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2026-08-10ftrace: deprecate disabling via ftrace_enabled sysctlAndrey Grodzovsky
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)
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 Su
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 Donnefort
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 Donnefort
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 Donnefort
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 Poimboeuf
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 Wu
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 Shelat
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 Hwang
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 Hwang
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 Hwang
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 Hwang
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)
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)
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 Borkmann
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 Yatsenko
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 Stoakes
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 Monaco
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>
2026-08-03bpf: Rename ARG_CONST_SIZE{,_OR_ZERO} to ARG_MEM_SIZE{,_OR_ZERO}Amery Hung
ARG_CONST_SIZE does not require a constant: check_mem_size_reg() accepts any bounded scalar and verifies the memory access against its maximum (reg_umax). Rename ARG_CONST_SIZE and ARG_CONST_SIZE_OR_ZERO to ARG_MEM_SIZE and ARG_MEM_SIZE_OR_ZERO to reflect that. ARG_CONST_ALLOC_ SIZE_OR_ZERO, which does require a constant, is left unchanged. Pure rename, no functional change. Signed-off-by: Amery Hung <ameryhung@gmail.com> Link: https://lore.kernel.org/bpf/20260801074633.1595644-10-ameryhung@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-07-31Merge tag 'trace-v7.2-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Reset dropped_count in mmio_reset_data() When mmio_reset_data() is called, it does not reset the dropped_count so that subsequent runs will have incorrect reporting. - Add NULL check for mmio_trace_array in logging functions The functions __trace_mmiotrace_rw() and __trace_mmiotrace_map() may have the 'tr' variable passed to it as NULL. But they both dereference it without checking if it is NULL first. - Check return value of __register_event() in trace_module_add_events() If __register_event() fails, the __add_event_to_tracers() call after it will create a file for it. If the module fails to load and its memory is freed, the file will still point to it and it will not be removed as the registering of the event did not complete. Only call __add_event_to_tracers() if the __register_event() was successful. - Fix false positive match in regex_match_full() The regex full matching uses a strncmp() to test against the match string and the value. It should not match if value is a prefix of the string to match. Check to make sure the length of the strings match before comparing. - Fix reader page read offset for remote buffers A page swapped in by __rb_get_reader_page_from_remote() retains its stale read offset, causing subsequent reads to skip events or read past valid data. - Fix memory leak of subbuf_ids in rb_allocate_cpu_buffer() Remote buffers allocate a subbuf_ids array. If the allocator function fails after it is allocated, it does not free it, resulting in a memory leak. * tag 'trace-v7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Fix subbuf_ids memory leak in rb_allocate_cpu_buffer() error path ring-buffer: Fix reader page read offset for remote buffers tracing/filters: Fix false positive match in regex_match_full() tracing: Check return value of __register_event() in trace_module_add_events() tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions tracing/mmiotrace: Reset dropped_count in mmio_reset_data()
2026-07-31ring-buffer: Fix subbuf_ids memory leak in rb_allocate_cpu_buffer() error pathMasami Hiramatsu (Google)
In rb_allocate_cpu_buffer(), cpu_buffer->subbuf_ids is allocated using kcalloc() when buffer->remote is non-NULL. If a subsequent page allocation fails (e.g., ring_buffer_desc_page() returns NULL or rb_allocate_pages() fails), execution jumps to fail_free_reader. While __free(kfree) automatically frees the outer cpu_buffer structure at scope exit, kfree(cpu_buffer) does not recursively free nested heap pointers such as cpu_buffer->subbuf_ids, resulting in a memory leak. Fix this by explicitly freeing cpu_buffer->subbuf_ids in the fail_free_reader error unwinding path when cpu_buffer->remote is set. Link: https://patch.msgid.link/178550740672.380917.6067449683620196150.stgit@devnote2 Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-31rv: Add KUnit tests for some LTL monitorsGabriele Monaco
