kcsan: Simplify debugfs counter to name mapping

Simplify counter ID to name mapping by using an array with designated
inits. This way, we can turn a run-time BUG() into a compile-time static
assertion failure if a counter name is missing.

No functional change intended.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
index 023e49c..3a9566a 100644 (file)
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -19,6 +19,18 @@
  * Statistics counters.
  */
 static atomic_long_t counters[KCSAN_COUNTER_COUNT];
+static const char *const counter_names[] = {
+       [KCSAN_COUNTER_USED_WATCHPOINTS]                = "used_watchpoints",
+       [KCSAN_COUNTER_SETUP_WATCHPOINTS]               = "setup_watchpoints",
+       [KCSAN_COUNTER_DATA_RACES]                      = "data_races",
+       [KCSAN_COUNTER_ASSERT_FAILURES]                 = "assert_failures",
+       [KCSAN_COUNTER_NO_CAPACITY]                     = "no_capacity",
+       [KCSAN_COUNTER_REPORT_RACES]                    = "report_races",
+       [KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN]            = "races_unknown_origin",
+       [KCSAN_COUNTER_UNENCODABLE_ACCESSES]            = "unencodable_accesses",
+       [KCSAN_COUNTER_ENCODING_FALSE_POSITIVES]        = "encoding_false_positives",
+};
+static_assert(ARRAY_SIZE(counter_names) == KCSAN_COUNTER_COUNT);
 
 /*
  * Addresses for filtering functions from reporting. This list can be used as a
@@ -39,24 +51,6 @@ static struct {
 };
 static DEFINE_SPINLOCK(report_filterlist_lock);
 
-static const char *counter_to_name(enum kcsan_counter_id id)
-{
-       switch (id) {
-       case KCSAN_COUNTER_USED_WATCHPOINTS:            return "used_watchpoints";
-       case KCSAN_COUNTER_SETUP_WATCHPOINTS:           return "setup_watchpoints";
-       case KCSAN_COUNTER_DATA_RACES:                  return "data_races";
-       case KCSAN_COUNTER_ASSERT_FAILURES:             return "assert_failures";
-       case KCSAN_COUNTER_NO_CAPACITY:                 return "no_capacity";
-       case KCSAN_COUNTER_REPORT_RACES:                return "report_races";
-       case KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN:        return "races_unknown_origin";
-       case KCSAN_COUNTER_UNENCODABLE_ACCESSES:        return "unencodable_accesses";
-       case KCSAN_COUNTER_ENCODING_FALSE_POSITIVES:    return "encoding_false_positives";
-       case KCSAN_COUNTER_COUNT:
-               BUG();
-       }
-       return NULL;
-}
-
 void kcsan_counter_inc(enum kcsan_counter_id id)
 {
        atomic_long_inc(&counters[id]);
@@ -271,8 +265,7 @@ static int show_info(struct seq_file *file, void *v)
        /* show stats */
        seq_printf(file, "enabled: %i\n", READ_ONCE(kcsan_enabled));
        for (i = 0; i < KCSAN_COUNTER_COUNT; ++i)
-               seq_printf(file, "%s: %ld\n", counter_to_name(i),
-                          atomic_long_read(&counters[i]));
+               seq_printf(file, "%s: %ld\n", counter_names[i], atomic_long_read(&counters[i]));
 
        /* show filter functions, and filter type */
        spin_lock_irqsave(&report_filterlist_lock, flags);