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-rw-r--r--kernel/trace/ftrace.c72
1 files changed, 18 insertions, 54 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index bce9e01a29c8..217caeca71cd 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1017,71 +1017,35 @@ static int
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ftrace_addr;
- unsigned long ip, fl;
+ unsigned long flag = 0UL;
ftrace_addr = (unsigned long)FTRACE_ADDR;
- ip = rec->ip;
-
/*
- * If this record is not to be traced and
- * it is not enabled then do nothing.
+ * If this record is not to be traced or we want to disable it,
+ * then disable it.
*
- * If this record is not to be traced and
- * it is enabled then disable it.
+ * If we want to enable it and filtering is off, then enable it.
*
+ * If we want to enable it and filtering is on, enable it only if
+ * it's filtered
*/
- if (rec->flags & FTRACE_FL_NOTRACE) {
- if (rec->flags & FTRACE_FL_ENABLED)
- rec->flags &= ~FTRACE_FL_ENABLED;
- else
- return 0;
-
- } else if (ftrace_filtered && enable) {
- /*
- * Filtering is on:
- */
-
- fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
-
- /* Record is filtered and enabled, do nothing */
- if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
- return 0;
-
- /* Record is not filtered or enabled, do nothing */
- if (!fl)
- return 0;
-
- /* Record is not filtered but enabled, disable it */
- if (fl == FTRACE_FL_ENABLED)
- rec->flags &= ~FTRACE_FL_ENABLED;
- else
- /* Otherwise record is filtered but not enabled, enable it */
- rec->flags |= FTRACE_FL_ENABLED;
- } else {
- /* Disable or not filtered */
-
- if (enable) {
- /* if record is enabled, do nothing */
- if (rec->flags & FTRACE_FL_ENABLED)
- return 0;
-
- rec->flags |= FTRACE_FL_ENABLED;
-
- } else {
+ if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) {
+ if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
+ flag = FTRACE_FL_ENABLED;
+ }
- /* if record is not enabled, do nothing */
- if (!(rec->flags & FTRACE_FL_ENABLED))
- return 0;
+ /* If the state of this record hasn't changed, then do nothing */
+ if ((rec->flags & FTRACE_FL_ENABLED) == flag)
+ return 0;
- rec->flags &= ~FTRACE_FL_ENABLED;
- }
+ if (flag) {
+ rec->flags |= FTRACE_FL_ENABLED;
+ return ftrace_make_call(rec, ftrace_addr);
}
- if (rec->flags & FTRACE_FL_ENABLED)
- return ftrace_make_call(rec, ftrace_addr);
- else
- return ftrace_make_nop(NULL, rec, ftrace_addr);
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
}
static void ftrace_replace_code(int enable)