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>

2 files changed, 16 insertions, 17 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 4a13e5a01ce3..61071fecc82e 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -147,7 +147,7 @@ config IRQSOFF_TRACER
           disabled by default and can be runtime (re-)started
           via:
 
-              echo 0 > /debugfs/tracing/tracing_max_latency
+              echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
 
           (Note that kernel size and overhead increases with this option
           enabled. This option and the preempt-off timing option can be
@@ -168,7 +168,7 @@ config PREEMPT_TRACER
           disabled by default and can be runtime (re-)started
           via:
 
-              echo 0 > /debugfs/tracing/tracing_max_latency
+              echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
 
           (Note that kernel size and overhead increases with this option
           enabled. This option and the irqs-off timing option can be
@@ -261,7 +261,7 @@ config PROFILE_ANNOTATED_BRANCHES
           This tracer profiles all the the likely and unlikely macros
           in the kernel. It will display the results in:
 
-          /debugfs/tracing/profile_annotated_branch
+          /sys/kernel/debug/tracing/profile_annotated_branch
 
           Note: this will add a significant overhead, only turn this
           on if you need to profile the system's use of these macros.
@@ -274,7 +274,7 @@ config PROFILE_ALL_BRANCHES
           taken in the kernel is recorded whether it hit or miss.
           The results will be displayed in:
 
-          /debugfs/tracing/profile_branch
+          /sys/kernel/debug/tracing/profile_branch
 
           This option also enables the likely/unlikely profiler.
 
@@ -323,7 +323,7 @@ config STACK_TRACER
         select KALLSYMS
         help
           This special tracer records the maximum stack footprint of the
-          kernel and displays it in debugfs/tracing/stack_trace.
+          kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
 
           This tracer works by hooking into every function call that the
           kernel executes, and keeping a maximum stack depth value and
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8acd9b81a5d7..c1878bfb2e1e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -344,7 +344,7 @@ static raw_spinlock_t ftrace_max_lock =
 /*
  * Copy the new maximum trace into the separate maximum-trace
  * structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /debugfs/tracing/latency_trace)
+ * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
  */
 static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
@@ -2414,21 +2414,20 @@ static const struct file_operations tracing_iter_fops = {
 
 static const char readme_msg[] =
         "tracing mini-HOWTO:\n\n"
-        "# mkdir /debug\n"
-        "# mount -t debugfs nodev /debug\n\n"
-        "# cat /debug/tracing/available_tracers\n"
+        "# mount -t debugfs nodev /sys/kernel/debug\n\n"
+        "# cat /sys/kernel/debug/tracing/available_tracers\n"
         "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
-        "# cat /debug/tracing/current_tracer\n"
+        "# cat /sys/kernel/debug/tracing/current_tracer\n"
         "nop\n"
-        "# echo sched_switch > /debug/tracing/current_tracer\n"
-        "# cat /debug/tracing/current_tracer\n"
+        "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n"
+        "# cat /sys/kernel/debug/tracing/current_tracer\n"
         "sched_switch\n"
-        "# cat /debug/tracing/trace_options\n"
+        "# cat /sys/kernel/debug/tracing/trace_options\n"
         "noprint-parent nosym-offset nosym-addr noverbose\n"
-        "# echo print-parent > /debug/tracing/trace_options\n"
-        "# echo 1 > /debug/tracing/tracing_enabled\n"
-        "# cat /debug/tracing/trace > /tmp/trace.txt\n"
-        "# echo 0 > /debug/tracing/tracing_enabled\n"
+        "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"
+        "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n"
+        "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n"
+        "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n"
 ;
 
 static ssize_t