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2025-12-05Merge tag 'trace-v6.19' of ↵Linus Torvalds1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Extend tracing option mask to 64 bits The trace options were defined by a 32 bit variable. This limits the tracing instances to have a total of 32 different options. As that limit has been hit, and more options are being added, increase the option mask to a 64 bit number, doubling the number of options available. As this is required for the kprobe topic branches as well as the tracing topic branch, a separate branch was created and merged into both. - Make trace_user_fault_read() available for the rest of tracing The function trace_user_fault_read() is used by trace_marker file read to allow reading user space to be done fast and without locking or allocations. Make this available so that the system call trace events can use it too. - Have system call trace events read user space values Now that the system call trace events callbacks are called in a faultable context, take advantage of this and read the user space buffers for various system calls. For example, show the path name of the openat system call instead of just showing the pointer to that path name in user space. Also show the contents of the buffer of the write system call. Several system call trace events are updated to make tracing into a light weight strace tool for all applications in the system. - Update perf system call tracing to do the same - And a config and syscall_user_buf_size file to control the size of the buffer Limit the amount of data that can be read from user space. The default size is 63 bytes but that can be expanded to 165 bytes. - Allow the persistent ring buffer to print system calls normally The persistent ring buffer prints trace events by their type and ignores the print_fmt. This is because the print_fmt may change from kernel to kernel. As the system call output is fixed by the system call ABI itself, there's no reason to limit that. This makes reading the system call events in the persistent ring buffer much nicer and easier to understand. - Add options to show text offset to function profiler The function profiler that counts the number of times a function is hit currently lists all functions by its name and offset. But this becomes ambiguous when there are several functions with the same name. Add a tracing option that changes the output to be that of '_text+offset' instead. Now a user space tool can use this information to map the '_text+offset' to the unique function it is counting. - Report bad dynamic event command If a bad command is passed to the dynamic_events file, report it properly in the error log. - Clean up tracer options Clean up the tracer option code a bit, by removing some useless code and also using switch statements instead of a series of if statements. - Have tracing options be instance specific Tracers can have their own options (function tracer, irqsoff tracer, function graph tracer, etc). But now that the same tracer can be enabled in multiple trace instances, their options are still global. The API is per instance, thus changing one affects other instances. This isn't even consistent, as the option take affect differently depending on when an tracer started in an instance. Make the options for instances only affect the instance it is changed under. - Optimize pid_list lock contention Whenever the pid_list is read, it uses a spin lock. This happens at every sched switch. Taking the lock at sched switch can be removed by instead using a seqlock counter. - Clean up the trace trigger structures The trigger code uses two different structures to implement a single tigger. This was due to trying to reuse code for the two different types of triggers (always on trigger, and count limited trigger). But by adding a single field to one structure, the other structure could be absorbed into the first structure making he code easier to understand. - Create a bulk garbage collector for trace triggers If user space has triggers for several hundreds of events and then removes them, it can take several seconds to complete. This is because each removal calls tracepoint_synchronize_unregister() that can take hundreds of milliseconds to complete. Instead, create a helper thread that will do the clean up. When a trigger is removed, it will create the kthread if it isn't already created, and then add the trigger to a llist. The kthread will take the items off the llist, call tracepoint_synchronize_unregister(), and then remove the items it took off. It will then check if there's more items to free before sleeping. This makes user space removing all these triggers to finish in less than a second. - Allow function tracing of some of the tracing infrastructure code Because the tracing code can cause recursion issues if it is traced by the function tracer the entire tracing directory disables function tracing. But not all of