Commit Graph

1029886 Commits

Author SHA1 Message Date
Masami Hiramatsu
5dfe50b055 bootconfig: Rename xbc_node_find_child() to xbc_node_find_subkey()
Rename xbc_node_find_child() to xbc_node_find_subkey() for
clarifying that function returns a key node (no value node).
Since there are xbc_node_for_each_child() (loop on all child
nodes) and xbc_node_for_each_subkey() (loop on only subkey
nodes), this name distinction is necessary to avoid confusing
users.

Link: https://lkml.kernel.org/r/163119459826.161018.11200274779483115300.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-09 19:14:33 -04:00
Masami Hiramatsu
5f8895b27d tracing/boot: Fix to check the histogram control param is a leaf node
Since xbc_node_find_child() doesn't ensure the returned node
is a leaf node (key-value pair or do not have subkeys),
use xbc_node_find_value to ensure the histogram control
parameter is a leaf node in trace_boot_compose_hist_cmd().

Link: https://lkml.kernel.org/r/163119459059.161018.18341288218424528962.stgit@devnote2

Fixes: e66ed86ca6 ("tracing/boot: Add per-event histogram action options")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-09 19:14:33 -04:00
Masami Hiramatsu
a3928f877e tracing/boot: Fix trace_boot_hist_add_array() to check array is value
trace_boot_hist_add_array() uses the combination of
xbc_node_find_child() and xbc_node_get_child() to get the
child node of the key node. But since it missed to check
the child node is data node or not, user can pass the
subkey node for the array node (anode).
To avoid this issue, check the array node is a data node.
Actually, there is xbc_node_find_value(node, key, vnode),
which ensures the @vnode is a value node, so use it in
trace_boot_hist_add_array() to fix this issue.

Link: https://lkml.kernel.org/r/163119458308.161018.1516455973625940212.stgit@devnote2

Fixes: e66ed86ca6 ("tracing/boot: Add per-event histogram action options")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-09 19:14:33 -04:00
Masami Hiramatsu
cfd799837d tracing/boot: Fix to loop on only subkeys
Since the commit e5efaeb8a8 ("bootconfig: Support mixing
a value and subkeys under a key") allows to co-exist a value
node and key nodes under a node, xbc_node_for_each_child()
is not only returning key node but also a value node.
In the boot-time tracing using xbc_node_for_each_child() to
iterate the events, groups and instances, but those must be
key nodes. Thus it must use xbc_node_for_each_subkey().

Link: https://lkml.kernel.org/r/163112988361.74896.2267026262061819145.stgit@devnote2

Fixes: e5efaeb8a8 ("bootconfig: Support mixing a value and subkeys under a key")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:44:32 -04:00
Steven Rostedt (VMware)
04178ea130 selftests/ftrace: Exclude "(fault)" in testing add/remove eprobe events
The original test for adding and removing eprobes used synthetic events
and retrieved the filename from the open system call at the end of the
system call. This would allow it to always be loaded into the page tables
when accessed.

Masami suggested that the test was too complex for just testing add and
remove, so it was changed to test just adding and removing an event probe
on top of the start of the open system call event. Now it is possible that
the filename will not be loaded into memory at the time the eprobe is
triggered, and will result in "(fault)" being displayed in the event. This
causes the test to fail.

Account for "(fault)" also being one of the values of the filename field
of the event probe.

Link: https://lkml.kernel.org/r/20210907230429.5783d519@rorschach.local.home

Fixes: 079db70794 ("selftests/ftrace: Add test case to test adding and removing of event probe")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:29:16 -04:00
Tom Zanussi
c910db943d tracing: Dynamically allocate the per-elt hist_elt_data array
Setting the hist_elt_data.field_var_str[] array unconditionally to a
size of SYNTH_FIELD_MAX elements wastes space unnecessarily.  The
actual number of elements needed can be calculated at run-time
instead.

