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-rw-r--r--kernel/trace/ftrace.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 406d0597c409..83362a155791 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1644,6 +1644,18 @@ ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_ex
static struct ftrace_ops *
ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+static bool skip_record(struct dyn_ftrace *rec)
+{
+ /*
+ * At boot up, weak functions are set to disable. Function tracing
+ * can be enabled before they are, and they still need to be disabled now.
+ * If the record is disabled, still continue if it is marked as already
+ * enabled (this is needed to keep the accounting working).
+ */
+ return rec->flags & FTRACE_FL_DISABLED &&
+ !(rec->flags & FTRACE_FL_ENABLED);
+}
+
static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
int filter_hash,
bool inc)
@@ -1693,7 +1705,7 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
int in_hash = 0;
int match = 0;
- if (rec->flags & FTRACE_FL_DISABLED)
+ if (skip_record(rec))
continue;
if (all) {
@@ -2126,7 +2138,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
ftrace_bug_type = FTRACE_BUG_UNKNOWN;
- if (rec->flags & FTRACE_FL_DISABLED)
+ if (skip_record(rec))
return FTRACE_UPDATE_IGNORE;
/*
@@ -2241,7 +2253,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
if (update) {
/* If there's no more users, clear all flags */
if (!ftrace_rec_count(rec))
- rec->flags = 0;
+ rec->flags &= FTRACE_FL_DISABLED;
else
/*
* Just disable the record, but keep the ops TRAMP
@@ -2634,7 +2646,7 @@ void __weak ftrace_replace_code(int mod_flags)
do_for_each_ftrace_rec(pg, rec) {
- if (rec->flags & FTRACE_FL_DISABLED)
+ if (skip_record(rec))
continue;
failed = __ftrace_replace_code(rec, enable);