linux/kernel/trace/trace.h, branch v6.3

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha

2023-02-25T20:49:29Z

Pull alpha updates from Al Viro: "Mostly small janitorial fixes but there's also more important ones: a patch to fix loading large modules from Edward Humes, and some fixes from Al Viro" [ The fixes from Al mostly came in separately through Al's trees too and are now duplicated.. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha: alpha: in_irq() cleanup alpha: lazy FPU switching alpha/boot/misc: trim unused declarations alpha/boot/tools/objstrip: fix the check for ELF header alpha/boot: fix the breakage from -isystem series... alpha: fix FEN fault handling alpha: Avoid comma separated statements alpha: fixed a typo in core_cia.c alpha: remove unused __SLOW_DOWN_IO and SLOW_DOWN_IO definitions alpha: update config files alpha: fix R_ALPHA_LITERAL reloc for large modules alpha: Add some spaces to ensure format specification alpha: replace NR_SYSCALLS by NR_syscalls alpha: Remove redundant local asm header redirections alpha: Implement "current_stack_pointer" alpha: remove redundant err variable alpha: osf_sys: reduce kernel log spamming on invalid osf_mount call typenr

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

2023-02-23T18:20:49Z

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 ...

alpha: replace NR_SYSCALLS by NR_syscalls

2023-02-14T17:37:17Z

Reference to other arch likes x86_64 or arm64 to do this replacement. To solve compile error when using NR_syscalls in kernel[1]. [1] https://lore.kernel.org/all/202203270449.WBYQF9X3-lkp@intel.com/ Signed-off-by: Yang Yang Signed-off-by: Matt Turner

tracing: Fix TASK_COMM_LEN in trace event format file

2023-02-12T15:23:39Z

After commit 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN"), the content of the format file under /sys/kernel/tracing/events/task/task_newtask was changed from field:char comm[16]; offset:12; size:16; signed:0; to field:char comm[TASK_COMM_LEN]; offset:12; size:16; signed:0; John reported that this change breaks older versions of perfetto. Then Mathieu pointed out that this behavioral change was caused by the use of __stringify(_len), which happens to work on macros, but not on enum labels. And he also gave the suggestion on how to fix it: :One possible solution to make this more robust would be to extend :struct trace_event_fields with one more field that indicates the length :of an array as an actual integer, without storing it in its stringified :form in the type, and do the formatting in f_show where it belongs. The result as follows after this change, $ cat /sys/kernel/tracing/events/task/task_newtask/format field:char comm[16]; offset:12; size:16; signed:0; Link: https://lore.kernel.org/lkml/Y+QaZtz55LIirsUO@google.com/ Link: https://lore.kernel.org/linux-trace-kernel/20230210155921.4610-1-laoar.shao@gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20230212151303.12353-1-laoar.shao@gmail.com Cc: stable@vger.kernel.org Cc: Alexei Starovoitov Cc: Kajetan Puchalski CC: Qais Yousef Fixes: 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN") Reported-by: John Stultz Debugged-by: Mathieu Desnoyers Suggested-by: Mathieu Desnoyers Suggested-by: Steven Rostedt Signed-off-by: Yafang Shao Signed-off-by: Steven Rostedt (Google)

tracing: Add enabling of events to boot instances

2023-02-07T17:49:56Z

Add the format of: trace_instance=foo,sched:sched_switch,irq_handler_entry,initcall That will create the "foo" instance and enable the sched_switch event (here were the "sched" system is explicitly specified), the irq_handler_entry event, and all events under the system initcall. Link: https://lkml.kernel.org/r/20230207173026.386114535@goodmis.org Cc: Masami Hiramatsu Cc: Andrew Morton Reviewed-by: Ross Zwisler Signed-off-by: Steven Rostedt (Google)

