xref: /openbmc/linux/Documentation/ABI/testing/sysfs-kernel-livepatch (revision c99a2be790b07752d8cc694434d3450afd4c5a00)

What:		/sys/kernel/livepatch
Date:		Nov 2014
KernelVersion:	3.19.0
Contact:	live-patching@vger.kernel.org
Description:
		Interface for kernel live patching

		The /sys/kernel/livepatch directory contains subdirectories for
		each loaded live patch module.

What:		/sys/kernel/livepatch/<patch>
Date:		Nov 2014
KernelVersion:	3.19.0
Contact:	live-patching@vger.kernel.org
Description:
		The patch directory contains subdirectories for each kernel
		object (vmlinux or a module) in which it patched functions.

What:		/sys/kernel/livepatch/<patch>/enabled
Date:		Nov 2014
KernelVersion:	3.19.0
Contact:	live-patching@vger.kernel.org
Description:
		A writable attribute that indicates whether the patched
		code is currently applied.  Writing 0 will disable the patch
		while writing 1 will re-enable the patch.

What:		/sys/kernel/livepatch/<patch>/transition
Date:		Feb 2017
KernelVersion:	4.12.0
Contact:	live-patching@vger.kernel.org
Description:
		An attribute which indicates whether the patch is currently in
		transition.

What:		/sys/kernel/livepatch/<patch>/signal
Date:		Nov 2017
KernelVersion:	4.15.0
Contact:	live-patching@vger.kernel.org
Description:
		A writable attribute that allows administrator to affect the
		course of an existing transition. Writing 1 sends a fake
		signal to all remaining blocking tasks. The fake signal
		means that no proper signal is delivered (there is no data in
		signal pending structures). Tasks are interrupted or woken up,
		and forced to change their patched state.

What:		/sys/kernel/livepatch/<patch>/force
Date:		Nov 2017
KernelVersion:	4.15.0
Contact:	live-patching@vger.kernel.org
Description:
		A writable attribute that allows administrator to affect the
		course of an existing transition. Writing 1 clears
		TIF_PATCH_PENDING flag of all tasks and thus forces the tasks to
		the patched or unpatched state. Administrator should not
		use this feature without a clearance from a patch
		distributor. Removal (rmmod) of patch modules is permanently
		disabled when the feature is used. See
		Documentation/livepatch/livepatch.txt for more information.

What:		/sys/kernel/livepatch/<patch>/<object>
Date:		Nov 2014
KernelVersion:	3.19.0
Contact:	live-patching@vger.kernel.org
Description:
		The object directory contains subdirectories for each function
		that is patched within the object.

What:		/sys/kernel/livepatch/<patch>/<object>/<function,sympos>
Date:		Nov 2014
KernelVersion:	3.19.0
Contact:	live-patching@vger.kernel.org
Description:
		The function directory contains attributes regarding the
		properties and state of the patched function.

		The directory name contains the patched function name and a
		sympos number corresponding to the nth occurrence of the symbol
		name in kallsyms for the patched object.

		There are currently no such attributes.