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9 daysMerge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds6-6/+20
Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure
12 daysring-buffer: Stop remote reader update when page swap failsIvan Immanuel Shaji1-2/+5
The remote swap_reader_page callback can return -EBUSY when the writer moves the head before the remote catches it, particularly during an event storm on a small buffer. __rb_get_reader_page_from_remote() currently warns about that failure but continues with the unchanged reader ID and rearranges the local page list as though the swap succeeded. Handle the callback failure as a recoverable error. Report it with pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader page as a failed attempt. This avoids splicing the same page as both the previous and new reader without flooding the log under contention. Cc: stable@vger.kernel.org Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-2-bb3461807a32@gmail.com Assisted-by: LLM sparse Signed-off-by: Ivan Immanuel Shaji <ivanimmanuel1234@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
12 daystracing: Fix retry exhaustion in simple ring buffer reader swapIvan Immanuel Shaji1-2/+2
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. The current !retry test reverses both outcomes. It returns an error after a successful final replacement, leaving the link update complete but the reader bookkeeping unfinished. After a failed final replacement, it falls through and updates the head and reader pointers as though the replacement succeeded, which can corrupt the ring. Treat only a negative counter as exhaustion and return the documented -EBUSY error. Cc: stable@vger.kernel.org Fixes: 34e5b958bdad ("tracing: Introduce simple_ring_buffer") Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-1-bb3461807a32@gmail.com Assisted-by: LLM sparse Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Ivan Immanuel Shaji <ivanimmanuel1234@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
12 daystracing/user_events: Clear copied tracing state before fork duplicationJérémy Jean1-0/+3
dup_task_struct() copies user_event_mm from the parent into the child, without grabbing a reference to it. user_event_mm_dup() should replace it, but it leaves that copied pointer unmodified if user_event_mm_alloc() fails. When the child exits, user_event_mm_remove() decrements a reference the child never owned, which ultimately frees user_event_mm, while the parent still as a stale pointer to it. This creates a UAF, which KASAN reports as: BUG: KASAN: slab-use-after-free in current_user_event_mm+0x51/0x1d0 Write of size 4 at addr ffff888005010d30 by task init/44 Call Trace: <TASK> kasan_report+0xce/0x100 kasan_check_range+0x10f/0x1e0 current_user_event_mm+0x51/0x1d0 user_events_ioctl+0x82e/0x15c0 __x64_sys_ioctl+0x139/0x1c0 do_syscall_64+0xce/0x450 entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task 44: __kasan_kmalloc+0x8f/0xa0 __kmalloc_cache_noprof+0x180/0x3a0 user_event_mm_alloc+0x3c/0x1f0 current_user_event_mm+0x88/0x1d0 Freed by task 42: __kasan_slab_free+0x43/0x70 kfree+0x13a/0x390 process_one_work+0x696/0xf90 worker_thread+0x420/0xba0 The fix simply clears the copied pointer before any possible failure. In case of failure, the child then has nothing to free. Cc: stable@vger.kernel.org Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement") Link: https://patch.msgid.link/20260827184321.2964601-2-Jeremy.Jean@oss.cyber.gouv.fr Assisted-by: Codex:gpt-5 Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr> Reviewed-by: Bradley Morgan <brads@mainlining.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-22tracing: Fix use-after-free in trace_pipe read on sub-buffer order changeDeepanshu Kartikey1-0/+3
Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(), which frees every sub-buffer of the ring buffer, including the reader page, and replaces them with newly allocated ones. Readers of trace_pipe hold pointers into those pages. ring_buffer_peek() looks up an event under cpu_buffer->reader_lock but returns the event pointer after dropping the lock, and peek_next_entry() then calls ring_buffer_event_length() and ring_buffer_event_data() on it. If the sub-buffer order is changed in that window, the reader dereferences freed memory: BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430 Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002 Freed by: free_buffer_page kernel/trace/ring_buffer.c:398 [inline] ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444 buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221 Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change. This is the lock trace_pipe readers already hold across their entire peek-and-print loop, so the swap can no longer race with a reader that is dereferencing a peeked event. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260817140655.5694-1-kartikey406@gmail.com Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Reported-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=685955db58555575fdd2 Tested-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com Reviewed-by: Bradley Morgan <include@grrlz.net> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-22tracing: Fix crash passing ERR_PTR to kthread_stop()Hui Su1-0/+2
event_test_stuff() calls kthread_run() and unconditionally passes the returned task_struct pointer to kthread_stop(). kthread_run() returns an error pointer such as ERR_PTR(-ENOMEM) when kthread creation fails, for example under memory pressure during the boot-time event self-test. kthread_stop() then dereferences the invalid pointer, crashing the kernel. Check the result of kthread_run() before passing it to kthread_stop(). Use WARN_ON() so that a failure to create the self-test thread does not go unnoticed, matching the ring-buffer self-test fix in commit 91542863abad ("ring-buffer: Fix crash passing ERR_PTR to kthread_stop()"). Cc: stable@vger.kernel.org Fixes: e6187007d6c3 ("tracing/events: add startup tests for events") Link: https://patch.msgid.link/20260817120642.668375-3-sh_def@163.com Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-22tracing: Fix use-after-free with same-name named triggersHui Su1-1/+3
When two hist triggers on different events are registered with the same name=, the second one reuses the first as named_data. Both are added to tr->hist_vars by save_hist_vars() during event_hist_trigger_parse(), because save_hist_vars() is called before event_trigger_register() while the named reuse is only detected later, in hist_register_trigger(). In the named-data branch hist_register_trigger() then frees the second histogram's hist_data via destroy_hist_data(), but never removes its tr->hist_vars list entry, leaving a dangling pointer and leaking the trace_array reference it holds. A later hist trigger that references a variable makes find_var_file() walk tr->hist_vars and dereference the freed hist_data. The bug is reproducible from userspace by writing three hist triggers to tracefs: cd /sys/kernel/tracing echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_switch/trigger echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_process_fork/trigger echo 'hist:keys=common_pid:vals=$x' > events/sched/sched_process_exit/trigger The third write panics the kernel: BUG: KASAN: slab-use-after-free in find_var_file.part.0+0x272/0x290 Read of size 8 at addr ffff888001f8a0e0 by task sh/1 CPU: 1 UID: 0 PID: 1 Comm: sh Tainted: G D N Call Trace: find_var_file.part.0 find_event_var parse_atom parse_expr __create_val_field event_hist_trigger_parse trigger_process_regex event_trigger_write vfs_write ksys_write do_syscall_64 entry_SYSCALL_64_after_hwframe Allocated by task 1: event_hist_trigger_parse Freed by task 1: hist_register_trigger+0x618/0xa30 event_hist_trigger_parse The buggy address belongs to freed 2048-byte region Oops: general protection fault ... RIP: find_var_file.part.0 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Fix by removing the hist_data from tr->hist_vars and releasing the trace_array reference in the named-data branch of hist_register_trigger() before freeing the hist_data. Cc: stable@vger.kernel.org Fixes: 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list") Link: https://patch.msgid.link/20260816100427.33642-3-sh_def@163.com Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-22tracing: Fix logged instance name on creation failureVincent Donnefort1-1/+2
When boot instance creation fails, the kernel incorrectly logs "(null)" as the instance name because strsep() consumes curr_str entirely during parsing. Print the properly parsed name variable instead. And while at it log the error code. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260807085423.4175161-1-vdonnefort@google.com Fixes: cb1f98c5e574 ("tracing: Add creation of instances at boot command line") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-20Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-1/+2
Pull MM updates from Andrew Morton: - "mm: drop "sub" prefix from various places" (Dev Jain) page->folio conversion and a naming cleanup - "mm/kasan: remove redundant initialization for kasan_flag_write_only" (Igor Putko) KASAN cleanup work - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling) Small speedup in the pagecaache read code - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng) Improve the vmalloc code - mainly the avoidance of GFP_KERNEL allocations when the caller asked for GFP_NOFS or GFP_NOIO - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno Leitao) Avoid a soft lockup watchdog trigger from the kmemleak scanning code in extreme situations - "mm/page_owner: misc cleanups" (Ye Liu) Cleanups to the page_owner code. For some reason lots of people have been working on the page_owner code this cycle. - "mm: convert to walk_page_range_vma() to eliminate find_vma()" (Kefeng Wang) Simplify and accelerate the page walking library function - "mm/migrate: preparatory cleanups for batch copy and offload" (Shivank Garg) Cleanups in the migration code - "mm/page_owner: add per-fd filter infrastructure for print_mode and NUMA filtering" (Zhen Ni) Per-fd filtering to page_owner in order to reduce the sometimes vast amount of output it can produce - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song) Fixes and preparatory cleanups around bootmem HugeTLB handling, sparse initialization ordering, and related vmemmap setup - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao) Reduce lock contention in zs_free(), which dominates the unmap path under memory pressure on Android (LMK kills) and on x86 servers running zswap-heavy workloads. Up to 1.83x improvement in microbenchmarking. - "move alloc_tag.c file under mm/" (Suren