tracing causes issues if it is traced. Namely, the event tracing code. Add a config that enables some of the tracing code to be traced to help in debugging it. Note, when this is enabled, it does add noise to general function tracing, especially if events are enabled as well (which is a common case). - Add boot-time backup instance for persistent buffer The persistent ring buffer is used mostly for kernel crash analysis in the field. One issue is that if there's a crash, the data in the persistent ring buffer must be read before tracing can begin using it. This slows down the boot process. Once tracing starts in the persistent ring buffer, the old data must be freed and the addresses no longer match and old events can't be in the buffer with new events. Create a way to create a backup buffer that copies the persistent ring buffer at boot up. Then after a crash, the always on tracer can begin immediately as well as the normal boot process while the crash analysis tooling uses the backup buffer. After the backup buffer is finished being read, it can be removed. - Enable function graph args and return address options at the same time Currently the when reading of arguments in the function graph tracer is enabled, the option to record the parent function in the entry event can not be enabled. Update the code so that it can. - Add new struct_offset() helper macro Add a new macro that takes a pointer to a structure and a name of one of its members and it will return the offset of that member. This allows the ring buffer code to simplify the following: From: size = struct_size(entry, buf, cnt - sizeof(entry->id)); To: size = struct_offset(entry, id) + cnt; There should be other simplifications that this macro can help out with as well * tag 'trace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (42 commits) overflow: Introduce struct_offset() to get offset of member function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously tracing: Add boot-time backup of persistent ring buffer ftrace: Allow tracing of some of the tracing code tracing: Use strim() in trigger_process_regex() instead of skip_spaces() tracing: Add bulk garbage collection of freeing event_trigger_data tracing: Remove unneeded event_mutex lock in event_trigger_regex_release() tracing: Merge struct event_trigger_ops into struct event_command tracing: Remove get_trigger_ops() and add count_func() from trigger ops tracing: Show the tracer options in boot-time created instance ftrace: Avoid redundant initialization in register_ftrace_direct tracing: Remove unused variable in tracing_trace_options_show() fgraph: Make fgraph_no_sleep_time signed tracing: Convert function graph set_flags() to use a switch() statement tracing: Have function graph tracer option sleep-time be per instance tracing: Move graph-time out of function graph options tracing: Have function graph tracer option funcgraph-irqs be per instance trace/pid_list: optimize pid_list->lock contention tracing: Have function graph tracer define options per instance tracing: Have function tracer define options per instance ...
2025-11-05Documentation/trace: Specify exact priority for timerlatTomas Glozar1-6/+6
The timerlat tracer documentation mentions that threads are created with real-time priority, but does not mention which priority and scheduling class is used. Add the information so that users do not have to look it up in trace_osnoise.c. Signed-off-by: Tomas Glozar <tglozar@redhat.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20251010083338.478961-9-tglozar@redhat.com>
2025-10-28tracing: Add a config and syscall_user_buf_size file to limit amount writtenSteven Rostedt1-0/+8
When a system call that can copy user space addresses into the ring buffer, it can copy up to 511 bytes of data. This can waste precious ring buffer space if the user isn't interested in the output. Add a new file "syscall_user_buf_size" that gets initialized to a new config CONFIG_SYSCALL_BUF_SIZE_DEFAULT that defaults to 63. The config also is used to limit how much perf can read from user space. Also lower the max down to 165, as this isn't to record everything that a system call may be passing through to the kernel. 165 is more than enough. The reason for 165 is because adding one for the nul terminating byte, as well as possibly needing to append the "..." string turns it into 170 bytes. As this needs to save up to 3 arguments and 3 * 170 is 510 which fits nicely in 512 bytes (a power of 2). Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Takaya Saeki <takayas@google.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ian Rogers <irogers@google.com> Cc: Douglas Raillard <douglas.raillard@arm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Link: https://lore.kernel.org/20251028231148.260068913@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-09-18Documentation: trace: histogram: Convert ftrace docs cross-referenceBagas Sanjaya1-2/+2
