1059251 Commits

Author SHA1 Message Date
Yinan Liu
35140d399d script/sorttable: Fix some initialization problems
elf_mcount_loc and mcount_sort_thread definitions are not
initialized immediately within the function, which can cause
the judgment logic to use uninitialized values when the
initialization logic of subsequent code fails.

Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com
Link: https://lkml.kernel.org/r/20220118065241.42364-1-yinan@linux.alibaba.com

Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init")
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-18 10:17:18 -05:00
Steven Rostedt
f37c3bbc63 tracing: Add ustring operation to filtering string pointers
Since referencing user space pointers is special, if the user wants to
filter on a field that is a pointer to user space, then they need to
specify it.

Add a ".ustring" attribute to the field name for filters to state that the
field is pointing to user space such that the kernel can take the
appropriate action to read that pointer.

Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/

Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers")
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-14 03:42:24 -05:00
Daniel Bristot de Oliveira
5dce5904e3 rtla: Add rtla timerlat hist documentation
Man page for rtla timerlat hist mode.

Link: https://lkml.kernel.org/r/4a184003fdb81e23be3fe5ec882b1c89d5a95458.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:44 -05:00
Daniel Bristot de Oliveira
df337d014b rtla: Add rtla timerlat top documentation
Man page for rtla timerlat top mode.

Link: https://lkml.kernel.org/r/58c3d6212e6c6f1f012deb2e998dd082da92075f.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
29380d4055 rtla: Add rtla timerlat documentation
Man page for rtla timerlat tool.

Link: https://lkml.kernel.org/r/78678b8d024bf5a3a79f831ac9441b96e8d2f56e.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
e7041c6b3c rtla: Add rtla osnoise hist documentation
Man page for rtla osnoise hist mode.

Link: https://lkml.kernel.org/r/d43cc5d516b8db180575c4b66c4aa67c6a724a8d.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
b1be48307d rtla: Add rtla osnoise top documentation
Man page for rtla osnoise top mode.

Link: https://lkml.kernel.org/r/445aa2173ca152fc2e68719e3c1a2547dd01efd3.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
496082df01 rtla: Add rtla osnoise man page
Man page for rtla osnoise command.

Link: https://lkml.kernel.org/r/304747c602e46f6396e3bb75dfdcb42ae3656dca.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
d40d48e1f1 rtla: Add Documentation
Adds the basis for rtla documentation. This patch also
includes the rtla(1) man page.

As suggested by Jonathan Corbet, we are placing these man
pages at Documentation/tools/rtla, using rst format. It
is not linked to the official documentation, though.

The Makefile is based on bpftool's Documentation one.

Link: https://lkml.kernel.org/r/5f510f3e962fc0cd531c43f5a815544dd720c3f2.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
1eeb6328e8 rtla/timerlat: Add timerlat hist mode
The rtla hist hist mode displays a histogram of each tracer event
occurrence, both for IRQ and timer latencies. The tool also allows
many configurations of the timerlat tracer and the collection of
the tracer output.

Here is one example of the rtla timerlat hist mode output:
  ---------- %< ----------
 [root@alien ~]# rtla timerlat hist -c 0-3 -d 1M
 # RTLA timerlat histogram
 # Time unit is microseconds (us)
 # Duration:   0 00:01:00
 Index   IRQ-000   Thr-000   IRQ-001   Thr-001   IRQ-002   Thr-002   IRQ-003   Thr-003
 0         58572         0     59373         0     58691         0     58895         0
 1          1422     57021       628     57241      1310     56160      1102     56805
 2             6      2931         0      2695         0      3567         4      3031
 3             1        40         0        53         0       260         0       142
 4             0         7         0         5         0         6         0        17
 5             0         2         0         5         0         7         0         4
 6             0         0         0         2         0         1         0         1
 8             0         0         0         0         0         0         0         1
 over:         0         0         0         0         0         0         0         0
 count:    60001     60001     60001     60001     60001     60001     60001     60001
 min:          0         1         0         1         0         1         0         1
 avg:          0         1         0         1         0         1         0         1
 max:          3         5         1         6         1         6         2         8
  ---------- >% ----------

Running
 - rtla timerlat hist --help
provides information about the available options.