Validate the functionality of LTL monitors by injecting events in a controlled environment (KUnit) and expecting reactions, just like it is done in DA monitors. Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260723074534.43521-15-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-07-31rv: Add KUnit mock for currentGabriele Monaco
Some monitors do not only rely on tracepoint arguments but also on the currently executing task. This makes it more challenging to mock events in KUnit. Define wrapper functions around current, the functionality is mocked only during KUnit, an additional function call is avoided using a static branch unless any (even unrelated) KUnit test is running. Rely on a global mock_current variable that is set only by the RV KUnit tests and cleared on teardown. Unrelated KUnit tests that happen to trigger RV handlers would see it null and use current. Reviewed-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Wen Yang <wen.yang@linux.dev> Link: https://lore.kernel.org/r/20260723074534.43521-14-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-07-31rv: Add KUnit tests for some DA/HA monitorsGabriele Monaco
Validate the functionality of DA monitors by injecting events in a controlled environment (KUnit) and expecting reactions. Events handlers are exported directly from the monitor source files without using system events and with dummy arguments (e.g. no real tasks). If the provided sequence of events incurs a violation, the test expects the stub version of rv_react() to be called. This testing method can validate the entire monitor implementation since it sits between the monitor and the system (in place of the tracepoints). All sorts of system and timing events can be emulated without affecting the running kernel. Handlers and monitor functions are exported as part of a struct to simplify the process of running KUnit tests from kernel modules. Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260723074534.43521-13-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-07-31rv: Export task monitor slot and react symbolsGabriele Monaco
Export rv_get_task_monitor_slot, rv_put_task_monitor_slot, and rv_react to GPL modules so they can be accessed by KUnit and future monitors built as kernel modules. Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260723074534.43521-12-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-07-31rv: Use generic rv_this for the rv_monitor variable in LTLGabriele Monaco
Align the rv_monitor variable name in LTL to the generic rv_this as it is already done for DA/HA monitors. This improves consistency and eases assumptions across model classes. Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260723074534.43521-2-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-07-29ring-buffer: Fix reader page read offset for remote buffersVincent Donnefort
A page swapped in by __rb_get_reader_page_from_remote() retains its stale read offset, causing subsequent reads to skip events or read past valid data. Fix it. Link: https://patch.msgid.link/20260729133609.4022734-1-vdonnefort@google.com Fixes: fbd1743ecba1 ("ring-buffer: Add non-consuming read for ring-buffer remotes") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Reviewed-by: Keir Fraser <keirf@google.com> Tested-by: Keir Fraser <keirf@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-29tracing/filters: Fix false positive match in regex_match_full()Masami Hiramatsu (Google)
regex_match_full() calls strncmp(str, r->pattern, len) where len is the target field buffer size. When len is smaller than r->len (the filter pattern length), strncmp() checks only len bytes of r->pattern against str. If those len bytes match, strncmp() returns 0, resulting in a false-positive match where a shorter string in a fixed-size field matches a longer filter pattern. For example, a 4-byte static string field containing "abcd" matched the filter pattern "abcdefgh" because strncmp("abcd", "abcdefgh", 4) returned 0. In this case, @len does NOT include '\0' because it is fixed-size array. Fix this by returning 0 (no match) early when len < r->len. Fixes: 1889d20922d1 ("tracing/filters: Provide basic regex support") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/178528488779.124250.5571741156199253769.stgit@devnote2 Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-29tracing: Check return value of __register_event() in trace_module_add_events()Masami Hiramatsu (Google)
trace_module_add_events() ignores the return value of __register_event() and unconditionally calls __add_event_to_tracers() for each event. If __register_event() fails (for example, if event_init() fails), the trace_event_call is not added to ftrace_events list, but __add_event_to_tracers() still creates a trace_event_file pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale trace_event_call pointer in trace_event_file, leading to a use-after-free when tracefs or tracing subsystem operations are later executed. Fix this by checking the return value of __register_event() and only calling __add_event_to_tracers() if event registration succeeded. Fixes: ae63b31e4d0e ("tracing: Separate out trace events from global variables") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/178528487878.124250.14170824576025743236.stgit@devnote2 Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-29tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functionsMasami Hiramatsu (Google)