In brief "Extended error information" section, details on error condition is referred to ftrace docs, which is written in :file: directive instead of a proper cross-reference. Convert it. Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250916054202.582074-7-bagasdotme@gmail.com>
2025-09-18Documentation: trace: histogram-design: Wrap introductory note in note:: ↵Bagas Sanjaya1-4/+5
directive Use Sphinx note:: directive for the introductory note at the beginning of docs, instead of aligned-text paragraph that renders as definition list. Reviewed-by: Tom Zanussi <zanussi@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250916054202.582074-6-bagasdotme@gmail.com>
2025-09-18Documentation: trace: historgram-design: Separate sched_waking histogram ↵Bagas Sanjaya1-1/+3
section heading and the following diagram Section heading for sched_waking histogram is shown as normal paragraph instead due to codeblock marker for the following diagram being in the same line as the section underline. Separate them. Fixes: daceabf1b494 ("tracing/doc: Fix ascii-art in histogram-design.rst") Reviewed-by: Tom Zanussi <zanussi@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250916054202.582074-5-bagasdotme@gmail.com>
2025-09-18Documentation: trace: histogram-design: Trim trailing vertices in diagram ↵Bagas Sanjaya1-81/+81
explanation text Diagram explanation text is supposed to be interleaved commentary between diagram parts that are spread out, but it outputs ugly in htmldocs due to trailing vertices as if both the explanation and the diagram are in the same literal code block. Trim trailing vertices. Reviewed-by: Tom Zanussi <zanussi@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250916054202.582074-4-bagasdotme@gmail.com>
2025-09-18Documentation: trace: histogram: Fix histogram trigger subsection number orderBagas Sanjaya1-17/+17
Section numbering in subsections of "Histogram Trigger Command" sections is inconsistent in order. In particular, "'hist' trigger examples" is erroneously numbered as 6.2, which is a leftover from b8df4a3634e08a ("tracing: Move hist trigger Documentation to histogram.txt"). Fix the order. Reviewed-by: Tom Zanussi <zanussi@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250916054202.582074-3-bagasdotme@gmail.com>
2025-09-03tracing: fix grammar error in debugging.rstRyan Chung1-1/+1
Signed-off-by: Ryan Chung <seokwoo.chung130@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250831101736.11519-3-seokwoo.chung130@gmail.com
2025-09-03tracing: rephrase for clearer documentationRyan Chung1-1/+1
Signed-off-by: Ryan Chung <seokwoo.chung130@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250831101736.11519-2-seokwoo.chung130@gmail.com
2025-08-21docs: Corrected typo in trace/eventsMehdi Ben Hadj Khelifa1-4/+4
-Changed 'Dyamically' to 'Dynamically' in trace/events.rst under sections 7.1 and 7.3 Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250819085040.974388-1-mehdi.benhadjkhelifa@gmail.com
2025-08-18Merge branch 'bjorn' into docs-mwJonathan Corbet4-10/+10
A big set of typo fixes from Bjorn Helgaas
2025-08-18Documentation: Fix trace typosBjorn Helgaas4-10/+10
Fix typos. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250813200526.290420-9-helgaas@kernel.org
2025-08-12Documentation/rv: Fix minor typo in monitor_synthesis pageGopi Krishna Menon1-1/+1
Specifically, fix spelling of "practice" Signed-off-by: Gopi Krishna Menon <krishnagopi487@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250810111249.93181-1-krishnagopi487@gmail.com
2025-08-01Merge tag 'trace-v6.17' of ↵Linus Torvalds2-0/+270
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing When tracefs was first introduced back in 2014, the directory /sys/kernel/tracing was added and is the designated location to mount tracefs. To keep backward compatibility, tracefs was auto-mounted in /sys/kernel/debug/tracing as well. All distros now mount tracefs on /sys/kernel/tracing. Having it seen in two different locations has lead to various issues and inconsistencies. The VFS folks have to also maintain debugfs_create_automount() for this single user. It's been over 10 years. Tooling and scripts should start replacing the debugfs location with the tracefs one. The reason tracefs was created in the first place was to allow access to the tracing facilities without the need to configure debugfs into the kernel. Using tracefs should now be more robust. A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED which is default y, so that the kernel is still built with the automount. This config allows those that want to remove the automount from debugfs to do so. When tracefs is accessed from /sys/kernel/debug/tracing, the following printk is triggerd: pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n"); This gives users another 5 years to fix their scripts. - Use queue_rcu_work() instead of call_rcu() for freeing event filters The number of filters to be free can be many depending on the number of events