From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE27C38AC80; Fri, 10 Apr 2026 07:57:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775807854; cv=none; b=tSdbjrWMTdYGrWQCW/yA+3Y12Uz2M1RfoyeVdEtU2OsSwY+eesagjvhYGKSNTn08r6r50CFBb1qMH8OOBPjxUE+xqoOfWtzxYlsIwC+ElivVsLnH0FFheYTKx4rzOrjHLfgvcbkOeYIJFh3cibCBwDD8fVpEYl1lw3kWRrn0T70= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775807854; c=relaxed/simple; bh=t5KBu+7awGUOMXi6m9ZOEzCXzmOw+JC05loV+9h6t38=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VA8O9t8QC5EYdcTl4CAaF59X4GjYjv5EaA9inJeBRv4kiiHW+A3X+FJLDQBd+TqkslX1FAXAWOLpK/yWsOB1R0L8CJ6OdraiXu8/tU5FXvx1G6ZbomWKEsUFcv4pJQCVe1hWNtKTLr1+DCSjlfqd7pXog8cs7Heq8PmBfXkGHSo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=izGGLCut; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="izGGLCut" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E29BDC2BC9E; Fri, 10 Apr 2026 07:57:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775807853; bh=t5KBu+7awGUOMXi6m9ZOEzCXzmOw+JC05loV+9h6t38=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=izGGLCutqqcBp82UmrmqyGceR/3RWlWXrH77qMbUb648eQTOwohHXwOdzcGTUbe4h f1nzujvepQF/aOjf7A5GS1ZDh4QnxMEqEF7kEhAbI3KuATaFpvQFP/j92KH+dm/Hrc krsg6oM7HO6oPRp00JL6nIdbbMy3a73oQTF5rSvQcWyHI+GsXORtommKmS/83NuP5H 1BdO+ixYMri3EfxNOTzAW/eePaEd9IOc/KIy5obQ074gUYeifemx3PolNWY+buLUnE ljL/xPUbQHj3yJZo0I1r2qYa7yO+oJQK7Zx95huq8PFs5eo2kI6lzEJtIA8MnHgk9C QFXUlJIplqKJA== Message-ID: <7a318c3c-7ccb-4f95-a416-19d09f42c97f@kernel.org> Date: Fri, 10 Apr 2026 09:57:27 +0200 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] selftests/mm: verify droppable mappings cannot be locked To: Anthony Yznaga , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: akpm@linux-foundation.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jannh@google.com, pfalcato@suse.de, Jason@zx2c4.com, shuah@kernel.org References: <20260409234915.11723-1-anthony.yznaga@oracle.com> <20260409234915.11723-3-anthony.yznaga@oracle.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/10/26 01:49, Anthony Yznaga wrote: > For configs that support MAP_DROPPABLE verify that a mapping created > with MAP_DROPPABLE cannot be locked via mlock(), and that it will not > be locked if it's created after mlockall(MCL_FUTURE). > > Signed-off-by: Anthony Yznaga > --- [...] > + > +#ifdef MAP_DROPPABLE > +/* > + * Droppable memory should not be lockable. > + */ Single-line comment. > +static void test_mlock_droppable(void) > +{ > + char *map; > + unsigned long page_size = getpagesize(); We could store that in a static global and query it once during main(). Feel free to keep it as is. > + > + /* > + * Ensure MCL_FUTURE is not set. > + */ Dito. > + if (munlockall()) { > + ksft_test_result_fail("munlockall() %s\n", strerror(errno)); > + return; > + } > + > + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, > + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0); > + if (map == MAP_FAILED) { > + if (errno == EOPNOTSUPP) > + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__); > + else > + ksft_test_result_fail("mmap error: %s\n", strerror(errno)); > + return; > + } > + > + if (mlock2_(map, 2 * page_size, 0)) Weird, is "mlock2_" actually correct? (not "mlock2") ? > + ksft_test_result_fail("mlock2(0): %s\n", strerror(errno)); > + else > + ksft_test_result(!unlock_lock_check(map, false), > + "%s: droppable memory not locked\n", __func__); > + > + munmap(map, 2 * page_size); > +} > + > +static void test_mlockall_future_droppable(void) > +{ > + char *map; > + unsigned long page_size = getpagesize(); > + > + if (mlockall(MCL_CURRENT | MCL_FUTURE)) { > + ksft_test_result_fail("mlockall(MCL_CURRENT | MCL_FUTURE): %s\n", strerror(errno)); > + return; > + } > + > + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, > + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0); > + > + if (map == MAP_FAILED) { > + if (errno == EOPNOTSUPP) > + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__); > + else > + ksft_test_result_fail("mmap error: %s\n", strerror(errno)); > + munlockall(); > + return; > + } > + > + ksft_test_result(!unlock_lock_check(map, false), "%s: droppable memory not locked\n", > + __func__); > + > + munlockall(); > munmap(map, 2 * page_size); > } > +#else > +static void test_mlock_droppable(void) > +{ > + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__); > +} > + > +static void test_mlockall_future_droppable(void) > +{ > + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__); > +} > +#endif /* MAP_DROPPABLE */ > Why not a above a #ifndef MAP_DROPPABLE #define MAP_DROPPABLE 0x08 #endif instead? > static void test_vma_management(bool call_mlock) > { > @@ -442,7 +522,7 @@ int main(int argc, char **argv) > > munmap(map, size); > > - ksft_set_plan(13); > + ksft_set_plan(15); > > test_mlock_lock(); > test_mlock_onfault(); > @@ -451,6 +531,8 @@ int main(int argc, char **argv) > test_lock_onfault_of_present(); > test_vma_management(true); > test_mlockall(); > + test_mlock_droppable(); > + test_mlockall_future_droppable(); > > ksft_finished(); > } Feel free to add Acked-by: David Hildenbrand (Arm) -- Cheers, David