Commit Graph

26 Commits

Author SHA1 Message Date
Steven Rostedt (Google) eb9d58947d tracing: Fix cpumask() example typo
The sample code for using cpumask used the wrong field for the
__get_cpumask() helper. It used "cpus" which is the bitmask (but would
still give a proper example) instead of the "cpum" that was there to be
used.

Although it produces the same output, fix it, because it's an example and
is confusing in how to properly use the cpumask() macro.

Link: https://lore.kernel.org/linux-trace-kernel/20221213221227.56560374@gandalf.local.home

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-12-14 11:17:55 -05:00
Steven Rostedt (Google) 8230f27b1c tracing: Add __cpumask to denote a trace event field that is a cpumask_t
The trace events have a __bitmask field that can be used for anything
that requires bitmasks. Although currently it is only used for CPU
masks, it could be used in the future for any type of bitmasks.

There is some user space tooling that wants to know if a field is a CPU
mask and not just some random unsigned long bitmask. Introduce
"__cpumask()" helper functions that work the same as the current
__bitmask() helpers but displays in the format file:

  field:__data_loc cpumask_t *[] mask;    offset:36;      size:4; signed:0;

Instead of:

  field:__data_loc unsigned long[] mask;  offset:32;      size:4; signed:0;

The main difference is the type. Instead of "unsigned long" it is
"cpumask_t *". Note, this type field needs to be a real type in the
__dynamic_array() logic that both __cpumask and__bitmask use, but the
comparison field requires it to be a scalar type whereas cpumask_t is a
structure (non-scalar). But everything works when making it a pointer.

Valentin added changes to remove the need of passing in "nr_bits" and the
__cpumask will always use nr_cpumask_bits as its size.

Link: https://lkml.kernel.org/r/20221014080456.1d32b989@rorschach.local.home

Requested-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-23 19:08:30 -05:00
Steven Rostedt (Google) fea6ac554d tracing: Add example and documentation for new __vstring() macro
Update the sample trace events to include an example that uses the new
__vstring() helpers for TRACE_EVENTS.

Link: https://lkml.kernel.org/r/20220715175555.16375a3b@gandalf.local.home

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24 19:11:17 -04:00
Geliang Tang ecbe794e77 tracing: Fix mismatched comment in __string_len
Here __assign_str_len() should be used for the __string_len type, instead
of __assign_str() in the comment.

Link: https://lkml.kernel.org/r/5c012db463392d0e6d4f0636203d778962ad060a.1640170494.git.geliang.tang@suse.com

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 883b4aee4d ("tracing: Add trace_event helper macros __string_len() and __assign_str_len()")
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:05 -05:00
Masami Hiramatsu b466b13321 samples/trace_event: Add '__rel_loc' using sample event
Add '__rel_loc' using sample event for testing.
User can use this for testing purpose. There is
no reason to use this macro from the kernel.

Link: https://lkml.kernel.org/r/163757343050.510314.2876529802471645178.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 15:37:22 -05:00
Steven Rostedt (VMware) 883b4aee4d tracing: Add trace_event helper macros __string_len() and __assign_str_len()
There's a few cases that a string that is to be recorded in a trace event,
does not have a terminating 'nul' character, and instead, the tracepoint
passes in the length of the string to record.

Add two helper macros to the trace event code that lets this work easier,
than tricks with "%.*s" logic.

  __string_len() which is similar to __string() for declaration, but takes a
                 length argument.

  __assign_str_len() which is similar to __assign_str() for assiging the
                 string, but it too takes a length argument.

Note, the TRACE_EVENT() macro will allocate the location on the ring
buffer to 'len + 1', that will be used to store the string into. It is a
requirement that the 'len' used for this is a most the length of the
string being recorded.

This string can still use __get_str() just like strings created with
__string() can use to retrieve the string.

Link: https://lore.kernel.org/linux-nfs/20210513105018.7539996a@gandalf.local.home/

Tested-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-17 11:47:52 -04:00
Wei Yang f094a233e1 tracing: Fix doc mistakes in trace sample
As the example below shows, DECLARE_EVENT_CLASS() is used instead of
DEFINE_EVENT_CLASS().

