ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms

Add synchronize_rcu() after list_del_rcu() in
ftrace_remove_trampoline_from_kallsyms() to protect readers of
ftrace_ops_trampoline_list (in ftrace_get_trampoline_kallsym)
which is used when kallsyms is read.

Link: https://lkml.kernel.org/r/20200901091617.31837-1-adrian.hunter@intel.com

Fixes: fc0ea795f5 ("ftrace: Add symbols for ftrace trampolines")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Adrian Hunter 2020-09-01 12:16:17 +03:00 committed by Steven Rostedt (VMware)
parent d5e47505e0
commit 478ece9573

View File

@ -2782,6 +2782,7 @@ static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
{
lockdep_assert_held(&ftrace_lock);
list_del_rcu(&ops->list);
synchronize_rcu();
}
/*