In most cases, this will save a lot of space since it's a per-elt
array which isn't normally close to being full.  It also allows us to
increase SYNTH_FIELD_MAX without worrying about even more wastage when
we do that.

Link: https://lkml.kernel.org/r/d52ae0ad5e1b59af7c4f54faf3fc098461fd82b3.camel@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:29:16 -04:00
Artem Bityutskiy
0be083cee4 tracing: synth events: increase max fields count
Sometimes it is useful to construct larger synthetic trace events. Increase
'SYNTH_FIELDS_MAX' (maximum number of fields in a synthetic event) from 32 to
64.

Link: https://lkml.kernel.org/r/20210901135513.3087062-1-dedekind1@gmail.com

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:29:16 -04:00
Masami Hiramatsu
47914d4e59 tools/bootconfig: Show whole test command for each test case
Show whole test command instead of only the 3rd argument.
This will clear to show what will be actually tested by
each test case.

Link: https://lkml.kernel.org/r/163077088607.222577.14786016266462495017.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:29:16 -04:00
Julio Faracco
903bd067fa bootconfig: Fix missing return check of xbc_node_compose_key function
The function `xbc_show_list should` handle the keys during the
composition. Even the errors returned by the compose function. Instead
of removing the `ret` variable, it should save the value and show the
exact error. This missing variable is causing a compilation issue also.

Link: https://lkml.kernel.org/r/163077087861.222577.12884543474750968146.stgit@devnote2

Fixes: e5efaeb8a8 ("bootconfig: Support mixing a value and subkeys under a key")
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:28:50 -04:00
Masami Hiramatsu
32ba9f0fb0 tools/bootconfig: Fix tracing_on option checking in ftrace2bconf.sh
Since tracing_on indicates only "1" (default) or "0", ftrace2bconf.sh
only need to check the value is "0".

Link: https://lkml.kernel.org/r/163077087144.222577.6888011847727968737.stgit@devnote2

Fixes: 55ed456077 ("tools/bootconfig: Add tracing_on support to helper scripts")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:10:41 -04:00
Masami Hiramatsu
26c9c72fd0 docs: bootconfig: Add how to use bootconfig for kernel parameters
Add a section to describe how to use the bootconfig for
specifying kernel and init parameters. This is an important
section because it is the reason why this document is under
the admin-guide.

Link: https://lkml.kernel.org/r/163077086399.222577.5881779375643977991.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:10:41 -04:00
Masami Hiramatsu
b66fbbe8d4 init/bootconfig: Reorder init parameter from bootconfig and cmdline
Reorder the init parameters from bootconfig and kernel cmdline
so that the kernel cmdline always be the last part of the
parameters as below.

 " -- "[bootconfig init params][cmdline init params]

This change will help us to prevent that bootconfig init params
overwrite the init params which user gives in the command line.

Link: https://lkml.kernel.org/r/163077085675.222577.5665176468023636160.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:10:41 -04:00
Masami Hiramatsu
40caa127f3 init: bootconfig: Remove all bootconfig data when the init memory is removed
Since the bootconfig is used only in the init functions,
it doesn't need to keep the data after boot. Free it when
the init memory is removed.

Link: https://lkml.kernel.org/r/163077084958.222577.5924961258513004428.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:10:41 -04:00
Qiang.Zhang
4b6b08f2e4 tracing/osnoise: Fix missed cpus_read_unlock() in start_per_cpu_kthreads()
When start_kthread() return error, the cpus_read_unlock() need
to be called.

Link: https://lkml.kernel.org/r/20210831022919.27630-1-qiang.zhang@windriver.com

Cc: <stable@vger.kernel.org>
Fixes: c8895e271f ("trace/osnoise: Support hotplug operations")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Qiang.Zhang <qiang.zhang@windriver.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-08 15:10:24 -04:00
Dan Carpenter
5615e088b4 tracing: Fix some alloc_event_probe() error handling bugs
There are two bugs in this code.  First, if the kzalloc() fails it leads
to a NULL dereference of "ep" on the next line.  Second, if the
alloc_event_probe() function returns an error then it leads to an
error pointer dereference in the caller.

