diff options
| author | Zhaolei <zhaolei@cn.fujitsu.com> | 2009-03-25 12:06:05 +0800 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-03-25 17:45:36 -0400 |
| commit | 2a4efa42450762cbfa5c5712aa4cc9f06924c9fd (patch) | |
| tree | 70af0a079541af99dec634fc89ce317dee2f1a33 | |
| parent | 759ee0915dd713361e72facb78b66600b5712d65 (diff) | |
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
"Because when we call ftrace_free_rec we change the rec->ip to point to the
next record in the chain. Something is very wrong if rec->ip >= s &&
rec->ip < e and the record is already free."
"Note, use FTRACE_WARN_ON() macro. This way it shuts down ftrace if it is
hit and helps to avoid further damage later."
-- Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| -rw-r--r-- | kernel/trace/ftrace.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7b8722baf15..1752a63f37c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -358,9 +358,14 @@ void ftrace_release(void *start, unsigned long size) mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { - if ((rec->ip >= s) && (rec->ip < e) && - !(rec->flags & FTRACE_FL_FREE)) + if ((rec->ip >= s) && (rec->ip < e)) { + /* + * rec->ip is changed in ftrace_free_rec() + * It should not between s and e if record was freed. + */ + FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); ftrace_free_rec(rec); + } } while_for_each_ftrace_rec(); mutex_unlock(&ftrace_lock); } |