tracing: Always use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:

/sys/kernel/debug/tracing

Many comments and Kconfig help messages in the tracing code still refer
to this older debugfs path, so let's update them to avoid confusion.

Link: https://lore.kernel.org/linux-trace-kernel/20230215223350.2658616-2-zwisler@google.com

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

scripts/tracing: Fix typo 'the the' in comment

Replace 'the the' with 'the' in the comment.

Link: https://lkml.kernel.org/r/20220722102907.81949-1-slark_xiao@163.com

Signed-off-by: Slark Xiao <slark_xiao@163.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

scripts/tracing: fix the bug that can't parse raw_trace_func

Since commit 77271ce4b2c0 ("tracing: Add irq, preempt-count and need resched info
to default trace output"), the default trace output format has been changed to:
<idle>-0 [009] d.h. 22420.068695: _raw_spin_lock_irqsave <-hrtimer_interrupt
<idle>-0 [000] ..s. 22420.068695: _nohz_idle_balance <-run_rebalance_domains
<idle>-0 [011] d.h. 22420.068695: account_process_tick <-update_process_times

origin trace output format:(before v3.2.0)
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
migration/0-6 [000] 50.025810: rcu_note_context_switch <-__schedule
migration/0-6 [000] 50.025812: trace_rcu_utilization <-rcu_note_context_switch
migration/0-6 [000] 50.025813: rcu_sched_qs <-rcu_note_context_switch
migration/0-6 [000] 50.025815: rcu_preempt_qs <-rcu_note_context_switch
migration/0-6 [000] 50.025817: trace_rcu_utilization <-rcu_note_context_switch
migration/0-6 [000] 50.025818: debug_lockdep_rcu_enabled <-__schedule
migration/0-6 [000] 50.025820: debug_lockdep_rcu_enabled <-__schedule

The draw_functrace.py(introduced in v2.6.28) can't parse the new version format trace_func,
So we need modify draw_functrace.py to adapt the new version trace output format.

Link: https://lkml.kernel.org/r/20210611022107.608787-1-suhui@zeku.com

Cc: stable@vger.kernel.org
Fixes: 77271ce4b2c0 tracing: Add irq, preempt-count and need resched info to default trace output
Signed-off-by: Hui Su <suhui@zeku.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166

Based on 1 normalized pattern(s):

licensed under the terms of the gnu gpl license version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 62 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.929121379@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts: Add Python 3 support to tracing/draw_functrace.py

Use the print function. This maintains Python 2 support and should have
no functional change.

Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kbuild: Make scripts executable

The Makefiles call the respective interpreter explicitly, but this makes
it easier to use the scripts manually.

Signed-off-by: Michal Marek <mmarek@suse.cz>

debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.

Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/"
directory name to mount debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.

And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.

debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
- debugfs related reference: http://lwn.net/Articles/334546/

Fix inconsistency of directory name to mount debugfs filesystem.

* From Steven Rostedt
- find_debugfs() and tracing_files() in this patch.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Acked-by : Inaky Perez-Gonzalez <inaky@linux.intel.com>
Reviewed-by : Steven Rostedt <rostedt@goodmis.org>
Reviewed-by : James Smart <james.smart@emulex.com>
CC: Jiri Kosina <trivial@kernel.org>
CC: David Airlie <airlied@linux.ie>
CC: Peter Osterlund <petero2@telia.com>
CC: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
CC: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

ftrace: add a script to produce a hierarchical view of a function trace

This script parses a function trace and then produces a hierarchical
view of the function call stack after processing it into a tree.

Changes on V2 thanks to the trace sent by Steven:

- Support both the files "trace" and "trace_pipe" (comments and space
differences)

- Correct the mini HOW-TO at the beginning.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>