Link: https://lkml.kernel.org/r/20210824115150.GI31143@kili

Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-07 20:58:23 -04:00
Thomas Gleixner
54357f0c91 tracing: Add migrate-disabled counter to tracing output.
migrate_disable() forbids task migration to another CPU. It is available
since v5.11 and has already users such as highmem or BPF. It is useful
to observe this task state in tracing which already has other states
like the preemption counter.

Instead of adding the migrate disable counter as a new entry to struct
trace_entry, which would extend the whole struct by four bytes, it is
squashed into the preempt-disable counter. The lower four bits represent
the preemption counter, the upper four bits represent the migrate
disable counter. Both counter shouldn't exceed 15 but if they do, there
is a safety net which caps the value at 15.

Add the migrate-disable counter to the trace entry so it shows up in the
trace. Due to the users mentioned above, it is already possible to
observe it:

|  bash-1108    [000] ...21    73.950578: rss_stat: mm_id=2213312838 curr=0 type=MM_ANONPAGES size=8192B
|  bash-1108    [000] d..31    73.951222: irq_disable: caller=flush_tlb_mm_range+0x115/0x130 parent=ptep_clear_flush+0x42/0x50
|  bash-1108    [000] d..31    73.951222: tlb_flush: pages:1 reason:local mm shootdown (3)

The last value is the migrate-disable counter.

Things that popped up:
- trace_print_lat_context() does not print the migrate counter. Not sure
  if it should. It is used in "verbose" mode and uses 8 digits and I'm
  not sure ther is something processing the value.

- trace_define_common_fields() now defines a different variable. This
  probably breaks things. No ide what to do in order to preserve the old
  behaviour. Since this is used as a filter it should be split somehow
  to be able to match both nibbles here.

Link: https://lkml.kernel.org/r/20210810132625.ylssabmsrkygokuv@linutronix.de

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: patch description.]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ SDR: Removed change to common_preempt_count field name ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-03 19:42:35 -04:00
Steven Rostedt (VMware)
4420f5b1be tracing/doc: Fix table format in histogram code
The addition of the buckets conversion for the histogram code, updated the
documentation table of available conversions, but did not update the format
to accommodate the extra size needed to cover the description.

Link: https://lkml.kernel.org/r/20210823100007.71ce2ba9@oasis.local.home

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-24 09:48:34 -04:00
Steven Rostedt (VMware)
297e1dcdca selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes
Add a selftest that makes sure that eprobes and kprobes can not be created
with the same group and name as existing events.

Link: https://lore.kernel.org/linux-kselftest/20210819152825.715290342@goodmis.org/
Link: https://lkml.kernel.org/r/20210820204742.653288346@goodmis.org

Cc: "Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-21 10:25:52 -04:00
Steven Rostedt (VMware)
8f022d3a76 selftests/ftrace: Add selftest for testing eprobe events on synthetic events
Add a test to test event probes, by creating a synthetic event across
sys_enter_openat and sys_exit_openat that passes the filename pointer from
the enter of the system call to the exit, and then add an event probe to
the synthetic event to make sure that the file name is seen.

Link: https://lore.kernel.org/linux-kselftest/20210819152825.526931866@goodmis.org/
Link: https://lkml.kernel.org/r/20210820204742.463259900@goodmis.org

Cc: "Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-21 10:25:34 -04:00
Steven Rostedt (VMware)
079db70794 selftests/ftrace: Add test case to test adding and removing of event probe
Add a test case that adds an event probe, makes sure that it works, and
then removes it.

