Merge tag 'linux_kselftest-kunit-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit updates from Shuah Khan:
 "Fixes to tool and kunit core and new features to both to support JUnit
  XML (primitive) and backtrace suppression API:
   - Core support for suppressing warning backtraces
   - Parse and print the reason tests are skipped
   - Add (primitive) support for outputting JUnit XML
   - Don't write to stdout when it should be disabled
   - Add backtrace suppression self-tests
   - Suppress intentional warning backtraces in scaling unit tests
   - Add documentation for warning backtrace suppression API
   - Fix spelling mistakes in comments and messages
   - gen_compile_commands: Ignore libgcc.a
   - qemu_configs: Add or1k / openrisc configuration"

* tag 'linux_kselftest-kunit-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit:tool: Don't write to stdout when it should be disabled
  kunit: tool: Add (primitive) support for outputting JUnit XML
  kunit: tool: Parse and print the reason tests are skipped
  kunit: Add documentation for warning backtrace suppression API
  drm: Suppress intentional warning backtraces in scaling unit tests
  kunit: Add backtrace suppression self-tests
  bug/kunit: Core support for suppressing warning backtraces
  kunit: Fix spelling mistakes in comments and messages
  kunit: qemu_configs: Add or1k / openrisc configuration
  gen_compile_commands: Ignore libgcc.a

2 files changed, 124 insertions, 0 deletions

diff --git a/include/kunit/test-bug.h b/include/kunit/test-bug.h
index 47aa8f21ccce..99869029fc68 100644
--- a/include/kunit/test-bug.h
+++ b/include/kunit/test-bug.h
@@ -10,6 +10,7 @@
 #define _KUNIT_TEST_BUG_H
 
 #include <linux/stddef.h> /* for NULL */
+#include <linux/types.h>  /* for bool */
 
 #if IS_ENABLED(CONFIG_KUNIT)
 
@@ -23,6 +24,7 @@ DECLARE_STATIC_KEY_FALSE(kunit_running);
 extern struct kunit_hooks_table {
 	__printf(3, 4) void (*fail_current_test)(const char*, int, const char*, ...);
 	void *(*get_static_stub_address)(struct kunit *test, void *real_fn_addr);
+	bool (*is_suppressed_warning)(bool count);
 } kunit_hooks;
 
 /**
@@ -60,9 +62,33 @@ static inline struct kunit *kunit_get_current_test(void)
 		}								\
 	} while (0)
 
+/**
+ * kunit_is_suppressed_warning() - Check if warnings are being suppressed
+ *                                 by the current KUnit test.
+ * @count: if true, increment the suppression counter on match.
+ *
+ * Returns true if the current task has active warning suppression.
+ * Uses the kunit_running static branch for zero overhead when no tests run.
+ *
+ * A single WARN*() may traverse multiple call sites in the warning path
+ * (e.g., __warn_printk() and __report_bug()). Pass @count = true at the
+ * primary suppression point to count each warning exactly once, and
+ * @count = false at secondary points to suppress output without
+ * inflating the count.
+ */
+static inline bool kunit_is_suppressed_warning(bool count)
+{
+	if (!static_branch_unlikely(&kunit_running))
+		return false;
+
+	return kunit_hooks.is_suppressed_warning &&
+	       kunit_hooks.is_suppressed_warning(count);
+}
+
 #else
 
 static inline struct kunit *kunit_get_current_test(void) { return NULL; }
+static inline bool kunit_is_suppressed_warning(bool count) { return false; }
 
 #define kunit_fail_current_test(fmt, ...) do {} while (0)
 
diff --git a/include/kunit/test.h b/include/kunit/test.h
index ce0573e196ce..e52452e58305 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -1796,4 +1796,102 @@ do {									       \
 // include resource.h themselves if they need it.
 #include <kunit/resource.h>
 
