linux/kernel/trace
Linus Torvalds 68010e7b3d Tracing fixes for 7.0:
- Fix possible dereference of uninitialized pointer
 
   When validating the persistent ring buffer on boot up, if the first
   validation fails, a reference to "head_page" is performed in the
   error path, but it skips over the initialization of that variable.
   Move the initialization before the first validation check.
 
 - Fix use of event length in validation of persistent ring buffer
 
   On boot up, the persistent ring buffer is checked to see if it is
   valid by several methods. One being to walk all the events in the
   memory location to make sure they are all valid. The length of the
   event is used to move to the next event. This length is determined
   by the data in the buffer. If that length is corrupted, it could
   possibly make the next event to check located at a bad memory location.
 
   Validate the length field of the event when doing the event walk.
 
 - Fix function graph on archs that do not support use of ftrace_ops
 
   When an architecture defines HAVE_DYNAMIC_FTRACE_WITH_ARGS, it means
   that its function graph tracer uses the ftrace_ops of the function
   tracer to call its callbacks. This allows a single registered callback
   to be called directly instead of checking the callback's meta data's
   hash entries against the function being traced.
 
   For architectures that do not support this feature, it must always
   call the loop function that tests each registered callback (even if
   there's only one). The loop function tests each callback's meta data
   against its hash of functions and will call its callback if the
   function being traced is in its hash map.
 
   The issue was that there was no check against this and the direct
   function was being called even if the architecture didn't support it.
   This meant that if function tracing was enabled at the same time
   as a callback was registered with the function graph tracer, its
   callback would be called for every function that the function tracer
   also traced, even if the callback's meta data only wanted to be
   called back for a small subset of functions.
 
   Prevent the direct calling for those architectures that do not support
   it.
 
 - Fix references to trace_event_file for hist files
 
   The hist files used event_file_data() to get a reference to the
   associated trace_event_file the histogram was attached to. This
   would return a pointer even if the trace_event_file is about to
   be freed (via RCU). Instead it should use the event_file_file()
   helper that returns NULL if the trace_event_file is marked to be
   freed so that no new references are added to it.
 
 - Wake up hist poll readers when an event is being freed
 
   When polling on a hist file, the task is only awoken when a hist
   trigger is triggered. This means that if an event is being freed
   while there's a task waiting on its hist file, it will need to wait
   until the hist trigger occurs to wake it up and allow the freeing
   to happen. Note, the event will not be completely freed until all
   references are removed, and a hist poller keeps a reference. But
   it should still be woken when the event is being freed.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYKADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCaZd4ExQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qqX5AP4powfnNnRfLSKH9idhTp+ltmJ+9roy
 L7kWTr/z20S2VQEAk331PNZ32uZu+/ZUETYpgtEx4SbRGZFehTBv1ddjfw4=
 =TWj5
 -----END PGP SIGNATURE-----

Merge tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix possible dereference of uninitialized pointer

   When validating the persistent ring buffer on boot up, if the first
   validation fails, a reference to "head_page" is performed in the
   error path, but it skips over the initialization of that variable.
   Move the initialization before the first validation check.

 - Fix use of event length in validation of persistent ring buffer

   On boot up, the persistent ring buffer is checked to see if it is
   valid by several methods. One being to walk all the events in the
   memory location to make sure they are all valid. The length of the
   event is used to move to the next event. This length is determined by
   the data in the buffer. If that length is corrupted, it could
   possibly make the next event to check located at a bad memory
   location.

   Validate the length field of the event when doing the event walk.

 - Fix function graph on archs that do not support use of ftrace_ops

   When an architecture defines HAVE_DYNAMIC_FTRACE_WITH_ARGS, it means
   that its function graph tracer uses the ftrace_ops of the function
   tracer to call its callbacks. This allows a single registered
   callback to be called directly instead of checking the callback's
   meta data's hash entries against the function being traced.

   For architectures that do not support this feature, it must always
   call the loop function that tests each registered callback (even if
   there's only one). The loop function tests each callback's meta data
   against its hash of functions and will call its callback if the
   function being traced is in its hash map.

   The issue was that there was no check against this and the direct
   function was being called even if the architecture didn't support it.
   This meant that if function tracing was enabled at the same time as a
   callback was registered with the function graph tracer, its callback
   would be called for every function that the function tracer also
   traced, even if the callback's meta data only wanted to be called
   back for a small subset of functions.

