kernel/linux.git/include/linux/tracepoint.h, branch v6.12.80

tracepoint: Support iterating tracepoints in a loading module

2024-09-25T14:23:44+00:00

Add for_each_tracepoint_in_module() function to iterate tracepoints in a module. This API is needed for handling tracepoints in a loading module from tracepoint_module_notifier callback function. This also update for_each_module_tracepoint() to pass the module to callback function so that it can find module easily. Link: https://lore.kernel.org/all/172397778740.286558.15781131277732977643.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google)

tracepoint: Support iterating over tracepoints on modules

2024-09-25T14:23:44+00:00

Add for_each_module_tracepoint() for iterating over tracepoints on modules. This is similar to the for_each_kernel_tracepoint() but only for the tracepoints on modules (not including kernel built-in tracepoints). Link: https://lore.kernel.org/all/172397777800.286558.14554748203446214056.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google)

cpumask: cleanup core headers inclusion

2024-06-25T05:25:02+00:00

Many core headers include cpumask.h for nothing. Drop it. Link: https://lkml.kernel.org/r/20240528005648.182376-6-yury.norov@gmail.com Signed-off-by: Yury Norov Cc: Amit Daniel Kachhap Cc: Anna-Maria Behnsen Cc: Christoph Lameter Cc: Daniel Lezcano Cc: Dennis Zhou Cc: Frederic Weisbecker Cc: Johannes Weiner Cc: Juri Lelli Cc: Kees Cook Cc: Mathieu Desnoyers Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Rasmus Villemoes Cc: Tejun Heo Cc: Thomas Gleixner Cc: Ulf Hansson Cc: Vincent Guittot Cc: Viresh Kumar Cc: Yury Norov Signed-off-by: Andrew Morton

tracepoints: Use WARN() and not WARN_ON() for warnings

2024-03-18T14:33:06+00:00

There are two WARN_ON*() warnings in tracepoint.h that deal with RCU usage. But when they trigger, especially from using a TRACE_EVENT() macro, the information is not very helpful and is confusing: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at include/trace/events/lock.h:24 lock_acquire+0x2b2/0x2d0 Where the above warning takes you to: TRACE_EVENT(lock_acquire, <<<--- line 24 in lock.h TP_PROTO(struct lockdep_map *lock, unsigned int subclass, int trylock, int read, int check, struct lockdep_map *next_lock, unsigned long ip), [..] Change the WARN_ON_ONCE() to WARN_ONCE() and add a string that allows someone to search for exactly where the bug happened. Link: https://lore.kernel.org/linux-trace-kernel/20240228133112.0d64fb1b@gandalf.local.home Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Thomas Gleixner Reported-by: Borislav Petkov Tested-by: Borislav Petkov (AMD) Reviewed-by: Paul E. McKenney Signed-off-by: Steven Rostedt (Google)

tracing/probes: Add tracepoint support on fprobe_events

2023-06-06T12:39:55+00:00

Allow fprobe_events to trace raw tracepoints so that user can trace tracepoints which don't have traceevent wrappers. This new event is always available if the fprobe_events is enabled (thus no kconfig), because the fprobe_events depends on the trace-event and traceporint. e.g. # echo 't sched_overutilized_tp' >> dynamic_events # echo 't 9p_client_req' >> dynamic_events # cat dynamic_events t:tracepoints/sched_overutilized_tp sched_overutilized_tp t:tracepoints/_9p_client_req 9p_client_req The event name is based on the tracepoint name, but if it is started with digit character, an underscore '_' will be added. NOTE: to avoid further confusion, this renames TPARG_FL_TPOINT to TPARG_FL_TEVENT because this flag is used for eprobe (trace-event probe). And reuse TPARG_FL_TPOINT for this raw tracepoint probe. Link: https://lore.kernel.org/all/168507471874.913472.17214624519622959593.stgit@mhiramat.roam.corp.google.com/ Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202305020453.afTJ3VVp-lkp@intel.com/ Signed-off-by: Masami Hiramatsu (Google)

Merge tag 'trace-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-03-15T00:07:54+00:00

