wireguard-linux/arch/um/include/asm/Kbuild, branch stable

Merge tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T08:51:14Z

Pull locking updates from Ingo Molnar: "Futex updates: - Optimize futex hash bucket access patterns (Peter Zijlstra) - Large series to address the robust futex unlock race for real, by Thomas Gleixner: "The robust futex unlock mechanism is racy in respect to the clearing of the robust_list_head::list_op_pending pointer because unlock and clearing the pointer are not atomic. The race window is between the unlock and clearing the pending op pointer. If the task is forced to exit in this window, exit will access a potentially invalid pending op pointer when cleaning up the robust list. That happens if another task manages to unmap the object containing the lock before the cleanup, which results in an UAF. In the worst case this UAF can lead to memory corruption when unrelated content has been mapped to the same address by the time the access happens. User space can't solve this problem without help from the kernel. This series provides the kernel side infrastructure to help it along: 1) Combined unlock, pointer clearing, wake-up for the contended case 2) VDSO based unlock and pointer clearing helpers with a fix-up function in the kernel when user space was interrupted within the critical section. ... with help by André Almeida: - Add a note about robust list race condition (André Almeida) - Add self-tests for robust release operations (André Almeida) Context analysis updates: - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche) - Bump required Clang version to 23 (Marco Elver) Guard infrastructure updates: - Series to remove NULL check from unconditional guards (Dmitry Ilvokhin) Lockdep updates: - Restore self-test migrate_disable() and sched_rt_mutex state on PREEMPT_RT (Karl Mehltretter) Membarriers updates: - Use per-CPU mutexes for targeted commands (Aniket Gattani) - Modernize membarrier_global_expedited with cleanup guards (Aniket Gattani) - Add rseq stress test for CFS throttle interactions (Aniket Gattani) percpu-rwsems updates: - Extract __percpu_up_read() to optimize inlining overhead (Dmitry Ilvokhin) Seqlocks updates: - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens) Lock tracing: - Add contended_release tracepoint to sleepable locks such as mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry Ilvokhin) MAINTAINERS updates: - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng) Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra, Dmitry Ilvokhin and Peter Zijlstra" * tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits) locking: Add contended_release tracepoint to sleepable locks locking/percpu-rwsem: Extract __percpu_up_read() tracing/lock: Remove unnecessary linux/sched.h include futex: Optimize futex hash bucket access patterns rust: sync: completion: Mark inline complete_all and wait_for_completion MAINTAINERS: Add RUST [SYNC] entry cleanup: Specify nonnull argument index selftests: futex: Add tests for robust release operations Documentation: futex: Add a note about robust list race condition x86/vdso: Implement __vdso_futex_robust_try_unlock() x86/vdso: Prepare for robust futex unlock support futex: Provide infrastructure to plug the non contended robust futex unlock race futex: Add robust futex unlock IP range futex: Add support for unlocking robust futexes futex: Cleanup UAPI defines x86: Select ARCH_MEMORY_ORDER_TSO uaccess: Provide unsafe_atomic_store_release_user() futex: Provide UABI defines for robust list entry modifiers futex: Move futex related mm_struct data into a struct futex: Make futex_mm_init() void ...

percpu: Sanitize __percpu_qual include hell

2026-06-03T09:38:48Z

Slapping __percpu_qual into the next available header is sloppy at best. It's required by __percpu which is defined in compiler_types.h and that is meant to be included without requiring a boatload of other headers so that a struct or function declaration can contain a __percpu qualifier w/o further prerequisites. This implicit dependency on linux/percpu.h makes that impossible and causes a major problem when trying to separate headers. Create asm/percpu_types.h and move it there. Include that from compiler_types.h and the whole recursion problem goes away. Fix up UM so it uses the generic header and includes it in the UM_HOST build, which pulls in compiler_types.h. The USER_CFLAGS fix was suggested by Richard. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260602090535.254874125@kernel.org

ring-buffer: Flush and stop persistent ring buffer on panic

2026-05-21T12:20:58Z

On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon Cc: Mathieu Desnoyers Cc: Ian Rogers Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Acked-by: Catalin Marinas Acked-by: Geert Uytterhoeven Signed-off-by: Steven Rostedt