Link: https://lkml.kernel.org/r/7049ed3c46b7d6aceab18ffe7770003dfc4ddceb.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
a828cd18bc rtla: Add timerlat tool and timelart top mode
The rtla timerlat tool is an interface for the timerlat tracer.
The timerlat tracer dispatches a kernel thread per-cpu. These threads set a
periodic timer to wake themselves up and go back to sleep. After the
wakeup, they collect and generate useful information for the debugging of
operating system timer latency.

The timerlat tracer outputs information in two ways. It periodically
prints the timer latency at the timer IRQ handler and the Thread handler.
It also provides information for each noise via the osnoise tracepoints.

The rtla timerlat top mode displays a summary of the periodic output from
the timerlat tracer.

Here is one example of the rtla timerlat tool output:
 ---------- %< ----------
[root@alien ~]# rtla timerlat top -c 0-3 -d 1m
                                     Timer Latency
  0 00:01:00   |          IRQ Timer Latency (us)        |         Thread Timer Latency (us)
CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max
  0 #60001     |        0         0         0         3 |        1         1         1         6
  1 #60001     |        0         0         0         3 |        2         1         1         5
  2 #60001     |        0         0         1         6 |        1         1         2         7
  3 #60001     |        0         0         0         7 |        1         1         1        11
 ---------- >% ----------

Running:
  # rtla timerlat --help
  # rtla timerlat top --help
provides information about the available options.

Link: https://lkml.kernel.org/r/e95032e20c2b88c962195bf7693bb53c9ebcced8.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
829a6c0b56 rtla/osnoise: Add the hist mode
The rtla osnoise hist tool collects all osnoise:sample_threshold
occurrence in a histogram, displaying the results in a user-friendly
way. The tool also allows many configurations of the osnoise tracer
and the collection of the tracer output.

Here is one example of the rtla osnoise hist tool output:
  ---------- %< ----------
 [root@f34 ~]# rtla osnoise hist --bucket-size 10 --entries 100 -c 0-8 -d 1M -r 9000 -P F:1
 # RTLA osnoise histogram
 # Time unit is microseconds (us)
 # Duration:   0 00:01:00
 Index   CPU-000   CPU-001   CPU-002   CPU-003   CPU-004   CPU-005   CPU-006   CPU-007   CPU-008
 0           430       434       352       455       440       463       467       436       484
 10           88        88        92       141       120       100       126       166       100
 20           19         7        12        22         8         8        13        13        16
 30            6         0         2         0         1         2         2         1         0
 50            0         0         0         0         0         0         1         0         0
 over:         0         0         0         0         0         0         0         0         0
 count:      543       529       458       618       569       573       609       616       600
 min:          0         0         0         0         0         0         0         0         0
 avg:          0         0         0         0         0         0         0         0         0
 max:         30        20        30        20        30        30        50        30        20
  ---------- >% ----------

Running
 - rtla osnoise hist --help

provides information about the available options.

Link: https://lkml.kernel.org/r/c68060544de89b8b62510ed91c7369f162eb465b.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:43 -05:00
Daniel Bristot de Oliveira
1eceb2fc2c rtla/osnoise: Add osnoise top mode
The rtla osnoise tool is an interface for the osnoise tracer. The
osnoise tracer dispatches a kernel thread per-cpu. These threads read
the time in a loop while with preemption, softirqs and IRQs enabled,
thus allowing all the sources of osnoise during its execution. The
osnoise threads take note of the entry and exit point of any source
of interferences, increasing a per-cpu interference counter. The
osnoise tracer also saves an interference counter for each source
of interference.

The rtla osnoise top mode displays information about the periodic
summary from the osnoise tracer.

