smp_call_function_interrupt: use typedef and %pf

Use the newly added smp_call_func_t in smp_call_function_interrupt for
the func variable, and make the comment above the WARN more assertive
and explicit.  Also, func is a function pointer and does not need an
offset, so use %pf not %pS.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/smp.c b/kernel/smp.c
index 954548906afbe870e979eb350253e05a4bd04fd8..7cbd0f293df4484682e18ae637cc5cbcd2ba87ba 100644 (file)
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -194,7 +194,7 @@ void generic_smp_call_function_interrupt(void)
         */
        list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
                int refs;
-               void (*func) (void *info);
+               smp_call_func_t func;
 
                /*
                 * Since we walk the list without any locks, we might
@@ -214,17 +214,17 @@ void generic_smp_call_function_interrupt(void)
                if (atomic_read(&data->refs) == 0)
                        continue;
 
-               func = data->csd.func;                  /* for later warn */
-               data->csd.func(data->csd.info);
+               func = data->csd.func;          /* save for later warn */
+               func(data->csd.info);
 
                /*
-                * If the cpu mask is not still set then it enabled interrupts,
-                * we took another smp interrupt, and executed the function
-                * twice on this cpu.  In theory that copy decremented refs.
+                * If the cpu mask is not still set then func enabled
+                * interrupts (BUG), and this cpu took another smp call
+                * function interrupt and executed func(info) twice
+                * on this cpu.  That nested execution decremented refs.
                 */
                if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) {
-                       WARN(1, "%pS enabled interrupts and double executed\n",
-                            func);
+                       WARN(1, "%pf enabled interrupts and double executed\n", func);
                        continue;
                }