tools headers UAPI: Sync openat2.h with the kernel sources

[linux-2.6-microblaze.git] / kernel / stop_machine.c

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 890b79c..971d8ac 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -42,11 +42,27 @@ struct cpu_stopper {
        struct list_head        works;          /* list of pending works */
 
        struct cpu_stop_work    stop_work;      /* for stop_cpus */
+       unsigned long           caller;
+       cpu_stop_fn_t           fn;
 };
 
 static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
 static bool stop_machine_initialized = false;
 
+void print_stop_info(const char *log_lvl, struct task_struct *task)
+{
+       /*
+        * If @task is a stopper task, it cannot migrate and task_cpu() is
+        * stable.
+        */
+       struct cpu_stopper *stopper = per_cpu_ptr(&cpu_stopper, task_cpu(task));
+
+       if (task != stopper->thread)
+               return;
+
+       printk("%sStopper: %pS <- %pS\n", log_lvl, stopper->fn, (void *)stopper->caller);
+}
+
 /* static data for stop_cpus */
 static DEFINE_MUTEX(stop_cpus_mutex);
 static bool stop_cpus_in_progress;
@@ -123,7 +139,7 @@ static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
 int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
 {
        struct cpu_stop_done done;
-       struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done };
+       struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done, .caller = _RET_IP_ };
 
        cpu_stop_init_done(&done, 1);
        if (!cpu_stop_queue_work(cpu, &work))
@@ -331,7 +347,8 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
        work1 = work2 = (struct cpu_stop_work){
                .fn = multi_cpu_stop,
                .arg = &msdata,
-               .done = &done
+               .done = &done,
+               .caller = _RET_IP_,
        };
 
        cpu_stop_init_done(&done, 2);
@@ -367,7 +384,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 bool stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
                        struct cpu_stop_work *work_buf)
 {
-       *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, };
+       *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, .caller = _RET_IP_, };
        return cpu_stop_queue_work(cpu, work_buf);
 }
 
@@ -487,6 +504,8 @@ repeat:
                int ret;
 
                /* cpu stop callbacks must not sleep, make in_atomic() == T */
+               stopper->caller = work->caller;
+               stopper->fn = fn;
                preempt_count_inc();
                ret = fn(arg);
                if (done) {
@@ -495,6 +514,8 @@ repeat:
                        cpu_stop_signal_done(done);
                }
                preempt_count_dec();
+               stopper->fn = NULL;
+               stopper->caller = 0;
                WARN_ONCE(preempt_count(),
                          "cpu_stop: %ps(%p) leaked preempt count\n", fn, arg);
                goto repeat;