within an event system. Freeing them from softirq context can potentially cause undesired latency. Use the RCU workqueue to free them instead. - Remove pointless memory barriers in latency code Memory barriers were added to some of the latency code a long time ago with the idea of "making them visible", but that's not what memory barriers are for. They are to synchronize access between different variables. There was no synchronization here making them pointless. - Remove "__attribute__()" from the type field of event format When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y and PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with the following: field:const char * filename; offset:24; size:8; signed:0; Turns into: field:const char __attribute__((btf_type_tag("user"))) * filename; offset:24; size:8; signed:0; This confuses parsers. Add code to strip these tags from the strings. - Add eprobe config option CONFIG_EPROBE_EVENTS Eprobes were added back in 5.15 but were only enabled when another probe was enabled (kprobe, fprobe, uprobe, etc). The eprobes had no config option of their own. Add one as they should be a separate entity. It's default y to keep with the old kernels but still has dependencies on TRACING and HAVE_REGS_AND_STACK_ACCESS_API. - Add eprobe documentation When eprobes were added back in 5.15 no documentation was added to describe them. This needs to be rectified. - Replace open coded cpumask_next_wrap() in move_to_next_cpu() - Have preemptirq_delay_run() use off-stack CPU mask - Remove obsolete comment about pelt_cfs event DECLARE_TRACE() appends "_tp" to trace events now, but the comment above pelt_cfs still mentioned appending it manually. - Remove EVENT_FILE_FL_SOFT_MODE flag The SOFT_MODE flag was required when the soft enabling and disabling of trace events was first introduced. But there was a bug with this approach as it only worked for a single instance. When multiple users required soft disabling and disabling the code was changed to have a ref count. The SOFT_MODE flag is now set iff the ref count is non zero. This is redundant and just reading the ref count is good enough. - Fix typo in comment * tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: Documentation: tracing: Add documentation about eprobes tracing: Have eprobes have their own config option tracing: Remove "__attribute__()" from the type field of event format tracing: Deprecate auto-mounting tracefs in debugfs tracing: Fix comment in trace_module_remove_events() tracing: Remove EVENT_FILE_FL_SOFT_MODE flag tracing: Remove pointless memory barriers tracing/sched: Remove obsolete comment on suffixes kernel: trace: preemptirq_delay_test: use offstack cpu mask tracing: Use queue_rcu_work() to free filters tracing: Replace opencoded cpumask_next_wrap() in move_to_next_cpu()
2025-07-31Merge tag 'docs-6.17' of git://git.lwn.net/linuxLinus Torvalds2-3/+3
Pull documentation updates from Jonathan Corbet: "It has been a relatively busy cycle for docs, especially the build system: - The Perl kernel-doc script was added to 2.3.52pre1 just after the turn of the millennium. Over the following 25 years, it accumulated a vast amount of cruft, all in a language few people want to deal with anymore. Mauro's Python replacement in 6.16 faithfully reproduced all of the cruft in the hope of avoiding regressions. Now that we have a more reasonable code base, though, we can work on cleaning it up; many of the changes this time around are toward that end. - A reorganization of the ext4 docs into the usual TOC format. - Various Chinese translations and updates. - A new script from Mauro to help with docs-build testing. - A new document for linked lists - A sweep through MAINTAINERS fixing broken GitHub git:// repository links. ...and lots of fixes and updates" * tag 'docs-6.17' of git://git.lwn.net/linux: (147 commits) scripts: add origin commit identification based on specific patterns sphinx: kernel_abi: fix performance regression with O=<dir> Documentation: core-api: entry: Replace deprecated KVM entry/exit functions docs: fault-injection: drop reference to md-faulty docs: document linked lists scripts: kdoc: make it backward-compatible with Python 3.7 docs: kernel-doc: emit warnings for ancient versions of Python Documentation/rtla: Describe exit status Documentation/rtla: Add include common_appendix.rst docs: kernel: Clarify printk_ratelimit_burst reset behavior Documentation: ioctl-number: Don't repeat macro names Documentation: ioctl-number: Shorten macros table Documentation: ioctl-number: Correct full path to papr-physical-attestation.h Documentation: ioctl-number: Extend "Include File" column width Documentation: ioctl-number: Fix linuxppc-dev mailto link overlayfs.rst: fix typos docs: kdoc: emit a warning for ancient versions of Python docs: kdoc: clean up check_sections() docs: kdoc: directly access the always-there KdocItem fields docs: kdoc: straighten up dump_declaration() ...
