The patch titled
Subject: kunit: add test cases for backtrace warning suppression
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kunit-add-test-cases-for-backtrace-warning-suppression.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kunit-add-test-cases-for-backtrace-warning-suppression.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Guenter Roeck <linux@xxxxxxxxxxxx>
Subject: kunit: add test cases for backtrace warning suppression
Date: Thu, 13 Mar 2025 11:43:18 +0000
Add unit tests to verify that warning backtrace suppression works.
If backtrace suppression does _not_ work, the unit tests will likely
trigger unsuppressed backtraces, which should actually help to get the
affected architectures / platforms fixed.
Link: https://lkml.kernel.org/r/20250313114329.284104-4-acarmina@xxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Alessandro Carminati <acarmina@xxxxxxxxxx>
Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Acked-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Arthur Grillo <arthurgrillo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Charlie Jenkins <charlie@xxxxxxxxxxxx>
Cc: Daniel Diaz <daniel.diaz@xxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Gow <davidgow@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: MaÃra Canal <mcanal@xxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Rae Moar <rmoar@xxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Thomas Zimemrmann <tzimmermann@xxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/kunit/Makefile | 7 +
lib/kunit/backtrace-suppression-test.c | 104 +++++++++++++++++++++++
2 files changed, 109 insertions(+), 2 deletions(-)
diff --git a/lib/kunit/backtrace-suppression-test.c a/lib/kunit/backtrace-suppression-test.c
new file mode 100644
--- /dev/null
+++ a/lib/kunit/backtrace-suppression-test.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for suppressing warning tracebacks
+ *
+ * Copyright (C) 2024, Guenter Roeck
+ * Author: Guenter Roeck <linux@xxxxxxxxxxxx>
+ */
+
+#include <kunit/test.h>
+#include <linux/bug.h>
+
+static void backtrace_suppression_test_warn_direct(struct kunit *test)
+{
+ DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
+
+ KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
+ WARN(1, "This backtrace should be suppressed");
+ KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
+
+ KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_direct), 1);
+}
+
+static void trigger_backtrace_warn(void)
+{
+ WARN(1, "This backtrace should be suppressed");
+}
+
+static void backtrace_suppression_test_warn_indirect(struct kunit *test)
+{
+ DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn);
+
+ KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn);
+ trigger_backtrace_warn();
+ KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn);
+
+ KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1);
+}
+
+static void backtrace_suppression_test_warn_multi(struct kunit *test)
+{
+ DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn);
+ DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
+
+ KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
+ KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn);
+ WARN(1, "This backtrace should be suppressed");
+ trigger_backtrace_warn();
+ KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn);
+ KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
+
+ KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_multi), 1);
+ KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1);
+}
+
+static void backtrace_suppression_test_warn_on_direct(struct kunit *test)
+{
+ DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
+
+ if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE) && !IS_ENABLED(CONFIG_KALLSYMS))
+ kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE or CONFIG_KALLSYMS");
+
+ KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
+ WARN_ON(1);
+ KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
+
+ KUNIT_EXPECT_EQ(test,
+ SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_on_direct), 1);
+}
+
+static void trigger_backtrace_warn_on(void)
+{
+ WARN_ON(1);
+}
+
+static void backtrace_suppression_test_warn_on_indirect(struct kunit *test)
+{
+ DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
+
+ if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE))
+ kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE");
+
+ KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
+ trigger_backtrace_warn_on();
+ KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
+
+ KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn_on), 1);
+}
+
+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),
+ {}
+};
+
+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");
--- a/lib/kunit/Makefile~kunit-add-test-cases-for-backtrace-warning-suppression
+++ a/lib/kunit/Makefile
@@ -18,11 +18,14 @@ endif
# KUnit 'hooks' and bug handling are built-in even when KUnit is built
# as a module.
-obj-y += hooks.o \
- bug.o
+obj-y += hooks.o
+obj-$(CONFIG_KUNIT_SUPPRESS_BACKTRACE) += bug.o
obj-$(CONFIG_KUNIT_TEST) += kunit-test.o
obj-$(CONFIG_KUNIT_TEST) += platform-test.o
+ifeq ($(CONFIG_KUNIT_SUPPRESS_BACKTRACE),y)
+obj-$(CONFIG_KUNIT_TEST) += backtrace-suppression-test.o
+endif
# string-stream-test compiles built-in only.
ifeq ($(CONFIG_KUNIT_TEST),y)
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxx are
bug-kunit-core-support-for-suppressing-warning-backtraces.patch
kunit-bug-count-suppressed-warning-backtraces.patch
kunit-add-test-cases-for-backtrace-warning-suppression.patch
kunit-add-documentation-for-warning-backtrace-suppression-api.patch
drm-suppress-intentional-warning-backtraces-in-scaling-unit-tests.patch
x86-add-support-for-suppressing-warning-backtraces.patch
arm64-add-support-for-suppressing-warning-backtraces.patch
loongarch-add-support-for-suppressing-warning-backtraces.patch
parisc-add-support-for-suppressing-warning-backtraces.patch
s390-add-support-for-suppressing-warning-backtraces.patch
sh-add-support-for-suppressing-warning-backtraces.patch
sh-move-defines-needed-for-suppressing-warning-backtraces.patch
riscv-add-support-for-suppressing-warning-backtraces.patch
powerpc-add-support-for-suppressing-warning-backtraces.patch