   Prevent the direct calling for those architectures that do not
   support it.

 - Fix references to trace_event_file for hist files

   The hist files used event_file_data() to get a reference to the
   associated trace_event_file the histogram was attached to. This would
   return a pointer even if the trace_event_file is about to be freed
   (via RCU). Instead it should use the event_file_file() helper that
   returns NULL if the trace_event_file is marked to be freed so that no
   new references are added to it.

 - Wake up hist poll readers when an event is being freed

   When polling on a hist file, the task is only awoken when a hist
   trigger is triggered. This means that if an event is being freed
   while there's a task waiting on its hist file, it will need to wait
   until the hist trigger occurs to wake it up and allow the freeing to
   happen. Note, the event will not be completely freed until all
   references are removed, and a hist poller keeps a reference. But it
   should still be woken when the event is being freed.

* tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Wake up poll waiters for hist files when removing an event
  tracing: Fix checking of freed trace_event_file for hist files
  fgraph: Do not call handlers direct when not using ftrace_ops
  tracing: ring-buffer: Fix to check event length before using
  ring-buffer: Fix possible dereference of uninitialized pointer
2026-02-20 15:05:26 -08:00
..
rv verification/rvgen: Remove unused variable declaration from containers 2026-01-12 07:43:51 +01:00
blktrace.c block-7.0-20260216 2026-02-17 08:48:45 -08:00
bpf_trace.c tracing updates for 7.0: 2026-02-13 19:25:16 -08:00
bpf_trace.h tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
error_report-traces.c
fgraph.c fgraph: Do not call handlers direct when not using ftrace_ops 2026-02-19 15:21:22 -05:00
fprobe.c tracing fixes for v6.19: 2025-12-06 13:49:40 -08:00
ftrace.c tracing updates for 7.0: 2026-02-13 19:25:16 -08:00
ftrace_internal.h function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE 2024-06-10 18:08:23 -04:00
Kconfig tracing updates for 7.0: 2026-02-13 19:25:16 -08:00
kprobe_event_gen_test.c
Makefile tracing: Move pid filtering into trace_pid.c 2026-02-08 21:01:13 -05:00
pid_list.c trace/pid_list: optimize pid_list->lock contention 2025-11-13 15:15:54 -05:00
pid_list.h trace/pid_list: optimize pid_list->lock contention 2025-11-13 15:15:54 -05:00
power-traces.c PM: cpufreq: powernv/tracing: Move powernv_throttle trace event 2025-07-21 16:40:56 -04:00
preemptirq_delay_test.c kernel: trace: preemptirq_delay_test: use offstack cpu mask 2025-07-08 18:17:38 -04:00
rethook.c rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get() 2024-05-01 23:18:48 +09:00
ring_buffer.c tracing: ring-buffer: Fix to check event length before using 2026-02-19 15:21:12 -05:00
ring_buffer_benchmark.c tracing: Fix typo in ring_buffer_benchmark.c 2025-12-05 15:43:40 -05:00
rpm-traces.c
synth_event_gen_test.c tracing / synthetic: Disable events after testing in synth_event_gen_test_init() 2023-12-21 10:04:45 -05:00
trace.c mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
trace.h tracing updates for 7.0: 2026-02-13 19:25:16 -08:00
trace_benchmark.c tracing: Improve benchmark test performance by using do_div() 2024-05-13 20:00:57 -04:00
trace_benchmark.h
trace_boot.c tracing: Allow creating instances with specified system events 2023-12-18 23:14:16 -05:00
trace_branch.c tracing: branch: Use trace_tracing_is_on_cpu() instead of "disabled" field 2025-05-09 15:19:10 -04:00
trace_btf.c tracing/probes: Fix to search structure fields correctly 2024-02-17 21:25:42 +09:00
trace_btf.h tracing/probes: Add a function to search a member of a struct/union 2023-08-23 09:40:16 +09:00
trace_clock.c tracing: Use atomic64_inc_return() in trace_clock_counter() 2024-10-09 19:59:49 -04:00