2025-07-30Merge tag 'trace-rv-6.17' of ↵Linus Torvalds6-186/+810
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull runtime verification updates from Steven Rostedt: - Added Linear temporal logic monitors for RT application Real-time applications may have design flaws causing them to have unexpected latency. For example, the applications may raise page faults, or may be blocked trying to take a mutex without priority inheritance. However, while attempting to implement DA monitors for these real-time rules, deterministic automaton is found to be inappropriate as the specification language. The automaton is complicated, hard to understand, and error-prone. For these cases, linear temporal logic is found to be more suitable. The LTL is more concise and intuitive. - Make printk_deferred() public The new monitors needed access to printk_deferred(). Make them visible for the entire kernel. - Add a vpanic() to allow for va_list to be passed to panic. - Add rtapp container monitor. A collection of monitors that check for common problems with real-time applications that cause unexpected latency. - Add page fault tracepoints to risc-v These tracepoints are necessary to for the RV monitor to run on risc-v. - Fix the behaviour of the rv tool with -s and idle tasks. - Allow the rv tool to gracefully terminate with SIGTERM - Adjusts dot2c not to create lines over 100 columns - Properly order nested monitors in the RV Kconfig file - Return the registration error in all DA monitor instead of 0 - Update and add new sched collection monitors Replace tss and sncid monitors with more complete sts: Not only prove that switches occur in scheduling context and scheduling needs interrupt disabled but also that each call to the scheduler disables interrupts to (optionally) switch. New monitor: nrp Preemption requires need resched which is cleared by any switch (includes a non optimal workaround for /nested/ preemptions) New monitor: sssw suspension requires setting the task to sleepable and, after the switch occurs, the task requires a wakeup to come back to runnable New monitor: opid waking and need-resched operations occur with interrupts and preemption disabled or in IRQ without explicitly disabling preemption" * tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits) rv: Add opid per-cpu monitor rv: Add nrp and sssw per-task monitors rv: Replace tss and sncid monitors with more complete sts sched: Adapt sched tracepoints for RV task model rv: Retry when da monitor detects race conditions rv: Adjust monitor dependencies rv: Use strings in da monitors tracepoints rv: Remove trailing whitespace from tracepoint string rv: Add da_handle_start_run_event_ to per-task monitors rv: Fix wrong type cast in reactors_show() and monitor_reactor_show() rv: Fix wrong type cast in monitors_show() rv: Remove struct rv_monitor::reacting rv: Remove rv_reactor's reference counter rv: Merge struct rv_reactor_def into struct rv_reactor rv: Merge struct rv_monitor_def into struct rv_monitor rv: Remove unused field in struct rv_monitor_def rv: Return init error when registering monitors verification/rvgen: Organise Kconfig entries for nested monitors tools/dot2c: Fix generated files going over 100 column limit tools/rv: Stop gracefully also on SIGTERM ...
2025-07-30Documentation: tracing: Add documentation about eprobesSteven Rostedt2-0/+270
Eprobes was added back in 5.15, but was never documented. It became a "secret" interface even though it has been a topic of several presentations. For some reason, when eprobes was added, documenting it never became a priority, until now. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/20250730140945.528135548@kernel.org Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Add opid per-cpu monitorGabriele Monaco1-0/+55
Add a per-cpu monitor as part of the sched model: * opid: operations with preemption and irq disabled Monitor to ensure wakeup and need_resched occur with irq and preemption disabled or in irq handlers. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250728135022.255578-10-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Acked-by: Nam Cao <namcao@linutronix.de> Tested-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Add nrp and sssw per-task monitorsGabriele Monaco1-0/+167
Add 2 per-task monitors as part of the sched model: * nrp: need-resched preempts Monitor to ensure preemption requires need resched. * sssw: set state sleep and wakeup Monitor to ensure sched_set_state to sleepable leads to sleeping and sleeping tasks require wakeup. Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20250728135022.255578-9-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Acked-by: Nam Cao <namcao@linutronix.de> Tested-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Replace tss and sncid monitors with more complete stsGabriele Monaco1-39/+48
The tss monitor currently guarantees task switches can happen only while scheduling, whereas the sncid monitor enforces scheduling occurs with interrupt disabled. Replace the monitors with a more comprehensive specification which implies both but also ensures that: * each scheduler call disable interrupts to switch * each task switch happens with interrupts disabled Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nam Cao <namcao@linutronix.de> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20250728135022.255578-8-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Support the 'next' operatorNam Cao1-0/+1