One example of rtla osnoise top output is:

[root@alien ~]# rtla osnoise top -c 0-3 -d 1m -q -r 900000 -P F:1
                                         Operating System Noise
duration:   0 00:01:00 | time is in us
CPU Period       Runtime        Noise  % CPU Aval   Max Noise   Max Single          HW          NMI          IRQ      Softirq       Thread
  0 #58         52200000         1031    99.99802          91           60           0            0        52285            0          101
  1 #59         53100000            5    99.99999           5            5           0            9        53122            0           18
  2 #59         53100000            7    99.99998           7            7           0            8        53115            0           18
  3 #59         53100000         8274    99.98441         277           23           0            9        53778            0          660

"rtla osnoise top --help" works and provide information about the
available options.

Link: https://lkml.kernel.org/r/0d796993abf587ae5a170bb8415c49368d4999e1.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Daniel Bristot de Oliveira
0605bf009f rtla: Add osnoise tool
The osnoise tool is the interface for the osnoise tracer. The osnoise
tool will have multiple "modes" with different outputs. At this point,
no mode is included.

The osnoise.c includes the osnoise_context abstraction. It serves to
read-save-change-restore the default values from tracing/osnoise/
directory. When the context is deleted, the default values are restored.

It also includes some other helper functions for managing osnoise
tracer sessions.

With these bits and pieces in place, we can start adding some
functionality to rtla.

Link: https://lkml.kernel.org/r/2d44c21ff561f503b4c7b1813892761818118460.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Daniel Bristot de Oliveira
b1696371d8 rtla: Helper functions for rtla
This is a set of utils and tracer helper functions. They are used by
rtla mostly to parse config, display data and some trace operations that
are not part of libtracefs (because they are only useful it for this
case).

Link: https://lkml.kernel.org/r/a94c128aba9e6e66d502b7094f2e8c7ac95b12e5.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Daniel Bristot de Oliveira
79ce8f43ac rtla: Real-Time Linux Analysis tool
The rtla is a meta-tool that includes a set of commands that aims
to analyze the real-time properties of Linux. But instead of testing
Linux as a black box, rtla leverages kernel tracing capabilities to
provide precise information about the properties and root causes of
unexpected results.

rtla --help works and provide information about the available options.

This is just the "main" and the Makefile, no function yet.

Link: https://lkml.kernel.org/r/bf9118ed43a09e6c054c9a491cbe7411ad1acd89.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Nikita Yushchenko
0878355b51 tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails
If start_per_cpu_kthreads() called from osnoise_workload_start() returns
error, event hooks are left in broken state: unhook_irq_events() called
but unhook_thread_events() and unhook_softirq_events() not called, and
trace_osnoise_callback_enabled flag not cleared.

On the next tracer enable, hooks get not installed due to
trace_osnoise_callback_enabled flag.

And on the further tracer disable an attempt to remove non-installed
hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func().

Fix the error path by adding the missing part of cleanup.
While at this, introduce osnoise_unhook_events() to avoid code
duplication between this error path and normal tracer disable.

Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com

Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Yuntao Wang
6e1b4bd191 tracing: Remove duplicate warnings when calling trace_create_file()
Since the same warning message is already printed in the
trace_create_file() function, there is no need to print it again.

Link: https://lkml.kernel.org/r/20220109162232.361747-1-ytcoode@gmail.com

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Xiangyang Zhang
dfea08a211 tracing/kprobes: 'nmissed' not showed correctly for kretprobe
The 'nmissed' column of the 'kprobe_profile' file for kretprobe is
not showed correctly, kretprobe can be skipped by two reasons,
shortage of kretprobe_instance which is counted by tk->rp.nmissed,
and kprobe itself is missed by some reason, so to show the sum.