Baghdasaryan) - "samples/damon: handle damon_{start,stop}() failures" (SJ Park) Fix improper handling of damon_start(), damon_stop(), and damon_call() failures across DAMON sample modules to prevent potential memory leaks, operation disruptions and use-after-free bugs - "mm/damon/sysfs: kobject_del() directories that users can create/remove" (SJ Park) Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE causeing creation failures due to duplicate directory names by adding missing kobject_del() calls before creating new directories - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand) Clean up the core pte handling code - "selftests/damon: misc fixes for test bugs" (Kunwu Chan) Fix several bugs in the DAMON selftests - "selftests/damon: fix memcg_path staging handling" (Cheng Nie) Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and add a test case for it in sysfs.py. - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev) Selftest coverage for DAMON's refresh_ms sysfs feature by updating the test control module and verifying that scheme stats update automatically without manual intervention - "mm/damon: five misc fixups" (Akinobu Mita) Miscellaneous DAMON fixups. - "mm/damon/core: detect internal variation above max_nr_regions/2" (Jiayuan Chen) Fix DAMON's region splitting behavior when region counts exceed half the maximum budget by dynamically scaling down the split fraction as the limit approaches, preventing large regions from staying un-split, and add corresponding KUnit test coverage - "mm: preparatory patches for PMD level swap entries" (Usama Arif) Refactor and clean up PMD softleaf helpers, call sites, and architecture flags to lay the groundwork for a follow-up series that introduces PMD page table swap entries - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ Park) Update DAMON design and ABI documentation, expands unit and selftest coverage, optimize damon_commit_target_regions(), and clean up recently added sysfs interface code for better readability - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2" (Usama Arif) Optimize vmpressure() by skipping unnecessary work on cgroup v2 for userspace event notifications and refactor v1-only eventfd handling into mm/memcontrol-v1.c to reduce memory overhead and code complexity - "selftests/mm: refactor pkey helpers and fix mmap error handling" (Hongfu Li) Refactor pkeys shared tracing and assertion helpers into a common file, unify protection key selftests to use consistent diagnostic logging and assertions, and enforce standardized MAP_FAILED return checks for mmap() calls across the tests - "mm/damon: optimize out nr_accesses_bp" (SJ Park) Replace the error-prone, continuously updated nr_accesses_bp field in damon_region with an on-demand moving sum function, reducing structure memory overhead and avoiding state corruption bugs - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng) Decouple HugeTLB folio allocation from VMA dependencies by introducing hugetlb_alloc_folio(), enabling subsystems like guest_memfd to allocate HugeTLB folios without standard VMA reservations or pseudo-VMAs - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park) Integrate DAMON's probe_hits attribute counter into the pseudo moving sum infrastructure, enabling real-time, online monitoring without waiting for full aggregation intervals - "mm: Some cleanups for page allocator APIs" (Brendan Jackman) Simplify and refactor the page allocator entry points and flags by unifying allocation paths, adding internal alloc_flags arguments, and eliminating redundant __ prefixed alloc_pages variants. - "Fix incorrect access of hugetlb pte entries" (Dev Jain) Enforce the consistent use of huge_ptep_get() instead of ptep_get() for HugeTLB entries and fixes an unaligned address issue in arm64's huge_ptep_get() implementation - "mm/damon: validate all parameters in the core" (SJ Park) Consolidate parameter validation into the DAMON core specifically within damon_start() and damon_commit_ctx() to centralize error checking, eliminate caller-side redundant checks and to improve maintenance efficiency - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong Chen) Rename is_need() to filter_record() for clearer return semantics, fix per-record allocation memory leaks and bound output copies in search_pattern() to address an existing buffer issue - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen) Mitigate a system-wide stall which occurs when a cgroup is removed while one of its memory control files is doing synchronous reclaim - "mm/memory-failure: add panic option for unrecoverable pages" (Breno Leitao) Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics the kernel on unrecoverable memory errors in kernel-owned pages to preserve error context and prevent delayed, silent data corruption - "mm/damon: refactor damon_{start,stop,commit}() for simple error handling" (SJ Park) Refactor the DAMON core API functions to guarantee that all contexts are fully stopped when damon_start(), damon_stop(), or damon_commit() fail, eliminating the need for complex and error-prone caller-side cleanup code - "Keep tail page private zero at free and folio split" (Zi Yan) Add checks to ensure tail_page->private is zero when freeing compound or high-order pages and when promoting tail pages during large folio splits. By validating these fields at free and split time, it allows the removal of redundant private field clearing inside prep_compound_tail() - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry Song) Eliminate redundant lru_add_drain() calls in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock contention and system overhead By validating folio refcounts against the LRU cache before draining and removing unnecessary drains in the swap path, it achieves up to a 30.5% reduction in drain calls during heavy swap workloads - "mm: clean up folio LRU and swap declarations" (Jianyue Wu) Reorganize folio LRU and swap code by relocating page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving MM-internal reclaim declarations into mm/internal.h. - "userfaultfd: working set tracking for VM guest memory" (Kiryl Shutsemau) Add userfaultfd support for tracking the working set of VM guest memory, so a VMM can identify hot pages and reclaim cold ones to tiered or remote storage - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David Hildenbrand) Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around freeing of reserved vmemmap pages on the way. - "mm/damon: update probe hits for runtime parameter commits" (SJ Park) Ensure that DAMON's probe_hits attribute counter is properly updated when monitoring intervals are changed at runtime, matching the behavior of nr_accesses. To achieve this, it refactors and renames existing helper functions for shared use, applies the updates to probe_hits, and handles edge cases in damon_probe_hits_mvsum() to maintain measurement accuracy. - "KSM: performance optimizations for rmap_walk_ksm" (xu xin) Resolve a severe KSM reverse-mapping performance bottleneck where thousands of split VMAs sharing a single anon_vma cause extended lock contention. By adding an interval-filtering check during the rmap walk, it reduces worst-case anon_vma lock hold times from over 500ms down to under 2ms, preventing application freezes and latency spikes under memory pressure. - "mm: split a couple of headers from internal.h" (Mike Rapoport) Split declarations related to mm_init, memblock, vmalloc and sparse into new headers - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin) Apply the interval tree optimization from rmap_walk_ksm() to collect_procs_ksm() to avoid iterating over non-matching VMAs during KSM memory error handling. It hoists loop-invariant address initialization and restricts the anon_vma_interval_tree_foreach walk to a targeted page offset range, reducing redundant checks and improving lookup efficiency. - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali Patil) Fix issues in the hugetlb and KSM MM selftest categories that can report failures when the prerequisites for the tests are not satisfied - "mm/damon: introduce data attributes only monitoring" (SJ Park) Introduce attribute-weighted region management in DAMON, allowing users to prioritize specific data attributes (such as page sizes or cgroups) over or instead of access monitoring. By assigning weights to attribute probes, DAMON can completely disable access tracking and adjust monitoring regions based on weighted probe-hit counters to optimize monitoring quality for attribute-focused workloads. - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings" (Stanislav Kinsburskii) Extend hmm_range_fault() to support userfaultfd-backed regions by allowing the mmap lock to be dropped during fault handling via a new hmm_range_fault_locked() helper. By accepting a locked pointer and signaling retry status when lock release occurs, it enables page fault resolution in userfaultfd regions while preserving backward compatibility for existing callers. - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes) Clean up and standardize how vma->vm_pgoff is accessed and manipulated across file-backed and anonymous mappings in the kernel It introduces dedicated helper functions such as vma_start_pgoff(), vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming rmap interval tree helpers to better reflect their functionality. These changes establish a cleaner foundation for future work that will unify virtual page offset indexing for all anonymous and CoW'd folios. - "mm: handle device-private PMDs in walk callbacks" (Usama Arif) Address kernel panics and state corruption caused by MM walk callbacks reaching non-present device-private PMD swap entries created during HMM migrations It ensures that functions which acquire pmd_trans_huge_lock() properly recognize device-private PMDs instead of assuming a present THP or a standard migration entry. - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain) Refactor try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree, and anonymous-swapbacked logic into dedicated functions, laying the structural groundwork for batched anonymous large folio unmapping. - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu) Fix typos and fills in missing entries in the DAMON sysfs ABI document - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price) Introduce an atomic sysfs state attribute and supporting DAX/MM infrastructure to prevent userland races when offlining and removing entire memory regions By adding an unplugged state alongside standard online modes, it enables whole-device atomic hotplug control while preserving backward compatibility. - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes) Continue