linux/kernel/trace, branch v6.14

Merge tag 'probes-fixes-v6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-03-17T21:30:31Z

Pull probes fixes from Masami Hiramatsu: - Clean up tprobe correctly when module unload Tracepoint probes do not set TRACEPOINT_STUB on the 'tpoint' pointer when unloading a module, thus they show as a normal 'fprobe' instead of 'tprobe' and never come back - Fix leakage of tprobe module refcount When a tprobe's target module is loaded, it gets the module's refcount in the module notifier but forgot to put it after registering the probe on it. Fix it by getting the refcount only when registering tprobe. * tag 'probes-fixes-v6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: tprobe-events: Fix leakage of module refcount tracing: tprobe-events: Fix to clean up tprobe correctly when module unload

Merge tag 'trace-v6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-03-16T19:05:00Z

Pull tracing fix from Steven Rostedt: "Fix ref count of trace_array in error path of histogram file open Tracing instances have a ref count to keep them around while files within their directories are open. This prevents them from being deleted while they are used. The histogram code had some files that needed to take the ref count and that was added, but the error paths did not decrement the ref counts. This caused the instances from ever being removed if a histogram file failed to open due to some error" * tag 'trace-v6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Correct the refcount if the hist/hist_debug file fails to open

tracing: tprobe-events: Fix leakage of module refcount

2025-03-14T23:37:47Z

When enabling the tracepoint at loading module, the target module refcount is incremented by find_tracepoint_in_module(). But it is unnecessary because the module is not unloaded while processing module loading callbacks. Moreover, the refcount is not decremented in that function. To be clear the module refcount handling, move the try_module_get() callsite to trace_fprobe_create_internal(), where it is actually required. Link: https://lore.kernel.org/all/174182761071.83274.18334217580449925882.stgit@devnote2/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google) Cc: stable@vger.kernel.org

tracing: tprobe-events: Fix to clean up tprobe correctly when module unload

2025-03-14T23:37:12Z

When unloading module, the tprobe events are not correctly cleaned up. Thus it becomes `fprobe-event` and never be enabled again even if loading the same module again. For example; # cd /sys/kernel/tracing # modprobe trace_events_sample # echo 't:my_tprobe foo_bar' >> dynamic_events # cat dynamic_events t:tracepoints/my_tprobe foo_bar # rmmod trace_events_sample # cat dynamic_events f:tracepoints/my_tprobe foo_bar As you can see, the second time my_tprobe starts with 'f' instead of 't'. This unregisters the fprobe and tracepoint callback when module is unloaded but marks the fprobe-event is tprobe-event. Link: https://lore.kernel.org/all/174158724946.189309.15826571379395619524.stgit@mhiramat.tok.corp.google.com/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google)

tracing: Correct the refcount if the hist/hist_debug file fails to open

2025-03-14T12:29:12Z

The function event_{hist,hist_debug}_open() maintains the refcount of 'file->tr' and 'file' through tracing_open_file_tr(). However, it does not roll back these counts on subsequent failure paths, resulting in a refcount leak. A very obvious case is that if the hist/hist_debug file belongs to a specific instance, the refcount leak will prevent the deletion of that instance, as it relies on the condition 'tr->ref == 1' within __remove_instance(). Fix this by calling tracing_release_file_tr() on all failure paths in event_{hist,hist_debug}_open() to correct the refcount. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Zheng Yejian Link: https://lore.kernel.org/20250314065335.1202817-1-wutengda@huaweicloud.com Fixes: 1cc111b9cddc ("tracing: Fix uaf issue when open the hist or hist_debug file") Signed-off-by: Tengda Wu Signed-off-by: Steven Rostedt (Google)

Merge tag 'probes-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-03-03T17:28:15Z