trace_dynevent.c tracing: Report wrong dynamic event command 2025-11-10 19:26:14 -05:00
trace_dynevent.h tracing: probes: Fix a possible race in trace_probe_log APIs 2025-05-13 22:23:34 +09:00
trace_entries.h tracing: Fix ftrace event field alignments 2026-02-05 09:47:11 -05:00
trace_eprobe.c Probes for v6.19 2025-12-05 10:55:47 -08:00
trace_event_perf.c perf: Remove unnecessary parameter of security check 2025-02-26 14:13:58 -05:00
trace_events.c tracing: Wake up poll waiters for hist files when removing an event 2026-02-19 15:25:11 -05:00
trace_events_filter.c tracing: Replace use of system_wq with system_dfl_wq 2026-01-26 17:44:05 -05:00
trace_events_filter_test.h
trace_events_hist.c tracing: Fix checking of freed trace_event_file for hist files 2026-02-19 15:23:49 -05:00
trace_events_inject.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_synth.c tracing: Remove notrace from trace_event_raw_event_synth() 2026-01-28 21:01:09 -05:00
trace_events_trigger.c tracing: Have all triggers expect a file parameter 2026-02-08 21:00:57 -05:00
trace_events_user.c tracing: Fix multiple typos in trace_events_user.c 2025-12-05 15:43:41 -05:00
trace_export.c tracing: Fix ftrace event field alignments 2026-02-05 09:47:11 -05:00
trace_fprobe.c tracing updates for v6.19: 2025-12-05 09:51:37 -08:00
trace_functions.c tracing: Have function tracer define options per instance 2025-11-12 09:59:54 -05:00
trace_functions_graph.c function_graph: Fix args pointer mismatch in print_graph_retval() 2026-01-23 13:34:38 -05:00
trace_hwlat.c tracing: Fix false sharing in hwlat get_sample() 2026-02-10 03:36:39 -05:00
trace_irqsoff.c tracing: Allow tracer to add more than 32 options 2025-11-04 21:44:00 +09:00
trace_kdb.c tracing: Allow tracer to add more than 32 options 2025-11-04 21:44:00 +09:00
trace_kprobe.c Probes for v7.0 2026-02-16 07:04:01 -08:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c tracing/mmiotrace: Remove reference to unused per CPU data pointer 2025-05-08 09:36:09 -04:00
trace_nop.c
trace_osnoise.c tracing: Fix multiple typos in trace_osnoise.c 2025-12-05 15:43:41 -05:00
trace_output.c tracing: Add bitmask-list option for human-readable bitmask display 2026-01-26 17:00:50 -05:00
trace_output.h tracing: Allow tracer to add more than 32 options 2025-11-04 21:44:00 +09:00
trace_pid.c tracing: Move pid filtering into trace_pid.c 2026-02-08 21:01:13 -05:00
trace_preemptirq.c tracing: Fix archs that still call tracepoints without RCU watching 2024-12-05 09:28:58 -05:00
trace_printk.c tracing updates for 7.0: 2026-02-13 19:25:16 -08:00
trace_probe.c tracing fixes for v6.19: 2025-12-06 13:49:40 -08:00
trace_probe.h tracing: probes: Use __free() for trace_probe_log 2025-11-01 01:10:28 +09:00
trace_probe_kernel.h
trace_probe_tmpl.h tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS 2024-12-26 10:50:04 -05:00
trace_recursion_record.c
trace_sched_switch.c tracing: Ensure optimized hashing works 2025-09-30 17:27:58 -04:00
trace_sched_wakeup.c tracing: Allow tracer to add more than 32 options 2025-11-04 21:44:00 +09:00
trace_selftest.c tracing: Rename trace_array field max_buffer to snapshot_buffer 2026-02-08 21:01:13 -05:00
trace_selftest_dynamic.c
trace_seq.c tracing: Add bitmask-list option for human-readable bitmask display 2026-01-26 17:00:50 -05:00
trace_stack.c tracing updates for v6.16: 2025-05-29 21:04:36 -07:00
trace_stat.c tracing: Switch trace_stat.c code over to use guard() 2024-12-26 10:38:37 -05:00
trace_stat.h
trace_synth.h
trace_syscalls.c tracing: Hide __NR_utimensat and _NR_mq_timedsend when not defined 2025-11-10 14:23:53 -05:00
trace_uprobe.c tracing: uprobe: eprobes: Allocate traceprobe_parse_context per probe 2025-11-01 01:10:29 +09:00
tracing_map.c tracing: Use vmalloc_array() to improve code 2025-09-23 09:31:58 -04:00
tracing_map.h