[PATCH 2/3] rcu: Fix rcu_dynticks_curr_cpu_in_eqs() vs noinstr

From: Peter Zijlstra
Date: Tue Sep 28 2021 - 04:43:27 EST


vmlinux.o: warning: objtool: rcu_nmi_enter()+0x36: call to __kasan_check_read() leaves .noinstr.text section

noinstr cannot have atomic_*() functions in because they're explicitly
annotated, use arch_atomic_*().

Fixes: 2be57f732889 ("rcu: Weaken ->dynticks accesses and updates")
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -327,7 +327,7 @@ static void rcu_dynticks_eqs_online(void
*/
static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void)
{
- return !(atomic_read(this_cpu_ptr(&rcu_data.dynticks)) & 0x1);
+ return !(arch_atomic_read(this_cpu_ptr(&rcu_data.dynticks)) & 0x1);
}

/*