Link: http://lkml.kernel.org/r/20200428214959.11259-1-richard.weiyang@gmail.com

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-07 13:32:57 -04:00
Linus Torvalds 9682b3dea2 Merge branch 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "The usual rocket-science from trivial tree for 4.15"

* 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  MAINTAINERS: relinquish kconfig
  MAINTAINERS: Update my email address
  treewide: Fix typos in Kconfig
  kfifo: Fix comments
  init/Kconfig: Fix module signing document location
  misc: ibmasm: Return error on error path
  HID: logitech-hidpp: fix mistake in printk, "feeback" -> "feedback"
  MAINTAINERS: Correct path to uDraw PS3 driver
  tracing: Fix doc mistakes in trace sample
  tracing: Kconfig text fixes for CONFIG_HWLAT_TRACER
  MIPS: Alchemy: Remove reverted CONFIG_NETLINK_MMAP from db1xxx_defconfig
  mm/huge_memory.c: fixup grammar in comment
  lib/xz: Add fall-through comments to a switch statement
2017-11-15 10:14:11 -08:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Jeremy Linton 2701997561 tracing: Fix doc mistakes in trace sample
The trace sample file has a couple mispellings, lets fix them.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-10-12 15:29:53 +02:00
Steven Rostedt (Red Hat) 8cf868affd tracing: Have the reg function allow to fail
Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.

Cc: David Howells <dhowells@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09 09:13:30 -05:00
Chunyan Zhang 67aedeb857 Sample: Trace_event: Correct the comments
The commit 889204278c ("tracing: Update trace-event-sample with
TRACE_SYSTEM_VAR documentation") changed TRACE_SYSTEM to 'sample-trace',
but didn't make the according change of its name in the comments.

Link: http://lkml.kernel.org/r/1443599650-23680-1-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:09:15 -05:00
Steven Rostedt (Red Hat) d6726c8145 tracing: Fix sample output of dynamic arrays
He Kuang noticed that the trace event samples for arrays was broken:

"The output result of trace_foo_bar event in traceevent samples is
 wrong. This problem can be reproduced as following:

  (Build kernel with SAMPLE_TRACE_EVENTS=m)

  $ insmod trace-events-sample.ko

  $ echo 1 > /sys/kernel/debug/tracing/events/sample-trace/foo_bar/enable

  $ cat /sys/kernel/debug/tracing/trace

  event-sample-980 [000] ....  43.649559: foo_bar: foo hello 21 0x15
  BIT1|BIT3|0x10 {0x1,0x6f6f6e53,0xff007970,0xffffffff} Snoopy
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 The array length is not right, should be {0x1}.
  (ffffffff,ffffffff)

  event-sample-980 [000] ....  44.653827: foo_bar: foo hello 22 0x16
  BIT2|BIT3|0x10
  {0x1,0x2,0x646e6147,0x666c61,0xffffffff,0xffffffff,0x750aeffe,0x7}
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 The array length is not right, should be {0x1,0x2}.
  Gandalf (ffffffff,ffffffff)"

This was caused by an update to have __print_array()'s second parameter
be the count of items in the array and not the size of the array.

As there is already users of __print_array(), it can not change. But
the sample code can and we can also improve on the documentation about
__print_array() and __get_dynamic_array_len().

Link: http://lkml.kernel.org/r/1436839171-31527-2-git-send-email-hekuang@huawei.com

Fixes: ac01ce1410 ("tracing: Make ftrace_print_array_seq compute buf_len")
Reported-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-17 14:15:13 -04:00
Steven Rostedt (Red Hat) 32eb3d0d09 tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
Document the use of TRACE_DEFINE_ENUM() by adding enums to the
trace-event-sample.h and using this macro to convert them in the format
files.

Also update the comments and sho the use of __print_symbolic() and
__print_flags() as well as adding comments abount __print_array().

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-08 09:39:58 -04:00
Steven Rostedt (Red Hat) 889204278c tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
Add documentation about TRACE_SYSTEM needing to be alpha-numeric or with
underscores, and that if it is not, then the use of TRACE_SYSTEM_VAR is
required to make something that is.