The 'next' operator is a unary operator. It is defined as: "next time, the operand must be true". Support this operator. For RV monitors, "next time" means the next invocation of ltl_validate(). Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/9c32cec04dd18d2e956fddd84b0e0a2503daa75a.1752239482.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Tested-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24Documentation/rv: Add documentation for linear temporal logic monitorsNam Cao3-16/+274
Add documents describing linear temporal logic runtime verification monitors and how to generate them using rvgen. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/be13719e66fd8da147d7c69d5365aa23c52b743f.1751634289.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24Documentation/rv: Prepare monitor synthesis document for LTL inclusionNam Cao2-11/+11
Monitor synthesis from deterministic automaton and linear temporal logic have a lot in common. Therefore a single document should describe both. Change da_monitor_synthesis.rst to monitor_synthesis.rst. LTL monitor synthesis will be added to this file by a follow-up commit. This makes the diff far easier to read. If renaming and adding LTL info is done in a single commit, git wouldn't recognize it as a rename, but a file removal and a file addition. While at it, correct the old dot2k commands to the new rvgen commands. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/d91c6e4600287f4732d68a014219e576a75ce6dc.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-22tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORDSteven Rostedt1-8/+4
Ftrace is tightly coupled with architecture specific code because it requires the use of trampolines written in assembly. This means that when a new feature or optimization is made, it must be done for all architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are added to denote which architecture has the new enhancement so that other architectures can still function until they too have been updated. The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the DYNAMIC_FTRACE work, but now every architecture that implements DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant with the HAVE_DYNAMIC_FTRACE. Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where applicable. Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add documentation for rtapp monitorNam Cao2-0/+134
Add documentation describing the rtapp monitor. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/df0242d74c12511e82cc9d73c082def91a160c74.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-08tracing: doc: fix "for a while" typoAhelenia Ziemiańska1-1/+1
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/xygdnynf7m55p7d27ovzqtdjaa7pua3bxuk5c22cnmoovaji5e@tarta.nabijaczleweli.xyz
2025-06-09docs: trace: boottime-trace.rst: fix typoRunji Liu1-2/+2
Replace misspelled "eariler" with "earlier" and drop the stray period after "example". Signed-off-by: Runji Liu <runjiliu.tech@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250526134046.1042-1-runjiliu.tech@gmail.com
2025-06-06Merge tag 'char-misc-6.16-rc1' of ↵Linus Torvalds1-0/+31
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / iio driver updates from Greg KH: "Here is the big char/misc/iio and other small driver subsystem pull request for 6.16-rc1. Overall, a lot of individual changes, but nothing major, just the normal constant forward progress of new device support and cleanups to existing subsystems. Highlights in here are: - Large IIO driver updates and additions and device tree changes - Android binder bugfixes and logfile fixes - mhi driver updates - comedi driver updates - counter driver updates and additions - coresight driver updates and additions - echo driver removal as there are no in-kernel users of it - nvmem driver updates - spmi driver updates - new amd-sbi driver "subsystem" and drivers added - rust miscdriver binding documentation fix - other small driver fixes and updates (uio, w1, acrn, hpet, xillybus, cardreader drivers, fastrpc and others) All of these have been in linux-next for quite a while with no reported problems" * tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (390 commits) binder: fix yet another UAF in binder_devices counter: microchip-tcb-capture: Add watch validation support dt-bindings: iio: adc: Add ROHM BD79100G iio: adc: add support for Nuvoton NCT7201 dt-bindings: iio: adc: add NCT7201 ADCs iio: chemical: Add driver for SEN0322 dt-bindings: trivial-devices: Document SEN0322 iio: adc: ad7768-1: reorganize driver headers iio: bmp280: zero-init buffer iio: ssp_sensors: optimalize -> optimize HID: sensor-hub: Fix typo and improve documentation iio: admv1013: replace redundant ternary operator with just len iio: chemical: mhz19b: Fix error code in probe() iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros iio: make IIO_DMA_MINALIGN minimum of 8 bytes ...
