[patch V4 part 1 15/36] kprobes: Lock kprobe_mutex while showing kprobe_blacklist

Thomas Gleixner
2020-05-05T14:13:59Z

From: Masami Hiramatsu <mhiramat@kernel.org>

Lock kprobe_mutex while showing kprobe_blacklist to prevent updating the
kprobe_blacklist.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/158523417665.24735.10253198878535635600.stgit@devnote2

---
kernel/kprobes.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2426,6 +2426,7 @@ static const struct file_operations debu
/* kprobes/blacklist -- shows which functions can not be probed */
static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos)
{
+ mutex_lock(&kprobe_mutex);
return seq_list_start(&kprobe_blacklist, *pos);
}

@@ -2452,10 +2453,15 @@ static int kprobe_blacklist_seq_show(str
return 0;
}

+static void kprobe_blacklist_seq_stop(struct seq_file *f, void *v)
+{
+ mutex_unlock(&kprobe_mutex);
+}
+
static const struct seq_operations kprobe_blacklist_seq_ops = {
.start = kprobe_blacklist_seq_start,
.next = kprobe_blacklist_seq_next,
- .stop = kprobe_seq_stop, /* Reuse void function */
+ .stop = kprobe_blacklist_seq_stop,
.show = kprobe_blacklist_seq_show,
};