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| author | Pasha Tatashin <pasha.tatashin@soleen.com> | 2025-11-01 10:23:17 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-27 14:24:31 -0800 |
| commit | 03d3963464a43654703938a66503cd686c5fc54e (patch) | |
| tree | fd42acc0e50c32e228d59072075a677f4a91ba72 /kernel/Kconfig.kexec | |
| parent | e6fbd1759c9ece5044d3470f30a5e2166dc9de89 (diff) | |
| download | lwn-03d3963464a43654703938a66503cd686c5fc54e.tar.gz lwn-03d3963464a43654703938a66503cd686c5fc54e.zip | |
kho: make debugfs interface optional
Patch series "liveupdate: Rework KHO for in-kernel users", v9.
This series refactors the KHO framework to better support in-kernel users
like the upcoming LUO. The current design, which relies on a notifier
chain and debugfs for control, is too restrictive for direct programmatic
use.
The core of this rework is the removal of the notifier chain in favor of a
direct registration API. This decouples clients from the shutdown-time
finalization sequence, allowing them to manage their preserved state more
flexibly and at any time.
In support of this new model, this series also:
- Makes the debugfs interface optional.
- Introduces APIs to unpreserve memory and fixes a bug in the abort
path where client state was being incorrectly discarded. Note that
this is an interim step, as a more comprehensive fix is planned as
part of the stateless KHO work [1].
- Moves all KHO code into a new kernel/liveupdate/ directory to
consolidate live update components.
This patch (of 9):
Currently, KHO is controlled via debugfs interface, but once LUO is
introduced, it can control KHO, and the debug interface becomes optional.
Add a separate config CONFIG_KEXEC_HANDOVER_DEBUGFS that enables the
debugfs interface, and allows to inspect the tree.
Move all debugfs related code to a new file to keep the .c files clear of
ifdefs.
Link: https://lkml.kernel.org/r/20251101142325.1326536-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20251101142325.1326536-2-pasha.tatashin@soleen.com
Link: https://lore.kernel.org/all/20251020100306.2709352-1-jasonmiu@google.com [1]
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/Kconfig.kexec')
| -rw-r--r-- | kernel/Kconfig.kexec | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec index 54e581072617..cc6743137946 100644 --- a/kernel/Kconfig.kexec +++ b/kernel/Kconfig.kexec @@ -100,7 +100,6 @@ config KEXEC_HANDOVER depends on !DEFERRED_STRUCT_PAGE_INIT select MEMBLOCK_KHO_SCRATCH select KEXEC_FILE - select DEBUG_FS select LIBFDT select CMA help @@ -118,6 +117,17 @@ config KEXEC_HANDOVER_DEBUG scenarios and the extra code might be adding overhead it is only optionally enabled. +config KEXEC_HANDOVER_DEBUGFS + bool "kexec handover debugfs interface" + default KEXEC_HANDOVER + depends on KEXEC_HANDOVER + select DEBUG_FS + help + Allow to control kexec handover device tree via debugfs + interface, i.e. finalize the state or aborting the finalization. + Also, enables inspecting the KHO fdt trees with the debugfs binary + blobs. + config CRASH_DUMP bool "kernel crash dumps" default ARCH_DEFAULT_CRASH_DUMP |