2025-05-29Merge tag 'trace-v6.16' of ↵Linus Torvalds2-6/+24
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Have module addresses get updated in the persistent ring buffer The addresses of the modules from the previous boot are saved in the persistent ring buffer. If the same modules are loaded and an address is in the old buffer points to an address that was both saved in the persistent ring buffer and is loaded in memory, shift the address to point to the address that is loaded in memory in the trace event. - Print function names for irqs off and preempt off callsites When ignoring the print fmt of a trace event and just printing the fields directly, have the fields for preempt off and irqs off events still show the function name (via kallsyms) instead of just showing the raw address. - Clean ups of the histogram code The histogram functions saved over 800 bytes on the stack to process events as they come in. Instead, create per-cpu buffers that can hold this information and have a separate location for each context level (thread, softirq, IRQ and NMI). Also add some more comments to the code. - Add "common_comm" field for histograms Add "common_comm" that uses the current->comm as a field in an event histogram and acts like any of the other fields of the event. - Show "subops" in the enabled_functions file When the function graph infrastructure is used, a subsystem has a "subops" that it attaches its callback function to. Instead of the enabled_functions just showing a function calling the function that calls the subops functions, also show the subops functions that will get called for that function too. - Add "copy_trace_marker" option to instances There are cases where an instance is created for tooling to write into, but the old tooling has the top level instance hardcoded into the application. New tools want to consume the data from an instance and not the top level buffer. By adding a copy_trace_marker option, whenever the top instance trace_marker is written into, a copy of it is also written into the instance with this option set. This allows new tools to read what old tools are writing into the top buffer. If this option is cleared by the top instance, then what is written into the trace_marker is not written into the top instance. This is a way to redirect the trace_marker writes into another instance. - Have tracepoints created by DECLARE_TRACE() use trace_<name>_tp() If a tracepoint is created by DECLARE_TRACE() instead of TRACE_EVENT(), then it will not be exposed via tracefs. Currently there's no way to differentiate in the kernel the tracepoint functions between those that are exposed via tracefs or not. A calling convention has been made manually to append a "_tp" prefix for events created by DECLARE_TRACE(). Instead of doing this manually, force it so that all DECLARE_TRACE() events have this notation. - Use __string() for task->comm in some sched events Instead of hardcoding the comm to be TASK_COMM_LEN in some of the scheduler events use __string() which makes it dynamic. Note, if these events are parsed by user space it they may break, and the event may have to be converted back to the hardcoded size. - Have function graph "depth" be unsigned to the user Internally to the kernel, the "depth" field of the function graph event is signed due to -1 being used for end of boundary. What actually gets recorded in the event itself is zero or positive. Reflect this to user space by showing "depth" as unsigned int and be consistent across all events. - Allow an arbitrary long CPU string to osnoise_cpus_write() The filtering of which CPUs to write to can exceed 256 bytes. If a machine has 256 CPUs, and the filter is to filter every other CPU, the write would take a string larger than 256 bytes. Instead of using a fixed size buffer on the stack that is 256 bytes, allocate it to handle what is passed in. - Stop having ftrace check the per-cpu data "disabled" flag The "disabled" flag in the data structure passed to most ftrace functions is checked to know if tracing has been disabled or not. This flag was added back in 2008 before the ring buffer had its own way to disable tracing. The "disable" flag is now not always set when needed, and the ring buffer flag should be used in all locations where the disabled is needed. Since the "disable" flag is redundant and incorrect, stop using it. Fix up some locations that use the "disable" flag to use the ring buffer info. - Use a new tracer_tracing_disable/enable() instead of data->disable flag There's a few cases that set the data->disable flag to stop tracing, but this flag is not consistently used. It is also an on/off switch where if a function set it and calls another function that sets it, the called function may incorrectly enable it. Use a new trace_tracing_disable() and tracer_tracing_enable() that uses a counter and can be nested. These use the ring buffer flags which are always checked making the