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tracing: Remove usage of list iterator after the loop body

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

Before, the code implicitly used the head when no element was found
when using &pos->list. Since the new variable is only set if an
element was found, the head needs to be used explicitly if the
variable is NULL.

Link: https://lkml.kernel.org/r/20220427170734.819891-2-jakobkoschel@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Jakob Koschel
2022-04-27 19:07:31 +02:00
committed by Steven Rostedt (Google)
parent 4d1257bbc2
commit 1da27a2505
1 changed files with 9 additions and 4 deletions
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13
kernel/trace/trace_output.c
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@ -692,7 +692,7 @@ static LIST_HEAD(ftrace_event_list);
static int trace_search_list(struct list_head **list) static int trace_search_list(struct list_head **list)
{ {
struct trace_event *e; struct trace_event *e = NULL, *iter;
int next = __TRACE_LAST_TYPE; int next = __TRACE_LAST_TYPE;
if (list_empty(&ftrace_event_list)) { if (list_empty(&ftrace_event_list)) {
@ -704,9 +704,11 @@ static int trace_search_list(struct list_head **list)
* We used up all possible max events, * We used up all possible max events,
* lets see if somebody freed one. * lets see if somebody freed one.
*/ */
list_for_each_entry(e, &ftrace_event_list, list) { list_for_each_entry(iter, &ftrace_event_list, list) {
if (e->type != next) if (iter->type != next) {
e = iter;
break; break;
}
next++; next++;
} }
@ -714,7 +716,10 @@ static int trace_search_list(struct list_head **list)
if (next > TRACE_EVENT_TYPE_MAX) if (next > TRACE_EVENT_TYPE_MAX)
return 0; return 0;
*list = &e->list; if (e)
*list = &e->list;
else
*list = &ftrace_event_list;
return next; return next;
} }