mmio_trace_rw() and mmio_trace_mapping() retrieve mmio_trace_array into tr and pass it to __trace_mmiotrace_rw() and __trace_mmiotrace_map(). If these functions are invoked while mmio_trace_array is NULL (e.g. before initialization or after disabled), accessing tr->array_buffer.buffer will result in a NULL pointer dereference crash. Fix this by adding an explicit NULL check for tr at the beginning of __trace_mmiotrace_rw() and __trace_mmiotrace_map(). Link: https://patch.msgid.link/178524300062.56416.8362487250709962380.stgit@devnote2 Fixes: f984b51e0779 ("ftrace: add mmiotrace plugin") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-29tracing/mmiotrace: Reset dropped_count in mmio_reset_data()Masami Hiramatsu (Google)
mmio_reset_data() is called during tracer initialization, reset, and start. While it resets overrun_detected and prev_overruns, it neglects to reset dropped_count. Consequently, dropped event counts from prior tracing sessions persist in dropped_count and corrupt overrun reports in subsequent runs. Fix this by explicitly calling atomic_set(&dropped_count, 0) in mmio_reset_data(). Link: https://patch.msgid.link/178524299122.56416.16277704230639425172.stgit@devnote2 Fixes: 173ed24ee2d6 ("mmiotrace: count events lost due to not recording") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-29fprobe: Fix module reference count leak on error in register_fprobe()Masami Hiramatsu (Google)
In register_fprobe(), get_ips_from_filter() resolves target function addresses and increments module reference counts via try_module_get() for symbols in kernel modules. If get_ips_from_filter() fails on the second pass and returns an error, register_fprobe() returned directly without releasing module references acquired up to that point. Fix this by ensuring the cleanup loop executing module_put() runs even when get_ips_from_filter() returns a negative error. Link: https://lore.kernel.org/all/178528125360.101985.4144133640239273153.stgit@devnote2/ Fixes: d24fa977eec5 ("tracing: fprobe: Fix to lock module while registering fprobe") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-29tracing/fprobe: Roll back on enable_trace_fprobe() failureRaushan Patel
enable_trace_fprobe() sets the file link or the TP_FLAG_PROFILE flag and then registers each trace_fprobe in the probe list. If __register_trace_fprobe() fails partway through, the function returns immediately without unregistering the trace_fprobes it already registered or undoing the file link / flag it set, leaving the event half-enabled and leaking the registered fprobe(s). enable_trace_kprobe() already handles this with a rollback path. Do the same for fprobe: on failure, unregister all probes and clear the file link or profile flag. Link: https://lore.kernel.org/all/20260724064208.480030-1-raushan.jhon@gmail.com/ Fixes: 334e5519c375 ("tracing/probes: Add fprobe events for tracing function entry and exit.") Cc: stable@vger.kernel.org Signed-off-by: Raushan Patel <raushan.jhon@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-28tracing/probes: Reject $arg0 in meta argument expansionRaushan Patel
traceprobe_expand_meta_args() parses $argN with simple_strtoul() and calls sprint_nth_btf_arg(n - 1, ...). For $arg0, n is 0 so the index is -1. Because ctx->nr_params is signed, the "idx >= nr_params" guard in sprint_nth_btf_arg() does not catch the negative index, and ctx->params[-1].name_off is read out of bounds. The normal per-argument path (parse_probe_vars()) already rejects $arg0 via its argument-number check, but meta-argument expansion runs before per-argument parsing and substitutes the value first, bypassing that check. Reject $arg0 explicitly during expansion. Link: https://lore.kernel.org/all/20260724054435.146279-1-raushan.jhon@gmail.com/ Fixes: 18b1e870a496 ("tracing/probes: Add $arg* meta argument for all function args") Cc: stable@vger.kernel.org Signed-off-by: Raushan Patel <raushan.jhon@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-28tracing/probes: Treating longer symbol name on event comparationMasami Hiramatsu (Google)
