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2026-08-04Merge branch 'misc' into nextMike Rapoport (Microsoft)1-1/+0
2026-07-25liveupdate: reject nonzero reserved value for SESSION_FINISHJackie Liu1-1/+5
The UAPI documents liveupdate_session_finish::reserved as requiring zero, but luo_session_finish() currently ignores it and finishes the session. Accepting nonzero values prevents the field from being safely repurposed by a future extension. Reject nonzero reserved values before changing session state, matching LIVEUPDATE_SESSION_GET_NAME. Fixes: 16cec0d26521 ("liveupdate: luo_session: add ioctls for file preservation") Assisted-by: Codex:gpt-5.6-sol Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Link: https://patch.msgid.link/20260716012607.22020-2-liu.yun@linux.dev Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-07-16liveupdate: fix GET_NAME ioctl argument validationJackie Liu1-1/+1
LIVEUPDATE_SESSION_GET_NAME was developed in the liveupdate/next branch while the session type validation change was carried in liveupdate-fixes. When the conflict between the two branches was resolved, the GET_NAME operation descriptor picked up the structure and last member from RETRIEVE_FD. This makes both its known size and minimum size 16 bytes rather than 72. A zero-initialized request still succeeds because luo_session_get_name() writes the full name before luo_ucmd_respond() copies the full GET_NAME response to userspace. However, copy_struct_from_user() treats the output-only name field as unknown trailing data and rejects the request with -E2BIG if any byte in that field is nonzero. Use the GET_NAME structure and its name field in the descriptor. Link: https://lore.kernel.org/all/ahWlYXNjGUbkKoHy@sirena.org.uk/ Assisted-by: Codex:gpt-5.6-sol Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Link: https://patch.msgid.link/20260716012607.22020-1-liu.yun@linux.dev Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-07-15liveupdate: Remove redundant INIT_LIST_HEAD in luo_session_allocHongfu Li1-1/+0
luo_session_alloc() calls INIT_LIST_HEAD(&session->file_set.files_list) followed immediately by luo_file_set_init(), which also performs INIT_LIST_HEAD() on the same list head. Remove the duplicate call. Signed-off-by: Hongfu Li <lihongfu@kylinos.cn> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Link: https://patch.msgid.link/20260714074056.95335-1-hongfu.li@linux.dev Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-03liveupdate: Remove limit on the number of sessionsPasha Tatashin1-60/+53
Currently, the number of LUO sessions is limited by a fixed number of pre-allocated pages for serialization (16 pages, allowing for ~819 sessions). This limitation is problematic if LUO is used to support things such as systemd file descriptor store, and would be used not just as VM memory but to save other states on the machine. Remove this limit by transitioning to a linked-block approach for session metadata serialization. Instead of a single contiguous block, session metadata is now stored in a chain of 16-page blocks. Each block starts with a header containing the physical address of the next block and the number of session entries in the current block. Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260603154402.468928-10-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-03liveupdate: defer session block allocation and physical address settingPasha Tatashin1-25/+43
Currently, luo_session_setup_outgoing() allocates the session block and sets its physical address in the header immediately. With upcoming dynamic block-based session management, this makes the first block different from the rest. Move the allocation to where it is first needed. Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260603154402.468928-9-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-03liveupdate: Extract luo_session_deserialize_one helperPasha Tatashin1-27/+36
Extract the logic for deserializing single entries for sessions into separate helper functions. In preparation to a linked-block serialization for sessions. This is a pure code movement, no other changes intended. Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260603154402.468928-7-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-03liveupdate: centralize state management into struct luo_serPasha Tatashin1-54/+10
