From 5a5d7e9badd2cb8065db171961bd30bd3595e4b6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 26 Jan 2023 16:08:31 +0100 Subject: cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG In order to avoid WARN/BUG from generating nested or even recursive warnings, force rcu_is_watching() true during WARN/lockdep_rcu_suspicious(). Notably things like unwinding the stack can trigger rcu_dereference() warnings, which then triggers more unwinding which then triggers more warnings etc.. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230126151323.408156109@infradead.org --- kernel/locking/lockdep.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/locking') diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e3375bc40dad..50d4863974e7 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -55,6 +55,7 @@ #include #include #include +#include #include @@ -6555,6 +6556,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) { struct task_struct *curr = current; int dl = READ_ONCE(debug_locks); + bool rcu = warn_rcu_enter(); /* Note: the following can be executed concurrently, so be careful. */ pr_warn("\n"); @@ -6595,5 +6597,6 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) lockdep_print_held_locks(curr); pr_warn("\nstack backtrace:\n"); dump_stack(); + warn_rcu_exit(rcu); } EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious); -- cgit v1.2.3