transitioning the kernel from the deprecated vm_flags_t type to vma_flags_t across core memory management infrastructure. It replaces legacy type usage in core functions such as do_mmap(), unmapped area allocation, mm->def_vma_flags, and VMA operations like mlock, mprotect, and mremap. - "Two small patches to clean up mm/mm_slot.h" (xu xin) Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate slot deletion sequences in khugepaged and KSM. It also adds code documentation explaining why mm_slot_lookup and mm_slot_insert must remain as preprocessor macros rather than static inline functions. - "mm/damon/core: hide core-private struct fields" (SJ Park) Clean up DAMON core structures by consistently marking internal-only fields with private: comment tags to prevent improper direct access from outer layers. It enforces encapsulation across core structures including damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to interact through approved access APIs instead of exposing raw struct members. - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races" (SJ Park) Address potential infinite loops, NULL dereferences, and race conditions identified in DAMON It fixes an infinite loop triggered by extreme user configurations, a NULL pointer dereference within unit tests and minor monitoring accuracy degradation caused by subtle runtime races. - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan Jackman) Fix an NMI safety flaw in __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks via non-PCP or isolated migration paths. It also resolves potential kernel crashes and privilege escalation risks triggered when BPF tracing runs in NMI context alongside memory hotplug or large allocation frees. - "mm/page_alloc: couple of followups for recent cleanups" (Brendan Jackman) Clean up and update page allocator nomenclature, documentation, and debug assertions. It aligns internal FPI_ flags with the public "nolock" naming convention, removes outdated internal implementation details from high-level page allocator comments, and eliminates obsolete VM_BUG_ON() assertions in allocation paths. - "mm/mseal: further cleanups" (Lorenzo Stoakes) Refactor and simplify the mseal implementation by clarifying API boundaries and removing unnecessary code complexity. It replaces generic do_mseal() usage outside the syscall with a dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates mm_struct parameters to enforce that sealing applies only to current->mm, and streamlines overall logic and comments with no functional changes intended. - "mm/vmscan: fix swappiness=max and clean up per-node proactive reclaim" (Ridong Chen) Resolve reclaim behavior bugs and clean up function parameters across memory reclaim paths It fixes swappiness=max in both standard reclaim and MGLRU so unswappable anonymous memory no longer falls back to evicting page cache, ensures reclaim_store() returns accurate error codes instead of collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask parameter from __node_reclaim(). - "mm: mincore: misc cleanups" (Kefeng Wang) Clean up and simplifies the mincore code. Most importantly, it removes the historical special behavior that always reports VM_PFNMAP pages as non-resident. - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau) Two trivial cleanups in the folio split API - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation bugs" (SJ Park) Resolve minor operational and testing bugs in DAMON identified by Sashiko. It initializes the damos->last_applied field to prevent occasional efficiency degradation and fixes invalid memory accesses in DAMON KUnit tests during test failure handling. - "cleanup for stable_page_flags()" (Jinjiang Tu) Clean up and refactor stable_page_flags() used by /proc/kpageflags without altering functionality. It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag bits, converts folio-specific flag checks to standard folio_test_*() helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling. - "Batch unmap of uffd-wp file folios" (Dev Jain) Extend batched folio unmapping support to file folios within userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities to pte_install_uffd_wp_if_needed(). This removes special-case restrictions on uffd-wp VMAs in try_to_unmap_one(), significantly simplifying the function's control flow and complexity. - "mm/early_ioremap: clarify and clean up early_ioremap_reset()" (Sang-Heon Jeon) Clarify and clean up the architecture-specific usage of __late_set_fixmap() and __late_clear_fixmap() after early_ioremap_reset() It adds explicit documentation regarding when early_ioremap_reset() must be called and removes redundant macro definitions and reset calls in the RISC-V and ARM64 architectures. - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner) Address severe performance regressions, swap storms, and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta production It updates the page allocator slowpath so non-movable allocation requests actively trigger direct reclaim and direct compaction at pageblock_order scale, allowing them to claim whole pageblocks rather than spinning unproductively. - "zram: lockmap tweaks" (Sebastian Siewior) Optimize and fix lockdep tracking for zram devices by consolidating per-entry lockmaps and isolate lock classes across multiple instances This reduces memory overhead by replacing per-entry lockdep_map instances with a single map per struct zram, and assigns a dynamic lock_class_key to each instance to prevent false deadlock reports when different zram devices are backed by distinct filesystems. * tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits) selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check selftests/mm: unpoison pages in memory-failure teardown mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn() mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro mm/zsmalloc: fix release order of locks in zs_page_migrate() Documentation: zram: remove sections numbering ksm: stop iterating VMAs when ksm_test_exit returns true mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch() zram: use a custom key for each zram object zram: move lockmap to be per-zram instead per table selftests/mm: fix gup_longterm EINVAL error message mm: page_alloc: fix non-movable reclaim storm in defrag_mode mm: page_alloc: move capture_control to the page allocator mm: compaction: support non-movable compaction for pageblock requests mm: page_alloc: __GFP_FS lockdep annotation for direct compaction hugetlb: evaluate subpool free state while locked mm/damon: remove trailing semicolons after function definitions mm/damon/ops-common: prevent migration fallback to non-target nodes mm/damon: update outdated comment about DAMOS filter handling ...
2026-08-20Merge tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds13-469/+1200
Pull probes updates from Masami Hiramatsu: "BTF typecasting and variable fetch enhancements: - Typecast support across probe events: Extended BTF typecasting syntax (e.g., (STRUCT)PARAM->MEMBER) to kprobes, uprobes, and fprobes on function entry and return - Nested typecasts: Added support for chaining and nesting typecasts up to 3 levels, including casting registers and stack variables - Field specifier option: Added (STRUCT,FIELD) syntax to emulate container_of(), allowing retrieval of parent structures from member pointers - $current variable support: Introduced $current special variable to access the running task_struct via BTF dereferencing - Per-CPU variable access: Added this_cpu_read() and this_cpu_ptr() fetcharg methods to trace CPU-local data safely - Fetcharg bytecode dumper: Added CONFIG_PROBE_EVENTS_DUMP_FETCHARG to dump the compiled fetcharg bytecode instructions as comments in dynamic_events - Extended symbol name handling: Removed the MAX_COMMON_HEAD_LEN limit and extended MAX_ARGSTR_LEN to 256 bytes, enabling probing of long symbols, mangled Rust symbols and complex BTF expressions - eprobe variable syntax: Allowed eprobes to reference event fields directly without requiring a '$' prefix - Cleanup unused parameters, redundant codes, duplicate macros and pointer arithmetic - Use a ternary operator for simplifying fetch_type_from_btf_type() Expanded boot time dynamic probe support: - Add boot-time tracing configuration support for event probes (eprobes), function probes (fprobes), and tracepoint probes (tprobes) - Allow comment lines ('#') in dynamic_events file Optimization, robustness, and cleanups: - Simplify fprobe_remove_ips() by reusing graph and ftrace helpers - Remove __packed attribute from struct __fprobe_header to avoid unaligned memory access penalties on RISC architectures - Remove redundant memset() calls in perf event probe handlers - Replace legacy __ASSEMBLY__ with __ASSEMBLER__ in header files Selftests & refactoring: - Refactor parse_probe_arg() and parse_probe_vars(), and eliminate recursion in probe argument parsing to protect kernel stack depth - Add selftests for BTF typecasts and module probing without module prefixes - Force LC_ALL=C in ftracetest to prevent test failures on localized systems - Refactor btf_type_skip_modifiers() to remove ignored id parameter - Sort ERRORS list in trace_probe.h alphabetically - Fix typo in fprobe docs, and trace_fprobe function name - Rename FETCH_OP_DATA to FETCH_OP_IMMSTR - Make file offset error message probe-agnostic" * tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (37 commits) fprobe: Simplify fprobe_remove_ips() by reusing existing helpers tracing/boot: Add support for eprobe, fprobe, and tprobe events selftests/ftrace: Force C locale in ftracetest tracing/probes: Treating longer symbol name on event comparation docs: trace: fprobe: fix 'thos' spelling tracing/probes: Fix extra whitespace in trace_probe_kernel.h tracing/kprobe: Remove redundant memset in kprobe_perf_func() tracing/fprobe: Remove redundant memset in fentry_perf_func() tracing/fprobe: Remove redundant snprintf in trace_fprobe_match_command_head() tracing/probes: Simplify BTF_KIND_PTR case in fetch_type_from_btf_type() tracing/probes: Cleanup pointer arithmetic in store_trace_entry_data() tracing/probes: Remove unused parameter from parse_probe_var_retval() tracing/probes: Remove redundant bounds check in trace_probe_compare_arg_type() tracing/probes: Remove redundant boolean conversion in trace_probe_has_single_file() tracing/probes: Remove duplicate MAX_ARRAY_LEN macro definition selftests/ftrace: Add test case for a symbol in a module without module name tracing/probes: Eliminate recursion in parse_probe_arg() tracing/probes: Extend max length of argument string tracing/probes: Sort ERRORS list in trace_probe.h alphabetically tracing/probes: Refactor parse_probe_arg() ...