MAX_COMMON_HEAD_LEN (63) was used to allocate a temporary buffer for formatting command heads in trace_kprobe_match_command_head() and trace_uprobe_match_command_head(). However, the buffer size is too short for some longer symbols. Especially, with rust code, the symbol can be mangled and become very long. Refactor trace_kprobe_match_command_head() to perform direct string comparisons using strcmp() and strncmp(), eliminating the need for a temporary buffer and removing the MAX_COMMON_HEAD_LEN string length restriction on probe symbol names. For trace_uprobe_match_command_head(), since tu->filename is already matched via strncmp(), use a fixed 64-byte stack buffer solely for formatting offset and ref_ctr_offset (which requires at most 39 bytes). With all users converted, remove the MAX_COMMON_HEAD_LEN definition from trace_probe.h. Link: https://lore.kernel.org/all/178521361102.34226.9650586522488974115.stgit@devnote2/ Reported-by: Zhan Xusheng <zhanxusheng1024@gmail.com> Link: https://lore.kernel.org/all/20260724023317.624074-1-zhanxusheng@xiaomi.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-28tracing: Use seq_buf for string concatenationWoradorn Laodhanadhaworn
In preparation for removing the strlcat API[1], replace the string concatenation logic with a struct seq_buf, which tracks the current position and the remaining space internally. Use seq_buf_str() to NUL-terminate before passing to early_enable_events(). Link: https://github.com/KSPP/linux/issues/370 [1] Link: https://patch.msgid.link/20260713045249.69942-1-woradorn.laon@gmail.com Signed-off-by: Woradorn Laodhanadhaworn <woradorn.laon@gmail.com> [ Moved placement of #include <linux/seq_buf.h> ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Use strscpy() instead of strcpy() in trace_sched_switchPo-Sheng Lin
Replace strcpy() with strscpy() in __trace_find_cmdline() for consistency with the existing strscpy() call in the same function, and to avoid potential buffer overflow as flagged by the Kernel Self Protection Project. Link: https://patch.msgid.link/20260705173648.5418-1-posheng.lin.tw@gmail.com Signed-off-by: Po-Sheng Lin <posheng.lin.tw@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Warn when an event dereferences a pointer in TP_printk()Steven Rostedt
Currently on boot up and when modules are loaded, the trace event infrastructure will examine the TP_printk's of every event looking to see if it dereferences pointers on the ring buffer via printk formats like "%pB" and such. What it doesn't do is check if the arguments themselves do a dereference from a pointer. This was brought with a fix[1] to the fsl_edma event that had in the arguments of the TP_printk(): "__entry->edma->membase" The __entry->edma is a pointer saved in the ring buffer. The dereference from TP_printk() happens when the user reads the "trace" file which can be seconds, minutes, hours, days, weeks, or even months later! There is no guarantee that the __entry->edma pointer will still be pointing to what it was when it was recorded, and could crash the kernel when a user reads the event. Add logic to the test_event_printk() that also checks for this case and warn if the event dereferences a pointer from the ring buffer. [1] https://lore.kernel.org/all/20260630200022.1826420-1-martin@kaiser.cx/ Link: https://patch.msgid.link/20260630184836.74d477b6@gandalf.local.home Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Reviewed-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Reject invalid preemptirq_delay_test CPU affinitySamuel Moelius
preemptirq_delay_test accepts cpu_affinity as a module parameter and, when it is non-negative, writes that CPU directly into a temporary cpumask from the worker thread. Values outside nr_cpu_ids can set a bit outside the allocated cpumask before the test reports a normal affinity error. Validate the requested CPU in preemptirq_delay_run() before setting it in the temporary cpumask. Invalid affinity requests are reported by the test thread and skipped before cpumask_set_cpu() can touch an out-of-range bit. Link: https://patch.msgid.link/20260628131021.2208632.6a5c6c959813.preemptirq-delay-test-invalid-cpu-affinity@trailofbits.com Assisted-by: Codex:gpt-5.5-cyber-preview Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28fgraph: Use trace_seq_putc() in print_graph_return()Markus Elfring
A single closing curly bracket should be put into a trace sequence buffer. Thus use the corresponding function “trace_seq_putc”. The source code was transformed by using the Coccinelle software. Link: https://patch.msgid.link/d215fa89-9a62-4067-86ec-833290f35c80@web.de Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing/user_events: Replace a seq_printf() call by seq_puts() in ↵Markus Elfring
user_seq_show() A single string should be put into a sequence within a loop. Thus use the corresponding function “seq_puts” for one selected call. The source code was transformed by using the Coccinelle software. Link: https://patch.msgid.link/1cf327f0-49a6-477f-a06f-2b22a167db24@web.de Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing/user_events: Use seq_putc() in two functionsMarkus Elfring
Single characters should be put into a sequence. Thus use the corresponding function “seq_putc” for selected calls. The source code was transformed by using the Coccinelle software. Link: https://patch.msgid.link/6bcaa4da-05c6-4097-90f5-3969f8a1dfbc@web.de Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Bound histogram expression strings with seq_bufPengpeng Hou
