From patchwork Thu Jul 21 18:02:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Latypov X-Patchwork-Id: 12925665 X-Patchwork-Delegate: brendanhiggins@google.com 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 A4828CCA485 for ; Thu, 21 Jul 2022 18:02:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232149AbiGUSC1 (ORCPT ); Thu, 21 Jul 2022 14:02:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229511AbiGUSC1 (ORCPT ); Thu, 21 Jul 2022 14:02:27 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE1058B4B6 for ; Thu, 21 Jul 2022 11:02:25 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id r17-20020a056a00217100b0052ab8271e11so1071404pff.22 for ; Thu, 21 Jul 2022 11:02:25 -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=RB2jOP3DJE7igCuPWPwpafzWrvgkOGEukNgncgY30Ss=; b=Nkqucz4Xgj5poC7ii3+Ggm7r66PaVVGf8ItlIahOIzMwAH+6RxP9SM8pzj6bE+N3B5 Zx2FbdftthkGT86bdPDwfW3nEAYceHXRmMez7wFj4eJuBV5voxQI9lTqjr2ENfTCMx04 fkUOVtKgwCwnX8iPdmVXQINFnBD4pSR4ZKO2O6Ft0E2CjiuHLLg6YpXwUxdVlEvFiqF3 /0Bpp+hz3u0wyMlu5e6Rs4rtBWHSSSWmmZSn2bQ4oB6OV1HMsqYTPGFIrxxduxVFOcJF GeBGcJn0yPkuZ9bRlXwVk+yRtQxmLme3MEUC+pRqshGVJUU+fgDyWtEYo3DOgQ0Oljdg kyLw== 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=RB2jOP3DJE7igCuPWPwpafzWrvgkOGEukNgncgY30Ss=; b=TtkTdPk5Y6exObqxt1ZeUNdL/ogECWfDqLCiQmqQDBK7sspyvgbqfv3h65bVWhL4yc TmUCMdy4MP0RgAJoXH4qfqp4b+uSQizXwVdCWfAarCHCUC1JBkculrYLFFMLkk6VSS86 2CGcna1O/J0IGPJgKxdIQSyYsgtKX7VuNTWFZgpDHXknyZ0CExUuVVcm19J6mKDp2Vt9 sl9G7aqbCOwmdgZjqNMZrl8JnT1W0E2EGqzqq9RVR8IxvlNP5uESeKGFMcNE74u+QP73 umcNJDDwnsDcK0Q5wfJb3tTkPLfC3hgqpV7aj05AJY8E1GEGya+Sfg7oFeoalC5j/CC0 j1jA== X-Gm-Message-State: AJIora+d0bYoItBUpA9BfbSYpUm2b3dGHrFQvgk/bnq9TFQIknmWNrbF bZcqHYZG6L7f74yulIG1WrSAapcZJTBH+g== X-Google-Smtp-Source: AGRyM1t2IpzFVpMpQ/fVMUMXE/kIZBLqojYsP6NJxMuU8Fw9yThIdW+j1+3O9PGlRaqXeTmu2lA5RKVGxp79KQ== X-Received: from dlatypov-spec.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3f35]) (user=dlatypov job=sendgmr) by 2002:a62:be04:0:b0:52a:e089:99ee with SMTP id l4-20020a62be04000000b0052ae08999eemr44556758pff.26.1658426545233; Thu, 21 Jul 2022 11:02:25 -0700 (PDT) Date: Thu, 21 Jul 2022 18:02:13 +0000 In-Reply-To: <20220721180214.3223778-1-dlatypov@google.com> Message-Id: <20220721180214.3223778-3-dlatypov@google.com> Mime-Version: 1.0 References: <20220721180214.3223778-1-dlatypov@google.com> X-Mailer: git-send-email 2.37.1.359.gd136c6c3e2-goog Subject: [PATCH 3/4] 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 --- 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