Transition the LUO to ABI v2, which centralizes state management into a single struct luo_ser header. Previously, LUO state was spread across multiple FDT properties and subnodes. ABI v2 simplifies this by placing all core state, including the liveupdate number and physical addresses for sessions and FLB headers into a centralized struct luo_ser. Note that this change introduces a semantic difference: the sessions and FLB serialization formats are no longer completely independent of the core LUO. Their metadata (such as physical addresses for sessions and FLB headers) is now coupled to and managed via the centralized struct luo_ser. Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260603154402.468928-4-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-03liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fdPasha Tatashin1-2/+3
Refactoring luo_session_retrieve_fd() to avoid mixing automated cleanup-style guards with goto-based resource release, which is not recommended under the Linux kernel coding style. Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260603154402.468928-3-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-01liveupdate: block session mutations during rebootPasha Tatashin1-3/+48
During the reboot() syscall, user processes may still be running concurrently and attempting to mutate sessions (e.g., creating, retrieving, or releasing sessions). To prevent this, introduce luo_session_serialize_rwsem to synchronize mutations with the serialization process. All session mutation operations (create, retrieve, release, ioctl) take the read lock. The serialization process (luo_session_serialize) takes the write lock and holds it indefinitely on success. This effectively freezes the LUO session subsystem during the transition to the new kernel. If serialization fails, the lock is released to allow recovery. Fixes: 0153094d03df ("liveupdate: luo_session: add sessions support") Reported-by: Oskar Gerlicz Kowalczuk <oskar@gerlicz.space> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Link: https://patch.msgid.link/20260527202737.1345192-4-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-01liveupdate: fix TOCTOU race in luo_session_retrieve()Pasha Tatashin1-6/+5
Extend the scope of the rwsem_read lock in luo_session_retrieve() to overlap with the acquisition of the session mutex. This prevents a concurrent thread from releasing and freeing the session between the lookup and the mutex lock. Fixes: 0153094d03df ("liveupdate: luo_session: add sessions support") Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://patch.msgid.link/20260527202737.1345192-3-pasha.tatashin@soleen.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-01liveupdate: validate session type before performing operationPratyush Yadav (Google)1-6/+33
The sessions ioctls are not applicable to all session types. PRESERVE_FD is only applicable to outgoing sessions. RETRIEVE_FD and FINISH are only valid for incoming session. Calling a incoming ioctl on an outgoing session is invalid and can cause file handlers to run into unexpected errors. For example, a user can create a (outgoing) session, preserve a memfd, and then immediately do a retrieve without doing a kexec in between. This would result in memfd's retrieve handler to run. The handlers expects to be called from a post-kexec context, and will try to do a kho_restore_vmalloc() or kho_restore_folio() to try and restore memory. KHO catches this (thanks to KHO_PAGE_MAGIC) and returns an error, but since this is considered an internal error and KHO throws out a bunch of WARN()s. Associate a type with each ioctl op and validate the type in luo_session_ioctl() before dispatching the ioctl handler to make sure the op is being called for the right session type. Fixes: 16cec0d26521 ("liveupdate: luo_session: add ioctls for file preservation") Cc: stable@vger.kernel.org Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org> Link: https://patch.msgid.link/20260519122428.2378446-1-pratyush@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-01liveupdate: add LIVEUPDATE_SESSION_GET_NAME ioctlLuca Boccassi1-0/+16
Userspace when requesting a session via the ioctl specifies a name and gets a FD, but then there is no ioctl to go back the other way and get the name given a LUO session FD. This is problematic especially when there is a userspace orchestrator that wants to check what FDs it is handling for clients without having to do manual string scraping of procfs, or without procfs at all. Add a ioctl to simply get the name from an FD. Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Link: https://lore.kernel.org/r/20260429212221.814107-4-luca.boccassi@gmail.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-01liveupdate: reject LIVEUPDATE_IOCTL_CREATE_SESSION with invalid name lengthLuca Boccassi1-0/+4
A session name must not be an empty string, and must not exceed the maximum size define in the uapi header, including null termination. Fixes: 0153094d03df ("liveupdate: luo_session: add sessions support") Cc: stable@vger.kernel.org Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Link: https://lore.kernel.org/r/20260429212221.814107-2-luca.boccassi@gmail.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-04-27liveupdate: fix return value on session allocation failurePasha Tatashin1-5/+10
