The last rescheduling opportunity while resuming to user is in exit_to_user_mode_loop(). This means that any wake up performed on the local runqueue after this point is going to have its rescheduling silently ignored. Perform sanity checks to report these situations. Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar<mingo@xxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxx> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- kernel/entry/common.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 8f3292b5f9b7..1dfb97762336 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -5,6 +5,7 @@ #include <linux/highmem.h> #include <linux/livepatch.h> #include <linux/audit.h> +#include <linux/sched.h> #include "common.h" @@ -23,6 +24,8 @@ static __always_inline void __enter_from_user_mode(struct pt_regs *regs) instrumentation_begin(); trace_hardirqs_off_finish(); instrumentation_end(); + + sched_resched_local_allow(); } void noinstr enter_from_user_mode(struct pt_regs *regs) @@ -206,6 +209,7 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs) if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) ti_work = exit_to_user_mode_loop(regs, ti_work); + sched_resched_local_forbid(); arch_exit_to_user_mode_prepare(regs, ti_work); /* Ensure that the address limit is intact and no locks are held */ -- 2.25.1