Pull tracing fixes from Steven Rostedt: - Do not allow histogram values to have modifies. They can cause a NULL pointer dereference if they do. - Warn if hist_field_name() is passed a NULL. Prevent the NULL pointer dereference mentioned above. - Fix invalid address look up race in lookup_rec() - Define ftrace_stub_graph conditionally to prevent linker errors - Always check if RCU is watching at all tracepoint locations * tag 'trace-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Make tracepoint lockdep check actually test something ftrace,kcfi: Define ftrace_stub_graph conditionally ftrace: Fix invalid address access in lookup_rec() when index is 0 tracing: Check field value in hist_field_name() tracing: Do not let histogram values have some modifiers

tracing: Make tracepoint lockdep check actually test something

2023-03-14T21:50:09+00:00

A while ago where the trace events had the following: rcu_read_lock_sched_notrace(); rcu_dereference_sched(...); rcu_read_unlock_sched_notrace(); If the tracepoint is enabled, it could trigger RCU issues if called in the wrong place. And this warning was only triggered if lockdep was enabled. If the tracepoint was never enabled with lockdep, the bug would not be caught. To handle this, the above sequence was done when lockdep was enabled regardless if the tracepoint was enabled or not (although the always enabled code really didn't do anything, it would still trigger a warning). But a lot has changed since that lockdep code was added. One is, that sequence no longer triggers any warning. Another is, the tracepoint when enabled doesn't even do that sequence anymore. The main check we care about today is whether RCU is "watching" or not. So if lockdep is enabled, always check if rcu_is_watching() which will trigger a warning if it is not (tracepoints require RCU to be watching). Note, that old sequence did add a bit of overhead when lockdep was enabled, and with the latest kernel updates, would cause the system to slow down enough to trigger kernel "stalled" warnings. Link: http://lore.kernel.org/lkml/20140806181801.GA4605@redhat.com Link: http://lore.kernel.org/lkml/20140807175204.C257CAC5@viggo.jf.intel.com Link: https://lore.kernel.org/lkml/20230307184645.521db5c9@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20230310172856.77406446@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Dave Hansen Cc: "Paul E. McKenney" Cc: Mathieu Desnoyers Cc: Joel Fernandes Acked-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Fixes: e6753f23d961 ("tracepoint: Make rcuidle tracepoint callers use SRCU") Signed-off-by: Steven Rostedt (Google)

Merge tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-02-23T18:20:49+00:00

Pull tracing updates from Steven Rostedt: - Add function names as a way to filter function addresses - Add sample module to test ftrace ops and dynamic trampolines - Allow stack traces to be passed from beginning event to end event for synthetic events. This will allow seeing the stack trace of when a task is scheduled out and recorded when it gets scheduled back in. - Add trace event helper __get_buf() to use as a temporary buffer when printing out trace event output. - Add kernel command line to create trace instances on boot up. - Add enabling of events to instances created at boot up. - Add trace_array_puts() to write into instances. - Allow boot instances to take a snapshot at the end of boot up. - Allow live patch modules to include trace events - Minor fixes and clean ups * tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits) tracing: Remove unnecessary NULL assignment tracepoint: Allow livepatch module add trace event tracing: Always use canonical ftrace path tracing/histogram: Fix stacktrace histogram Documententation tracing/histogram: Fix stacktrace key tracing/histogram: Fix a few problems with stacktrace variable printing tracing: Add BUILD_BUG() to make sure stacktrace fits in strings tracing/histogram: Don't use strlen to find length of stacktrace variables tracing: Allow boot instances to have snapshot buffers tracing: Add trace_array_puts() to write into instance tracing: Add enabling of events to boot instances tracing: Add creation of instances at boot command line tracing: Fix trace_event_raw_event_synth() if else statement samples: ftrace: Make some global variables static ftrace: sample: avoid open-coded 64-bit division samples: ftrace: Include the nospec-branch.h only for x86 tracing: Acquire buffer from temparary trace sequence tracing/histogram: Wrap remaining shell snippets in code blocks tracing/osnoise: No need for schedule_hrtimeout range bpf/tracing: Use stage6 of tracing to not duplicate macros ...

tracing: Always use canonical ftrace path

2023-02-18T19:34:09+00:00

The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and Kconfig help messages in the tracing code still refer to this older debugfs path, so let's update them to avoid confusion. Link: https://lore.kernel.org/linux-trace-kernel/20230215223350.2658616-2-zwisler@google.com Acked-by: Masami Hiramatsu (Google) Reviewed-by: Mukesh Ojha Signed-off-by: Ross Zwisler Signed-off-by: Steven Rostedt (Google)

tracing: WARN on rcuidle

2023-01-13T10:48:16+00:00

ARCH_WANTS_NO_INSTR (a superset of CONFIG_GENERIC_ENTRY) disallows any and all tracing when RCU isn't enabled. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195541.416110581@infradead.org