From patchwork Fri Jul 22 17:15:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Latypov X-Patchwork-Id: 592676 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 B4D1BC433EF for ; Fri, 22 Jul 2022 17:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235882AbiGVRPx (ORCPT ); Fri, 22 Jul 2022 13:15:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235785AbiGVRPw (ORCPT ); Fri, 22 Jul 2022 13:15:52 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAC3E1CFDD for ; Fri, 22 Jul 2022 10:15:50 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id u6-20020a25b7c6000000b00670862c5b16so4084795ybj.12 for ; Fri, 22 Jul 2022 10:15:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=fHf/2y2ImS8+g0A88yDniXGhaU3PcBI0GaxEtqPM90E=; b=KPDS4nOtrJFuhxfRuEPmu6keOaCejjdI4L8zfS7T8WvzBIjnBggIF903aLC/t2LP2I qs0GJzxxwcWZTCyznbQcKz/ax8qo9gJ56zr4JFcCfNbnKmYs80X0u5aOWaETsBaOvvT8 3/IzwJbrOZvgun8XL9IDlJuQMbyEFAmvkftxX5byvo1sc/ybR4Pq3c2mLdb6pc0vTLdz kZOOiE3o/ncmoMtM+hNK40IgNqdjmE6masrljJDeXwk4iJ90u+IX8BmLxcHY2G21QN70 Rlj4aRmoUo4EeaZq5FBE/DI6V4hlXdPpv6JFEhiOB4VNkJG8Hq8iqZ5BvtKxFULf+UD3 eJ0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=fHf/2y2ImS8+g0A88yDniXGhaU3PcBI0GaxEtqPM90E=; b=THgxoh7UZGNLip/AqlQnqjLvl3LTWUe3XIleC275PmBG4f161UhTckbGkcshGg9IrK CotdOMiK3WNlJ92ayTT++Du6sjpV0FdCLkkbBT5UkyKr1LVvbiKu49GxtmDNxumVK50G yiYflulkZzsP90G25kzpXL5AB9cgmpgqNit6anOhlW3TcfeHtuG80ikPB6iNjzdGLn7i 9gAdi2CC6eIgrszRKVknr0xGaL5qvJpQLoxAD8a/1QK5XasA/rauf9bGnb2UD8y+HJiY tEvAhzRxj4e4lSkVVAo3afts5XVXfJoGRGu97bCN8C5XwHLN40SlFVnscOt2T3jaD2Zm J6EQ== X-Gm-Message-State: AJIora819y9xd0KIoNLGl6661X0sh/k6xuFL4fgseXUR0Xb0JpjCZo5V QHDQgqFshgenHFvCCfecdcUNdK+vb+RJTw== X-Google-Smtp-Source: AGRyM1s1MTEqIuf9GSvKTbAzIhLe0gqPi896Xp1NxiIVUp1bME6wgEMhY5v/yecLl67eFteJez0fVHI6FiNpdw== X-Received: from dlatypov-spec.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3f35]) (user=dlatypov job=sendgmr) by 2002:a25:9f87:0:b0:669:4345:a8c0 with SMTP id u7-20020a259f87000000b006694345a8c0mr871017ybq.472.1658510149999; Fri, 22 Jul 2022 10:15:49 -0700 (PDT) Date: Fri, 22 Jul 2022 17:15:32 +0000 In-Reply-To: <20220722171534.3576419-1-dlatypov@google.com> Message-Id: <20220722171534.3576419-3-dlatypov@google.com> Mime-Version: 1.0 References: <20220722171534.3576419-1-dlatypov@google.com> X-Mailer: git-send-email 2.37.1.359.gd136c6c3e2-goog Subject: [PATCH v2 3/5] kunit: make kunit_kfree() only work on pointers from kunit_malloc() and friends From: Daniel Latypov To: brendanhiggins@google.com, davidgow@google.com Cc: linux-kernel@vger.kernel.org, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, skhan@linuxfoundation.org, Daniel Latypov Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org kunit_kfree() exists to clean up allocations from kunit_kmalloc() and friends early instead of waiting for this to happen automatically at the end of the test. But it can be used on *anything* registered with the kunit resource API. E.g. the last 2 statements are equivalent: struct kunit_resource *res = something(); kfree(res->data); kunit_put_resource(res); The problem is that there could be multiple resources that point to the same `data`. E.g. you can have a named resource acting as a pseudo-global variable in a test. If you point it to data allocated with kunit_kmalloc(), then calling `kunit_kfree(ptr)` has the chance to delete either the named resource or to kfree `ptr`. Which one it does depends on the order the resources are registered as kunit_kfree() will delete resources in LIFO order. So this patch restricts kunit_kfree() to only working on resources created by kunit_kmalloc(). Calling it is therefore guaranteed to free the memory, not do anything else. Note: kunit_resource_instance_match() wasn't used outside of KUnit, so it should be safe to remove from the public interface. It's also generally dangerous, as shown above, and shouldn't be used. Signed-off-by: Daniel Latypov Reviewed-by: David Gow Reviewed-by: Brendan Higgins --- v1 -> v2: no changes --- include/kunit/resource.h | 16 ---------------- lib/kunit/kunit-test.c | 7 +++++++ lib/kunit/test.c | 10 ++++++++-- 3 files changed, 15 insertions(+), 18 deletions(-) diff --git a/include/kunit/resource.h b/include/kunit/resource.h index 09c2b34d1c61..cf6fb8f2ac1b 100644 --- a/include/kunit/resource.h +++ b/include/kunit/resource.h @@ -300,22 +300,6 @@ typedef bool (*kunit_resource_match_t)(struct kunit *test, struct kunit_resource *res, void *match_data); -/** - * kunit_resource_instance_match() - Match a resource with the same instance. - * @test: Test case to which the resource belongs. - * @res: The resource. - * @match_data: The resource pointer to match against. - * - * An instance of kunit_resource_match_t that matches a resource whose - * allocation matches @match_data. - */ -static inline bool kunit_resource_instance_match(struct kunit *test, - struct kunit_resource *res, - void *match_data) -{ - return res->data == match_data; -} - /** * kunit_resource_name_match() - Match a resource with the same name. * @test: Test case to which the resource belongs. diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index 13d0bd8b07a9..4df0335d0d06 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -161,6 +161,13 @@ static void kunit_resource_test_alloc_resource(struct kunit *test) kunit_put_resource(res); } +static inline bool kunit_resource_instance_match(struct kunit *test, + struct kunit_resource *res, + void *match_data) +{ + return res->data == match_data; +} + /* * Note: tests below use kunit_alloc_and_get_resource(), so as a consequence * they have a reference to the associated resource that they must release diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 0fb2771ca03e..82019a78462e 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -689,12 +689,18 @@ void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp) } EXPORT_SYMBOL_GPL(kunit_kmalloc_array); +static inline bool kunit_kfree_match(struct kunit *test, + struct kunit_resource *res, void *match_data) +{ + /* Only match resources allocated with kunit_kmalloc() and friends. */ + return res->free == kunit_kmalloc_array_free && res->data == match_data; +} + void kunit_kfree(struct kunit *test, const void *ptr) { struct kunit_resource *res; - res = kunit_find_resource(test, kunit_resource_instance_match, - (void *)ptr); + res = kunit_find_resource(test, kunit_kfree_match, (void *)ptr); /* * Removing the resource from the list of resources drops the