Link: https://lkml.kernel.org/r/20220107150242.5019-1-xyz.sun.ok@gmail.com

Cc: stable@vger.kernel.org
Fixes: 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Xiangyang Zhang <xyz.sun.ok@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00
Steven Rostedt
77360f9bbc tracing: Add test for user space strings when filtering on string pointers
Pingfan reported that the following causes a fault:

  echo "filename ~ \"cpu\"" > events/syscalls/sys_enter_openat/filter
  echo 1 > events/syscalls/sys_enter_at/enable

The reason is that trace event filter treats the user space pointer
defined by "filename" as a normal pointer to compare against the "cpu"
string. The following bug happened:

 kvm-03-guest16 login: [72198.026181] BUG: unable to handle page fault for address: 00007fffaae8ef60
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0001) - permissions violation
 PGD 80000001008b7067 P4D 80000001008b7067 PUD 2393f1067 PMD 2393ec067 PTE 8000000108f47867
 Oops: 0001 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.14.0-32.el9.x86_64 #1
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:strlen+0x0/0x20
 Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11
       48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8
       48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31
 RSP: 0018:ffffb5b900013e48 EFLAGS: 00010246
 RAX: 0000000000000018 RBX: ffff8fc1c49ede00 RCX: 0000000000000000
 RDX: 0000000000000020 RSI: ffff8fc1c02d601c RDI: 00007fffaae8ef60
 RBP: 00007fffaae8ef60 R08: 0005034f4ddb8ea4 R09: 0000000000000000
 R10: ffff8fc1c02d601c R11: 0000000000000000 R12: ffff8fc1c8a6e380
 R13: 0000000000000000 R14: ffff8fc1c02d6010 R15: ffff8fc1c00453c0
 FS:  00007fa86123db40(0000) GS:ffff8fc2ffd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fffaae8ef60 CR3: 0000000102880001 CR4: 00000000007706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  filter_pred_pchar+0x18/0x40
  filter_match_preds+0x31/0x70
  ftrace_syscall_enter+0x27a/0x2c0
  syscall_trace_enter.constprop.0+0x1aa/0x1d0
  do_syscall_64+0x16/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fa861d88664

The above happened because the kernel tried to access user space directly
and triggered a "supervisor read access in kernel mode" fault. Worse yet,
the memory could not even be loaded yet, and a SEGFAULT could happen as
well. This could be true for kernel space accessing as well.

To be even more robust, test both kernel and user space strings. If the
string fails to read, then simply have the filter fail.

Note, TASK_SIZE is used to determine if the pointer is user or kernel space
and the appropriate strncpy_from_kernel/user_nofault() function is used to
copy the memory. For some architectures, the compare to TASK_SIZE may always
pick user space or kernel space. If it gets it wrong, the only thing is that
the filter will fail to match. In the future, this needs to be fixed to have
the event denote which should be used. But failing a filter is much better
than panicing the machine, and that can be solved later.

Link: https://lore.kernel.org/all/20220107044951.22080-1-kernelfans@gmail.com/
Link: https://lkml.kernel.org/r/20220110115532.536088fd@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reported-by: Pingfan Liu <kernelfans@gmail.com>
Tested-by: Pingfan Liu <kernelfans@gmail.com>
Fixes: 87a342f5db69d ("tracing/filters: Support filtering for char * strings")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:00:45 -05:00
Steven Rostedt
3e2a56e6f6 tracing: Have syscall trace events use trace_event_buffer_lock_reserve()
Currently, the syscall trace events call trace_buffer_lock_reserve()
directly, which means that it misses out on some of the filtering
optimizations provided by the helper function
trace_event_buffer_lock_reserve(). Have the syscall trace events call that
instead, as it was missed when adding the update to use the temp buffer
when filtering.

Link: https://lkml.kernel.org/r/20220107225839.823118570@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0fc1b09ff1ff4 ("tracing: Use temp buffer when filtering events")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:05 -05:00
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: 883b4aee4dec6 ("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
Steven Rostedt (VMware)
8147dc78e6 ftrace: Add test to make sure compiled time sorts work
Now that ftrace function pointers are sorted at compile time, add a test
that makes sure they are sorted at run time. This test is only run if it is
configured in.

Link: https://lkml.kernel.org/r/20211206151858.4d21a24d@gandalf.local.home

Cc: Yinan Liu <yinan@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2022-01-13 16:23:05 -05:00
Yinan Liu
72b3942a17 scripts: ftrace - move the sort-processing in ftrace_init
When the kernel starts, the initialization of ftrace takes
up a portion of the time (approximately 6~8ms) to sort mcount
addresses. We can save this time by moving mcount-sorting to
compile time.

Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com

Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:04 -05:00
Xiaoke Wang
1c1857d400 tracing/probes: check the return value of kstrndup() for pbuf
kstrndup() is a memory allocation-related function, it returns NULL when
some internal memory errors happen. It is better to check the return
value of it so to catch the memory error in time.

Link: https://lkml.kernel.org/r/tencent_4D6E270731456EB88712ED7F13883C334906@qq.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:04 -05:00
Xiaoke Wang
8c72242455 tracing/uprobes: Check the return value of kstrdup() for tu->filename
kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it so to catch the memory error in
time.

Link: https://lkml.kernel.org/r/tencent_3C2E330722056D7891D2C83F29C802734B06@qq.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:04 -05:00
Sebastian Andrzej Siewior
289e7b0f7e tracing: Account bottom half disabled sections.
Disabling only bottom halves via local_bh_disable() disables also
preemption but this remains invisible to tracing. On a CONFIG_PREEMPT
kernel one might wonder why there is no scheduling happening despite the
N flag in the trace. The reason might be the a rcu_read_lock_bh()
section.

Add a 'b' to the tracing output if in task context with disabled bottom
halves.

Link: https://lkml.kernel.org/r/YbcbtdtC/bjCKo57@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:04 -05:00
Tom Zanussi
86599dbe2c tracing: Add helper functions to simplify event_command.parse() callback handling
The event_command.parse() callback is responsible for parsing and
registering triggers.  The existing command implementions for this
callback duplicate a lot of the same code, so to clean up and
consolidate those implementations, introduce a handful of helper
functions for implementors to use.

This also makes it easier for new commands to be implemented and
allows them to focus more on the customizations they provide rather
than obscuring and complicating it with boilerplate code.

Link: https://lkml.kernel.org/r/c1ff71f594d45177706571132bd3119491097221.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:11 -05:00
Tom Zanussi
2378a2d6b6 tracing: Remove ops param from event_command reg()/unreg() callbacks
The event_trigger_ops for an event_command are already accessible via
event_trigger_data.ops so remove the redundant ops from the callback.

Link: https://lkml.kernel.org/r/4c6f2a41820452f9cacddc7634ad442928aa2aa6.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:11 -05:00
Tom Zanussi
fb339e531b tracing: Change event_trigger_ops func() to trigger()
The name of the func() callback on event_trigger_ops is too generic
and is easily confused with other callbacks with that name, so change
it to something that reflects its actual purpose.

In this case, the main purpose of the callback is to implement an
event trigger, so call it trigger() instead.

Also add some more documentation to event_trigger_ops describing the
callbacks a bit better.

Link: https://lkml.kernel.org/r/36ab812e3ee74ee03ae0043fda41a858ee728c00.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:10 -05:00
Tom Zanussi
9ec5a7d168 tracing: Change event_command func() to parse()
The name of the func() callback on event_command is too generic and is
easily confused with other callbacks with that name, so change it to
something that reflects its actual purpose.

In this case, the main purpose of the callback is to parse an event
command, so call it parse() instead.

Link: https://lkml.kernel.org/r/7784e321840752ed88aac0b349c0c685fc9247b1.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:10 -05:00
Steven Rostedt (VMware)
2768c1e7f9 tracing: Use trace_iterator_reset() in tracing_read_pipe()
Currently tracing_read_pipe() open codes trace_iterator_reset(). Just have
it use trace_iterator_reset() instead.

Link: https://lkml.kernel.org/r/20211210202616.64d432d2@gandalf.local.home

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Xiu Jianfeng
dba8796722 tracing: Use memset_startat helper in trace_iterator_reset()
Make use of memset_startat helper to simplify the code, there should be
no functional change as a result of this patch.

Link: https://lkml.kernel.org/r/20211210012245.207489-1-xiujianfeng@huawei.com

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Beau Belgrave
4f67cca70c tracing: Do not let synth_events block other dyn_event systems during create
synth_events is returning -EINVAL if the dyn_event create command does
not contain ' \t'. This prevents other systems from getting called back.
synth_events needs to return -ECANCELED in these cases when the command
is not targeting the synth_event system.

