From patchwork Tue May 20 20:48:40 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 891403 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (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 7C09825EFBD; Tue, 20 May 2025 20:49:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747774172; cv=none; b=RiHSa+Voh7Gi7LXO54fJLL5FEyV3665khuvWRk3GKQvX4xCvmM2kpQgzTAb/2+RRj4xhfVqogDLWuv2ZQwWAxEGXo9mxHbVlM8Ao4IFCNVLmR60BLHnp0zI+O3k1gEP86Dq8NolE2SHeu6Mqai7O+rf5nX1qI+0qna9srlkHcLs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747774172; c=relaxed/simple; bh=PecueBhb3qx1RHFBN98VuO4lhdtWIZM9jToHkTc/HLE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=iQKks8mHcmANwcZRZ7aGfTGEFB4XcJ+TOgvcYZvEHWMN9yQx8dOIyYPOAbI4Wydi06yzO7YBaA70KXPP3Ttvt5HOJun4IHjhBauxsE5wadBtTr754VadjGE/n8T6B0M/bU4kg0pt5qxn526MOiqIsu72HWDNmPowIyEc5HjZxmY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=QsSmc2fi; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="QsSmc2fi" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=N5VA/SwJ6w5fExHAtI2s26hUsQkblQRmCfj6Ybce2s4=; b=QsSmc2fiAU/dBhF6op4s9dOnK7 8A3Swh8uMNx8/HOxBSDFeLbp7OchiP7AwIIYTYhbh0dGOQdtoLWkfPzx4K/sSmsnMItb22Yg5WuIT 9TJN/Iobd5w3dk8Fe3JtzZ6WocNrTnIPSaloUI5wSC3JLmDx0jX06jwLZH8AwdL/9rh6OqoiPL/lI abZ2y1DIZUNj4Z2NF9OngOkhGyY7HMDqRL8KR4fsGPRFw7T5REVcU5L/j36YnRRmfkofguADoOO/e NT2quKhTnOkkkam8WlovpGUb/FUw1WWCngOjFJrXyzFFZsmBg7L3lBZEJ6UIIcGJ41YES7jSOyHcF MoykCUew==; Received: from [191.204.192.64] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1uHTtr-00AsVE-NH; Tue, 20 May 2025 22:49:23 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Tue, 20 May 2025 17:48:40 -0300 Subject: [PATCH v4 7/7] selftests: futex: Expand robust list test for the new interface Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250520-tonyk-robust_futex-v4-7-1123093e59de@igalia.com> References: <20250520-tonyk-robust_futex-v4-0-1123093e59de@igalia.com> In-Reply-To: <20250520-tonyk-robust_futex-v4-0-1123093e59de@igalia.com> To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , Davidlohr Bueso , Shuah Khan , Arnd Bergmann , Sebastian Andrzej Siewior , Waiman Long Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.14.2 Expand the current robust list test for the new set_robust_list2 syscall. Create an option to make it possible to run the same tests using the new syscall, and also add two new relevant test: test long lists (bigger than ROBUST_LIST_LIMIT) and for unaligned addresses. Signed-off-by: André Almeida --- .../selftests/futex/functional/robust_list.c | 160 ++++++++++++++++++++- 1 file changed, 156 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c index 42690b2440fd29a9b12c46f67f9645ccc93d1147..004ad79ff6171c411fd47e699e3c38889544218e 100644 --- a/tools/testing/selftests/futex/functional/robust_list.c +++ b/tools/testing/selftests/futex/functional/robust_list.c @@ -35,16 +35,45 @@ #include #include #include +#include #define STACK_SIZE (1024 * 1024) #define FUTEX_TIMEOUT 3 +#define SYS_set_robust_list2 468 + +enum robust_list2_type { + ROBUST_LIST_32BIT, + ROBUST_LIST_64BIT, +}; + static pthread_barrier_t barrier, barrier2; +bool robust2 = false; + int set_robust_list(struct robust_list_head *head, size_t len) { - return syscall(SYS_set_robust_list, head, len); + int ret, flags; + + if (!robust2) { + return syscall(SYS_set_robust_list, head, len); + } + + if (sizeof(head) == 8) + flags = ROBUST_LIST_64BIT; + else + flags = ROBUST_LIST_32BIT; + + /* + * We act as we have just one list here. We try to use the first slot, + * but if it hasn't been alocated yet we allocate it. + */ + ret = syscall(SYS_set_robust_list2, head, 0, flags); + if (ret == -1 && errno == ENOENT) + ret = syscall(SYS_set_robust_list2, head, -1, flags); + + return ret; } int get_robust_list(int pid, struct robust_list_head **head, size_t *len_ptr) @@ -246,6 +275,11 @@ static void test_set_robust_list_invalid_size(void) size_t head_size = sizeof(struct robust_list_head); int ret; + if (robust2) { + ksft_test_result_skip("This test is only for old robust interface\n"); + return; + } + ret = set_robust_list(&head, head_size); ASSERT_EQ(ret, 