diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bug.c | 14 | ||||
| -rw-r--r-- | lib/kunit/Makefile | 4 | ||||
| -rw-r--r-- | lib/kunit/backtrace-suppression-test.c | 198 | ||||
| -rw-r--r-- | lib/kunit/bug.c | 120 | ||||
| -rw-r--r-- | lib/kunit/hooks-impl.h | 2 |
5 files changed, 335 insertions, 3 deletions
diff --git a/lib/bug.c b/lib/bug.c index 224f4cfa4aa3..d99e369bc110 100644 --- a/lib/bug.c +++ b/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; diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 656f1fa35abc..2e8a6b71a2ab 100644 --- a/lib/kunit/Makefile +++ b/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) diff --git a/lib/kunit/backtrace-suppression-test.c b/lib/kunit/backtrace-suppression-test.c new file mode 100644 index 000000000000..7a2a59c6a780 --- /dev/null +++ b/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"); diff --git a/lib/kunit/bug.c b/lib/kunit/bug.c new file mode 100644 index 000000000000..8579235c9ca6 --- /dev/null +++ b/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; +} diff --git a/lib/kunit/hooks-impl.h b/lib/kunit/hooks-impl.h index 4e71b2d0143b..d8720f261692 100644 --- a/lib/kunit/hooks-impl.h +++ b/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 */ |