x86/asm: Remove ANNOTATE_DATA_SPECIAL usage

2025-12-03T15:53:19Z

Instead of manually annotating each __ex_table entry, just make the section mergeable and store the entry size in the ELF section header. Either way works for objtool create_fake_symbols(), this way produces cleaner code generation. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://patch.msgid.link/b858cb7891c1ba0080e22a9c32595e6c302435e2.1764694625.git.jpoimboe@kernel.org

loongarch, um, xtensa: get rid of generated arch/$ARCH/include/asm/param.h

2025-06-25T02:02:05Z

For loongarch and xtensa that gets them to do what x86 et.al. are doing - have asm/param.h resolve to uapi variant, which is generated by mandatory-y += param.h and contains exact same include. On um it will resolve to x86 uapi variant instead, which also contains the same include (um doesn't have uapi headers, but it does build the host ones). Reviewed-by: Arnd Bergmann Signed-off-by: Al Viro

um: x86: clean up elf specific definitions

2025-03-18T13:48:31Z

The file arch/x86/um/asm/module.h is equivalent to the definition of asm-generic. Thus this commit cleans up to use it. Signed-off-by: Hajime Tazaki Link: https://patch.msgid.link/2d70a0ed79ee0a0bef80ad4790063f4833dd9bed.1737348399.git.thehajime@gmail.com Signed-off-by: Johannes Berg

um: move thread info into task

2024-11-12T13:50:31Z

This selects the THREAD_INFO_IN_TASK option for UM and changes the way that the current task is discovered. This is trivial though, as UML already tracks the current task in cpu_tasks[] and this can be used to retrieve it. Also remove the signal handler code that copies the thread information into the IRQ stack. It is obsolete now, which also means that the mentioned race condition cannot happen anymore. Signed-off-by: Benjamin Berg Reviewed-by: Hajime Tazaki Link: https://patch.msgid.link/20241111102910.46512-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Use generic runtime constant implementation

2024-07-17T00:25:59Z

UML should not be using the architecture native runtime constants, since that requires also having the appropriate instruction fixups (and all the linker script details). Not that using that code would be impossible, but it's not worth it. Just point UML at the generic version. Reported-by: Nathan Chancellor Fixes: e3c92e81711d ("runtime constants: add x86 architecture support") Link: https://lore.kernel.org/all/20240716143644.GA1827132@thelio-3990X/ Signed-off-by: Linus Torvalds

um: don't generate asm/bpf_perf_event.h

2024-07-10T12:23:30Z

If we start validating the existence of the asm-generic side of generated headers, this one causes a warning: make[3]: *** No rule to make target 'arch/um/include/generated/asm/bpf_perf_event.h', needed by 'all'. Stop. The problem is that the asm-generic header only exists for the uapi variant, but arch/um has no uapi headers and instead uses the x86 userspace API. Add a custom file with an explicit redirect to avoid this. Signed-off-by: Arnd Bergmann

arch: Rename fbdev header and source files

2024-05-03T15:07:50Z

The per-architecture fbdev code has no dependencies on fbdev and can be used for any video-related subsystem. Rename the files to 'video'. Use video-sti.c on parisc as the source file depends on CONFIG_STI_CORE. On arc, arm, arm64, sh, and um the asm header file is an empty wrapper around the file in asm-generic. Let Kbuild generate the file. The build system does this automatically. Only um needs to generate video.h explicitly, so that it overrides the host architecture's header. The latter would otherwise interfere with the build. Further update all includes statements, include guards, and Makefiles. Also update a few strings and comments to refer to video instead of fbdev. v3: - arc, arm, arm64, sh: generate asm header via build system (Sam, Helge, Arnd) - um: rename fb.h to video.h - fix typo in commit message (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Cc: Vineet Gupta Cc: Catalin Marinas Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Geert Uytterhoeven Cc: Thomas Bogendoerfer Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Yoshinori Sato Cc: Rich Felker Cc: John Paul Adrian Glaubitz Cc: "David S. Miller" Cc: Andreas Larsson Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Signed-off-by: Arnd Bergmann