2026-08-20Merge tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextLinus Torvalds1-32/+87
Pull bpf updates from Daniel Borkmann: "Major changes: - Redesign the verifier error reporting: failures now carry source and instruction annotations along with the causal event history that led to them, making program rejections far easier to debug and repair (Kumar Kartikeya Dwivedi) - Add arena argument support to kfuncs and struct_ops through the new __arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan, Kumar Kartikeya Dwivedi, Ihor Solodrai) - Signed BPF program loader rework to accommodate both BPF and security community needs where the kernel runs the signature verification at BPF_PROG_LOAD time before the LSM admission hook (Daniel Borkmann) - Add a set of ksock kfuncs which let BPF LSM and syscall programs create, connect and send on UDP sockets in order to emit telemetry data (Mahe Tardy) - Unify helper and kfunc call argument verification and classify kfunc arguments purely from BTF into a generated bpf_func_proto which is computed once at add-call time (Amery Hung) Other features and fixes: - Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport) - Add bidirectional VLAN support to bpf_fib_lookup() through the new BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags (Avinash Duduskar) - Infer zext_dst from static register liveness analysis to fix 32-bit zero-extension semantics, and remove the artificial limitations on pointer types eligible for spilling (Eduard Zingerman) - Inline the numeric open-coded iterator kfuncs so that bpf_for() loops no longer pay a kfunc call on every iteration (Puranjay Mohan) - Add an arena-based bitmap data structure to libarena along with serial and parallel selftests (Emil Tsalapatis) - Teach resolve_btfids to discover kfuncs from the kernel's BTF ID sets and to emit kfunc BTF decl tags, reducing the kernel build's dependency on pahole features (Ihor Solodrai) - Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that tunnel decapsulation can update the GSO and encapsulation state of the skb (Nick Hudson) - Fix the ring buffer pending_pos walk and the available-data accounting on 32-bit position wrap (Israel Téllez García) - Add memory usage accounting for arena maps and fix an mmap_lock deadlock on arena lock failure (Jiayuan Chen) - Add tracing_multi link info support to the kernel UAPI and bpftool, and refactor the stack map code to run with preemption disabled (Jiri Olsa) - Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the egress direction of the target's peer device (Jordan Rife) - Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular modules, can declare kfuncs safe to call under bpf_spin_lock instead of relying on the verifier's hard-coded allowlist (Kaitao Cheng) - Introduce global percpu data for BPF programs with libbpf probing and bpftool skeleton support, and stop exposing uninitialized kernel heap memory when copying per-CPU map values (Leon Hwang) - Add s390 JIT support for load-acquire and store-release instructions (Maxim Khmelevskii) - Fix a CFI mismatch in the task work callback and an arm64 KASAN false positive after bpf_throw() (Mykyta Yatsenko) - Reject writes through untrusted BTF pointers and bound the rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar) - Invalidate RCU pointers only after the final spin unlock and account for preempt and IRQ disabled regions as overlapping RCU protection (Ning Ding) - Support mixing bpf2bpf calls and tail calls on RV64, add signed operations and 32-bit atomics to the RV32 JIT, and add timed may_goto support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang) - Fix a use-after-free on mm_struct in bpf_find_vma() for foreign tasks and an mmap_lock leak in the irq_work path (Sanghyun Park) - Populate mmap-able BPF array map memory lazily which makes mmap() O(1) instead of proportional to the map size (Song Liu) - Introduce a jit_required flag and reject programs with inlined helpers when no JIT is available, where the interpreter would otherwise jump into an invalid address (Tiezhu Yang) - Fix the x86 JIT per-CPU address resolution into an extended register where the REX prefix dropped the high destination register bit (Vineet Gupta) - Reject MEM_ALLOC BTF accesses past object bounds, arena frees below the arena base, and mixed arena and ordinary atomic paths (Yiyang Chen) - Fix the trampoline handling of 128-bit arguments and of return values larger than 8 bytes (Yonghong Song) - Ensure that any fault prone load is rewritten with exception table handling, and fix the arena load-acquire and atomic fetch handling in the x86, arm64, riscv and s390 JITs (Daniel Borkmann) - Many more fixes and cleanups across the verifier, arena, trampolines, sockmap, cgroup, ring buffer, x86/arm64/riscv/s390 JITs, libbpf, bpftool, resolve_btfids and selftests" * tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (373 commits) selftests/bpf: Add tests for a store on a fault prone qdisc pointer selftests/bpf: Add tests for fault prone loads out of RCU pointers selftests/bpf: Add tests for pointer type merge at a shared load selftests/bpf: Remove duplicate copies of the arena spinlock qnodes selftests/bpf: Retry stat generation in cgroup_iter_memcg selftests/bpf: Test pseudo-function policy diagnostics bpf: Distinguish function references in policy diagnostics bpf: Preserve source attribution without source text selftests/bpf: Test kfunc argument diagnostics bpf: Correct kfunc argument diagnostics bpf: Use canonical stack argument names in diagnostics bpf: Preserve R0 lineage across helper calls selftests/bpf: Exercise negative optlen in cgroup getsockopt hook bpf: Reject negative optlen in cgroup getsockopt hook selftests/bpf: tc_tunnel - validate decap GSO and encapsulation state bpf: Clear decap state on skb_adjust_room shrink path bpf: Allow new DECAP flags and add guard rails bpf: Add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation bpf: Refactor masks for ADJ_ROOM flags and encap validation bpf: Name the enum for BPF_FUNC_skb_adjust_room flags ...