An example of this is shown in samples/trace_events/trace-events-sample.h

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-08 09:39:55 -04:00
Steven Rostedt (Red Hat) 7496946a88 tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()
Add to samples/trace_events/ the macros DECLARE_EVENT_CLASS() and
DEFINE_EVENT() and recommend using them over multiple TRACE_EVENT()
macros if the multiple events have the same format.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09 18:05:51 -05:00
Steven Rostedt (Red Hat) 6adc13f8c0 tracing: Add TRACE_EVENT_FN example
If a function should be called before a tracepoint is enabled
and/or after it is disabled, the TRACE_EVENT_FN() serves this
purpose. But it is not well documented. Having it as a sample would
help developers to know how to use it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09 18:05:39 -05:00
Steven Rostedt (Red Hat) c4c7eb2938 tracing: Add TRACE_EVENT_CONDITION sample
The sample code lacks an example of TRACE_EVENT_CONDITION, and it
has been expressed to me that this feature for TRACE_EVENT is not
well known and not used when it could be.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09 16:05:55 -05:00
Steven Rostedt (Red Hat) 4e20e3a60b tracing: Update the TRACE_EVENT fields available in the sample code
The sample code in samples/trace_events/ is extremely out of date and does
not show all the new fields that have been added since the sample code
was written. As most people are unaware of these new fields, adding sample
code and explanations of those fields should help out.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09 15:27:04 -05:00
Zhao Hongjiang d8fae2f644 tracing: Change trace event sample to use strlcpy instead of strncpy
Strings should be copied with strlcpy instead of strncpy when they will
later be printed via %s. This guarantees that they terminate with a
NUL '\0' character and do not run pass the end of the allocated string.

This is only for sample code, but it should stil represent a good
role model.

Link: http://lkml.kernel.org/p/51C2E204.1080501@huawei.com

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-01 07:13:33 -04:00
Steven Rostedt 4d4c9cc839 tracing: Add __field_struct macro for TRACE_EVENT()
Currently the __field() macro in TRACE_EVENT is only good for primitive
values, such as integers and pointers, but it fails on complex data types
such as structures or unions. This is because the __field() macro
determines if the variable is signed or not with the test of:

  (((type)(-1)) < (type)1)

Unfortunately, that fails when type is a structure.

Since trace events should support structures as fields a new macro
is created for such a case called __field_struct() which acts exactly
the same as __field() does but it does not do the signed type check
and just uses a constant false for that answer.

Cc: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-21 00:18:42 -04:00
GeunSik Lim 088a4eed28 debugfs: Change debuhgfs directory of trace-events-sample.h
Default directory of debug filesystem for ftrace is /sys/kernel/debug/.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:48 -07:00
Li Zefan d0b6e04a4c tracing/events: Move TRACE_SYSTEM outside of include guard
If TRACE_INCLDUE_FILE is defined, <trace/events/TRACE_INCLUDE_FILE.h>
will be included and compiled, otherwise it will be
<trace/events/TRACE_SYSTEM.h>

So TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.

Imaging this scenario:

 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == foo
 ...
 #include <trace/events/bar.h>
    -> TRACE_SYSTEM == bar
 ...
 #define CREATE_TRACE_POINTS
 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == bar !!!

and then bar.h will be included and compiled.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-13 10:59:55 +02:00
Steven Rostedt 44ad18e0a6 tracing: update sample event documentation
The comments in the sample code is a bit confusing. This patch
cleans them up a little.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-16 19:53:07 -04:00
Steven Rostedt 71e1c8ac42 tracing: update sample with TRACE_INCLUDE_FILE
When creating trace events for ftrace, the header file with the TRACE_EVENT
macros must also have a macro called TRACE_SYSTEM. This macro describes
the name of the system the TRACE_EVENTS are defined for. It also doubles
as a way for the define_trace.h file to include the file that included
it.

For example:

in irq.h

 #define TRACE_SYSTEM irq

[...]

 #include <trace/define_trace.h>

The define_trace will use TRACE_SYSTEM to include irq.h. But if the name
of the trace system does not match the name of the trace header file,
one can override it with:

Which will change define_trace.h to inclued foo_trace.h instead of foo.h

The sample comments this, but people that use the sample code will more
likely use the code and not read the comments. This patch changes the
sample code to use the TRACE_INCLUDE_FILE to better show developers how to
use it.

[ Impact: make sample less confusing to developers ]

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06 23:10:42 -04:00
Steven Rostedt 9cfe06f8cd tracing/events: add trace-events-sample
This patch adds a sample to the samples directory on how to create
and use TRACE_EVENT trace points.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:09:18 -04:00