Messages in this thread Patch in this message |  | | From | Jakob Koschel <> | Subject | [PATCH v2 2/4] tracing: Remove usage of list iterator variable after the loop | Date | Sat, 2 Apr 2022 12:33:39 +0200 |
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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] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> --- kernel/trace/trace_events.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e11e167b7809..97c7eb2f55e5 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -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()) @@ -1734,14 +1734,16 @@ 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 */ - if (dir->nr_events) { + if (iter_dir->nr_events) { __get_system_dir(dir); system = dir->subsystem; } + tr = iter_tr; + dir = iter_dir; goto exit_loop; } } @@ -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); -- 2.25.1
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