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

Documentation/dev-tools/kunit/run_wrapper.rst

@@ -324,6 +324,9 @@ command line arguments:
 - ``--json``: If set, stores the test results in a JSON format and prints to `stdout` or
   saves to a file if a filename is specified.
 
+- ``--junit``: If set, stores the test results in JUnit XML format and prints to `stdout` or
+  saves to a file if a filename is specified.
+
 - ``--filter``: Specifies filters on test attributes, for example, ``speed!=slow``.
   Multiple filters can be used by wrapping input in quotes and separating filters
   by commas. Example: ``--filter "speed>slow, module=example"``.

Documentation/dev-tools/kunit/usage.rst

@@ -157,6 +157,50 @@ Alternatively, one can take full control over the error message by using
 	if (some_setup_function())
 		KUNIT_FAIL(test, "Failed to setup thing for testing");
 
+Suppressing warning backtraces
+------------------------------
+
+Some unit tests trigger warning backtraces either intentionally or as a side
+effect. Such backtraces are normally undesirable since they distract from
+the actual test and may result in the impression that there is a problem.
+
+Backtraces can be suppressed with **task-scoped suppression**: while
+suppression is active on the current task, the backtrace and stack dump from
+``WARN*()``, ``WARN_ON*()``, and related macros on that task are suppressed.
+Two API forms are available.
+
+- Scoped suppression is the simplest form. Wrap the code that triggers
+  warnings in a ``kunit_warning_suppress()`` block:
+
+.. code-block:: c
+
+	static void some_test(struct kunit *test)
+	{
+		kunit_warning_suppress(test) {
+			trigger_backtrace();
+			KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+		}
+	}
+
+.. note::
+   The warning count must be checked inside the block; the suppression handle
+   is not accessible after the block exits.
+
+- Direct functions return an explicit handle pointer. Use them when the handle
+  needs to be retained or passed across helper functions:
+
+.. code-block:: c
+
+	static void some_test(struct kunit *test)
+	{
+		struct kunit_suppressed_warning *w;
+
+		w = kunit_start_suppress_warning(test);
+		trigger_backtrace();
+		kunit_end_suppress_warning(test, w);
+
+		KUNIT_EXPECT_EQ(test, kunit_suppressed_warning_count(w), 1);
+	}
 
 Test Suites
 ~~~~~~~~~~~
@@ -1211,4 +1255,4 @@ For example:
 		dev_managed_string = devm_kstrdup(fake_device, "Hello, World!");
 
 		// Everything is cleaned up automatically when the test ends.
-	}
+	}

drivers/gpu/drm/tests/drm_rect_test.c

@@ -10,6 +10,7 @@
 #include <drm/drm_rect.h>
 #include <drm/drm_mode.h>
 
+#include <linux/limits.h>
 #include <linux/string_helpers.h>
 #include <linux/errno.h>
 
@@ -407,10 +408,27 @@ KUNIT_ARRAY_PARAM(drm_rect_scale, drm_rect_scale_cases, drm_rect_scale_case_desc
 static void drm_test_rect_calc_hscale(struct kunit *test)
 {
 	const struct drm_rect_scale_case *params = test->param_value;
-	int scaling_factor;
+	int expected_warnings = params->expected_scaling_factor == -EINVAL;
+	int scaling_factor = INT_MIN;
 
-	scaling_factor = drm_rect_calc_hscale(&params->src, &params->dst,
-					      params->min_range, params->max_range);
+	/*
+	 * Without CONFIG_BUG, WARN_ON() is a no-op and the suppressed warning
+	 * count stays zero, failing the assertion.
+	 */
+	if (expected_warnings && !IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	/*
+	 * drm_rect_calc_hscale() generates a warning backtrace whenever bad
+	 * parameters are passed to it. This affects unit tests with -EINVAL
+	 * error code in expected_scaling_factor.
+	 */
+	kunit_warning_suppress(test) {
+		scaling_factor = drm_rect_calc_hscale(&params->src, &params->dst,
+						      params->min_range,
+						      params->max_range);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, expected_warnings);
+	}
 
 	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }
@@ -418,10 +436,26 @@ static void drm_test_rect_calc_hscale(struct kunit *test)
 static void drm_test_rect_calc_vscale(struct kunit *test)
 {
 	const struct drm_rect_scale_case *params = test->param_value;
-	int scaling_factor;
+	int expected_warnings = params->expected_scaling_factor == -EINVAL;
+	int scaling_factor = INT_MIN;
 
-	scaling_factor = drm_rect_calc_vscale(&params->src, &params->dst,
-					      params->min_range, params->max_range);
+	/*
+	 * Without CONFIG_BUG, WARN_ON() is a no-op and the suppressed warning
+	 * count stays zero, failing the assertion.