When session allocation fails during deserialization, the global 'err' variable was not updated before returning. This caused subsequent calls to luo_session_deserialize() to incorrectly report success. Ensure 'err' is set to the error code from PTR_ERR(session). This ensures that an error is correctly returned to userspace when it attempts to open /dev/liveupdate in the new kernel if deserialization failed. Link: https://lore.kernel.org/20260415193738.515491-1-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Cc: David Matlack <dmatlack@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Samiullah Khawaja <skhawaja@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-19Merge tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-44/+2
Pull more MM updates from Andrew Morton: - "Eliminate Dying Memory Cgroup" (Qi Zheng and Muchun Song) Address the longstanding "dying memcg problem". A situation wherein a no-longer-used memory control group will hang around for an extended period pointlessly consuming memory - "fix unexpected type conversions and potential overflows" (Qi Zheng) Fix a couple of potential 32-bit/64-bit issues which were identified during review of the "Eliminate Dying Memory Cgroup" series - "kho: history: track previous kernel version and kexec boot count" (Breno Leitao) Use Kexec Handover (KHO) to pass the previous kernel's version string and the number of kexec reboots since the last cold boot to the next kernel, and print it at boot time - "liveupdate: prevent double preservation" (Pasha Tatashin) Teach LUO to avoid managing the same file across different active sessions - "liveupdate: Fix module unloading and unregister API" (Pasha Tatashin) Address an issue with how LUO handles module reference counting and unregistration during module unloading - "zswap pool per-CPU acomp_ctx simplifications" (Kanchana Sridhar) Simplify and clean up the zswap crypto compression handling and improve the lifecycle management of zswap pool's per-CPU acomp_ctx resources - "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race" (SeongJae Park) Address unlikely but possible leaks and deadlocks in damon_call() and damon_walk() - "mm/damon/core: validate damos_quota_goal->nid" (SeongJae Park) Fix a couple of root-only wild pointer dereferences - "Docs/admin-guide/mm/damon: warn commit_inputs vs other params race" (SeongJae Park) Update the DAMON documentation to warn operators about potential races which can occur if the commit_inputs parameter is altered at the wrong time - "Minor hmm_test fixes and cleanups" (Alistair Popple) Bugfixes and a cleanup for the HMM kernel selftests - "Modify memfd_luo code" (Chenghao Duan) Cleanups, simplifications and speedups to the memfd_lou code - "mm, kvm: allow uffd support in guest_memfd" (Mike Rapoport) Support for userfaultfd in guest_memfd - "selftests/mm: skip several tests when thp is not available" (Chunyu Hu) Fix several issues in the selftests code which were causing breakage when the tests were run on CONFIG_THP=n kernels - "mm/mprotect: micro-optimization work" (Pedro Falcato) A couple of nice speedups for mprotect() - "MAINTAINERS: update KHO and LIVE UPDATE entries" (Pratyush Yadav) Document upcoming changes in the maintenance of KHO, LUO, memfd_luo, kexec, crash, kdump and probably other kexec-based things - they are being moved out of mm.git and into a new git tree * tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (121 commits) MAINTAINERS: add page cache reviewer mm/vmscan: avoid false-positive -Wuninitialized warning MAINTAINERS: update Dave's kdump reviewer email address MAINTAINERS: drop include/linux/liveupdate from LIVE UPDATE MAINTAINERS: drop include/linux/kho/abi/ from KHO MAINTAINERS: update KHO and LIVE UPDATE maintainers MAINTAINERS: update kexec/kdump maintainers entries mm/migrate_device: remove dead migration entry check in migrate_vma_collect_huge_pmd() selftests: mm: skip charge_reserved_hugetlb without killall userfaultfd: allow registration of ranges below mmap_min_addr mm/vmstat: fix vmstat_shepherd double-scheduling vmstat_update mm/hugetlb: fix early boot crash on parameters without '=' separator zram: reject unrecognized type= values in recompress_store() docs: proc: document ProtectionKey in smaps mm/mprotect: special-case small folios when applying permissions mm/mprotect: move softleaf code out of the main function mm: remove '!root_reclaim' checking in should_abort_scan() mm/sparse: fix comment for section map alignment mm/page_io: use sio->len for PSWPIN accounting in sio_read_complete() selftests/mm: transhuge_stress: skip the test when thp not available ...
