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| author | Jakob Koschel <jakobkoschel@gmail.com> | 2022-04-27 19:07:32 +0200 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-04-27 17:19:30 -0400 |
| commit | 99d8ae4ec8a90ecf6c2a6a141bd4db4a3bc5146c (patch) | |
| tree | aacec8774ced46e00cf29259b3cc23edd306851d /kernel/trace | |
| parent | 1da27a25054f7660f7bb27ad4ccf036ee6ba51e9 (diff) | |
| download | lwn-99d8ae4ec8a90ecf6c2a6a141bd4db4a3bc5146c.tar.gz lwn-99d8ae4ec8a90ecf6c2a6a141bd4db4a3bc5146c.zip | |
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: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_events.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e11e167b7809..e4a442060707 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()) @@ -1734,10 +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); |