduler folks would feel about that ;-) So, let me try and page all that back in.... :-) KLP needs to un...

...kpatch's > timeout period due to busy vhost worker kthreads. In looking for a solution the > only answer I found was to call klp_update_patch_state() from a safe location. > I tried adding this call to vhost_worker(), and it works, but this creates the > potential for problems if a livepatch attempted to patch vhost_worker(). > Without a call to klp_update_patch_state() fully loaded vhost kthreads can > never switch because vhost_worker() will always appear on the stack, but with > the call these kthreads can switch but will still be running the old version of > vhost_worke...

...I hadn't > considered. Could you please provide some more details about the test system? Is there anything important to make it reproducible? The following aspects come to my mind. It might require: + more workers running on the same system + have a dedicated CPU for the worker + livepatching the function called by work->fn() + running the same work again and again + huge and overloaded system > > Honestly, kpatch's timeout 1 minute looks incredible low to me. Note > > that the transition is tried only once per minute. It means that there > > are &quo...

...t means that there are "only" 60 attempts. Just by chance, does it help you to increase the timeout, please? This low timeout might be useful for testing. But in practice, it does not matter when the transition is lasting one hour or even longer. It takes much longer time to prepare the livepatch. Best Regards, Petr

Hi, I am running CentOS Linux release 7.7.1908 (Core). Does CentOS Linux kernel 3.10.0-1062.1.1.el7.x86_64 support kernel updates without rebooting (Live Patching)? I look forward to hearing from you and thanks in advance. Best Regards, Kaushal

On Wed, Oct 9, 2019 at 11:27 AM Kaushal Shriyan <kaushalshriyan at gmail.com> wrote: > Hi, > > I am running CentOS Linux release 7.7.1908 (Core). Does CentOS Linux kernel > 3.10.0-1062.1.1.el7.x86_64 support kernel updates without rebooting (Live > Patching)? > > I look forward to hearing from you and thanks in advance. > > > this was just discussed in length

...kmap_ctrl; #ifdef CONFIG_DEBUG_ATOMIC_SLEEP unsigned long task_state_change; #endif --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -2,6 +2,7 @@ #include <linux/context_tracking.h> #include <linux/entry-common.h> +#include <linux/highmem.h> #include <linux/livepatch.h> #include <linux/audit.h> @@ -194,6 +195,7 @@ static void exit_to_user_mode_prepare(st /* Ensure that the address limit is intact and no locks are held */ addr_limit_user_check(); + kmap_assert_nomap(); lockdep_assert_irqs_disabled(); lockdep_sys_exit(); } --- a/kernel/fork...

Hello, While testing Virt-SIG Xen 4.12 rpms on CentOS7 I noticed the following problem with libvirt/virt-manager when manually installing a new HVM guest from virt-manager GUI.. basicly the VM installation won't start, because libvirt/virt-manager is not able to start the VM, due to "missing" qemu-system-i386 binary: Unable to complete install: 'unsupported configuration:

...encons xencov_split xen-cpuid (version-wrapped, where necessary). - Likewise very many utilities and daemons in /usr/sbin: gdbsx xen-bugtool xen-ringwatch xen-tmem-list-parse xenmon xenpmd flask-* xen-kdd xen-diag xen-hptool xen-hvmcrash xen-hvmctx xen-livepatch xen-lowmemd xen-mfndump xenbaked xenconsoled xencov xenlockprof xenstored xenwatchdogd - xend and xm are long gone, so remove the support for the TOOLSTACK setting in /etc/default/xen. /usr/sbin/xen just runs xl now. Remove mentions of xend-config.sxp a...

Following up to the discussion in: https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de and the second version of this: https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de this series provides a preemptible variant of kmap_atomic & related interfaces. This is achieved by: - Removing the RT dependency from migrate_disable/enable() - Consolidating all

Following up to the discussion in: https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de and the second version of this: https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de this series provides a preemptible variant of kmap_atomic & related interfaces. This is achieved by: - Removing the RT dependency from migrate_disable/enable() - Consolidating all

Following up to the discussion in: https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de and the second version of this: https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de this series provides a preemptible variant of kmap_atomic & related interfaces. This is achieved by: - Removing the RT dependency from migrate_disable/enable() - Consolidating all

This series adds new functions to the mmu interval notifier API to allow device drivers with MMUs to dynamically mirror a process' page tables based on device faults and invalidation callbacks. The Nouveau driver is updated to use the extended API and a set of stand alone self tests is added to help validate and maintain correctness. The patches are based on linux-5.5.0-rc6 and are for