0); @@ -321,6 +355,11 @@ static void test_get_robust_list_child(void) struct robust_list_head head, *get_head; size_t len_ptr; + if (robust2) { + ksft_test_result_skip("Not implemented in the new robust interface\n"); + return; + } + ret = pthread_barrier_init(&barrier, NULL, 2); ret = pthread_barrier_init(&barrier2, NULL, 2); ASSERT_EQ(ret, 0); @@ -332,7 +371,7 @@ static void test_get_robust_list_child(void) ret = get_robust_list(tid, &get_head, &len_ptr); ASSERT_EQ(ret, 0); - ASSERT_EQ(&head, get_head); + ASSERT_EQ(get_head, &head); pthread_barrier_wait(&barrier2); @@ -507,11 +546,119 @@ static void test_circular_list(void) ksft_test_result_pass("%s\n", __func__); } +#define ROBUST_LIST_LIMIT 2048 +#define CHILD_LIST_LIMIT (ROBUST_LIST_LIMIT + 10) + +static int child_robust_list_limit(void *arg) +{ + struct lock_struct *locks; + struct robust_list *list; + struct robust_list_head head; + int ret, i; + + locks = (struct lock_struct *) arg; + + ret = set_list(&head); + if (ret) + ksft_test_result_fail("set_list error\n"); + + /* + * Create a very long list of locks + */ + head.list.next = &locks[0].list; + + list = head.list.next; + for (i = 0; i < CHILD_LIST_LIMIT - 1; i++) { + list->next = &locks[i+1].list; + list = list->next; + } + list->next = &head.list; + + /* + * Grab the lock in the last one, and die without releasing it + */ + mutex_lock(&locks[CHILD_LIST_LIMIT], &head, false); + pthread_barrier_wait(&barrier); + + sleep(1); + + return 0; +} + +/* + * The old robust list used to have a limit of 2048 items from the kernel side. + * After this limit the kernel stops walking the list and ignore the other + * futexes, causing deadlocks. + * + * For the new interface, test if we can wait for a list of more than 2048 + * elements. + */ +static void test_robust_list_limit(void) +{ + struct lock_struct locks[CHILD_LIST_LIMIT + 1]; + _Atomic(unsigned int) *futex = &locks[CHILD_LIST_LIMIT].futex; + struct robust_list_head head; + int ret; + + if (!robust2) { + ksft_test_result_skip("This test is only for new robust interface\n"); + return; + } + + *futex = 0; + + ret = set_list(&head); + ASSERT_EQ(ret, 0); + + ret = pthread_barrier_init(&barrier, NULL, 2); + ASSERT_EQ(ret, 0); + + create_child(child_robust_list_limit, locks); + + /* + * After the child thread creates the very long list of locks, wait on + * the last one. + */ + pthread_barrier_wait(&barrier); + ret = mutex_lock(&locks[CHILD_LIST_LIMIT], &head, false); + + if (ret != 0) + printf("futex wait returned %d\n", errno); + ASSERT_EQ(ret, 0); + + ASSERT_TRUE(*futex | FUTEX_OWNER_DIED); + + wait(NULL); + pthread_barrier_destroy(&barrier); + + ksft_test_result_pass("%s\n", __func__); +} + +/* + * The kernel should refuse an unaligned head pointer + */ +static void test_unaligned_address(void) +{ + struct robust_list_head head, *h; + int ret; + + if (!robust2) { + ksft_test_result_skip("This test is only for new robust interface\n"); + return; + } + + h = (struct robust_list_head *) ((uintptr_t) &head + 1); + ret = set_list(h); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, EINVAL); +} + void usage(char *prog) { printf("Usage: %s\n", prog); printf(" -c Use color\n"); printf(" -h Display this help message\n"); + printf(" -n Use robust2 syscall\n"); printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", VQUIET, VCRITICAL, VINFO); } @@ -520,7 +667,7 @@ int main(int argc, char *argv[]) { int c; - while ((c = getopt(argc, argv, "cht:v:")) != -1) { + while ((c = getopt(argc, argv, "chnt:v:")) != -1) { switch (c) { case 'c': log_color(1); @@ -531,6 +678,9 @@ int main(int argc, char *argv[]) case 'v': log_verbosity(atoi(optarg)); break; + case 'n': + robust2 = true; + break; default: usage(basename(argv[0])); exit(1); @@ -538,7 +688,7 @@ int main(int argc, char *argv[]) } ksft_print_header(); - ksft_set_plan(7); + ksft_set_plan(8); test_robustness(); @@ -548,6 +698,8 @@ int main(int argc, char *argv[]) test_set_list_op_pending(); test_robust_list_multiple_elements(); test_circular_list(); + test_robust_list_limit(); + test_unaligned_address(); ksft_print_cnts(); return 0;