Commit 99d8ae4e authored by Jakob Koschel's avatar Jakob Koschel Committed by Steven Rostedt (Google)
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tracing: Remove usage of list iterator variable after the loop 

In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element
[1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Link: https://lkml.kernel.org/r/20220427170734.819891-3-jakobkoschel@gmail.com



Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: default avatarJakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1da27a25

kernel/trace/trace_events.c

+7 −8
Original line number Diff line number Diff line
@@ -1723,9 +1723,9 @@ static LIST_HEAD(event_subsystems); 


static int subsystem_open(struct inode *inode, struct file *filp)

{

	struct trace_subsystem_dir *dir = NULL, *iter_dir;

	struct trace_array *tr = NULL, *iter_tr;

	struct event_subsystem *system = NULL;

	struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */

	struct trace_array *tr;

	int ret;



	if (tracing_is_disabled())
@@ -1734,10 +1734,12 @@ static int subsystem_open(struct inode *inode, struct file *filp) 
	/* Make sure the system still exists */

	mutex_lock(&event_mutex);

	mutex_lock(&trace_types_lock);

	list_for_each_entry(tr, &ftrace_trace_arrays, list) {

		list_for_each_entry(dir, &tr->systems, list) {

			if (dir == inode->i_private) {

	list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) {

		list_for_each_entry(iter_dir, &iter_tr->systems, list) {

			if (iter_dir == inode->i_private) {

				/* Don't open systems with no events */

				tr = iter_tr;

				dir = iter_dir;

				if (dir->nr_events) {

					__get_system_dir(dir);

					system = dir->subsystem;
@@ -1753,9 +1755,6 @@ static int subsystem_open(struct inode *inode, struct file *filp) 
	if (!system)

		return -ENODEV;



	/* Some versions of gcc think dir can be uninitialized here */

	WARN_ON(!dir);



	/* Still need to increment the ref count of the system */

	if (trace_array_get(tr) < 0) {

		put_system(dir);