disabling more consistent. - Save the trace clock in the persistent ring buffer Save what clock was used for tracing in the persistent ring buffer and set it back to that clock after a reboot. - Remove unused reference to a per CPU data pointer in mmiotrace functions - Remove unused buffer_page field from trace_array_cpu structure - Remove more strncpy() instances - Other minor clean ups and fixes * tag 'trace-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (36 commits) tracing: Fix compilation warning on arm32 tracing: Record trace_clock and recover when reboot tracing/sched: Use __string() instead of fixed lengths for task->comm tracepoint: Have tracepoints created with DECLARE_TRACE() have _tp suffix tracing: Cleanup upper_empty() in pid_list tracing: Allow the top level trace_marker to write into another instances tracing: Add a helper function to handle the dereference arg in verifier tracing: Remove unnecessary "goto out" that simply returns ret is trigger code tracing: Fix error handling in event_trigger_parse() tracing: Rename event_trigger_alloc() to trigger_data_alloc() tracing: Replace deprecated strncpy() with strscpy() for stack_trace_filter_buf tracing: Remove unused buffer_page field from trace_array_cpu structure tracing: Use atomic_inc_return() for updating "disabled" counter in irqsoff tracer tracing: Convert the per CPU "disabled" counter to local from atomic tracing: branch: Use trace_tracing_is_on_cpu() instead of "disabled" field ring-buffer: Add ring_buffer_record_is_on_cpu() tracing: Do not use per CPU array_buffer.data->disabled for cpumask ftrace: Do not disabled function graph based on "disabled" field tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled tracing: Use tracer_tracing_disable() instead of "disabled" field for ftrace_dump_one() ...
2025-05-19docs: fix "incase" typo in coresight/panic.rstHendrik Hamerlinck1-2/+2
Corrects a spelling mistake in Documentation/trace/coresight/panic.rst where "incase" was used instead of "in case". Signed-off-by: Hendrik Hamerlinck <hendrik.hamerlinck@hammernet.be> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20250513110931.15072-1-hendrik.hamerlinck@hammernet.be>
2025-05-14tracepoint: Have tracepoints created with DECLARE_TRACE() have _tp suffixSteven Rostedt1-6/+11
Most tracepoints in the kernel are created with TRACE_EVENT(). The TRACE_EVENT() macro (and DECLARE_EVENT_CLASS() and DEFINE_EVENT() where in reality, TRACE_EVENT() is just a helper macro that calls those other two macros), will create not only a tracepoint (the function trace_<event>() used in the kernel), it also exposes the tracepoint to user space along with defining what fields will be saved by that tracepoint. There are a few places that tracepoints are created in the kernel that are not exposed to userspace via tracefs. They can only be accessed from code within the kernel. These tracepoints are created with DEFINE_TRACE() Most of these tracepoints end with "_tp". This is useful as when the developer sees that, they know that the tracepoint is for in-kernel only (meaning it can only be accessed inside the kernel, either directly by the kernel or indirectly via modules and BPF programs) and is not exposed to user space. Instead of making this only a process to add "_tp", enforce it by making the DECLARE_TRACE() append the "_tp" suffix to the tracepoint. This requires adding DECLARE_TRACE_EVENT() macros for the TRACE_EVENT() macro to use that keeps the original name. Link: https://lore.kernel.org/all/20250418083351.20a60e64@gandalf.local.home/ Cc: netdev <netdev@vger.kernel.org> Cc: Jiri Olsa <olsajiri@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@kernel.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/20250510163730.092fad5b@gandalf.local.home Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-05-14Documentation: coresight: Document AUX pause and resumeLeo Yan1-0/+31
This adds description for AUX pause and resume. It gives introduction for what's AUX pause and resume and records usage examples. Signed-off-by: Leo Yan <leo.yan@arm.com> Reviewed-by: James Clark <james.clark@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20250401180708.385396-8-leo.yan@arm.com
2025-05-09tracing: Allow the top level trace_marker to write into another instancesSteven Rostedt1-0/+13
There are applications that have it hard coded to write into the top level trace_marker instance (/sys/kernel/tracing/trace_marker). This can be annoying if a profiler is using that instance for other work, or if it needs all writes to go into a new instance. A new option is created called "copy_trace_marker". By default, the top level has this set, as that is the default buffer that writing into the top level trace_marker file will go to. But now if an instance is created and sets this option, all writes into the top level trace_marker will also be written into that instance buffer just as if an application were to write into the instanc