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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 978F8C4332F for ; Tue, 18 Oct 2022 17:17:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230077AbiJRRRR (ORCPT ); Tue, 18 Oct 2022 13:17:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229678AbiJRRRM (ORCPT ); Tue, 18 Oct 2022 13:17:12 -0400 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16D2C72864 for ; Tue, 18 Oct 2022 10:17:10 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1666113429; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=5qXG9FN8q1BZCzLXn/AJyCLf0ifsZsE4nXpgEgyO44I=; b=guGKFGP/lx166oSzfSx1vR29JCW6JtRkWlZG/eAGpzqrkKaSFiGPPHTKJ2gDasaX8yg/Yj 7By7hwSct4gEuJq4b6iFnVJBvv0ZcW9hvSQA3yjP44OUK528jDAHTQWbXDJYHb6nUxURZ1 W1imCZcuTePj6DbTwmO+F0uiNzm2lz0= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v3 1/3] kasan: switch kunit tests to console tracepoints Date: Tue, 18 Oct 2022 19:17:04 +0200 Message-Id: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Konovalov Switch KUnit-compatible KASAN tests from using per-task KUnit resources to console tracepoints. This allows for two things: 1. Migrating tests that trigger a KASAN report in the context of a task other than current to KUnit framework. This is implemented in the patches that follow. 2. Parsing and matching the contents of KASAN reports. This is not yet implemented. Reviewed-by: Marco Elver Signed-off-by: Andrey Konovalov --- Changed v2->v3: - Rebased onto 6.1-rc1 Changes v1->v2: - Remove kunit_kasan_status struct definition. --- lib/Kconfig.kasan | 2 +- mm/kasan/kasan.h | 8 ---- mm/kasan/kasan_test.c | 85 +++++++++++++++++++++++++++++++------------ mm/kasan/report.c | 31 ---------------- 4 files changed, 63 insertions(+), 63 deletions(-) diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index ca09b1cf8ee9..ba5b27962c34 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -181,7 +181,7 @@ config KASAN_VMALLOC config KASAN_KUNIT_TEST tristate "KUnit-compatible tests of KASAN bug detection capabilities" if !KUNIT_ALL_TESTS - depends on KASAN && KUNIT + depends on KASAN && KUNIT && TRACEPOINTS default KUNIT_ALL_TESTS help A KUnit-based KASAN test suite. Triggers different kinds of diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index abbcc1b0eec5..a84491bc4867 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -261,14 +261,6 @@ struct kasan_stack_ring { #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ -#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) -/* Used in KUnit-compatible KASAN tests. */ -struct kunit_kasan_status { - bool report_found; - bool sync_fault; -}; -#endif - #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) static inline const void *kasan_shadow_to_mem(const void *shadow_addr) diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c index 0d59098f0876..0ff20bfa3376 100644 --- a/mm/kasan/kasan_test.c +++ b/mm/kasan/kasan_test.c @@ -5,8 +5,12 @@ * Author: Andrey Ryabinin */ +#define pr_fmt(fmt) "kasan_test: " fmt + +#include #include #include +#include #include #include #include @@ -14,21 +18,28 @@ #include #include #include +#include #include #include +#include #include -#include #include -#include +#include #include -#include - #include "kasan.h" #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) +static bool multishot; + +/* Fields set based on lines observed in the console. */ +static struct { + bool report_found; + bool async_fault; +} test_status; + /* * Some tests use these global variables to store return values from function * calls that could otherwise be eliminated by the compiler as dead code. @@ -36,35 +47,61 @@ void *kasan_ptr_result; int kasan_int_result; -static struct kunit_resource resource; -static struct kunit_kasan_status test_status; -static bool multishot; +/* Probe for console output: obtains test_status lines of interest. */ +static void probe_console(void *ignore, const char *buf, size_t len) +{ + if (strnstr(buf, "BUG: KASAN: ", len)) + WRITE_ONCE(test_status.report_found, true); + else if (strnstr(buf, "Asynchronous fault: ", len)) + WRITE_ONCE(test_status.async_fault, true); +} -/* - * Temporarily