Link: https://lore.kernel.org/linux-trace-devel/20210930223821.11025-1-beaub@linux.microsoft.com

Fixes: c9e759b1e8456 ("tracing: Rework synthetic event command parsing")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Jiri Olsa
e161c6bf39 tracing: Iterate trace_[ku]probe objects directly
As suggested by Linus [1] using list_for_each_entry to iterate
directly trace_[ku]probe objects so we can skip another call to
container_of in these loops.

[1] https://lore.kernel.org/r/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com

Link: https://lkml.kernel.org/r/20211125202852.406405-1-jolsa@kernel.org

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Steven Rostedt (VMware)
ee34c52c71 tracefs: Use d_inode() helper function to get the dentry inode
Instead of referencing the inode from a dentry via dentry->d_inode, use
the helper function d_inode(dentry) instead. This is the considered the
correct way to access it.

Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Reported: https://lore.kernel.org/all/20211208104454.nhxyvmmn6d2qhpwl@wittgenstein/
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:31 -05:00
Yinan Liu
c8a7ff13f5 script/sorttable: Code style improvements
Modified the code style issue of if() {},
keep the code style consistent.

Link: https://lkml.kernel.org/r/20211207151348.54921-3-yinan@linux.alibaba.com

Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:31 -05:00
John Keeping
2972e3050e tracing: Make trace_marker{,_raw} stream-like
The tracing marker files are write-only streams with no meaningful
concept of file position.  Using stream_open() to mark them as
stream-link indicates this and has the added advantage that a single
file descriptor can now be used from multiple threads without contention
thanks to clearing FMODE_ATOMIC_POS.

Note that this has the potential to break existing userspace by since
both lseek(2) and pwrite(2) will now return ESPIPE when previously lseek
would have updated the stored offset and pwrite would have appended to
the trace.  A survey of libtracefs and several other projects found to
use trace_marker(_raw) [1][2][3] suggests that everyone limits
themselves to calling write(2) and close(2) on these file descriptors so
there is a good chance this will go unnoticed and the benefits of
reduced overhead and lock contention seem worth the risk.

[1] https://github.com/google/perfetto
[2] https://github.com/intel/media-driver/
[3] https://w1.fi/cgit/hostap/

Link: https://lkml.kernel.org/r/20211207142558.347029-1-john@metanate.com

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-07 22:05:49 -05:00
Uladzislau Rezki (Sony)
a6ed2aee54 tracing: Switch to kvfree_rcu() API
Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

Link: https://lkml.kernel.org/r/20211124110308.2053-10-urezki@gmail.com

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 17:53:50 -05:00
Qiujun Huang
1d83c3a20b tracing: Fix synth_event_add_val() kernel-doc comment
It's named field here.

Link: https://lkml.kernel.org/r/20210516022410.64271-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 17:53:50 -05:00
Steven Rostedt (VMware)
b7d5eb267f tracing/uprobes: Use trace_event_buffer_reserve() helper
To be consistent with kprobes and eprobes, use
trace_event_buffer_reserver() and trace_event_buffer_commit(). This will
ensure that any updates to trace events will also be implemented on uprobe
events.

Link: https://lkml.kernel.org/r/20211206162440.69fbf96c@gandalf.local.home

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 17:53:23 -05:00
Steven Rostedt (VMware)
5e6cd84e2f tracing/kprobes: Do not open code event reserve logic
As kprobe events use trace_event_buffer_commit() to commit the event to
the ftrace ring buffer, for consistency, it should use
trace_event_buffer_reserve() to allocate it, as the two functions are
related.

Link: https://lkml.kernel.org/r/20211130024319.257430762@goodmis.org

Acked-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)
3e8b1a29a0 tracing: Have eprobes use filtering logic of trace events
The eprobes open code the reserving of the event on the ring buffer for
ftrace instead of using the ftrace event wrappers, which means that it
doesn't get affected by the filters, breaking the filtering logic on user
space.