expr_str() allocates a fixed MAX_FILTER_STR_VAL buffer and then builds expression names with a series of raw strcat() appends. Nested operands, constants, field flags, and generated field names can push the rendered string past that fixed limit before the name is attached to the hist field. Build expression strings with seq_buf and return -E2BIG when the rendered name would exceed MAX_FILTER_STR_VAL. This keeps the existing tracing-side limit while replacing the raw append logic with bounded construction. Link: https://patch.msgid.link/20260611055945.22348-4-pengpeng@iscas.ac.cn Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Return ERR_PTR() from expr_str()Pengpeng Hou
expr_str() currently reports all failure cases as NULL, so callers cannot distinguish invalid recursion depth from allocation failure or later string construction errors. Return ERR_PTR()-encoded errors from expr_str() and make parse_unary() and parse_expr() propagate them. Clear expr->name before destroying the hist field so the error pointer is not freed as a string. Link: https://patch.msgid.link/20260611055945.22348-3-pengpeng@iscas.ac.cn Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Use __free() for expr_str() bufferPengpeng Hou
expr_str() allocates a temporary expression buffer and manually frees it on some error paths. Convert the buffer to __free(kfree) and return it with return_ptr() on success. This keeps ownership handling separate from the later ERR_PTR() conversion and string-bound change. Link: https://patch.msgid.link/20260611055945.22348-2-pengpeng@iscas.ac.cn Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28kernel/trace/trace_printk: Use kstrdup() instead of kmalloc() and strcpy()David Laight
Link: https://patch.msgid.link/20260606202633.5018-34-david.laight.linux@gmail.com Signed-off-by: David Laight <david.laight.linux@gmail.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Point constant hist field type to string literalYu Peng
The HIST_FIELD_FL_CONST path uses the fixed "u64" type string. Point hist_field->type directly to the string literal, matching the HIST_FIELD_FL_HITCOUNT path. The release path already uses kfree_const(), so no duplication is needed. Link: https://patch.msgid.link/20260527023450.2137639-1-pengyu@kylinos.cn Signed-off-by: Yu Peng <pengyu@kylinos.cn> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-28tracing: Expose tracepoint BTF ids via tracefsMykyta Yatsenko
Add events/<sys>/<event>/btf_ids, a per-template file that exposes the BTF ids resolve_btfids fills in for each tracepoint: btf_obj_id BTF object owning the ids below raw_btf_id FUNC_PROTO of __bpf_trace_<call> (named args), consumed by raw_tp / tp_btf BPF programs tp_btf_id trace_event_raw_<call> ring-buffer record, consumed by classic BPF_PROG_TYPE_TRACEPOINT programs DECLARE_EVENT_CLASS now emits a 2-entry BTF_ID_LIST (FUNC __bpf_trace_* and STRUCT trace_event_raw_*) and stores the pointer in trace_event_class. Per-syscall events under syscalls/ share the handcrafted classes event_class_syscall_{enter,exit} instead of going through DECLARE_EVENT_CLASS. Wire those classes to the BTF id lists generated for sys_enter / sys_exit so all ~700 per-syscall events expose the shared dispatcher prototype and record. The per-syscall events do not own their own tracepoint (they share sys_enter/sys_exit), so raw_btf_id is reported as 0 on those events; the meaningful raw_btf_id is exposed on raw_syscalls/sys_{enter,exit}/btf_ids where raw_tp / tp_btf programs can actually attach. Link: https://patch.msgid.link/20260518-generic_tracepoint-v2-2-b755a5cf67bb@meta.com Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-26Merge tag 'trace-v7.2-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Move rb_desc->nr_page_va before updating dynamic array The rb_descr->page_va is a dynamic array counted by nr_page_va. But the updating of the page_va[] is done before the nr_page_va is incremented causing a build with CONFIG_UBSAN_BOUNDS to flag it as an overflow. Move the increment of the counted by value before the array element is updated. - Propagate errors from remote event bulk updates The return value of trace_remote_enable_event() was not being checked by remote_events_dir_enable_write() where it would silently fail. Have it check the return value and propagate that back up to user space. - Fix resource leak on mmiotrace trace_pipe close The mmiotrace tracer was created in 2008 before the trace_pipe had a close callback to allow tracers to do clean up from trace_pipe open. The trace_pipe close cleanup callback was added in 2009 but the mmiotrace tracer was not updated. It had a hack to do the cleanup in the read call, where it may leak if user space did not read the entire buffer. Add a callback to mmiotrace trace_pipe close do to the cleanup properly. - Fix a possible NULL pointer dereference in the mmiotrace tracer If the mmio_pipe_open() fails