+	 */
+	if (expected_warnings && !IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	/*
+	 * drm_rect_calc_vscale() generates a warning backtrace whenever bad
+	 * parameters are passed to it. This affects unit tests with -EINVAL
+	 * error code in expected_scaling_factor.
+	 */
+	kunit_warning_suppress(test) {
+		scaling_factor = drm_rect_calc_vscale(&params->src, &params->dst,
+						      params->min_range, params->max_range);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, expected_warnings);
+	}
 
 	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }

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)
 

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 */

kernel/panic.c

@@ -39,6 +39,7 @@
 #include <linux/sys_info.h>
 #include <trace/events/error_report.h>
 #include <asm/sections.h>
+#include <kunit/test-bug.h>
 
 #define PANIC_TIMER_STEP 100
 #define PANIC_BLINK_SPD 18
@@ -1124,6 +1125,11 @@ void warn_slowpath_fmt(const char *file, int line, unsigned taint,
 	bool rcu = warn_rcu_enter();
 	struct warn_args args;
 
+	if (kunit_is_suppressed_warning(true)) {
+		warn_rcu_exit(rcu);
+		return;
+	}
+
 	pr_warn(CUT_HERE);
 
 	if (!fmt) {
@@ -1146,6 +1152,11 @@ void __warn_printk(const char *fmt, ...)
 	bool rcu = warn_rcu_enter();
 	va_list args;
 
+	if (kunit_is_suppressed_warning(false)) {
+		warn_rcu_exit(rcu);
+		return;
+	}
+
 	pr_warn(CUT_HERE);
 
 	va_start(args, fmt);

lib/bug.c

@@ -48,6 +48,7 @@
 #include <linux/rculist.h>
 #include <linux/ftrace.h>
 #include <linux/context_tracking.h>
+#include <kunit/test-bug.h>
 
 extern struct bug_entry __start___bug_table[], __stop___bug_table[];
 
@@ -209,8 +210,6 @@ static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long buga
 			return BUG_TRAP_TYPE_NONE;
 	}
 
-	disable_trace_on_warning();
-
 	bug_get_file_line(bug, &file, &line);
 	fmt = bug_get_format(bug);
 
@@ -220,6 +219,17 @@ static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long buga
 	no_cut   = bug->flags & BUGFLAG_NO_CUT_HERE;
 	has_args = bug->flags & BUGFLAG_ARGS;
 
+#ifdef CONFIG_KUNIT
+	/*
+	 * Before the once logic so suppressed warnings do not consume
+	 * the single-fire budget of WARN_ON_ONCE().
+	 */
+	if (warning && kunit_is_suppressed_warning(true))
+		return BUG_TRAP_TYPE_WARN;
+#endif
+
+	disable_trace_on_warning();
+
 	if (warning && once) {
 		if (done)
 			return BUG_TRAP_TYPE_WARN;

lib/kunit/Makefile

@@ -10,7 +10,8 @@ kunit-objs +=				test.o \
 					executor.o \
 					attributes.o \
 					device.o \
-					platform.o
+					platform.o \
+					bug.o
 
 ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
 kunit-objs +=				debugfs.o
@@ -21,6 +22,7 @@ obj-$(if $(CONFIG_KUNIT),y) +=		hooks.o
 
 obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
 obj-$(CONFIG_KUNIT_TEST) +=		platform-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		backtrace-suppression-test.o
 
 # string-stream-test compiles built-in only.
 ifeq ($(CONFIG_KUNIT_TEST),y)

lib/kunit/backtrace-suppression-test.c

@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for suppressing warning tracebacks.
+ *
+ * Copyright (C) 2024, Guenter Roeck
+ * Author: Guenter Roeck <linux@roeck-us.net>
+ */
+
+#include <kunit/test.h>
+#include <linux/bug.h>
+#include <linux/completion.h>
+#include <linux/kthread.h>
+
+static void backtrace_suppression_test_warn_direct(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	kunit_warning_suppress(test) {
+		WARN(1, "This backtrace should be suppressed");
+		/*
+		 * Count must be checked inside the scope; the handle
+		 * is not accessible after the block exits.
