1 files changed, 49 insertions, 66 deletions

diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index d8441bed065c..ba924f110c95 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -434,13 +434,11 @@ static void print_report(enum kcsan_value_change value_change,
 
 static void release_report(unsigned long *flags, struct other_info *other_info)
 {
-	if (other_info)
-		/*
-		 * Use size to denote valid/invalid, since KCSAN entirely
-		 * ignores 0-sized accesses.
-		 */
-		other_info->ai.size = 0;
-
+	/*
+	 * Use size to denote valid/invalid, since KCSAN entirely ignores
+	 * 0-sized accesses.
+	 */
+	other_info->ai.size = 0;
 	raw_spin_unlock_irqrestore(&report_lock, *flags);
 }
 
@@ -573,61 +571,6 @@ discard:
 	return false;
 }
 
-/*
- * Depending on the report type either sets @other_info and returns false, or
- * awaits @other_info and returns true. If @other_info is not required for the
- * report type, simply acquires @report_lock and returns true.
- */
-static noinline bool prepare_report(unsigned long *flags,
-				    enum kcsan_report_type type,
-				    const struct access_info *ai,
-				    struct other_info *other_info)
-{
-	switch (type) {
-	case KCSAN_REPORT_CONSUMED_WATCHPOINT:
-		prepare_report_producer(flags, ai, other_info);
-		return false;
-	case KCSAN_REPORT_RACE_SIGNAL:
-		return prepare_report_consumer(flags, ai, other_info);
-	default:
-		/* @other_info not required; just acquire @report_lock. */
-		raw_spin_lock_irqsave(&report_lock, *flags);
-		return true;
-	}
-}
-
-static void kcsan_report(const struct access_info *ai, enum kcsan_value_change value_change,
-			 enum kcsan_report_type type, struct other_info *other_info)
-{
-	unsigned long flags = 0;
-
-	kcsan_disable_current();
-
-	/*
-	 * Because we may generate reports when we're in scheduler code, the use
-	 * of printk() could deadlock. Until such time that all printing code
-	 * called in print_report() is scheduler-safe, accept the risk, and just
-	 * get our message out. As such, also disable lockdep to hide the
-	 * warning, and avoid disabling lockdep for the rest of the kernel.
-	 */
-	lockdep_off();
-
-	if (prepare_report(&flags, type, ai, other_info)) {
-		/*
-		 * Never report if value_change is FALSE, only if we it is
-		 * either TRUE or MAYBE. In case of MAYBE, further filtering may
-		 * be done once we know the full stack trace in print_report().
-		 */
-		if (value_change != KCSAN_VALUE_CHANGE_FALSE)
-			print_report(value_change, type, ai, other_info);
-
-		release_report(&flags, other_info);
-	}
-
-	lockdep_on();
-	kcsan_enable_current();
-}
-
 static struct access_info prepare_access_info(const volatile void *ptr, size_t size,
 					      int access_type)
 {
@@ -644,22 +587,62 @@ void kcsan_report_set_info(const volatile void *ptr, size_t size, int access_typ
 			   int watchpoint_idx)
 {
 	const struct access_info ai = prepare_access_info(ptr, size, access_type);
+	unsigned long flags;
+
+	kcsan_disable_current();
+	lockdep_off(); /* See kcsan_report_known_origin(). */
 
-	kcsan_report(&ai, KCSAN_VALUE_CHANGE_MAYBE, KCSAN_REPORT_CONSUMED_WATCHPOINT,
-		     &other_infos[watchpoint_idx]);
+	prepare_report_producer(&flags, &ai, &other_infos[watchpoint_idx]);
+
+	lockdep_on();
+	kcsan_enable_current();
 }
 
 void kcsan_report_known_origin(const volatile void *ptr, size_t size, int access_type,
 			       enum kcsan_value_change value_change, int watchpoint_idx)
 {
 	const struct access_info ai = prepare_access_info(ptr, size, access_type);
+	struct other_info *other_info = &other_infos[watchpoint_idx];
+	unsigned long flags = 0;
 
-	kcsan_report(&ai, value_change, KCSAN_REPORT_RACE_SIGNAL, &other_infos[watchpoint_idx]);
+	kcsan_disable_current();
+	/*
+	 * Because we may generate reports when we're in scheduler code, the use
+	 * of printk() could deadlock. Until such time that all printing code
+	 * called in print_report() is scheduler-safe, accept the risk, and just
+	 * get our message out. As such, also disable lockdep to hide the
+	 * warning, and avoid disabling lockdep for the rest of the kernel.
+	 */
+	lockdep_off();
+
+	if (!prepare_report_consumer(&flags, &ai, other_info))
+		goto out;
+	/*
+	 * Never report if value_change is FALSE, only when it is
+	 * either TRUE or MAYBE. In case of MAYBE, further filtering may
+	 * be done once we know the full stack trace in print_report().
+	 */
+	if (value_change != KCSAN_VALUE_CHANGE_FALSE)
+		print_report(value_change, KCSAN_REPORT_RACE_SIGNAL, &ai, other_info);
+
+	release_report(&flags, other_info);
+out:
+	lockdep_on();
+	kcsan_enable_current();
 }
 
 void kcsan_report_unknown_origin(const volatile void *ptr, size_t size, int access_type)
 {
 	const struct access_info ai = prepare_access_info(ptr, size, access_type);
+	unsigned long flags;
+
+	kcsan_disable_current();
+	lockdep_off(); /* See kcsan_report_known_origin(). */
+
+	raw_spin_lock_irqsave(&report_lock, flags);
+	print_report(KCSAN_VALUE_CHANGE_TRUE, KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, &ai, NULL);
+	raw_spin_unlock_irqrestore(&report_lock, flags);
 
-	kcsan_report(&ai, KCSAN_VALUE_CHANGE_TRUE, KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, NULL);
+	lockdep_on();
+	kcsan_enable_current();
 }