+/*
+ * Warning backtrace suppression API.
+ *
+ * Suppresses WARN*() backtraces on the current task while active. Two forms
+ * are provided:
+ *
+ * - Scoped: kunit_warning_suppress(test) { ... }
+ *   Suppression is active for the duration of the block. On normal exit,
+ *   the for-loop increment deactivates suppression. On early exit (break,
+ *   return, goto), the __cleanup attribute fires. On kthread_exit() (e.g.,
+ *   a failed KUnit assertion), kunit_add_action() cleans up at test
+ *   teardown. The suppression handle is only accessible inside the block,
+ *   so warning counts must be checked before the block exits.
+ *
+ * - Direct: kunit_start_suppress_warning() / kunit_end_suppress_warning()
+ *   The underlying functions, returning an explicit handle pointer. Use
+ *   when the handle needs to be retained (e.g., for post-suppression
+ *   count checks) or passed across helper functions.
+ */
+struct kunit_suppressed_warning;
+
+struct kunit_suppressed_warning *
+kunit_start_suppress_warning(struct kunit *test);
+void kunit_end_suppress_warning(struct kunit *test,
+				struct kunit_suppressed_warning *w);
+int kunit_suppressed_warning_count(struct kunit_suppressed_warning *w);
+void __kunit_suppress_auto_cleanup(struct kunit_suppressed_warning **wp);
+bool kunit_has_active_suppress_warning(void);
+
+/**
+ * kunit_warning_suppress() - Suppress WARN*() backtraces for the duration
+ *                            of a block.
+ * @test: The test context object.
+ *
+ * Scoped form of the suppression API. Suppression starts when the block is
+ * entered and ends automatically when the block exits through any path. See
+ * the section comment above for the cleanup guarantees on each exit path.
+ * Fails the test if suppression is already active; nesting is not supported.
+ *
+ * The warning count can be checked inside the block via
+ * KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(). The handle is not accessible
+ * after the block exits.
+ *
+ * Example::
+ *
+ *   kunit_warning_suppress(test) {
+ *       trigger_warning();
+ *       KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+ *   }
+ */
+#define kunit_warning_suppress(test)					\
+	for (struct kunit_suppressed_warning *__kunit_suppress		\
+	     __cleanup(__kunit_suppress_auto_cleanup) =			\
+	     kunit_start_suppress_warning(test);			\
+	     __kunit_suppress;						\
+	     kunit_end_suppress_warning(test, __kunit_suppress),	\
+	     __kunit_suppress = NULL)
+
+/**
+ * KUNIT_SUPPRESSED_WARNING_COUNT() - Returns the suppressed warning count.
+ *
+ * Returns the number of WARN*() calls suppressed since the current
+ * suppression block started, or 0 if the handle is NULL. Usable inside a
+ * kunit_warning_suppress() block.
+ */
+#define KUNIT_SUPPRESSED_WARNING_COUNT() \
+	kunit_suppressed_warning_count(__kunit_suppress)
+
+/**
+ * KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT() - Sets an expectation that the
+ *                                           suppressed warning count equals
+ *                                           @expected.
+ * @test: The test context object.
+ * @expected: an expression that evaluates to the expected warning count.
+ *
+ * Sets an expectation that the number of suppressed WARN*() calls equals
+ * @expected. This is semantically equivalent to
+ * KUNIT_EXPECT_EQ(@test, KUNIT_SUPPRESSED_WARNING_COUNT(), @expected).
+ * See KUNIT_EXPECT_EQ() for more information.
+ */
+#define KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, expected) \
+	KUNIT_EXPECT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(), expected)
+
+/**
+ * KUNIT_ASSERT_SUPPRESSED_WARNING_COUNT() - Sets an assertion that the
+ *                                           suppressed warning count equals
+ *                                           @expected.
+ * @test: The test context object.
+ * @expected: an expression that evaluates to the expected warning count.
+ *
+ * Sets an assertion that the number of suppressed WARN*() calls equals
+ * @expected. This is the same as KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(),
+ * except it causes an assertion failure (see KUNIT_ASSERT_TRUE()) when the
+ * assertion is not met.
+ */
+#define KUNIT_ASSERT_SUPPRESSED_WARNING_COUNT(test, expected) \
+	KUNIT_ASSERT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(), expected)
+
 #endif /* _KUNIT_TEST_H */