+		 */
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+	KUNIT_EXPECT_FALSE(test, kunit_has_active_suppress_warning());
+}
+
+static noinline void trigger_backtrace_warn(void)
+{
+	WARN(1, "This backtrace should be suppressed");
+}
+
+static void backtrace_suppression_test_warn_indirect(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	kunit_warning_suppress(test) {
+		trigger_backtrace_warn();
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+}
+
+static void backtrace_suppression_test_warn_multi(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	kunit_warning_suppress(test) {
+		WARN(1, "This backtrace should be suppressed");
+		trigger_backtrace_warn();
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 2);
+	}
+}
+
+static void backtrace_suppression_test_warn_on_direct(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+	if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE) && !IS_ENABLED(CONFIG_KALLSYMS))
+		kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE or CONFIG_KALLSYMS");
+
+	kunit_warning_suppress(test) {
+		WARN_ON(1);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+}
+
+static noinline void trigger_backtrace_warn_on(void)
+{
+	WARN_ON(1);
+}
+
+static void backtrace_suppression_test_warn_on_indirect(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+	if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE))
+		kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE");
+
+	kunit_warning_suppress(test) {
+		trigger_backtrace_warn_on();
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+}
+
+static void backtrace_suppression_test_count(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+
+	kunit_warning_suppress(test) {
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 0);
+
+		WARN(1, "suppressed");
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+
+		WARN(1, "suppressed again");
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 2);
+	}
+}
+
+static void backtrace_suppression_test_active_state(struct kunit *test)
+{
+	KUNIT_EXPECT_FALSE(test, kunit_has_active_suppress_warning());
+
+	kunit_warning_suppress(test) {
+		KUNIT_EXPECT_TRUE(test, kunit_has_active_suppress_warning());
+	}
+
+	KUNIT_EXPECT_FALSE(test, kunit_has_active_suppress_warning());
+
+	kunit_warning_suppress(test) {
+		KUNIT_EXPECT_TRUE(test, kunit_has_active_suppress_warning());
+	}
+
+	KUNIT_EXPECT_FALSE(test, kunit_has_active_suppress_warning());
+}
+
+static void backtrace_suppression_test_multi_scope(struct kunit *test)
+{
+	struct kunit_suppressed_warning *sw1, *sw2;
+
+	if (!IS_ENABLED(CONFIG_BUG))
+		kunit_skip(test, "requires CONFIG_BUG");
+	if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE))
+		kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE");
+
+	sw1 = kunit_start_suppress_warning(test);
+	trigger_backtrace_warn_on();
+	WARN(1, "suppressed by sw1");
+	kunit_end_suppress_warning(test, sw1);
+
+	sw2 = kunit_start_suppress_warning(test);
+	WARN(1, "suppressed by sw2");
+	kunit_end_suppress_warning(test, sw2);
+
+	KUNIT_EXPECT_EQ(test, kunit_suppressed_warning_count(sw1), 2);
+	KUNIT_EXPECT_EQ(test, kunit_suppressed_warning_count(sw2), 1);
+}
+
+struct cross_kthread_data {
+	bool was_active;
+	struct completion done;
+};
+
+static int cross_kthread_fn(void *data)
+{
+	struct cross_kthread_data *d = data;
+
+	d->was_active = kunit_has_active_suppress_warning();
+	complete(&d->done);
+	while (!kthread_should_stop())
+		schedule();
+	return 0;
+}
+
+static void backtrace_suppression_test_cross_kthread(struct kunit *test)
+{
+	struct cross_kthread_data data;
+	struct task_struct *task;
+
+	data.was_active = false;
+	init_completion(&data.done);
+
+	kunit_warning_suppress(test) {
+		task = kthread_run(cross_kthread_fn, &data, "kunit-cross-test");
+		KUNIT_ASSERT_FALSE(test, IS_ERR(task));
+		wait_for_completion(&data.done);
+		kthread_stop(task);
+	}
+
+	KUNIT_EXPECT_FALSE(test, data.was_active);
+}
+
+static struct kunit_case backtrace_suppression_test_cases[] = {
+	KUNIT_CASE(backtrace_suppression_test_warn_direct),
+	KUNIT_CASE(backtrace_suppression_test_warn_indirect),
+	KUNIT_CASE(backtrace_suppression_test_warn_multi),
+	KUNIT_CASE(backtrace_suppression_test_warn_on_direct),
+	KUNIT_CASE(backtrace_suppression_test_warn_on_indirect),
+	KUNIT_CASE(backtrace_suppression_test_count),
+	KUNIT_CASE(backtrace_suppression_test_active_state),
