Messages in this thread Patch in this message |  | | From | Jakob Koschel <> | Subject | [PATCH v2 3/4] tracing: Replace usage of found with dedicated list iterator variable | Date | Sat, 2 Apr 2022 12:33:40 +0200 |
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To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body.
To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable instead of a found boolean [1].
This removes the need to use a found variable and simply checking if the variable was set, can determine if the break/goto was hit.
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_hist.c | 17 ++++++++--------- kernel/trace/trace_events_trigger.c | 28 +++++++++++++--------------- 2 files changed, 21 insertions(+), 24 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 44db5ba9cabb..7f60d04d5b6e 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -6089,32 +6089,31 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_data *data, struct trace_event_file *file) { + struct event_trigger_data *test = NULL, *iter, *named_data = NULL; struct hist_trigger_data *hist_data = data->private_data; - struct event_trigger_data *test, *named_data = NULL; - bool unregistered = false; lockdep_assert_held(&event_mutex); if (hist_data->attrs->name) named_data = find_named_trigger(hist_data->attrs->name); - list_for_each_entry(test, &file->triggers, list) { - if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - if (!hist_trigger_match(data, test, named_data, false)) + list_for_each_entry(iter, &file->triggers, list) { + if (iter->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, iter, named_data, false)) continue; - unregistered = true; - list_del_rcu(&test->list); + test = iter; + list_del_rcu(&iter->list); trace_event_trigger_enable_disable(file, 0); update_cond_flag(file); break; } } - if (unregistered && test->ops->free) + if (test && test->ops->free) test->ops->free(test->ops, test); if (hist_data->enable_timestamps) { - if (!hist_data->remove || unregistered) + if (!hist_data->remove || test) tracing_set_filter_buffering(file->tr, false); } } diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 7eb9d04f1c2e..1ba54a489416 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -614,22 +614,21 @@ static void unregister_trigger(char *glob, struct event_trigger_data *test, struct trace_event_file *file) { - struct event_trigger_data *data; - bool unregistered = false; + struct event_trigger_data *data = NULL, *iter; lockdep_assert_held(&event_mutex); - list_for_each_entry(data, &file->triggers, list) { - if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { - unregistered = true; - list_del_rcu(&data->list); + list_for_each_entry(iter, &file->triggers, list) { + if (iter->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { + data = iter; + list_del_rcu(&iter->list); trace_event_trigger_enable_disable(file, 0); update_cond_flag(file); break; } } - if (unregistered && data->ops->free) + if (data && data->ops->free) data->ops->free(data->ops, data); } @@ -1976,27 +1975,26 @@ void event_enable_unregister_trigger(char *glob, struct trace_event_file *file) { struct enable_trigger_data *test_enable_data = test->private_data; + struct event_trigger_data *data = NULL, *iter; struct enable_trigger_data *enable_data; - struct event_trigger_data *data; - bool unregistered = false; lockdep_assert_held(&event_mutex); - list_for_each_entry(data, &file->triggers, list) { - enable_data = data->private_data; + list_for_each_entry(iter, &file->triggers, list) { + enable_data = iter->private_data; if (enable_data && - (data->cmd_ops->trigger_type == + (iter->cmd_ops->trigger_type == test->cmd_ops->trigger_type) && (enable_data->file == test_enable_data->file)) { - unregistered = true; - list_del_rcu(&data->list); + data = iter; + list_del_rcu(&iter->list); trace_event_trigger_enable_disable(file, 0); update_cond_flag(file); break; } } - if (unregistered && data->ops->free) + if (data && data->ops->free) data->ops->free(data->ops, data); } -- 2.25.1
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