2026-04-18liveupdate: remove luo_session_quiesce()Pasha Tatashin1-43/+0
Now that FLB module references are handled dynamically during active sessions, we can safely remove the luo_session_quiesce() and luo_session_resume() mechanism. Link: https://lore.kernel.org/20260327033335.696621-7-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Cc: David Matlack <dmatlack@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Samiullah Khawaja <skhawaja@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-18liveupdate: safely print untrusted stringsPasha Tatashin1-1/+2
Patch series "liveupdate: Fix module unloading and unregister API", v3. This patch series addresses an issue with how LUO handles module reference counting and unregistration during a module unload (e.g., via rmmod). Currently, modules that register live update file handlers are pinned for the entire duration they are registered. This prevents the modules from being unloaded gracefully, even when no live update session is in progress. Furthermore, if a module is forcefully unloaded, the unregistration functions return an error (e.g. -EBUSY) if a session is active, which is ignored by the kernel's module unload path, leaving dangling pointers in the LUO global lists. To resolve these issues, this series introduces the following changes: 1. Adds a global read-write semaphore (luo_register_rwlock) to protect the registration lists for both file handlers and FLBs. 2. Reduces the scope of module reference counting for file handlers and FLBs. Instead of pinning modules indefinitely upon registration, references are now taken only when they are actively used in a live update session (e.g., during preservation, retrieval, or deserialization). 3. Removes the global luo_session_quiesce() mechanism since module unload behavior now handles active sessions implicitly. 4. Introduces auto-unregistration of FLBs during file handler unregistration to prevent leaving dangling resources. 5. Changes the unregistration functions to return void instead of an error code. 6. Fixes a data race in luo_flb_get_private() by introducing a spinlock for thread-safe lazy initialization. 7. Strengthens security by using %.*s when printing untrusted deserialized compatible strings and session names to prevent out-of-bounds reads. This patch (of 10): Deserialized strings from KHO data (such as file handler compatible strings and session names) are provided by the previous kernel and might not be null-terminated if the data is corrupted or maliciously crafted. When printing these strings in error messages, use the %.*s format specifier with the maximum buffer size to prevent out-of-bounds reads into adjacent kernel memory. Link: https://lore.kernel.org/20260327033335.696621-1-pasha.tatashin@soleen.com Link: https://lore.kernel.org/20260327033335.696621-2-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org> Cc: David Matlack <dmatlack@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Samiullah Khawaja <skhawaja@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-06liveupdate: propagate file deserialization failuresLeo Timmins1-2/+7
luo_session_deserialize() ignored the return value from luo_file_deserialize(). As a result, a session could be left partially restored even though the /dev/liveupdate open path treats deserialization failures as fatal. Propagate the error so a failed file deserialization aborts session deserialization instead of silently continuing. Link: https://lkml.kernel.org/r/20260325044608.8407-1-leotimmins1974@gmail.com Link: https://lkml.kernel.org/r/20260325044608.8407-2-leotimmins1974@gmail.com Fixes: 16cec0d26521 ("liveupdate: luo_session: add ioctls for file preservation") Signed-off-by: Leo Timmins <leotimmins1974@gmail.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds1-1/+1
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-1/+1
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-11-27liveupdate: luo_session: add ioctls for file preservationPasha Tatashin1-2/+185
Introducing the userspace interface and internal logic required to manage the lifecycle of file descriptors within a session. Previously, a session was merely a container; this change makes it a functional management unit. The following capabilities are added: A new set of ioctl commands are added, which operate on the file descriptor returned by CREATE_SESSION. This allows userspace to: - LIVEUPDATE_SESSION_PRESERVE_FD: Add a file descriptor to a session to be preserved across the live update. - LIVEUPDATE_SESSION_RETRIEVE_FD: Retrieve a preserved file in the new kernel using its unique token. - LIVEUPDATE_SESSION_FINISH: finish session The session's .release handler is enhanced to be state-aware. When a session's file descriptor is closed, it correctly unpreserves the session based on its current state before freeing all associated file resources. Link: https://lkml.kernel.org/r/20251125165850.3389713-8-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_session: add sessions supportPasha Tatashin1-0/+463
Introduce concept of "Live Update Sessions" within the LUO framework. LUO sessions provide a mechanism to group and manage `struct file *` instances (representing file descriptors) that need to be preserved across a kexec-based live update. Each session is identified by a unique name and acts as a container for file objects whose state is critical to a userspace workload, such as a virtual machine or a high-performance database, aiming to maintain their functionality across a kernel transition. This groundwork establishes the framework for preserving file-backed state across kernel updates, with the actual file data preservation mechanisms to be implemented in subsequent patches. [dan.carpenter@linaro.org: fix use after free in luo_session_deserialize()] Link: https://lkml.kernel.org/r/c5dd637d7eed3a3be48c5e9fedb881596a3b1f5a.1764163896.git.dan.carpenter@linaro.org Link: https://lkml.kernel.org/r/20251125165850.3389713-5-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>