+	KUNIT_CASE(backtrace_suppression_test_multi_scope),
+	KUNIT_CASE(backtrace_suppression_test_cross_kthread),
+	{}
+};
+
+static struct kunit_suite backtrace_suppression_test_suite = {
+	.name = "backtrace-suppression-test",
+	.test_cases = backtrace_suppression_test_cases,
+};
+kunit_test_suites(&backtrace_suppression_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("KUnit test to verify warning backtrace suppression");

lib/kunit/bug.c

@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit helpers for backtrace suppression
+ *
+ * Copyright (C) 2025 Alessandro Carminati <acarmina@redhat.com>
+ * Copyright (C) 2024 Guenter Roeck <linux@roeck-us.net>
+ */
+
+#include <kunit/resource.h>
+#include <linux/export.h>
+#include <linux/rculist.h>
+#include <linux/sched.h>
+#include <linux/sched/task.h>
+#include <linux/spinlock.h>
+
+#include "hooks-impl.h"
+
+struct kunit_suppressed_warning {
+	struct list_head node;
+	struct task_struct *task;
+	struct kunit *test;
+	atomic_t counter;
+};
+
+static LIST_HEAD(suppressed_warnings);
+static DEFINE_SPINLOCK(suppressed_warnings_lock);
+
+static void kunit_suppress_warning_remove(struct kunit_suppressed_warning *w)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&suppressed_warnings_lock, flags);
+	list_del_rcu(&w->node);
+	spin_unlock_irqrestore(&suppressed_warnings_lock, flags);
+	put_task_struct(w->task);
+}
+
+KUNIT_DEFINE_ACTION_WRAPPER(kunit_suppress_warning_cleanup,
+			    kunit_suppress_warning_remove,
+			    struct kunit_suppressed_warning *);
+
+bool kunit_has_active_suppress_warning(void)
+{
+	return __kunit_is_suppressed_warning_impl(false);
+}
+EXPORT_SYMBOL_GPL(kunit_has_active_suppress_warning);
+
+struct kunit_suppressed_warning *
+kunit_start_suppress_warning(struct kunit *test)
+{
+	struct kunit_suppressed_warning *w;
+	unsigned long flags;
+	int ret;
+
+	if (kunit_has_active_suppress_warning()) {
+		KUNIT_FAIL(test, "Another suppression block is already active");
+		return NULL;
+	}
+
+	w = kunit_kzalloc(test, sizeof(*w), GFP_KERNEL);
+	if (!w) {
+		KUNIT_FAIL(test, "Failed to allocate suppression handle.");
+		return NULL;
+	}
+
+	w->task = get_task_struct(current);
+	w->test = test;
+
+	spin_lock_irqsave(&suppressed_warnings_lock, flags);
+	list_add_rcu(&w->node, &suppressed_warnings);
+	spin_unlock_irqrestore(&suppressed_warnings_lock, flags);
+
+	ret = kunit_add_action_or_reset(test,
+					kunit_suppress_warning_cleanup, w);
+	if (ret) {
+		KUNIT_FAIL(test, "Failed to add suppression cleanup action.");
+		return NULL;
+	}
+
+	return w;
+}
+EXPORT_SYMBOL_GPL(kunit_start_suppress_warning);
+
+void kunit_end_suppress_warning(struct kunit *test,
+				struct kunit_suppressed_warning *w)
+{
+	if (!w)
+		return;
+	kunit_release_action(test, kunit_suppress_warning_cleanup, w);
+}
+EXPORT_SYMBOL_GPL(kunit_end_suppress_warning);
+
+void __kunit_suppress_auto_cleanup(struct kunit_suppressed_warning **wp)
+{
+	if (*wp)
+		kunit_end_suppress_warning((*wp)->test, *wp);
+}
+EXPORT_SYMBOL_GPL(__kunit_suppress_auto_cleanup);
+
+int kunit_suppressed_warning_count(struct kunit_suppressed_warning *w)
+{
+	return w ? atomic_read(&w->counter) : 0;
+}
+EXPORT_SYMBOL_GPL(kunit_suppressed_warning_count);
+
+bool __kunit_is_suppressed_warning_impl(bool count)
+{
+	struct kunit_suppressed_warning *w;
+
+	guard(rcu)();
+	list_for_each_entry_rcu(w, &suppressed_warnings, node) {
+		if (w->task == current) {
+			if (count)
+				atomic_inc(&w->counter);
+			return true;
+		}
+	}
+
+	return false;
+}

lib/kunit/hooks-impl.h

@@ -19,6 +19,7 @@ void __printf(3, 4) __kunit_fail_current_test_impl(const char *file,
 						   int line,
 						   const char *fmt, ...);
 void *__kunit_get_static_stub_address_impl(struct kunit *test, void *real_fn_addr);
+bool __kunit_is_suppressed_warning_impl(bool count);
 
 /* Code to set all of the function pointers. */
 static inline void kunit_install_hooks(void)
@@ -26,6 +27,7 @@ static inline void kunit_install_hooks(void)
 	/* Install the KUnit hook functions. */
 	kunit_hooks.fail_current_test = __kunit_fail_current_test_impl;
 	kunit_hooks.get_static_stub_address = __kunit_get_static_stub_address_impl;
+	kunit_hooks.is_suppressed_warning = __kunit_is_suppressed_warning_impl;
 }
 
 #endif /* _KUNIT_HOOKS_IMPL_H */

scripts/clang-tools/gen_compile_commands.py

@@ -201,6 +201,8 @@ def main():
