From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1E987CD3445 for ; Fri, 8 May 2026 15:03:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7F4E110F548; Fri, 8 May 2026 15:03:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="A+BKxeab"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id CDA9E10F548 for ; Fri, 8 May 2026 15:03:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778252609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XN7RJMkZbwU/+oNQFrZVFJ0TZE8D9N2ZdrT8gwrLswo=; b=A+BKxeabyaaNAC1zp6uwTcjdgCCCIPxD3vJBkGPbWfom0XgEPAe3KHDpz7/wmn3e612LtG io4lUUF9CqrDY/RfGQd9Mb4iyPsH2iLH99KO58qo6ISVxXnU0zRPVB4CbkYPMXjbd7tq46 XvTUzRVMWMKfBfUj11nA+u6tO+1Jbcs= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-481-rR9xWvIIPJqNPVu23r5Lcw-1; Fri, 08 May 2026 11:03:22 -0400 X-MC-Unique: rR9xWvIIPJqNPVu23r5Lcw-1 X-Mimecast-MFC-AGG-ID: rR9xWvIIPJqNPVu23r5Lcw_1778252598 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7D4DA19560A7; Fri, 8 May 2026 15:03:17 +0000 (UTC) Received: from [192.168.1.153] (headnet01.pony-001.prod.iad2.dc.redhat.com [10.2.32.101]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 28EF318001EF; Fri, 8 May 2026 15:03:09 +0000 (UTC) From: Albert Esteve Date: Fri, 08 May 2026 17:02:46 +0200 Subject: [PATCH v9 2/4] kunit: Add backtrace suppression self-tests MIME-Version: 1.0 Message-Id: <20260508-kunit_add_support-v9-2-99df7aa880f6@redhat.com> References: <20260508-kunit_add_support-v9-0-99df7aa880f6@redhat.com> In-Reply-To: <20260508-kunit_add_support-v9-0-99df7aa880f6@redhat.com> To: Arnd Bergmann , Brendan Higgins , David Gow , Rae Moar , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jonathan Corbet , Shuah Khan , Andrew Morton , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, dri-devel@lists.freedesktop.org, workflows@vger.kernel.org, linux-riscv@lists.infradead.org, linux-doc@vger.kernel.org, peterz@infradead.org, Guenter Roeck , Linux Kernel Functional Testing , Alessandro Carminati , Albert Esteve , Dan Carpenter , Kees Cook X-Developer-Signature: v=1; a=ed25519-sha256; t=1778252571; l=7126; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=ihPZEIO16j1okyfyZgMud8QmQNYwfosM6DWzDekF42U=; b=I8w2KtMZlEr4GVCpdV9rQcebNER6WPhbt7P3v8LqaTmHSDSX9ws4tWezcmPkKAYjgua4ptZ7N F9fT/xeXdvwAZyMbS69qWM3opA560MuIl5hvN1I/xef2Cbb4H/Y3DDo X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-MFC-PROC-ID: tOulQ7ytPjHjqkaBwH_Gs0rRS2r4cSDcDjRyxPNaluI_1778252598 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Guenter Roeck Add unit tests to verify that warning backtrace suppression works. Tests cover both API forms: - Scoped: kunit_warning_suppress() with in-block count verification and post-block inactivity check. - Direct functions: kunit_start/end_suppress_warning() with sequential independent suppression blocks and per-block counts. Furthermore, tests verify incremental warning counting, that kunit_has_active_suppress_warning() transitions correctly around suppression boundaries, and that suppression active in the test kthread does not leak to a separate kthread. 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. Tested-by: Linux Kernel Functional Testing Acked-by: Dan Carpenter Reviewed-by: Kees Cook Signed-off-by: Guenter Roeck Signed-off-by: Alessandro Carminati Reviewed-by: David Gow Signed-off-by: Albert Esteve --- lib/kunit/Makefile | 1 + lib/kunit/backtrace-suppression-test.c | 176 +++++++++++++++++++++++++++++++++ 2 files changed, 177 insertions(+) diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 4592f9d0aa8dd..2e8a6b71a2ab0 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -22,6 +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 0000000000000..3f0b2ae83312f --- /dev/null +++ b/lib/kunit/backtrace-suppression-test.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit test for suppressing warning tracebacks. + * + * Copyright (C) 2024, Guenter Roeck + * Author: Guenter Roeck + */ + +#include +#include +#include +#include + +static void backtrace_suppression_test_warn_direct(struct kunit *test) +{ + 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 void trigger_backtrace_warn(void) +{ + WARN(1, "This backtrace should be suppressed"); +} + +static void backtrace_suppression_test_warn_indirect(struct kunit *test) +{ + kunit_warning_suppress(test) { + trigger_backtrace_warn(); + KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1); + } +} + +static void backtrace_suppression_test_warn_multi(struct kunit *test) +{ + 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_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 void trigger_backtrace_warn_on(void) +{ + WARN_ON(1); +} + +static void backtrace_suppression_test_warn_on_indirect(struct kunit *test) +{ + 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) +{ + 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_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); + return 0; +} + +static void backtrace_suppression_test_cross_kthread(struct kunit *test) +{ + struct cross_kthread_data data; + struct task_struct *task; + + 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); + } + + 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"); -- 2.53.0