Subject: [PATCH v3 02/15] kunit: bug: Count suppressed warning backtraces

From: Guenter Roeck <[email-masked]>
Date: Wed, 3 Apr 2024 06:19:23 -0700

Count suppressed warning backtraces to enable code which suppresses
warning backtraces to check if the expected backtrace(s) have been
observed.

Using atomics for the backtrace count resulted in build errors on some
architectures due to include file recursion, so use a plain integer
for now.

Acked-by: Dan Carpenter <[email-masked]>
Reviewed-by: Kees Cook <[email-masked]>
Tested-by: Linux Kernel Functional Testing <[email-masked]>
Signed-off-by: Guenter Roeck <[email-masked]>
---
v2:
- Rebased to v6.9-rc1
- Added Tested-by:, Acked-by:, and Reviewed-by: tags
- Introduced KUNIT_SUPPRESS_BACKTRACE configuration option
v3:
- Rebased to v6.9-rc2

 include/kunit/bug.h | 7 ++++++-
 lib/kunit/bug.c     | 4 +++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/kunit/bug.h b/include/kunit/bug.h
index bd0fe047572b..72e9fb23bbd5 100644
--- a/include/kunit/bug.h
+++ b/include/kunit/bug.h
@@ -20,6 +20,7 @@
 struct __suppressed_warning {
 	struct list_head node;
 	const char *function;
+	int counter;
 };
 
 void __start_suppress_warning(struct __suppressed_warning *warning);
@@ -28,7 +29,7 @@ bool __is_suppressed_warning(const char *function);
 
 #define DEFINE_SUPPRESSED_WARNING(func)	\
 	struct __suppressed_warning __kunit_suppress_##func = \
-		{ .function = __stringify(func) }
+		{ .function = __stringify(func), .counter = 0 }
 
 #define START_SUPPRESSED_WARNING(func) \
 	__start_suppress_warning(&__kunit_suppress_##func)
@@ -39,12 +40,16 @@ bool __is_suppressed_warning(const char *function);
 #define IS_SUPPRESSED_WARNING(func) \
 	__is_suppressed_warning(func)
 
+#define SUPPRESSED_WARNING_COUNT(func) \
+	(__kunit_suppress_##func.counter)
+
 #else /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
 
 #define DEFINE_SUPPRESSED_WARNING(func)
 #define START_SUPPRESSED_WARNING(func)
 #define END_SUPPRESSED_WARNING(func)
 #define IS_SUPPRESSED_WARNING(func) (false)
+#define SUPPRESSED_WARNING_COUNT(func) (0)
 
 #endif /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
 #endif /* __ASSEMBLY__ */
diff --git a/lib/kunit/bug.c b/lib/kunit/bug.c
index f93544d7a9d1..13b3d896c114 100644
--- a/lib/kunit/bug.c
+++ b/lib/kunit/bug.c
@@ -32,8 +32,10 @@ bool __is_suppressed_warning(const char *function)
 		return false;
 
 	list_for_each_entry(warning, &suppressed_warnings, node) {
-		if (!strcmp(function, warning->function))
+		if (!strcmp(function, warning->function)) {
+			warning->counter++;
 			return true;
+		}
 	}
 	return false;
 }
-- 
2.39.2