         # Modules are listed in modules.order.
         if os.path.isdir(path):
             cmdfiles = cmdfiles_in_dir(path)
+        elif os.path.basename(path) == 'libgcc.a':
+            cmdfiles = []
         elif path.endswith('.a'):
             cmdfiles = cmdfiles_for_a(path, ar)
         elif path.endswith('modules.order'):

tools/testing/kunit/kunit.py

@@ -21,6 +21,7 @@ from enum import Enum, auto
 from typing import Iterable, List, Optional, Sequence, Tuple
 
 import kunit_json
+import kunit_junit
 import kunit_kernel
 import kunit_parser
 from kunit_printer import stdout, null_printer
@@ -49,6 +50,7 @@ class KunitBuildRequest(KunitConfigRequest):
 class KunitParseRequest:
 	raw_output: Optional[str]
 	json: Optional[str]
+	junit: Optional[str]
 	summary: bool
 	failed: bool
 
@@ -268,6 +270,13 @@ def parse_tests(request: KunitParseRequest, metadata: kunit_json.Metadata, input
 			stdout.print_with_timestamp("Test results stored in %s" %
 				os.path.abspath(request.json))
 
+	if request.junit:
+		if request.junit == 'stdout':
+			kunit_junit.print_junit_result(test=test)
+		else:
+			kunit_junit.write_junit_result(test=test,filename=request.junit)
+			stdout.print_with_timestamp(f"Test results stored in {os.path.abspath(request.junit)}")
+
 	if test.status != kunit_parser.TestStatus.SUCCESS:
 		return KunitResult(KunitStatus.TEST_FAILURE, parse_time), test
 
@@ -309,6 +318,7 @@ def run_tests(linux: kunit_kernel.LinuxSourceTree,
 # So we hackily automatically rewrite --json => --json=stdout
 pseudo_bool_flag_defaults = {
 		'--json': 'stdout',
+		'--junit': 'stdout',
 		'--raw_output': 'kunit',
 }
 def massage_argv(argv: Sequence[str]) -> Sequence[str]:
@@ -459,6 +469,11 @@ def add_parse_opts(parser: argparse.ArgumentParser) -> None:
 			    help='Prints parsed test results as JSON to stdout or a file if '
 			    'a filename is specified. Does nothing if --raw_output is set.',
 			    type=str, const='stdout', default=None, metavar='FILE')
+	parser.add_argument('--junit',
+			    nargs='?',
+			    help='Prints parsed test results as JUnit XML to stdout or a file if '
+			    'a filename is specified. Does nothing if --raw_output is set.',
+			    type=str, const='stdout', default=None, metavar='FILE')
 	parser.add_argument('--summary',
 			    help='Prints only the summary line for parsed test results.'
 				'Does nothing if --raw_output is set.',
@@ -502,6 +517,7 @@ def run_handler(cli_args: argparse.Namespace) -> None:
 					jobs=cli_args.jobs,
 					raw_output=cli_args.raw_output,
 					json=cli_args.json,
+					junit=cli_args.junit,
 					summary=cli_args.summary,
 					failed=cli_args.failed,
 					timeout=cli_args.timeout,
@@ -552,6 +568,7 @@ def exec_handler(cli_args: argparse.Namespace) -> None:
 	exec_request = KunitExecRequest(raw_output=cli_args.raw_output,
 					build_dir=cli_args.build_dir,
 					json=cli_args.json,
+					junit=cli_args.junit,
 					summary=cli_args.summary,
 					failed=cli_args.failed,
 					timeout=cli_args.timeout,
@@ -580,7 +597,9 @@ def parse_handler(cli_args: argparse.Namespace) -> None:
 	# We know nothing about how the result was created!
 	metadata = kunit_json.Metadata()
 	request = KunitParseRequest(raw_output=cli_args.raw_output,
-					json=cli_args.json, summary=cli_args.summary,
+					json=cli_args.json,
+					junit=cli_args.junit,
+					summary=cli_args.summary,
 					failed=cli_args.failed)
 	result, _ = parse_tests(request, metadata, kunit_output)
 	if result.status != KunitStatus.SUCCESS:

tools/testing/kunit/kunit_junit.py

@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generates JUnit XML files from KUnit test results
+#
+# Copyright (C) 2026, Google LLC and David Gow.
