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Subject[RFC][PATCH 1/6] ftrace: Remove incorrect setting of glob search field
From: "Steven Rostedt (VMware)" <>

__unregister_ftrace_function_probe() will incorrectly parse the glob filter
because it resets the search variable that was setup by filter_parse_regex().

Al Viro reported this:

After that call of filter_parse_regex() we could have not
equal to glob only if glob started with '!' or '*'. In the former case
we would've buggered off with -EINVAL (not = 1). In the latter we
would've set equal to glob + 1, calculated the length of
that thing in func_g.len and proceeded to reset back to

Suppose the glob is e.g. *foo*. We end up with
func_g.type = MATCH_MIDDLE_ONLY;
func_g.len = 3; = "*foo";
Feeding that to ftrace_match_record() will not do anything sane - we
will be looking for names containing "*foo" (->len is ignored for that


Cc: Dmitry Safonov <>
Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure")
Reported-by: Al Viro <>
Signed-off-by: Steven Rostedt (VMware) <>
kernel/trace/ftrace.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index dabd9d167d42..eac9ce2c57a2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4456,7 +4456,6 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
func_g.type = filter_parse_regex(glob, strlen(glob),
&, &not);
func_g.len = strlen(;
- = glob;

/* we do not support '!' for function probes */
if (WARN_ON(not))

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