2026-08-19Merge tag 'trace-ringbuffer-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds1-112/+160
Pull ring-buffer updates from Steven Rostedt: - Remove unneeded semicolon A macro ended with a semicolon that wasn't needed. - Fix freeing cpu_buffer extra subbuffer with order greater than zero When the cpu_buffer was being freed, its "free" page, was using free_page() to free it when it could be more than one page. - Hold the cpu_buffer lock when resizing the subbuffer The freeing of the "free" page of the cpu_buffer was done without locking. The order of the data was being saved and then the "free" page was set to NULL. But there is a race that the "free" page could have been updated between those two operations. Add locking around it to prevent the race. - Save the order of the data along with the data in the free page The cpu_buffer would store just the data portion of the subbuffer page in its descriptor. But it did not store the order of the data pages. The order was being saved in the global buffer descriptor. But this leads to races. Have the cpu_buffer save the subbuf data along with its metadata (which includes the order of the page) to make sure when it frees it, it frees the correct order along with it. - Remove the subbuf_size and use the order directly when needed Having a size field for the size of the subbufer along with its order allowed for races to have them get out of sync. Remove the subbuf_size and use the order from the subbuf meta data directly under locks. Use the subbuf_order for other calculations in the ring buffer. - Remove the useless "cpus" field of trace_buffer The code has been restructured and the "cpus" field is no longer used. Remove it. - Remove the "mapped" field of the ring buffer and use a helper function instead. The "mapped" field has become a bit overused and made the code come complex in using a counter for what is denoted as being mapped or not. There are other fields that are set when the ring buffer is considered mapped. Add a helper function to check those fields and use that instead of keeping track of a counter. * tag 'trace-ringbuffer-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Remove ring_buffer_per_cpu::mapped ring-buffer: Remove trace_buffer::cpus ring-buffer: Dynamically calculate max_data_size ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page() ring-buffer: Fix subbuf resize race with ring buffer readers ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page ring-buffer: Hold cpu_buffer::lock when resizing a subbuf ring-buffer: Free cpu_buffer::free_page with subbuf_order ring-buffer: drop unneeded semicolon
2026-08-19Merge tag 'tracefs-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds1-6/+7
Pull tracefs updates from Steven Rostedt: - Define event fields before directory creation Move the event_define_fields() call in event_create_dir() before the eventfs directory creation. Previously, a failure after directory creation wouldn't clean up eventfs_inode because the error path didn't call eventfs_remove_dir(). This eliminates the need to clean up the eventfs directories if event_define_fields() fails. - Add warning for out of bounds pos in __eventfs_iterate() Sashiko complains about the ctx->pos causing issues if it is less than 2 or greater than MAX_INT in __eventfs_iterate(). The thing is, the logic prevents that from happening. But to make Sashiko happy, add a WARN_ON() and exit safely if the function ever does get input that is out of the range the function expects. * tag 'tracefs-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: eventfs: Add warning for out of bounds pos in __eventfs_iterate() eventfs: Define event fields before directory creation
2026-08-19Merge tag 'trace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds12-73/+239
Pull tracing updates from Steven Rostedt: - Expose btf_ids to trace events In order to allow BPF programs to attach to system call trace events (which are actually pseudo trace events built on top of raw_syscall events), expose the BTF ID of the events. This will allow BPF programs better precision in attaching to events. - Use "u64" to assign to hist_field->type Instead of using kstrdup("u64", GFP_KERNEL) to assign the hist_field->type, just point it to "u64" instead. The hist_field->type is freed via kfree_const(). - Replace kmalloc()/strcpy() with kstrdup() for trace_printk Instead of having two calls to copy the module format string, just use kstrdup(). - Use __free() in trace event histograms and triggres where possible - Use seq_buf in trace event code instead of strcat() Instead of calculating the size of the buffer to use and filling it with strcat(), use the seq_buf infrastructure that takes care of making sure not to overflow the string size. - Reject invalid preemptirq_delay_test CPU affinity The preempt_delay_test module can take an invalid CPU affinity mask and create confusing output. Simply have the module reject invalid affinity masks. - Prevent division by zero in ftrace_ops sample module code If the ftrace_ops sample module code receives the module parameter nr_function_calls set to zero, it can cause a division by zero error. - Warn when an event dereferences a parameter in TP_printk() On boot up and module load, the trace event TP_printk() is scanned for possible bugs. As the TP_printk() code is executed when the user reads the "trace" file and processes the data written when the trace_event executed, the data it reads can be literally days old. The scan currently checks for dereferencing printk formats like "%pI6". But it does not check if the parameters themselves have a dereference like: TP_printk("offset %08x: value %08x", (u32)(__entry->addr - __entry->edma->membase), __entry->value) __entry represents the pointer to the event on the ring buffer. The __entry->edma->membase is dereferencing a pointer on the ring buffer to find membase, but the __entry->edma may no longer be a valid pointer. Warn on this case too. - Replace some strcpy() with strscpy() - Clean up mmiotrace events to use assign_type() macro The assign_type() macro makes sure the event type is indeed the type that is being parsed. The mmiotrace trace was written before that macro was created so it just simply typecasted the pointer. Replace the typecasting with the macro. - Have the ENUM processing to numbers only process what is added The code that converts ENUMs to their numbers in the trace events scanned all events to do the processing. This was true when a module was loaded too. That is, instead of processing just the events for the module, it processed *all* events. Even the builtin ones that were processed at boot up. Add a check for the event->module matching mod if it is a module before processing it. * tag 'trace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (21 commits) tracing: Have trace_event_update_all() only handle module that is loading tracing: Cleanup event_enable_trigger_parse() by using __free() tracing: Report every TP_printk double dereference tracing/mmiotrace: Use trace_assign_type() in mmio_print_mark() tracing: Make per-template BTF id lists file-local tracing: Use seq_buf for string concatenation tracing: Use strscpy() instead of strcpy() in trace_sched_switch tracing: Warn when an event dereferences a pointer in TP_printk() samples/ftrace: Prevent division by zero when nr_function_calls is zero tracing: Reject invalid preemptirq_delay_test CPU affinity fgraph: Use trace_seq_putc() in print_graph_return() tracing/user_events: Replace a seq_printf() call by seq_puts() in user_seq_show() tracing/user_events: Use seq_putc() in two functions tracing: Bound histogram expression strings with seq_buf tracing: Return ERR_PTR() from expr_str() tracing: Use __free() for expr_str() buffer kernel/trace/trace_printk: Use kstrdup() instead of kmalloc() and strcpy() tracing: Point constant hist field type to string literal selftests/bpf: Add test for tracepoint btf_ids tracefs file tracing: Expose tracepoint BTF ids via tracefs ...
2026-08-19Merge tag 'ftrace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds1-37/+6
Pull ftrace updates from Steven Rostedt: - Deprecrate ftrace_enabled in disabling ftrace The file /proc/sys/kernel/ftrace_enabled was created when ftrace was first introduced back in 2008. It was to be a "kill switch" if something was to go wrong. It was also used as a way to turn off function tracing for the latency tracers that would have it on by default. But in 2013 (Linux 3.10) the option "function-trace" was introduced to disable function tracing for the latency tracers as the "ftrace_enabled" file was considered too big of a hammer and caused too many side effects. When live kernel patching came along, disabling ftrace via the ftrace_enabled file would put the system into an unstable state if a live kernel patch was installed. This created the need to mark some function hooks as "PERMANENT". Now there's a need for BPF usage marked as PERMANENT for the same reasons. The file "ftrace_enabled" usage is no longer viable. It doesn't do what it says it does and there is no reason to use it. Make writing '0' to it a nop and print a message saying its usage is deprecated. The return value of writing '0' is -EOPNOTSUPP so that user space will error on that write (hopefully to inform any developer that it no longer works). Eventually the file should be removed completely, but for now just making it not do anything is the path forward to that. - Update the livepatch tests to handle ftrace_enabled being disabled Because in the past, livepatch was broken by ftrace_enabled being turned off, there's a test case that checks to make sure it still doesn't break. But having the write of '0' return an error caused that test to break. Updated the test to handle the new change. * tag 'ftrace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: selftests/livepatch: update test-ftrace.sh for deprecated ftrace_enabled ftrace: deprecate disabling via ftrace_enabled sysctl