Pull probe events fixes from Masami Hiramatsu: - probe-events: Remove unused MAX_ARG_BUF_LEN macro - it is not used - fprobe-events: Log error for exceeding the number of entry args. Since the max number of entry args is limited, it should be checked and rejected when the parser detects it. - tprobe-events: Reject invalid tracepoint name If a user specifies an invalid tracepoint name (e.g. including '/') then the new event is not defined correctly in the eventfs. - tprobe-events: Fix a memory leak when tprobe defined with $retval There is a memory leak if tprobe is defined with $retval. * tag 'probes-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: probe-events: Remove unused MAX_ARG_BUF_LEN macro tracing: fprobe-events: Log error for exceeding the number of entry args tracing: tprobe-events: Reject invalid tracepoint name tracing: tprobe-events: Fix a memory leak when tprobe with $retval

tracing: probe-events: Remove unused MAX_ARG_BUF_LEN macro

2025-03-03T02:17:54Z

Commit 18b1e870a496 ("tracing/probes: Add $arg* meta argument for all function args") introduced MAX_ARG_BUF_LEN but it is not used. Remove it. Link: https://lore.kernel.org/all/174055075876.4079315.8805416872155957588.stgit@mhiramat.tok.corp.google.com/ Fixes: 18b1e870a496 ("tracing/probes: Add $arg* meta argument for all function args") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google)

ftrace: Avoid potential division by zero in function_stat_show()

2025-02-28T02:02:10Z

Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64} produce zero and skip stddev computation in that case. For now don't care about rec->counter * rec->counter overflow because rec->time * rec->time overflow will likely happen earlier. Cc: stable@vger.kernel.org Cc: Wen Yang Cc: Mark Rutland Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250206090156.1561783-1-kniv@yandex-team.ru Fixes: e31f7939c1c27 ("ftrace: Avoid potential division by zero in function profiler") Signed-off-by: Nikolay Kuratov Signed-off-by: Steven Rostedt (Google)

tracing: Fix bad hist from corrupting named_triggers list

2025-02-28T02:01:34Z

The following commands causes a crash: ~# cd /sys/kernel/tracing/events/rcu/rcu_callback ~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger bash: echo: write error: Invalid argument ~# echo 'hist:name=bad:keys=common_pid' > trigger Because the following occurs: event_trigger_write() { trigger_process_regex() { event_hist_trigger_parse() { data = event_trigger_alloc(..); event_trigger_register(.., data) { cmd_ops->reg(.., data, ..) [hist_register_trigger()] { data->ops->init() [event_hist_trigger_init()] { save_named_trigger(name, data) { list_add(&data->named_list, &named_triggers); } } } } ret = create_actions(); (return -EINVAL) if (ret) goto out_unreg; [..] ret = hist_trigger_enable(data, ...) { list_add_tail_rcu(&data->list, &file->triggers); <<<---- SKIPPED!!! (this is important!) [..] out_unreg: event_hist_unregister(.., data) { cmd_ops->unreg(.., data, ..) [hist_unregister_trigger()] { list_for_each_entry(iter, &file->triggers, list) { if (!hist_trigger_match(data, iter, named_data, false)) <- never matches continue; [..] test = iter; } if (test && test->ops->free) <<<-- test is NULL test->ops->free(test) [event_hist_trigger_free()] { [..] if (data->name) del_named_trigger(data) { list_del(&data->named_list); <<<<-- NEVER gets removed! } } } } [..] kfree(data); <<<-- frees item but it is still on list The next time a hist with name is registered, it causes an u-a-f bug and the kernel can crash. Move the code around such that if event_trigger_register() succeeds, the next thing called is hist_trigger_enable() which adds it to the list. A bunch of actions is called if get_named_trigger_data() returns false. But that doesn't need to be called after event_trigger_register(), so it can be moved up, allowing event_trigger_register() to be called just before hist_trigger_enable() keeping them together and allowing the file->triggers to be properly populated. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250227163944.1c37f85f@gandalf.local.home Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers") Reported-by: Tomas Glozar Tested-by: Tomas Glozar Reviewed-by: Tom Zanussi Closes: https://lore.kernel.org/all/CAP4=nvTsxjckSBTz=Oe_UYh8keD9_sZC4i++4h72mJLic4_W4A@mail.gmail.com/ Signed-off-by: Steven Rostedt (Google)

tracing: fprobe-events: Log error for exceeding the number of entry args

2025-02-27T00:11:51Z

Add error message when the number of entry argument exceeds the maximum size of entry data. This is currently checked when registering fprobe, but in this case no error message is shown in the error_log file. Link: https://lore.kernel.org/all/174055074269.4079315.17809232650360988538.stgit@mhiramat.tok.corp.google.com/ Fixes: 25f00e40ce79 ("tracing/probes: Support $argN in return probe (kprobe and fprobe)") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google)