to find a PCI device, it will set the hiter->dev pointer to NULL. The read function will blindly dereference that pointer. Fix the read call to check to see if that pointer is populated before dereferencing it. - Fix union collision of module and refcnt for dynamic events In 'struct trace_event_call', the 'module' pointer and the 'refcnt' atomic variable share the same memory space in a union. The filter on module logic only checked if the 'module' was set to determine if the event belonged to the module. As dynamic events are always builtin, it doesn't need the 'module' field of the structure and used a refcount. But the module filtering logic would then mistaken these dynamic events as a module and call module_name(event->module) on it. Add a check to see if the event is a dynamic event and if so, do not check it for being part of the given module. - Reset the top level buffer in selftests before running instances The ftracetest selftest initializes each instance before executing the tests. But it does not reset the top level buffer. Dynamic events are only added and removed by the top level so any left over dynamic events will not be removed by the reset in the instances. Left over dynamic events can cause the tests to incorrectly fail. Reset the top level buffer before running the instances. - Make the context_switch counter 64 bit The code to read user space for a system call trace event or for a trace_marker will disable migration, enable preemption, read user space into a per CPU buffer, disable preemption and enable migration again. It checks if the per CPU context switch counter to see if it changed, and if it did not, it would know that the per CPU buffer was not touched by another task. But the save counter was 32 bit and it would compare it to the 64 bit context_switch variable. A long running system could have the context_switch variable greater that 1<<32 in which case the compare will always fail. The compare will promote the 32 bit int saved value to 64 bit and compare it to the full 64 bit counter. Since the top 32 bits of the saved value was zero, it would never match. - Fix a use-after-free of the event_enable trigger The event_enable trigger allows for enabling one event when another event is triggered. When the trigger is removed, it must go through a synchronization phase to make sure it is not triggered again. The trigger itself is delayed by the "bulk delay" logic that was recently added. But the code that frees the event_enable data used to rely on the trigger code to do the synchronization. Now that the code uses the call RCU functions (and a workqueue), that delay no longer is there. Add a callback private_data_free() function that allows triggers to clean up data after the synchronization phase has completed. - Move the module_ref counter into the delay callback Since an event of the event_enable trigger can enable an event for a module, it ups the module ref count for that event's module. This prevents the event from trying to enable an event that no longer exists and cause a use-after-free bug. The ref counter was set back down when the trigger was removed but not after thy synchronization phase. This could lead to the module data being accessed after module was unloaded. Move the module ref decrement into the private_data_free() callback of the event_enable trigger. - Add mutex to protect parser in ftrace filtering The set_ftrace_filter file uses a parsing descriptor that is allocated at open and modified by writes. If multiple threads were to write to the descriptor at the same time, it can corrupt the parser. Add a mutex around the modifications of the parser descriptor. - Fix possible corruption in perf syscall tracing The perf system call trace events can now read user space. To do so, the reads of user space enable preemption and disables it again. During this time that preemption is enabled, the task can migrate. The perf event list head is assigned via a per CPU pointer. It is done before the user space part is called. If the user space reading migrates the task to another CPU, then the head pointer is no longer valid. Re-assign the head pointer after the reading of user space to keep it using the correct data. * tag 'trace-v7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: perf: Fix stale head for perf syscall tracing ftrace: Add global mutex to serialize trace_parser access tracing: Delay module ref count for "enable_event" trigger tracing: Fix use-after-free freeing trigger private data tracing: Fix context switch counter truncation selftests/ftrace: Reset triggers at top level before instance loop tracing: Fix union collision of module and refcnt for dynamic events tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev tracing: Fix resource leak on mmiotrace trace_pipe close tracing: Propagate errors from remote event bulk updates tracing/remotes: Fix page_va[] access before counter update in trace_remote_alloc_buffer()