Commit Graph

14 Commits

Author SHA1 Message Date
Linus Torvalds
fefa636d81 Updates for tracing and bootconfig:
- Add support for "bool" type in synthetic events
 
 - Add per instance tracing for bootconfig
 
 - Support perf-style return probe ("SYMBOL%return") in kprobes and uprobes
 
 - Allow for kprobes to be enabled earlier in boot up
 
 - Added tracepoint helper function to allow testing if tracepoints are
   enabled in headers
 
 - Synthetic events can now have dynamic strings (variable length)
 
 - Various fixes and cleanups
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Merge tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Updates for tracing and bootconfig:

   - Add support for "bool" type in synthetic events

   - Add per instance tracing for bootconfig

   - Support perf-style return probe ("SYMBOL%return") in kprobes and
     uprobes

   - Allow for kprobes to be enabled earlier in boot up

   - Added tracepoint helper function to allow testing if tracepoints
     are enabled in headers

   - Synthetic events can now have dynamic strings (variable length)

   - Various fixes and cleanups"

* tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (58 commits)
  tracing: support "bool" type in synthetic trace events
  selftests/ftrace: Add test case for synthetic event syntax errors
  tracing: Handle synthetic event array field type checking correctly
  selftests/ftrace: Change synthetic event name for inter-event-combined test
  tracing: Add synthetic event error logging
  tracing: Check that the synthetic event and field names are legal
  tracing: Move is_good_name() from trace_probe.h to trace.h
  tracing: Don't show dynamic string internals in synthetic event description
  tracing: Fix some typos in comments
  tracing/boot: Add ftrace.instance.*.alloc_snapshot option
  tracing: Fix race in trace_open and buffer resize call
  tracing: Check return value of __create_val_fields() before using its result
  tracing: Fix synthetic print fmt check for use of __get_str()
  tracing: Remove a pointless assignment
  ftrace: ftrace_global_list is renamed to ftrace_ops_list
  ftrace: Format variable declarations of ftrace_allocate_records
  ftrace: Simplify the calculation of page number for ftrace_page->records
  ftrace: Simplify the dyn_ftrace->flags macro
  ftrace: Simplify the hash calculation
  ftrace: Use fls() to get the bits for dup_hash()
  ...
2020-10-15 15:51:28 -07:00
Tom Zanussi
bd82631d7c tracing: Add support for dynamic strings to synthetic events
Currently, sythetic events only support static string fields such as:

  # echo 'test_latency u64 lat; char somename[32]' > /sys/kernel/debug/tracing/synthetic_events

Which is fine, but wastes a lot of space in the event.

It also prevents the most commonly-defined strings in the existing
trace events e.g. those defined using __string(), from being passed to
synthetic events via the trace() action.

With this change, synthetic events with dynamic fields can be defined:

  # echo 'test_latency u64 lat; char somename[]' > /sys/kernel/debug/tracing/synthetic_events

And the trace() action can be used to generate events using either
dynamic or static strings:

  # echo 'hist:keys=name:lat=common_timestamp.usecs-$ts0:onmatch(sys.event).test_latency($lat,name)' > /sys/kernel/debug/tracing/events

The synthetic event dynamic strings are implemented in the same way as
the existing __data_loc strings and appear as such in the format file.

[ <rostedt@goodmis.org>: added __set_synth_event_print_fmt() changes:

  I added the following to make it work with trace-cmd. Dynamic strings
  must have __get_str() for events in the print_fmt otherwise it can't be
  parsed correctly. ]

Link: https://lore.kernel.org/r/cover.1601588066.git.zanussi@kernel.org
Link: https://lkml.kernel.org/r/3ed35b6d0e390f5b94cb4a9ba1cc18f5982ab277.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 19:32:18 -04:00
Christian Brauner
eea11285da
tracing: switch to kernel_clone()
The old _do_fork() helper is removed in favor of the new kernel_clone() helper.
The latter adheres to naming conventions for kernel internal syscall helpers.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Xiao Yang <yangx.jy@cn.fujitsu.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Link: https://lore.kernel.org/r/20200819104655.436656-11-christian.brauner@ubuntu.com
2020-08-20 13:12:59 +02:00
Masanari Iida
fe4ec72cca docs: tracing: Fix typos in histogram.rst
This patch fixes some spelling typos in histogram.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-29 15:49:01 -06:00
Linus Torvalds
d2d8b14604 The major changes in this tracing update includes:
- Removing of non-DYNAMIC_FTRACE from 32bit x86
 
  - Removing of mcount support from x86
 
  - Emulating a call from int3 on x86_64, fixes live kernel patching
 
  - Consolidated Tracing Error logs file
 
 Minor updates:
 
  - Removal of klp_check_compiler_support()
 
  - kdb ftrace dumping output changes
 
  - Accessing and creating ftrace instances from inside the kernel
 
  - Clean up of #define if macro
 
  - Introduction of TRACE_EVENT_NOP() to disable trace events based on config
    options
 