Link: https://lore.kernel.org/linux-kselftest/20210819152825.526931866@goodmis.org/
Link: https://lkml.kernel.org/r/20210820204742.274591200@goodmis.org

Cc: "Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-21 10:25:19 -04:00
Steven Rostedt (VMware)
210f9df026 selftests/ftrace: Fix requirement check of README file
The selftest for ftrace checks some features by checking if the README has
text that states the feature is supported by that kernel. Unfortunately,
this check gives false positives because it many not be checked if there's
spaces in the string to check. This is due to the compare between the
required variable with the ":README" string stripped, because neither has
quotes around them.

Link: https://lkml.kernel.org/r/20210820204742.087177341@goodmis.org

Cc: "Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 1b8eec510b ("selftests/ftrace: Support ":README" suffix for requires")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-21 10:25:00 -04:00
Steven Rostedt (VMware)
aaac2820a3 selftests/ftrace: Add clear_dynamic_events() to test cases
Add a function to remove all dynamic events from the tracing directory. It
requires a loop as some of the dynamic events may depend on others being
removed first. Also add a safety that prevents it from looping infinitely
due to a bug where an event never gets removed.

Link: https://lkml.kernel.org/r/20210819152825.348941368@goodmis.org

Cc: "Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-20 14:19:27 -04:00
Tzvetomir Stoyanov (VMware)
7491e2c442 tracing: Add a probe that attaches to trace events
A new dynamic event is introduced: event probe. The event is attached
to an existing tracepoint and uses its fields as arguments. The user
can specify custom format string of the new event, select what tracepoint
arguments will be printed and how to print them.
An event probe is created by writing configuration string in
'dynamic_events' ftrace file:
 e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS]	- Set an event probe
 -:SNAME/ENAME					- Delete an event probe

Where:
 SNAME	- System name, if omitted 'eprobes' is used.
 ENAME	- Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used.
 SYSTEM	- Name of the system, where the tracepoint is defined, mandatory.
 EVENT	- Name of the tracepoint event in SYSTEM, mandatory.
 FETCHARGS - Arguments:
  <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print
			   it as given TYPE with given name. Supported
			   types are:
	                    (u8/u16/u32/u64/s8/s16/s32/s64), basic type
        	            (x8/x16/x32/x64), hexadecimal types
			    "string", "ustring" and bitfield.

Example, attach an event probe on openat system call and print name of the
file that will be opened:
 echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events
A new dynamic event is created in events/esys/eopen/ directory. It
can be deleted with:
 echo "-:esys/eopen" >> dynamic_events

Filters, triggers and histograms can be attached to the new event, it can
be matched in synthetic events. There is one limitation - an event probe
can not be attached to kprobe, uprobe or another event probe.

Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com
Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-20 14:18:40 -04:00
Masami Hiramatsu
8e242060c6 tracing/probes: Reject events which have the same name of existing one
Since kprobe_events and uprobe_events only check whether the
other same-type probe event has the same name or not, if the
user gives the same name of the existing tracepoint event (or
the other type of probe events), it silently fails to create
the tracefs entry (but registered.) as below.

/sys/kernel/tracing # ls events/task/task_rename
enable   filter   format   hist     id       trigger
/sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events
[  113.048508] Could not create tracefs 'task_rename' directory
/sys/kernel/tracing # cat kprobe_events
p:task/task_rename vfs_read

To fix this issue, check whether the existing events have the
same name or not in trace_probe_register_event_call(). If exists,
it rejects to register the new event.

Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:15:19 -04:00
Steven Rostedt (VMware)
8565a45d08 tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
In preparation to allow event probes to use the process_fetch_insn()
callback in trace_probe_tmpl.h, change the data passed to it from a
pointer to pt_regs, as the event probe will not be using regs, and make it
a void pointer instead.

Update the process_fetch_insn() callers for kprobe and uprobe events to
have the regs defined in the function and just typecast the void pointer
parameter.

Link: https://lkml.kernel.org/r/20210819041842.291622924@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:09:03 -04:00
Steven Rostedt (VMware)
007517a019 tracing/probe: Change traceprobe_set_print_fmt() to take a type
Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.

Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:08:29 -04:00
Steven Rostedt (VMware)
845cbf3e11 tracing/probes: Use struct_size() instead of defining custom macros
Remove SIZEOF_TRACE_KPROBE() and SIZEOF_TRACE_UPROBE() and use
struct_size() as that's what it is made for. No need to have custom
macros. Especially since struct_size() has some extra memory checks for
correctness.

Link: https://lkml.kernel.org/r/20210817035027.795000217@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
bc1b973455 tracing/probes: Allow for dot delimiter as well as slash for system names
Kprobe and uprobe events can add a "system" to the events that are created
via the kprobe_events and uprobe_events files respectively. If they do not
include a "system" in the name, then the default "kprobes" or "uprobes" is
used. The current notation to specify a system for one of these probe
events is to add a '/' delimiter in the name, where the content before the
'/' will be the system to use, and the content after will be the event
name.

 echo 'p:my_system/my_event' > kprobe_events

But this is inconsistent with the way histogram triggers separate their
system / event names. The histogram triggers use a '.' delimiter, which
can be confusing.

To allow this to be more consistent, as well as keep backward
compatibility, allow the kprobe and uprobe events to denote a system name
with either a '/' or a '.'.

That is:

  echo 'p:my_system/my_event' > kprobe_events

is equivalent to:

  echo 'p:my_system.my_event' > kprobe_events

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.580493202@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
fcd9db51df tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
The two places that call traceprobe_parse_probe_arg() allocate a temporary
buffer to copy the argv[i] into, because argv[i] is constant and the
traceprobe_parse_probe_arg() will modify it to do the parsing. These two
places allocate this buffer and then free it right after calling this
function, leaving the onus of this allocation to the caller.

As there's about to be a third user of this function that will have to do
the same thing, instead of having the caller allocate the temporary
buffer, simply move that allocation into the traceprobe_parse_probe_arg()
itself, which will simplify the code of the callers.

Link: https://lkml.kernel.org/r/20210817035027.385422828@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
1d18538e6a tracing: Have dynamic events have a ref counter
As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the dynamic event from going away.

Since dynamic events do not need the "mod" pointer of the event structure,
make a union out of it in order to save memory (there's one structure for
each of the thousand+ events in the kernel), and have any event with the
DYNAMIC flag set to use a ref counter instead.

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:47 -04:00
Steven Rostedt (VMware)
8b0e6c744f tracing: Add DYNAMIC flag for dynamic events
To differentiate between static and dynamic events, add a new flag
DYNAMIC to the event flags that all dynamic events have set. This will
allow to differentiate when attaching to a dynamic event from a static
event.

Static events have a mod pointer that references the module they were
created in (or NULL for core kernel). This can be incremented when the
event has something attached to it. But there exists no such mechanism for
dynamic events. This is dangerous as the dynamic events may now disappear
without the "attachment" knowing that it no longer exists.

To enforce the dynamic flag, change dyn_event_add() to pass the event that
is being created such that it can set the DYNAMIC flag of the event. This
helps make sure that no location that creates a dynamic event misses
setting this flag.

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035026.936958254@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:10:32 -04:00
Sebastian Andrzej Siewior
99c37d1a63 tracing: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Link: https://lkml.kernel.org/r/20210803141621.780504-37-bigeasy@linutronix.de

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-17 15:47:14 -04:00
Steven Rostedt (VMware)
db396be6dd MAINTAINERS: Add an entry for os noise/latency
The "latency" tracers have some different requirements than normal
tracing, and also includes Daniel as a maintainer. Add a section in the
MAINTAINERS file to help direct patches and bug reports to these tracers
to the right people.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 13:49:20 -04:00
zhaoxiao
bd74095389 tracepoint: Fix kerneldoc comments
Fix function name in tracepoint.c kernel-doc comment
to remove a warning found by clang_w1.

kernel/tracepoint.c:589: warning: expecting prototype for register_tracepoint_notifier(). Prototype was for register_tracepoint_module_notifier() instead
kernel/tracepoint.c:613: warning: expecting prototype for unregister_tracepoint_notifier(). Prototype was for unregister_tracepoint_module_notifier() instead