+
+from xml.sax.saxutils import quoteattr, XMLGenerator
+import xml.etree.ElementTree as ET
+from kunit_parser import Test, TestStatus
+from typing import Optional
+
+# Get a string representing a tes suite (including subtests) in JUnit XML
+def get_test_suite(test: Test, parent: Optional[ET.Element]) -> ET.Element:
+	suite_attrs = {
+		'name': test.name,
+		'tests': str(test.counts.total()),
+		'failures': str(test.counts.failed),
+		'skipped': str(test.counts.skipped),
+		'errors': str(test.counts.crashed + test.counts.errors),
+	}
+
+	if parent is not None:
+		test_suite_element = ET.SubElement(parent, 'testsuite', suite_attrs)
+	else:
+		test_suite_element = ET.Element('testsuite', suite_attrs)
+
+	for subtest in test.subtests:
+		if subtest.subtests:
+			get_test_suite(subtest, test_suite_element)
+			continue
+		test_case_element = ET.SubElement(test_suite_element, 'testcase', {'name': subtest.name})
+		if subtest.status == TestStatus.FAILURE:
+			ET.SubElement(test_case_element, 'failure', {}).text = 'Test Failed'
+		elif subtest.status == TestStatus.SKIPPED:
+			ET.SubElement(test_case_element, 'skipped', {}).text = subtest.skip_reason
+		elif subtest.status == TestStatus.TEST_CRASHED:
+			ET.SubElement(test_case_element, 'error', {}).text = 'Test Crashed'
+
+		if subtest.log:
+			ET.SubElement(test_case_element, 'system-out', {}).text = "\n".join(subtest.log)
+
+	return test_suite_element
+
+# Get a string for an entire XML file for the test structure starting at test
+def get_junit_result(test: Test) -> str:
+	root_element = get_test_suite(test, None)
+	ET.indent(root_element)
+	return ET.tostring(root_element, encoding="unicode", xml_declaration=True)
+
+# Print a JUnit result to stdout.
+def print_junit_result(test: Test) -> None:
+	root_element = get_test_suite(test, None)
+	ET.indent(root_element)
+	ET.dump(root_element)
+
+# Write an entire XML file for the test structure starting at test
+def write_junit_result(test: Test, filename: str) -> None:
+	root_element = get_test_suite(test, None)
+	ET.indent(root_element)
+	root_et = ET.ElementTree(root_element)
+	root_et.write(filename, encoding='utf-8', xml_declaration=True)

tools/testing/kunit/kunit_kernel.py

@@ -218,7 +218,7 @@ def _get_qemu_ops(config_path: str,
 	# exists (I learned this through experimentation and could not find it
 	# anywhere in the Python documentation).
 	#
-	# Bascially, we completely ignore the actual file location of the config
+	# Basically, we completely ignore the actual file location of the config
 	# we are loading and just tell Python that the module lives in the
 	# QEMU_CONFIGS_DIR for import purposes regardless of where it actually
 	# exists as a file.

tools/testing/kunit/kunit_parser.py

@@ -17,7 +17,7 @@ import textwrap
 from enum import Enum, auto
 from typing import Iterable, Iterator, List, Optional, Tuple
 
-from kunit_printer import Printer, stdout
+from kunit_printer import Printer
 
 class Test:
 	"""
@@ -44,11 +44,12 @@ class Test:
 		self.subtests = []  # type: List[Test]
 		self.log = []  # type: List[str]
 		self.counts = TestCounts()
+		self.skip_reason = ''
 
 	def __str__(self) -> str:
 		"""Returns string representation of a Test class object."""
 		return (f'Test({self.status}, {self.name}, {self.expected_count}, '
-			f'{self.subtests}, {self.log}, {self.counts})')
+			f'{self.subtests}, {self.log}, {self.counts}, {self.skip_reason})')
 
 	def __repr__(self) -> str:
 		"""Returns string representation of a Test class object."""
@@ -57,7 +58,7 @@ class Test:
 	def add_error(self, printer: Printer, error_message: str) -> None:
 		"""Records an error that occurred while parsing this test."""
 		self.counts.errors += 1
-		printer.print_with_timestamp(stdout.red('[ERROR]') + f' Test: {self.name}: {error_message}')
+		printer.print_with_timestamp(printer.red('[ERROR]') + f' Test: {self.name}: {error_message}')
 
 	def ok_status(self) -> bool:
 		"""Returns true if the status was ok, i.e. passed or skipped."""
@@ -268,7 +269,7 @@ def check_version(version_num: int, accepted_versions: List[int],
 	if version_num < min(accepted_versions):
 		test.add_error(printer, f'{version_type} version lower than expected!')
 	elif version_num > max(accepted_versions):
-		test.add_error(printer, f'{version_type} version higer than expected!')
+		test.add_error(printer, f'{version_type} version higher than expected!')