Link: https://lkml.kernel.org/r/20211130024319.068451680@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 15:37:22 -05:00
Steven Rostedt (VMware)
6c536d76cf tracing: Disable preemption when using the filter buffer
In case trace_event_buffer_lock_reserve() is called with preemption
enabled, the algorithm that defines the usage of the per cpu filter buffer
may fail if the task schedules to another CPU after determining which
buffer it will use.

Disable preemption when using the filter buffer. And because that same
buffer must be used throughout the call, keep preemption disabled until
the filter buffer is released.

This will also keep the semantics between the use case of when the filter
buffer is used, and when the ring buffer itself is used, as that case also
disables preemption until the ring buffer is released.

Link: https://lkml.kernel.org/r/20211130024318.880190623@goodmis.org

[ Fixed warning of assignment in if statement
  Reported-by: kernel test robot <lkp@intel.com> ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 15:37:22 -05:00
Steven Rostedt (VMware)
e07a1d5762 tracing: Use __this_cpu_read() in trace_event_buffer_lock_reserver()
The value read by this_cpu_read() is used later and its use is expected to
stay on the same CPU as being read. But this_cpu_read() does not warn if
it is called without preemption disabled, where as __this_cpu_read() will
check if preemption is disabled on CONFIG_DEBUG_PREEMPT

Currently all callers have preemption disabled, but there may be new
callers in the future that may not.

Link: https://lkml.kernel.org/r/20211130024318.698165354@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-06 15:37:22 -05:00
Masami Hiramatsu
7c689c8397 tools/perf: Add '__rel_loc' event field parsing support
Add new '__rel_loc' dynamic data location attribute support.
This type attribute is similar to the '__data_loc' but records the
offset from the field itself.
The libtraceevent adds TEP_FIELD_IS_RELATIVE to the
'tep_format_field::flags' with TEP_FIELD_IS_DYNAMIC for'__rel_loc'.

Link: https://lkml.kernel.org/r/163757344810.510314.12449413842136229871.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
Masami Hiramatsu
cd7729043b libtraceevent: Add __rel_loc relative location attribute support
Add '__rel_loc' new dynamic data location attribute which encodes
the data location from the next to the field itself. This is similar
to the '__data_loc' but the location offset is not from the event
entry but from the next of the field.

This patch adds '__rel_loc' decoding support in the libtraceevent.

Link: https://lkml.kernel.org/r/163757343994.510314.13241077597729303802.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
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
Masami Hiramatsu
55de2c0b56 tracing: Add '__rel_loc' using trace event macros
Add '__rel_loc' using trace event macros. These macros are usually
not used in the kernel, except for testing purpose.
This also add "rel_" variant of macros for dynamic_array string,
and bitmask.

Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.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 15:37:21 -05:00
Masami Hiramatsu
05770dd0ad tracing: Support __rel_loc relative dynamic data location attribute
Add '__rel_loc' new dynamic data location attribute which encodes
the data location from the next to the field itself.

The '__data_loc' is used for encoding the dynamic data location on
the trace event record. But '__data_loc' is not useful if the writer
doesn't know the event header (e.g. user event), because it records
the dynamic data offset from the entry of the record, not the field
itself.

This new '__rel_loc' attribute encodes the data location relatively
from the next of the field. For example, when there is a record like
below (the number in the parentheses is the size of fields)

 |header(N)|common(M)|fields(K)|__data_loc(4)|fields(L)|data(G)|

In this case, '__data_loc' field will be

 __data_loc = (G << 16) | (N+M+K+4+L)

If '__rel_loc' is used, this will be

 |header(N)|common(M)|fields(K)|__rel_loc(4)|fields(L)|data(G)|

where

 __rel_loc = (G << 16) | (L)

This case shows L bytes after the '__rel_loc' attribute  field,
if there is no fields after the __rel_loc field, L must be 0.

This is relatively easy (and no need to consider the kernel header
change) when the event data fields are composed by user who doesn't
know header and common fields.

Link: https://lkml.kernel.org/r/163757341258.510314.4214431827833229956.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 15:37:21 -05:00