Link: https://lkml.kernel.org/r/20210816052430.16539-1-zhaoxiao@uniontech.com

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: zhaoxiao <zhaoxiao@uniontech.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:39:51 -04:00
Masami Hiramatsu
54b3498d71 bootconfig/tracing/ktest: Update ktest example for boot-time tracing
Update ktest example for the boot-time tracing with histogram
options. Note that since the histogram option uses "trace()" action
instead of "EVENT()", this updates the matching pattern too.

Link: https://lkml.kernel.org/r/162856130208.203126.4458319094852152589.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:39:51 -04:00
Masami Hiramatsu
1eaad3ac3f tools/bootconfig: Use per-group/all enable option in ftrace2bconf script
Use per-group/all enable option instead of ftrace.events option.
This will make the bootconfig file more readable.

Link: https://lkml.kernel.org/r/162856129436.203126.12462564671412940618.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:39:50 -04:00
Masami Hiramatsu
f134ebb281 tools/bootconfig: Add histogram syntax support to bconf2ftrace.sh
Add histogram syntax support to bconf2ftrace.sh script.

Link: https://lkml.kernel.org/r/162856128672.203126.8240335908303312607.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:39:50 -04:00
Masami Hiramatsu
1d8365a553 tools/bootconfig: Support per-group/all event enabling option
Add group or all event enabling syntax support to bconf2ftrace.sh.
User can pass a bootconfig file which includes

ftrace[.instance.INSTANCE].event.enable

    and

ftrace[.instance.INSTANCE].event.GROUP.enable

correctly.

Link: https://lkml.kernel.org/r/162856127850.203126.16694505101982548237.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:23 -04:00
Masami Hiramatsu
5597895392 Documentation: tracing: Add histogram syntax to boot-time tracing
Add the documentation about histogram syntax in boot-time tracing.
This will allow user to write the histogram setting in a structured
parameters.

Link: https://lkml.kernel.org/r/162856127129.203126.15551542847575916525.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
64dc7f6958 tracing/boot: Show correct histogram error command
Since trigger_process_regex() modifies given trigger actions
while parsing, the error message couldn't show what command
was passed to the trigger_process_regex() when it returns
an error.

To fix that, show the backed up trigger action command
instead of parsed buffer.

Link: https://lkml.kernel.org/r/162856126413.203126.9465564928450701424.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
17abd7c36c tracing/boot: Support multiple histograms for each event
Add multiple histograms support for each event. This allows
user to set multiple histograms to an event.

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
...
}

The 'N' is a digit started string and it can be omitted
for the default histogram.

For example, multiple hist triggers example in the
Documentation/trace/histogram.rst can be written as below;

ftrace.event.net.netif_receive_skb.hist {
	1 {
		keys = skbaddr.hex
		values = len
		filter = len < 0
	}
	2 {
		keys = skbaddr.hex
		values = len
		filter = len > 4096
	}
	3 {
		keys = skbaddr.hex
		values = len
		filter = len == 256
	}
	4 {
		keys = skbaddr.hex
		values = len
	}
	5 {
		keys = len
		values = common_preempt_count
	}
}

Link: https://lkml.kernel.org/r/162856125628.203126.15846930277378572120.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
8993665abc tracing/boot: Support multiple handlers for per-event histogram
Support multiple handlers for per-event histogram in boot-time tracing.
Since the histogram can register multiple same handler-actions with
different parameters, this expands the syntax to support such cases.

With this update, the 'onmax', 'onchange' and 'onmatch' handler subkeys
under per-event histogram option will take a number subkeys optionally
as below. (see [.N])

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
     onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] }
     onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] }
}

The 'N' must be a digit (or digit started word).