tracing: Allow synthetic events to pass around stacktraces

2023-01-25T15:31:24Z

Allow a stacktrace from one event to be displayed by the end event of a synthetic event. This is very useful when looking for the longest latency of a sleep or something blocked on I/O. # cd /sys/kernel/tracing/ # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 1||prev_state == 2' > events/sched/sched_switch/trigger # echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(block_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger The above creates a "block_lat" synthetic event that take the stacktrace of when a task schedules out in either the interruptible or uninterruptible states, and on a new per process max $delta (the time it was scheduled out), will print the process id and the stacktrace. # echo 1 > events/synthetic/block_lat/enable # cat trace # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | kworker/u16:0-767 [006] d..4. 560.645045: block_lat: pid=767 delta=66 stack=STACK: => __schedule => schedule => pipe_read => vfs_read => ksys_read => do_syscall_64 => 0x966000aa -0 [003] d..4. 561.132117: block_lat: pid=0 delta=413787 stack=STACK: => __schedule => schedule => schedule_hrtimeout_range_clock => do_sys_poll => __x64_sys_poll => do_syscall_64 => 0x966000aa <...>-153 [006] d..4. 562.068407: block_lat: pid=153 delta=54 stack=STACK: => __schedule => schedule => io_schedule => rq_qos_wait => wbt_wait => __rq_qos_throttle => blk_mq_submit_bio => submit_bio_noacct_nocheck => ext4_bio_write_page => mpage_submit_page => mpage_process_page_bufs => mpage_prepare_extent_to_map => ext4_do_writepages => ext4_writepages => do_writepages => __writeback_single_inode Link: https://lkml.kernel.org/r/20230117152236.010941267@goodmis.org Cc: Masami Hiramatsu Cc: Andrew Morton Cc: Tom Zanussi Cc: Ross Zwisler Cc: Ching-lin Yu Signed-off-by: Steven Rostedt (Google)

tracing: Make sure trace_printk() can output as soon as it can be used

2023-01-24T16:27:29Z

Currently trace_printk() can be used as soon as early_trace_init() is called from start_kernel(). But if a crash happens, and "ftrace_dump_on_oops" is set on the kernel command line, all you get will be: [ 0.456075] -0 0dN.2. 347519us : Unknown type 6 [ 0.456075] -0 0dN.2. 353141us : Unknown type 6 [ 0.456075] -0 0dN.2. 358684us : Unknown type 6 This is because the trace_printk() event (type 6) hasn't been registered yet. That gets done via an early_initcall(), which may be early, but not early enough. Instead of registering the trace_printk() event (and other ftrace events, which are not trace events) via an early_initcall(), have them registered at the same time that trace_printk() can be used. This way, if there is a crash before early_initcall(), then the trace_printk()s will actually be useful. Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Fixes: e725c731e3bb1 ("tracing: Split tracing initialization into two for early initialization") Reported-by: "Joel Fernandes (Google)" Tested-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (Google)

tracing: Fix some checker warnings

2022-12-10T18:36:05Z

Fix some checker warnings in the trace code by adding __printf attributes to a number of trace functions and their declarations. Changes: ======== ver #2) - Dropped the fix for the unconditional tracing_max_lat_fops decl[1]. Link: https://lore.kernel.org/r/20221205180617.9b9d3971cbe06ee536603523@kernel.org/ [1] Link: https://lore.kernel.org/r/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ # v1 Link: https://lkml.kernel.org/r/167023571258.382307.15314866482834835192.stgit@warthog.procyon.org.uk Signed-off-by: David Howells Signed-off-by: Steven Rostedt (Google)

tracing: Fix complicated dependency of CONFIG_TRACER_MAX_TRACE

2022-12-10T04:48:05Z

Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the CONFIG_TRACER_MAX_TRACE code, but that is complicated and has introduced a bug; It declares tracing_max_lat_fops data structure outside of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that declaration comes to a definition(!). To fix this issue, and do not repeat the similar problem, makes CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the CONFIG_TRACER_MAX_TRACE always. It has there benefits; - Fix the tracing_max_lat_fops bug - Simplify the #ifdefs - CONFIG_TRACER_MAX_TRACE code is fully enabled, or not. Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3 Fixes: 424b650f35c7 ("tracing: Fix missing osnoise tracer on max_latency") Cc: Daniel Bristot de Oliveira Cc: stable@vger.kernel.org Reported-by: David Howells Reported-by: kernel test robot Signed-off-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ (original thread and v1) Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@intel.com/T/#u (v1 error report) Signed-off-by: Steven Rostedt (Google)

tracing/probes: Handle system names with hyphens

2022-12-10T04:48:05Z

When creating probe names, a check is done to make sure it matches basic C standard variable naming standards. Basically, starts with alphabetic or underline, and then the rest of the characters have alpha-numeric or underline in them. But system names do not have any true naming conventions, as they are created by the TRACE_SYSTEM macro and nothing tests to see what they are. The "xhci-hcd" trace events has a '-' in the system name. When trying to attach a eprobe to one of these trace points, it fails because the system name does not follow the variable naming convention because of the hyphen, and the eprobe checks fail on this. Allow hyphens in the system name so that eprobes can attach to the "xhci-hcd" trace events. Link: https://lore.kernel.org/all/Y3eJ8GiGnEvVd8%2FN@macondo/ Link: https://lore.kernel.org/linux-trace-kernel/20221122122345.160f5077@gandalf.local.home Cc: Masami Hiramatsu Cc: stable@vger.kernel.org Fixes: 5b7a96220900e ("tracing/probe: Check event/group naming rule at parsing") Reported-by: Rafael Mendonca Signed-off-by: Steven Rostedt (Google)