2026-08-19Merge tag 'trace-rv-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds35-181/+1212
Pull Real-time Verifier updates from Steven Rostedt: - Switch LTL and DOT parsers to Lark in code generation tool The rvgen code generation tool originally parsed DOT files and LTL specifications using custom string parsing and Ply, which is no longer maintained. The DOT parser was fragile and prone to failure on minor format variations. Both LTL and DOT parsers have been rewritten to use the Lark parsing library. - Simplify Hybrid Automata clock variables The clock variables in hybrid automata monitors now use a single representation of the elapsed time since the clock was reset, rather than converting between invariant and guard representations. This allows simpler code generation for the newly refactored parser. - Generate cleanup hook for per-obj monitor The code generation scripts now adds a cleanup function to per-obj monitors for the user to wire to the appropriate event (e.g. sched_process_exit for tasks). - Reduce read_lock scope during per-task cleanup Take the tasklist_lock only when necessary, that is when iterating over for_each_process_thread(). - Simplify task monitor slot management Only rely on the slot array for per-task slot management to avoid inconsistency with the unused counter. - Improve rvgen code robustness and templates Use pathlib in rvgen and improve kernel path discovery. Also improve consistency across templates when generating code (e.g. author placeholder and monitor struct name). - Update rtapp sleep monitor Simplify the sleep monitor by excluding kernel threads and updating the nanosleep check to focus only on CLOCK_REALTIME. Also switch to use the sched_exit tracepoint to run in the context of the offending (wakee) task. - Add wakeup monitor Add the new rtapp/wakeup monitor to detect when lower-priority tasks wake up higher-priority ones, complementing the existing sleep monitor by running in the waker context and capturing its stack trace. - Fix tools/rv exit status on failure Ensure the rv tool returns a failure exit code when a monitor fails to start because it was already running. - Add automated selftests for tools/rv and rvgen Introduced automated bash selftests to validate rv monitor listing and execution under different configurations. Added tests for the rvgen code generator, validating generated files against expected output (golden). Tests are reachable via make check. - Add KUnit test coverage for verification monitors Added comprehensive KUnit tests to validate the functionality of deterministic, hybrid, and LTL monitors by emulating event sequences and timing in a mock environment without affecting the running kernel while expecting mock reactions to fire. Ensure real RV monitors cannot run during KUnit tests to avoid state corruption. - Mock current in rv monitors Mock the call to current in rv monitors when the KUnit tests are built to allow them to run the test on dummy tasks. No overhead is expected when KUnit tests aren't running. - Introduce rvgen kunit subcommand Added a new 'kunit' subcommand to rvgen to automatically patch an already generated monitor with KUnit integration templates by parsing its event handlers and creating the required mock structures and initializations. - Refine kernel verification selftests Added new selftests for the deadline and stall monitors and rearranged the existing wwnr_printk test to resolve flakiness. Additionally, fixed an issue in the selftests framework where negative assertion failures were not correctly propagated due to shell rules. - Fix 32-bit build of nomiss KUnit test A previous commit introduced a division between an u64 and a constant value and that doesn't build on 32-bit systems. Use div_u64() instead. - Document changes in sleep monitor The sleep monitor introduced some changes in the past like allowing epoll_wait() as a valid sleep and a task going to runnable before scheduling as a valid wakeup. Document both. * tag 'trace-rv-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (40 commits) Documentation/rv: Explain epoll and aborted sleeps rv: Fix 32-bit build of nomiss KUnit test selftests/verification: Add selftests for deadline and stall monitors selftests/verification: Rearrange the wwnr_printk test selftests/verification: Fix wrong errexit assumption rv: Add KUnit tests for some LTL monitors rv: Add KUnit mock for current rv: Add KUnit tests for some DA/HA monitors rv: Export task monitor slot and react symbols verification/rvgen: Add selftests for rvgen kunit verification/rvgen: Add the rvgen kunit subcommand verification/rvgen: Add selftests verification/rvgen: Add golden and spec folders for tests tools/rv: Add selftests verification/rvgen: Improve consistency in template files verification/rvgen: Use pathlib instead of os.path verification/rvgen: Improve rv_dir discovery in RVGenerator tools/rv: Fix exit status when monitor execution fails rv: Use generic rv_this for the rv_monitor variable in LTL rv/rtapp: Add wakeup monitor ...
2026-08-14ring-buffer: Remove ring_buffer_per_cpu::mappedVincent Donnefort1-28/+17
ring_buffer_per_cpu::mapped tracks if a ring-buffer is either mapped by user-space or if it is a persistent buffer. We already have user_mapped for the former and ring_meta for the latter. Get rid of mapped and instead create rb_is_static(). A static ring-buffer cannot be resized, swapped or have its pages extracted. Link: https://patch.msgid.link/20260813131152.3589632-10-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Remove trace_buffer::cpusVincent Donnefort1-2/+0
The 'cpus' field in struct trace_buffer became useless in commit 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order"). Remove it Link: https://patch.msgid.link/20260813131152.3589632-9-vdonnefort@google.com Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Dynamically calculate max_data_sizeVincent Donnefort1-10/+24
The ring buffer order can be dynamically modified and temporarily disables writing to do so. It is therefore safe to use the updated value to calculate the maximum event size which can be written onto the ring buffer. However, notice it is hardly making any difference for trace_marker because of the TRACE_MARKER_MAX_SIZE limit. For an 8KiB subbuf size, trace_marker can take 4096 characters while it can 'only' take 4054 bytes for smaller subbufs. Link: https://patch.msgid.link/20260813131152.3589632-8-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()Vincent Donnefort1-1/+1
ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set, it can allocate a reader page with an outdated order. This isn't a big issue, the user can still re-allocate a new reader page and try again. However, what is more problematic is if the value of subbuf_order changes in the middle of ring_buffer_alloc_read_page(). In that case, bpage->order might not match the actual allocated memory. Use bpage->order for the allocation to prevent this race. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-6-vdonnefort@google.com Fixes: bce761d75745 ("ring-buffer: Read and write to ring buffers with custom sub buffer size") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Fix subbuf resize race with ring buffer readersVincent Donnefort1-61/+106
trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and ring_buffer_read_start(), while it can simultaneously be resized with ring_buffer_subbuf_order_set(). Instead of trace_buffer::subbuf_size, use bpage::order in ring_buffer_read_start() and ring_buffer_read_page(). In ring_buffer_read_start(), even with resize_disabled, there is still a possibility of a race with a buffer modification. Hold the trace_buffer mutex to synchronise with any pending ring buffer order modification. trace_buffer::subbuf_size is now actually useless, remove it. Also, create accessors rb_subbuf_capacity() and rb_page_capacity() which return the actual size available for storing events, while rb_subbuf_size() returns the actual subbuf page-size. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-5-vdonnefort@google.com Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260805153225.2096152-1-vdonnefort%40google.com # patch 1 Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Make cpu_buffer::free_page a buffer_data_read_pageVincent Donnefort1-10/+10
Discarding a cached reader page after a concurrent ring buffer resize uses the new global subbuf_order for the free_pages() call. This mismatched order may crashes the kernel or leaks memory because the cached page was allocated under the old size. Save the actual free_page order alongside the page address to ensure we always refer to the correct value and do not rely on the potentially stalled cpu_buffer->subbuf_order value. The simplest is to make free_page a buffer_data_read_page which already covers exactly what we need: a page address and a page order. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-4-vdonnefort@google.com Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Hold cpu_buffer::lock when resizing a subbufVincent Donnefort1-0/+2
Because, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page, hold cpu_buffer->lock to prevent races with ring_buffer_alloc_read_page() and ring_buffer_free_read_page(). Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-3-vdonnefort@google.com Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order") Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260810125633.3344684-1-vdonnefort%40google.com # patch 3 Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14ring-buffer: Free cpu_buffer::free_page with subbuf_orderVincent Donnefort1-1/+1
When sub-buffers use an order greater than 0, cpu_buffer->free_page is allocated with subbuf_order. Use the correct order for cpu_buffer->free_page. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-2-vdonnefort@google.com Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260806211306.3704194-1-vdonnefort%40google.com # patch 3 Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-14tracing: Have trace_event_update_all() only handle module that is loadingSteven Rostedt3-4/+8