enable multi-shot mode. Otherwise, KASAN would only report the - * first detected bug and panic the kernel if panic_on_warn is enabled. For - * hardware tag-based KASAN also allow tag checking to be reenabled for each - * test, see the comment for KUNIT_EXPECT_KASAN_FAIL(). - */ -static int kasan_test_init(struct kunit *test) +static void register_tracepoints(struct tracepoint *tp, void *ignore) +{ + check_trace_callback_type_console(probe_console); + if (!strcmp(tp->name, "console")) + WARN_ON(tracepoint_probe_register(tp, probe_console, NULL)); +} + +static void unregister_tracepoints(struct tracepoint *tp, void *ignore) +{ + if (!strcmp(tp->name, "console")) + tracepoint_probe_unregister(tp, probe_console, NULL); +} + +static int kasan_suite_init(struct kunit_suite *suite) { if (!kasan_enabled()) { - kunit_err(test, "can't run KASAN tests with KASAN disabled"); + pr_err("Can't run KASAN tests with KASAN disabled"); return -1; } + /* + * Temporarily enable multi-shot mode. Otherwise, KASAN would only + * report the first detected bug and panic the kernel if panic_on_warn + * is enabled. + */ multishot = kasan_save_enable_multi_shot(); - test_status.report_found = false; - test_status.sync_fault = false; - kunit_add_named_resource(test, NULL, NULL, &resource, - "kasan_status", &test_status); + + /* + * Because we want to be able to build the test as a module, we need to + * iterate through all known tracepoints, since the static registration + * won't work here. + */ + for_each_kernel_tracepoint(register_tracepoints, NULL); return 0; } -static void kasan_test_exit(struct kunit *test) +static void kasan_suite_exit(struct kunit_suite *suite) { kasan_restore_multi_shot(multishot); - KUNIT_EXPECT_FALSE(test, test_status.report_found); + for_each_kernel_tracepoint(unregister_tracepoints, NULL); + tracepoint_synchronize_unregister(); +} + +static void kasan_test_exit(struct kunit *test) +{ + KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found)); } /** @@ -106,11 +143,12 @@ static void kasan_test_exit(struct kunit *test) if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \ kasan_sync_fault_possible()) { \ if (READ_ONCE(test_status.report_found) && \ - READ_ONCE(test_status.sync_fault)) \ + !READ_ONCE(test_status.async_fault)) \ kasan_enable_tagging(); \ migrate_enable(); \ } \ WRITE_ONCE(test_status.report_found, false); \ + WRITE_ONCE(test_status.async_fault, false); \ } while (0) #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \ @@ -1447,9 +1485,10 @@ static struct kunit_case kasan_kunit_test_cases[] = { static struct kunit_suite kasan_kunit_test_suite = { .name = "kasan", - .init = kasan_test_init, .test_cases = kasan_kunit_test_cases, .exit = kasan_test_exit, + .suite_init = kasan_suite_init, + .suite_exit = kasan_suite_exit, }; kunit_test_suite(kasan_kunit_test_suite); diff --git a/mm/kasan/report.c b/mm/kasan/report.c index df3602062bfd..31355851a5ec 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -30,8 +30,6 @@ #include -#include - #include "kasan.h" #include "../slab.h" @@ -114,41 +112,12 @@ EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); #endif -#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) -static void update_kunit_status(bool sync) -{ - struct kunit *test; - struct kunit_resource *resource; - struct kunit_kasan_status *status; - - test = current->kunit_test; - if (!test) - return; - - resource = kunit_find_named_resource(test, "kasan_status"); - if (!resource) { - kunit_set_failure(test); - return; - } - - status = (struct kunit_kasan_status *)resource->data; - WRITE_ONCE(status->report_found, true); - WRITE_ONCE(status->sync_fault, sync); - - kunit_put_resource(resource); -} -#else -static void update_kunit_status(bool sync) { } -#endif - static DEFINE_SPINLOCK(report_lock); static void start_report(unsigned long *flags, bool sync) { /* Respect the /proc/sys/kernel/traceoff_on_warning interface. */ disable_trace_on_warning(); - /* Update status of the currently running KASAN test. */ - update_kunit_status(sync); /* Do not allow LOCKDEP mangling KASAN reports. */ lockdep_off(); /* Make sure we don't end up in loop. */ -- 2.25.1