Thus user can add several handler-actions to the histogram,
for example,

ftrace.event.SOMEGROUP.SOMEEVENT.hist {
   keys = SOME_ID; lat = common_timestamp.usecs-$ts0
   onmatch.1 {
	event = GROUP1.STARTEVENT1
	trace = latency_event, SOME_ID, $lat
   }
   onmatch.2 {
	event = GROUP2.STARTEVENT2
	trace = latency_event, SOME_ID, $lat
   }
}

Then, it can trace the elapsed time from GROUP1.STARTEVENT1 to
SOMEGROUP.SOMEEVENT, and from GROUP2.STARTEVENT2 to
SOMEGROUP.SOMEEVENT with SOME_ID key.

Link: https://lkml.kernel.org/r/162856124905.203126.14913731908137885922.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
e66ed86ca6 tracing/boot: Add per-event histogram action options
Add a hist-trigger action syntax support to boot-time tracing.
Currently, boot-time tracing supports per-event actions as option
strings. However, for the histogram action, it has a special syntax
and usually needs a long action definition.
To make it readable and fit to the bootconfig syntax, this introduces
a new options for histogram.

Here are the histogram action options for boot-time tracing.

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
     keys = <KEY>[,...]
     values = <VAL>[,...]
     sort = <SORT-KEY>[,...]
     size = <ENTRIES>
     name = <HISTNAME>
     var { <VAR> = <EXPR> ... }
     pause|continue|clear
     onmax|onchange { var = <VAR>; <ACTION> [= <PARAM>] }
     onmatch { event = <EVENT>; <ACTION> [= <PARAM>] }
     filter = <FILTER>
}

Where <ACTION> is one of below;

     trace = <EVENT>, <ARG1>[, ...]
     save = <ARG1>[, ...]
     snapshot

Link: https://lkml.kernel.org/r/162856124106.203126.10501871028479029087.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Huang Shijie
c3b1c377f0 tracing: Fix a typo in tracepoint.h
It should be @prev_pid, not @prev_prid.

Link: https://lkml.kernel.org/r/20210802140234.5383-1-shijie@os.amperecomputing.com

Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masahiro Yamada
4aae683f13 tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig
Make architectures select TRACE_IRQFLAGS_SUPPORT instead of
having many defines.

Link: https://lkml.kernel.org/r/20210731052233.4703-2-masahiroy@kernel.org

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   #arch/arc
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masahiro Yamada
de32951b29 tracing: Simplify the Kconfig dependency of FTRACE
The entire FTRACE block is surrounded by 'if TRACING_SUPPORT' ...
'endif'.

Using 'depends on' is a simpler way to guard FTRACE.

Link: https://lkml.kernel.org/r/20210731052233.4703-1-masahiroy@kernel.org

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
ed2cf90735 tracing: Allow execnames to be passed as args for synthetic events
Allow common_pid.execname to be saved in a variable in one histogram to be
passed to another histogram that can pass it as a parameter to a synthetic
event.

 ># echo 'hist:keys=pid:__arg__1=common_timestamp.usecs:arg2=common_pid.execname' \
       > events/sched/sched_waking/trigger
 ># echo 'wakeup_lat s32 pid; u64 delta; char wake_comm[]' > synthetic_events
 ># echo 'hist:keys=next_pid:pid=next_pid,delta=common_timestamp.usecs-$__arg__1,exec=$arg2'\
':onmatch(sched.sched_waking).trace(wakeup_lat,$pid,$delta,$exec)' \
 > events/sched/sched_switch/trigger

The above is a wake up latency synthetic event setup that passes the execname
of the common_pid that woke the task to the scheduling of that task, which
triggers a synthetic event that passes the original execname as a
parameter to display it.