 And other minor fixes and clean ups
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Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major changes in this tracing update includes:

   - Removal of non-DYNAMIC_FTRACE from 32bit x86

   - Removal of mcount support from x86

   - Emulating a call from int3 on x86_64, fixes live kernel patching

   - Consolidated Tracing Error logs file

  Minor updates:

   - Removal of klp_check_compiler_support()

   - kdb ftrace dumping output changes

   - Accessing and creating ftrace instances from inside the kernel

   - Clean up of #define if macro

   - Introduction of TRACE_EVENT_NOP() to disable trace events based on
     config options

  And other minor fixes and clean ups"

* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  x86: Hide the int3_emulate_call/jmp functions from UML
  livepatch: Remove klp_check_compiler_support()
  ftrace/x86: Remove mcount support
  ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
  tracing: Simplify "if" macro code
  tracing: Fix documentation about disabling options using trace_options
  tracing: Replace kzalloc with kcalloc
  tracing: Fix partial reading of trace event's id file
  tracing: Allow RCU to run between postponed startup tests
  tracing: Fix white space issues in parse_pred() function
  tracing: Eliminate const char[] auto variables
  ring-buffer: Fix mispelling of Calculate
  tracing: probeevent: Fix to make the type of $comm string
  tracing: probeevent: Do not accumulate on ret variable
  tracing: uprobes: Re-enable $comm support for uprobe events
  ftrace/x86_64: Emulate call function while updating in breakpoint handler
  x86_64: Allow breakpoints to emulate call instructions
  x86_64: Add gap to int3 to allow for call emulation
  tracing: kdb: Allow ftdump to skip all but the last few entries
  tracing: Add trace_total_entries() / trace_total_entries_cpu()
  ...
2019-05-15 16:05:47 -07:00
Tzvetomir Stoyanov
39a39d5b6b Documentation/trace: Add clarification how histogram onmatch works
The current trace documentation, the section describing histogram's "onmatch"
is not straightforward enough about how this action is applied. It is not
clear what criteria are used to "match" both events. A short note is added,
describing what exactly is compared in order to match the events.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[jc: fixed trivial conflict with docs-next]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08 14:32:05 -06:00
Mauro Carvalho Chehab
3df5ffd2e5 docs: trace: fix some Sphinx warnings
There are some warnings produced when building trace. Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-16 09:08:32 -06:00
Tom Zanussi
26a9449179 tracing: Add tracing/error_log Documentation
Move most of the hist trigger extended error documentation to
ftrace.rst and expand on it to fully document tracing/error_log.

Link: http://lkml.kernel.org/r/c5d53c8f643ef6844d6ad8d0200c116936730b01.1554072478.git.tom.zanussi@linux.intel.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-08 09:22:50 -04:00
Tom Zanussi
e91eefd731 tracing: Add alternative synthetic event trace action syntax
Add a 'trace(synthetic_event_name, params)' alternative to
synthetic_event_name(params).

Currently, the syntax used for generating synthetic events is to
invoke synthetic_event_name(params) i.e. use the synthetic event name
as a function call.

Users requested a new form that more explicitly shows that the
synthetic event is in effect being traced.  In this version, a new
'trace()' keyword is used, and the synthetic event name is passed in
as the first argument.

In addition, for the sake of consistency with other actions, change
the documention to emphasize the trace() form over the function-call
form, which remains documented as equivalent.

Link: http://lkml.kernel.org/r/d082773e50232a001480cf837679a1e01c1a2eb7.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
ff0d35e2e1 tracing: Add hist trigger onchange() handler Documentation
Add Documentation for the hist:onchange($var) handler.

Link: http://lkml.kernel.org/r/ab54b7383b265609fda52648a8fbfbd2631a640f.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
fd451a3d92 tracing: Add hist trigger snapshot() action Documentation
Add Documentation for the hist:handlerXXX($var).snapshot() action.

Link: http://lkml.kernel.org/r/445861d7822cd4b6aeaea1cecfcdbda466502148.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
5032b38189 tracing: Make hist trigger Documentation better reflect actions/handlers
The action/handler code refactoring didn't change the action/handler
syntax, but did generalize it - the Documentation should reflect that.

Link: http://lkml.kernel.org/r/c2fe4144678829c70cad67aaa847dca27d57cb83.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:06 -05:00
Masanari Iida
aea74de4b2 docs: Fix typos in histogram.rst
This patch fixes some spelling typos.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-18 12:33:08 -06:00
Mauro Carvalho Chehab
ea272257cc docs: histogram.txt: convert it to ReST file format
Despite being mentioned at Documentation/trace/ftrace.rst as a
rst file, this file was still a text one, with several issues.

Convert it to ReST and add it to the trace index:
- Mark the document title as such;
- Identify and indent the literal blocks;
- Use the proper markups for table.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-02 11:26:02 -06:00