The function trace_event_update_all() does a scan of events looking to replace enums with their values in the strings that get exported to the event format files. It's run at boot up on all events and again when a module loads. The issue is that when a module loads, it still runs on *all* events. There's no reason to process every event when a module loads as the previous events have already been processed. Only execute on the events that are loaded with the module. Link: https://patch.msgid.link/20260813204226.29563591@gandalf.local.home Fixes: 3673b8e4ce723 ("tracing: Allow for modules to convert their enums to values") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-13tracing: Fix race between update_event_fields and, event_define_fieldsMichael Wu1-0/+2
The following sequence may leads race between event_define_fields() and update_event_fields(): CPU0 (loads module A) CPU1 (loads module B) =============================== =============================== load_module(A) load_module(B) notifier_call_chain notifier_call_chain trace_module_notify trace_module_notify mutex_lock(&event_mutex) trace_event_update_all() trace_module_add_events(A) down_write(&trace_event_sem) __register_event(call_A) __add_event_to_tracers(call_A) event_define_fields(call_A) for each f: list_for_each_entry(field, list_add(&f->link, &class->fields, link) &class->fields) field = class->fields->next; Where access to the class->fields is not protected by the event_mutex in trace_event_update_all(). This produces the following panic: Unable to handle kernel access ... at virtual address 0000000000000018 pc : update_event_fields+0xf8/0x368 Call trace: update_event_fields+0xf8/0x368 trace_event_update_all+0x7c/0x2b4 trace_module_notify+0x4c/0x1dc notifier_call_chain+0x84/0x168 blocking_notifier_call_chain_robust+0x64/0xd4 load_module+0x10c8/0x123c __arm64_sys_finit_module+0x230/0x31c Fix by taking event_mutex in trace_event_update_all() before trace_event_sem. Cc: stable@vger.kernel.org Fixes: b3bc8547d3be ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well") Link: https://patch.msgid.link/2e5730d2-c631-da41-3a3a-ae35bb4895f3@allwinnertech.com Signed-off-by: Michael Wu <michael@allwinnertech.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-13tracing: Fix NULL pointer dereference in module event cache removalHui Su1-1/+1
A module-only event filter such as ":mod:foo" is cached with a NULL event_mod->match when foo has not been loaded. If a later write tries to remove a specific match from the same module, remove_cache_mod() passes the NULL cached match to strcmp(), causing a NULL pointer dereference. The issue can be reproduced from userspace: echo ':mod:trace_events_kunit_missing' > /sys/kernel/tracing/set_event echo '!foo_bar:mod:trace_events_kunit_missing' >> /sys/kernel/tracing/set_event The second write must be a concatenation (">>") to not include O_TRUNC as that would cause ftrace_clear_events() to clear the cached modules lines. The crash was reproduced on x86_64 QEMU while KUnit workers contended on the event tracing path: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode RIP: 0010:strcmp+0x10/0x30 Call Trace: __ftrace_set_clr_event_nolock+0x373/0x4a0 ftrace_set_clr_event+0xf0/0x180 ftrace_event_write+0xdf/0x110 vfs_write+0xf6/0x440 ksys_write+0x68/0xe0 do_syscall_64+0xf9/0x540 entry_SYSCALL_64_after_hwframe+0x77/0x7f Check event_mod->match before comparing it, consistent with the existing NULL checks for the cached system and event fields. The mismatched removal continues to return -EINVAL; a broad cached module filter is removed with "!:mod:<module>". Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260811173902.1927376-2-sh_def@163.com Fixes: b355247df104 ("tracing: Cache \":mod:\" events for modules not loaded yet") Reported-by: syzbot+4d3143c8e28f6266c636@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/6a7a6b7f.9c11d2ce.289b96.00f8.GAE@google.com/ Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-13bpf: Make bpf_trampoline_multi_detach return voidHui Zhu1-1/+1
bpf_trampoline_multi_detach() always returns 0 and the sole caller ignores the return value. Change it to return void and drop the WARN_ON_ONCE at the call site. Signed-off-by: Hui Zhu <zhuhui@kylinos.cn> Acked-by: Leon Hwang <leon.hwang@linux.dev> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/12beba657f5c9e86a016a097750209287a2f262a.1786412280.git.zhuhui@kylinos.cn Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-08-11ring-buffer: drop unneeded semicolonJulia Lawall1-2/+2
When a function-like macro expands to an expression, that expression doesn't need a semicolon after it. All uses have been verified to have their own semicolons. This was found using the following Coccinelle semantic patch: @r@ identifier i : script:ocaml() { String.lowercase_ascii i = i }; expression e; @@ *#define i(...) e; Link: https://patch.msgid.link/20260801191002.1383835-6-Julia.Lawall@inria.fr Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-11tracing: Cleanup event_enable_trigger_parse() by using __free()Steven Rostedt1-8/+8
The enable_data variable gets freed on most error paths in event_enable_trigger_parse(). Use free() to free it and just before returning normally, call retain_and_null_ptr(enable_data) just before a successful exit to keep it from being freed. On success, the enable_data is assigned to the trigger_data->private_data field. Also add a comment to why event_trigger_free(trigger_data) is being called before a successful exit. Link: https://patch.msgid.link/20260807113558.0ff14e96@gandalf.local.home Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-11tracing: Report every TP_printk double dereferenceDavid Carlier1-0/+2
WARN_ONCE() splats once per call site, so only the first offending event registered is ever reported. The tree currently has six: ice_{rx,tx}_dim_template, two hfi1 txq events, mtu3_ep and edma_log_io. Whichever registers first hides the rest, and each has to be found again on the next boot. Add a pr_warn() next to the WARN_ONCE() so every offender is listed, the same way test_event_printk() already pairs WARN_ON_ONCE() with pr_warn() for unsafe %p* dereferences. The WARN_ONCE() stays so the condition still fails tests and panics under panic_on_warn. Link: https://patch.msgid.link/20260806215256.1680267-1-devnexen@gmail.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: David Carlier <devnexen@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-10ftrace: deprecate disabling via ftrace_enabled sysctlAndrey Grodzovsky1-37/+6
Writing 0 to kernel.ftrace_enabled has not reliably disabled ftrace for years (FTRACE_OPS_FL_PERMANENT users already block it, and more callers rely on ftrace always being on). Refuse the write instead of leaving it in an inconsistent "disables some, not all" state: return -EOPNOTSUPP and log a message. Reads and enabling (writing 1) are unaffected. Update the docs to note the deprecation up front. Link: https://patch.msgid.link/20260806153000.4184871-2-andrey.grodzovsky@crowdstrike.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@crowdstrike.com> Acked-by: Song Liu <song@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-10fprobe: Simplify fprobe_remove_ips() by reusing existing helpersMasami Hiramatsu (Google)1-9/+2
fprobe_remove_ips() manually duplicates the unregister and filter-removal logic for both graph and ftrace ops. Simplify it by delegating to the existing fprobe_graph_remove_ips() and fprobe_ftrace_remove_ips() helpers. Link: https://lore.kernel.org/all/178528139798.102586.5349128066643420018.stgit@devnote2/ Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ring-buffer: Fix crash passing ERR_PTR to kthread_stop()Hui Su1-1/+1
In test_ringbuffer()'s out_free cleanup loop, the check `!rb_threads[cpu]` only catches NULL entries and misses entries that hold an ERR_PTR. rb_threads[] is static, so unassigned slots are NULL. But when kthread_run_on_cpu() fails for a cpu, it stores ERR_PTR(-ENOMEM) (or -EINTR) in rb_threads[cpu] before the creation loop jumps to out_free. That entry is non-NULL, so the old `!ptr` check does not break, and the cleanup proceeds to call kthread_stop() on the ERR_PTR. kthread_stop() then dereferences the bogus pointer, crashing the kernel during the late_initcall self-test. crash logs: BUG: kernel NULL pointer dereference, address: 000000000000001c Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 1 Comm: swapper/0 Not tainted 7.2.0-rc6-dirty #7 PREEMPT(lazy) RIP: 0010:kthread_stop+0x2e/0x220 RBX: fffffffffffffff4 CR2: 000000000000001c Call Trace: <TASK> test_ringbuffer+0x1ec/0x650 do_one_initcall+0x6c/0x2c0 kernel_init_freeable+0x21d/0x420 kernel_init+0x15/0x1c0 ret_from_fork+0x21b/0x320 </TASK> Kernel panic - not syncing: Fatal exception Cc: stable@vger.kernel.org Fixes: 64ed3a049e3e ("ring-buffer: make use of the helper function kthread_run_on_cpu()") Link: https://patch.msgid.link/20260807154145.2846521-2-sh_def@163.com Signed-off-by: Hui Su <sh_def@163.com> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()Vincent Donnefort1-0/+1
In rb_allocate_cpu_buffer(), bpage->order was omitted, leaving it as 0. This is an issue for a ring-buffer with subbufs bigger than PAGE_SIZE if when freed: free_buffer_page() relies on this value. Align the value with the actual allocation size (buffer::subbuf_order). Cc: stable@vger.kernel.org Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Link: https://patch.msgid.link/20260806211306.3704194-4-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ring-buffer: Prevent subbuf order change when resizing is disabledVincent Donnefort1-1/+1
Because ring_buffer_subbuf_order_set() frees buffer pages, we can't allow it when resizing is disabled. A non-consuming reader is at risk of use-after-free (rb_advance_iter()). Return -EBUSY on resize_disabled, matching ring_buffer_resize() behaviour. Cc: stable@vger.kernel.org Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Link: https://patch.msgid.link/20260806211306.3704194-3-vdonnefort@google.com Reported-by: syzbot+e0cc44465d6bae735679@syzkaller.appspotmail.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ring-buffer: Prevent resizing of persistent ring bufferVincent Donnefort1-0/+2