 
 def parse_ktap_header(lines: LineStream, test: Test, printer: Printer) -> bool:
 	"""
@@ -352,9 +353,9 @@ def parse_test_plan(lines: LineStream, test: Test) -> bool:
 	lines.pop()
 	return True
 
-TEST_RESULT = re.compile(r'^\s*(ok|not ok) ([0-9]+) ?(- )?([^#]*)( # .*)?$')
+TEST_RESULT = re.compile(r'^\s*(ok|not ok) ([0-9]+) ?(:?- )?([^#]*)( # .*)?$')
 
-TEST_RESULT_SKIP = re.compile(r'^\s*(ok|not ok) ([0-9]+) ?(- )?(.*) # SKIP ?(.*)$')
+TEST_RESULT_SKIP = re.compile(r'^\s*(ok|not ok) ([0-9]+) ?(:?- )?(.*) # SKIP ?(.*)$')
 
 def peek_test_name_match(lines: LineStream, test: Test) -> bool:
 	"""
@@ -418,7 +419,7 @@ def parse_test_result(lines: LineStream, test: Test,
 
 	# Set name of test object
 	if skip_match:
-		test.name = skip_match.group(4) or skip_match.group(5)
+		test.name = skip_match.group(4)
 	else:
 		test.name = match.group(4)
 
@@ -431,6 +432,7 @@ def parse_test_result(lines: LineStream, test: Test,
 	status = match.group(1)
 	if skip_match:
 		test.status = TestStatus.SKIPPED
+		test.skip_reason = skip_match.group(5) or ''
 	elif status == 'ok':
 		test.status = TestStatus.SUCCESS
 	else:
@@ -539,12 +541,15 @@ def format_test_result(test: Test, printer: Printer) -> str:
 	if test.status == TestStatus.SUCCESS:
 		return printer.green('[PASSED] ') + test.name
 	if test.status == TestStatus.SKIPPED:
-		return printer.yellow('[SKIPPED] ') + test.name
+		skip_message = printer.yellow('[SKIPPED] ') + test.name
+		if test.skip_reason != '':
+			skip_message += printer.yellow(' (' + test.skip_reason + ')')
+		return skip_message
 	if test.status == TestStatus.NO_TESTS:
 		return printer.yellow('[NO TESTS RUN] ') + test.name
 	if test.status == TestStatus.TEST_CRASHED:
 		print_log(test.log, printer)
-		return stdout.red('[CRASHED] ') + test.name
+		return printer.red('[CRASHED] ') + test.name
 	print_log(test.log, printer)
 	return printer.red('[FAILED] ') + test.name
 
@@ -651,11 +656,11 @@ def print_summary_line(test: Test, printer: Printer) -> None:
 	printer - Printer object to output results
 	"""
 	if test.status == TestStatus.SUCCESS:
-		color = stdout.green
+		color = printer.green
 	elif test.status in (TestStatus.SKIPPED, TestStatus.NO_TESTS):
-		color = stdout.yellow
+		color = printer.yellow
 	else:
-		color = stdout.red
+		color = printer.red
 	printer.print_with_timestamp(color(f'Testing complete. {test.counts}'))
 
 	# Summarize failures that might have gone off-screen since we had a lot

tools/testing/kunit/kunit_tool_test.py

@@ -24,6 +24,7 @@ import kunit_config
 import kunit_parser
 import kunit_kernel
 import kunit_json
+import kunit_junit
 import kunit
 from kunit_printer import stdout
 
@@ -235,10 +236,27 @@ class KUnitParserTest(unittest.TestCase):
 		with open(skipped_log) as file:
 			result = kunit_parser.parse_run_tests(file.readlines(), stdout)
 
+		# The test result is skipped, and the skip reason is valid
+		self.assertEqual(kunit_parser.TestStatus.SKIPPED, result.subtests[1].subtests[1].status)
+		self.assertEqual("this test should be skipped", result.subtests[1].subtests[1].skip_reason)