 ># echo 1 > events/synthetic/enable
 ># cat trace
    <idle>-0       [006] d..4   186.863801: wakeup_lat: pid=1306 delta=65 wake_comm=kworker/u16:3
    <idle>-0       [000] d..4   186.863858: wakeup_lat: pid=163 delta=27 wake_comm=<idle>
    <idle>-0       [001] d..4   186.863903: wakeup_lat: pid=1307 delta=36 wake_comm=kworker/u16:4
    <idle>-0       [000] d..4   186.863927: wakeup_lat: pid=163 delta=5 wake_comm=<idle>
    <idle>-0       [006] d..4   186.863957: wakeup_lat: pid=1306 delta=24 wake_comm=kworker/u16:3
      sshd-1306    [006] d..4   186.864051: wakeup_lat: pid=61 delta=62 wake_comm=<idle>
    <idle>-0       [000] d..4   186.965030: wakeup_lat: pid=609 delta=18 wake_comm=<idle>
    <idle>-0       [006] d..4   186.987582: wakeup_lat: pid=1306 delta=65 wake_comm=kworker/u16:3
    <idle>-0       [000] d..4   186.987639: wakeup_lat: pid=163 delta=27 wake_comm=<idle>

Link: https://lkml.kernel.org/r/20210722142837.458596338@goodmis.org

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
3347d80baa tracing: Have histogram types be constant when possible
Instead of kstrdup("const", GFP_KERNEL), have the hist_field type simply
assign the constant hist_field->type = "const"; And when the value passed
to it is a variable, use "kstrdup_const(var, GFP_KERNEL);" which will just
copy the value if the variable is already a constant. This saves on having
to allocate when not needed.

All frees of the hist_field->type will need to use kfree_const().

Link: https://lkml.kernel.org/r/20210722142837.280718447@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
3703643519 tracing/histogram: Update the documentation for the buckets modifier
Update both the tracefs README file as well as the histogram.rst to
include an explanation of what the buckets modifier is and how to use it.
Include an example with the wakeup_latency example for both log2 and the
buckets modifiers as there was no existing log2 example.

Link: https://lkml.kernel.org/r/20210707213922.167218794@goodmis.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
de9a48a360 tracing: Add linear buckets to histogram logic
There's been several times I wished the histogram logic had a "grouping"
feature for the buckets. Currently, each bucket has a size of one. That
is, if you trace the amount of requested allocations, each allocation is
its own bucket, even if you are interested in what allocates 100 bytes or
less, 100 to 200, 200 to 300, etc.

Also, without grouping, it fills up the allocated histogram buckets
quickly. If you are tracking latency, and don't care if something is 200
microseconds off, or 201 microseconds off, but want to track them by say
10 microseconds each. This can not currently be done.

There is a log2 but that grouping get's too big too fast for a lot of
cases.

Introduce a "buckets=SIZE" command to each field where it will record in a
rounded number. For example:

 ># echo 'hist:keys=bytes_req.buckets=100:sort=bytes_req' > events/kmem/kmalloc/trigger
 ># cat events/kmem/kmalloc/hist
 # event histogram
 #
 # trigger info:
 hist:keys=bytes_req.buckets=100:vals=hitcount:sort=bytes_req.buckets=100:size=2048
 [active]
 #

 { bytes_req: ~ 0-99 } hitcount:       3149
 { bytes_req: ~ 100-199 } hitcount:       1468
 { bytes_req: ~ 200-299 } hitcount:         39
 { bytes_req: ~ 300-399 } hitcount:        306
 { bytes_req: ~ 400-499 } hitcount:        364
 { bytes_req: ~ 500-599 } hitcount:         32
 { bytes_req: ~ 600-699 } hitcount:         69
 { bytes_req: ~ 700-799 } hitcount:         37
 { bytes_req: ~ 1200-1299 } hitcount:         16
 { bytes_req: ~ 1400-1499 } hitcount:         30
 { bytes_req: ~ 2000-2099 } hitcount:          6
 { bytes_req: ~ 4000-4099 } hitcount:       2168
 { bytes_req: ~ 5000-5099 } hitcount:          6

 Totals:
     Hits: 7690
     Entries: 13
     Dropped: 0

Link: https://lkml.kernel.org/r/20210707213921.980359719@goodmis.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00