Dynamically resizing a persistent ring buffer is not possible. Disable the feature. Cc: stable@vger.kernel.org Fixes: be68d63a139b ("ring-buffer: Add ring_buffer_alloc_range()") Link: https://patch.msgid.link/20260806211306.3704194-2-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ftrace: Fix off-by-one fentry site disable in ftrace_free_mem()Josh Poimboeuf1-1/+5
When a module's init text is freed, do_init_module() calls ftrace_free_mem() with a half-open [start, end) range. However the ftrace_cmp_recs() comparator treats the upper bound as inclusive, as all its other users do, passing 'ip + size - 1'. So ftrace_free_mem() can delete a record sitting exactly at 'end', which is outside the freed range. For a kernel without CFI or IBT, the first record of a function is at the function start, which for the first function in a module is also the base of its text allocation. As the module allocator packs its regions, that address is often the 'end' passed by a neighboring module's do_init_module(), causing the first function's ftrace location to get disabled, preventing an attempt to livepatch it: livepatch: failed to find location for function 'pcspkr_probe' Convert the exclusive end to the inclusive 'end - 1' the comparator expects, and return early for an empty range to avoid the subtraction from underflowing when the init text size is zero. Cc: stable@vger.kernel.org Fixes: 42c269c88dc1 ("ftrace: Allow for function tracing to record init functions on boot up") Link: https://patch.msgid.link/1b5ccfa8095bdb1277f84af1c2c2e2205aca03ae.1785992188.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ring-buffer: Use current_context for safe per-CPU buffer swapTengda Wu1-4/+4
The ring_buffer_swap_cpu() function currently checks the per-CPU committing counter to determine if a buffer is actively being written to before performing the swap. However, there exists a race window where this check can be bypassed: ring_buffer_lock_reserve cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a rb_reserve_next_event rb_start_commit // inc committing if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...} __rb_reserve_next rb_move_tail rb_end_commit(cpu_buffer); // dec committing => 0 /* interrupt hits here, successfully swaps! */ local_inc(&cpu_buffer->committing); ring_buffer_unlock_commit cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b rb_commit rb_end_commit RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)) // triggers warning The committing counter can temporarily drop to 0 during a single write operation (within rb_move_tail), creating a window where swap can succeed even though the write is still in progress. This leads to inconsistent buffer state and triggers the RB_WARN_ON in rb_commit(). Replace the committing counter check with current_context checks, which are set at the entry of ring_buffer_lock_reserve() and remain valid throughout the entire write operation, providing a reliable indicator of buffer busy state during swap. Cc: stable@vger.kernel.org Fixes: 4239c38fe0b3 ("ring-buffer: Process commits whenever moving to a new page.") Link: https://patch.msgid.link/20260803005640.2445666-2-wutengda@huaweicloud.com Signed-off-by: Tengda Wu <wutengda@huaweicloud.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08eventfs: Define event fields before directory creationAnubhav Shelat1-6/+7
Move the event_define_fields() call in event_create_dir() before the eventfs directory creation. Previously, a failure after directory creation wouldn't clean up eventfs_inode because the error path didn't call eventfs_remove_dir(). This eliminates the need to clean up the eventfs directories if event_define_fields() fails. Link: https://patch.msgid.link/20260715135231.338535-3-ashelat@redhat.com Signed-off-by: Anubhav Shelat <ashelat@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ftrace: Drop extra comma in trace_buffered_event_enableLeon Hwang1-1/+1
Drop the extra comma in "scoped_guard()" to cleanup the code. Link: https://patch.msgid.link/20260730150411.88667-5-leon.hwang@linux.dev Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ftrace: Protect direct_functions in update_ftrace_direct_modLeon Hwang1-3/+8
Fix accessing the __rcu pointer direct_functions with RCU protection. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260730150411.88667-4-leon.hwang@linux.dev Fixes: e93672f770d7 ("ftrace: Add update_ftrace_direct_mod function") Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ftrace: Protect direct_functions in update_ftrace_direct_delLeon Hwang1-5/+8
Fix accessing the __rcu pointer direct_functions with RCU protection. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260730150411.88667-3-leon.hwang@linux.dev Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function") Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08ftrace: Protect direct_functions in ftrace_find_rec_directLeon Hwang1-1/+2
Fix accessing the __rcu pointer direct_functions with RCU protection. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260730150411.88667-2-leon.hwang@linux.dev Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use") Acked-by: Jiri Olsa <jolsa@kernel.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-08tracing/boot: Add support for eprobe, fprobe, and tprobe eventsMasami Hiramatsu (Google)2-0/+102
Boot-time tracing currently supports kprobe-events and synthetic-events under per-event configuration options. Extend boot-time tracing to support newly added dynamic probe types: - event probes (eprobe) under the "eprobes" event group - function probes (fprobe) under the "fprobes" event group - tracepoint probes (tprobe) under the "tracepoints" or "tprobes" event group To support this cleanly, update dyn_event_create() in trace_dynevent.c so that passing NULL as the type parameter delegates to create_dyn_event(), allowing generic creation of any registered dynamic event type from a raw command string. Update Documentation/trace/boottime-trace.rst accordingly to describe the new per-event bootconfig options. Link: https://lore.kernel.org/all/178613905149.259829.18185480460810689421.stgit@devnote2/ Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Changes in v3: - Check return values of strscpy() and snprintf() in trace_boot_add_probe_event() to prevent silent buffer truncation when constructing probe event strings. Changes in v2: - Fix raw command detection logic for eprobes, fprobes, and tprobes by requiring ':' or isspace() after type prefix. - Consolidate duplicate loop logic into trace_boot_add_probe_event() helper function.
2026-08-07tracing/mmiotrace: Use trace_assign_type() in mmio_print_mark()Masami Hiramatsu (Google)1-2/+5
In mmio_print_mark(), a raw C cast (struct print_entry *)entry is used to obtain the print_entry pointer. Use the standard trace_assign_type() macro instead, matching the usage in mmio_print_rw() and mmio_print_map(). Link: https://patch.msgid.link/178524301013.56416.9116249028160618790.stgit@devnote2 Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.2-rc7Daniel Borkmann14-21/+94
Cross-merge BPF and other fixes after downstream PR. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2026-08-05tracing: Make per-template BTF id lists file-localMykyta Yatsenko1-13/+14
DECLARE_EVENT_CLASS emitted __bpf_trace_btf_ids_<call> through BTF_ID_LIST_GLOBAL, i.e. a global symbol named after the event class. The class name is not unique across the kernel, so the symbol multiply-defines whenever two translation units instantiate the same class. Switch to the file-local BTF_ID_LIST: the list is reached only through the event_class_<call>.btf_ids pointer, initialised in the same unit, so tracefs readers never reference the symbol by name and resolve_btfids still fills the now-local .BTF_ids entries. The handcrafted syscall classes are the one cross-unit consumer: give them their own local BTF_ID_LIST rather than importing the generated sys_{enter,exit} lists. Link: https://patch.msgid.link/20260730-b4-fix_btf_tracefs-v2-1-6b66da8dc103@meta.com Fixes: eadc0725ab8d3 ("tracing: Expose tracepoint BTF ids via tracefs") Reported-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/all/ff58b01c-3f5e-4d55-be82-609d2faaf12e@sirena.org.uk/ Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-04mm: prefer vma_[start,end]_pgoff() to vma->vm_pgoff in kernel/Lorenzo Stoakes1-1/+2
Be consistent in using vma_start_pgoff() and vma_end_pgoff(), which clearly indicates which part of the VMA the page offset refers to and aids greppability. This is part of a broader series laying the ground to provide a virtual page offset for MAP_PRIVATE-file backed anon folios. No functional change intended. Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-19-2a5aa403d977@kernel.org Signed-off-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> # for kernel/dma Reviewed-by: Gregory Price <gourry@gourry.net> Acked-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Ackerley Tng <ackerleytng@google.com> Cc: David Hildenbrand (Arm) <david@kernel.org> Cc: Kai Huang <kai.huang@intel.com> Cc: SJ Park <sj@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04rv: Fix 32-bit build of nomiss KUnit testGabriele Monaco1-1/+1
Commit 8da2a8838365 ("rv: Add KUnit tests for some DA/HA monitors") introduced a division of a 64-bit value by 1000 in the nomiss KUnit test. This does not compile on 32-bit systems, as standard division of 64-bit values leads to an undefined reference to __udivdi3. Fix the build on 32-bit systems by using div_u64(). Fixes: 8da2a8838365 ("rv: Add KUnit tests for some DA/HA monitors") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202608020311.hYjqOG5k-lkp@intel.com Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260803150622.322806-1-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>