+
 		# A skipped test does not fail the whole suite.
 		self.assertEqual(kunit_parser.TestStatus.SUCCESS, result.status)
 		self.assertEqual(result.counts, kunit_parser.TestCounts(passed=4, skipped=1))
 
+	def test_skipped_reason_parse(self):
+		skipped_log = _test_data_path('test_skip_all_tests.log')
+		with open(skipped_log) as file:
+			result = kunit_parser.parse_run_tests(file.readlines(), stdout)
+
+		# The first test is skipped, with the correct reaons
+		self.assertEqual(kunit_parser.TestStatus.SKIPPED, result.subtests[0].subtests[0].status)
+		self.assertEqual("all tests skipped", result.subtests[0].subtests[0].skip_reason)
+
+		# The first suite is skipped, with no reason
+		self.assertEqual(kunit_parser.TestStatus.SKIPPED, result.subtests[0].status)
+		self.assertEqual("", result.subtests[0].skip_reason)
+
 	def test_skipped_all_tests(self):
 		skipped_log = _test_data_path('test_skip_all_tests.log')
 		with open(skipped_log) as file:
@@ -676,6 +694,38 @@ class StrContains(str):
 	def __eq__(self, other):
 		return self in other
 
+class KUnitJUnitTest(unittest.TestCase):
+	def setUp(self):
+		self.print_mock = mock.patch('kunit_printer.Printer.print').start()
+		self.addCleanup(mock.patch.stopall)
+
+	def _junit_string(self, log_file):
+		with open(_test_data_path(log_file)) as file:
+			test_result = kunit_parser.parse_run_tests(file, stdout)
+			junit_string = kunit_junit.get_junit_result(
+					test=test_result)
+		print(junit_string)
+		return junit_string
+
+	def test_failed_test_junit(self):
+		result = self._junit_string('test_is_test_passed-failure.log')
+		self.assertTrue("<failure>" in result)
+
+	def test_skipped_test_junit(self):
+		result = self._junit_string('test_skip_tests.log')
+		self.assertTrue("<skipped>" in result)
+		self.assertTrue("skipped=\"1\"" in result)
+
+	def test_crashed_test_junit(self):
+		result = self._junit_string('test_kernel_panic_interrupt.log')
+		self.assertTrue("<error>" in result);
+
+	def test_no_tests_junit(self):
+		result = self._junit_string('test_is_test_passed-no_tests_run_with_header.log')
+		self.assertTrue("tests=\"0\"" in result)
+		self.assertFalse("testcase" in result)
+
+
 class KUnitMainTest(unittest.TestCase):
 	def setUp(self):
 		path = _test_data_path('test_is_test_passed-all_passed.log')
@@ -923,7 +973,7 @@ class KUnitMainTest(unittest.TestCase):
 		self.linux_source_mock.run_kernel.return_value = ['TAP version 14', 'init: random output'] + want
 
 		got = kunit._list_tests(self.linux_source_mock,
-				     kunit.KunitExecRequest(None, None, False, False, '.kunit', 300, 'suite*', '', None, None, 'suite', False, False, False))
+				     kunit.KunitExecRequest(None, None, None, False, False, '.kunit', 300, 'suite*', '', None, None, 'suite', False, False, False))
 		self.assertEqual(got, want)
 		# Should respect the user's filter glob when listing tests.
 		self.linux_source_mock.run_kernel.assert_called_once_with(
@@ -936,7 +986,7 @@ class KUnitMainTest(unittest.TestCase):
 
 		# Should respect the user's filter glob when listing tests.
 		mock_tests.assert_called_once_with(mock.ANY,
-				     kunit.KunitExecRequest(None, None, False, False, '.kunit', 300, 'suite*.test*', '', None, None, 'suite', False, False, False))
+				     kunit.KunitExecRequest(None, None, None, False, False, '.kunit', 300, 'suite*.test*', '', None, None, 'suite', False, False, False))
 		self.linux_source_mock.run_kernel.assert_has_calls([
 			mock.call(args=None, build_dir='.kunit', filter_glob='suite.test*', filter='', filter_action=None, timeout=300),
 			mock.call(args=None, build_dir='.kunit', filter_glob='suite2.test*', filter='', filter_action=None, timeout=300),
@@ -949,7 +999,7 @@ class KUnitMainTest(unittest.TestCase):
 
 		# Should respect the user's filter glob when listing tests.
 		mock_tests.assert_called_once_with(mock.ANY,
-				     kunit.KunitExecRequest(None, None, False, False, '.kunit', 300, 'suite*', '', None, None, 'test', False, False, False))
+				     kunit.KunitExecRequest(None, None, None, False, False, '.kunit', 300, 'suite*', '', None, None, 'test', False, False, False))
 		self.linux_source_mock.run_kernel.assert_has_calls([
 			mock.call(args=None, build_dir='.kunit', filter_glob='suite.test1', filter='', filter_action=None, timeout=300),
 			mock.call(args=None, build_dir='.kunit', filter_glob='suite.test2', filter='', filter_action=None, timeout=300),

tools/testing/kunit/qemu_configs/or1k.py

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+from ..qemu_config import QemuArchParams
+
+QEMU_ARCH = QemuArchParams(linux_arch='openrisc',
+			   kconfig='''
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_POWER_RESET=y
+CONFIG_POWER_RESET_SYSCON=y
+''',
+			   qemu_arch='or1k',
+			   kernel_path='vmlinux',
+			   kernel_command_line='console=ttyS0',
+			   extra_qemu_params=[
+					    '-machine', 'virt',
+                        '-m', '512',
+			  ])