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 X-Spam-Level: X-Spam-Status: No, score=-14.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12053C4727F for ; Tue, 29 Sep 2020 07:56:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B482E20897 for ; Tue, 29 Sep 2020 07:56:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="4vdOoSI8"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="kAji2NG2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727698AbgI2H4z (ORCPT ); Tue, 29 Sep 2020 03:56:55 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:44352 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727484AbgI2H4v (ORCPT ); Tue, 29 Sep 2020 03:56:51 -0400 Date: Tue, 29 Sep 2020 07:56:46 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1601366207; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h07DlkCi9A3A/nWY/LwUmSrlCEq+f166PIWhtfsUbb0=; b=4vdOoSI8AK2EHLJLUQEMNGpmXQZcMYsWzznOkPIHpUR/cRDVJo5QosuKwNiVORw1lX0FQI LCk+vhTg31YaRxwhc4G+NiWueNn5IDnpbYqUswg6oJRdB0B/Mv/+qIHnAXPjChstgeejNf dtQTBAZ/nlo58cux80AI3CYz8OUEmQqeE/+oHwfsQz2Z6jyhIL2S2FFgaFs/DPnmqrS5qG xzemKEXwQGxe882GhtdmLU3CmsTTlXWSj/V2S5RbFxR3Up7lib0VWTF7hL41QHIMR7728G q4YvNVcil0UJfLL/agW6uEQhHhm894ZvOYwjNVZSBs/YbmZ9mYjz4HKnS4C58Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1601366207; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h07DlkCi9A3A/nWY/LwUmSrlCEq+f166PIWhtfsUbb0=; b=kAji2NG2IIDlRnfjrkwt+qkeS9kxCr0b0yybWNEDHQnRqWgIrGtslEOG+mVjb2oawoeTVQ K8G/SOBv1SrFObBg== From: "tip-bot2 for Peter Oskolkov" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] rseq/selftests: Test MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ Cc: Peter Oskolkov , "Peter Zijlstra (Intel)" , Mathieu Desnoyers , x86 , LKML In-Reply-To: <20200923233618.2572849-3-posk@google.com> References: <20200923233618.2572849-3-posk@google.com> MIME-Version: 1.0 Message-ID: <160136620672.7002.7894847614657872856.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: f166b111e0491486fca0d105f09655ab718bd1c8 Gitweb: https://git.kernel.org/tip/f166b111e0491486fca0d105f09655ab718bd1c8 Author: Peter Oskolkov AuthorDate: Wed, 23 Sep 2020 16:36:18 -07:00 Committer: Peter Zijlstra CommitterDate: Fri, 25 Sep 2020 14:23:27 +02:00 rseq/selftests: Test MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ Based on Google-internal RSEQ work done by Paul Turner and Andrew Hunter. This patch adds a selftest for MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ. The test quite often fails without the previous patch in this patchset, but consistently passes with it. Signed-off-by: Peter Oskolkov Signed-off-by: Peter Zijlstra (Intel) Acked-by: Mathieu Desnoyers Link: https://lkml.kernel.org/r/20200923233618.2572849-3-posk@google.com --- tools/testing/selftests/rseq/param_test.c | 223 +++++++++++++++- tools/testing/selftests/rseq/run_param_test.sh | 2 +- 2 files changed, 224 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c index e8a657a..3845890 100644 --- a/tools/testing/selftests/rseq/param_test.c +++ b/tools/testing/selftests/rseq/param_test.c @@ -1,8 +1,10 @@ // SPDX-License-Identifier: LGPL-2.1 #define _GNU_SOURCE #include +#include #include #include +#include #include #include #include @@ -1131,6 +1133,220 @@ static int set_signal_handler(void) return ret; } +struct test_membarrier_thread_args { + int stop; + intptr_t percpu_list_ptr; +}; + +/* Worker threads modify data in their "active" percpu lists. */ +void *test_membarrier_worker_thread(void *arg) +{ + struct test_membarrier_thread_args *args = + (struct test_membarrier_thread_args *)arg; + const int iters = opt_reps; + int i; + + if (rseq_register_current_thread()) { + fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n", + errno, strerror(errno)); + abort(); + } + + /* Wait for initialization. */ + while (!atomic_load(&args->percpu_list_ptr)) {} + + for (i = 0; i < iters; ++i) { + int ret; + + do { + int cpu = rseq_cpu_start(); + + ret = rseq_offset_deref_addv(&args->percpu_list_ptr, + sizeof(struct percpu_list_entry) * cpu, 1, cpu); + } while (rseq_unlikely(ret)); + } + + if (rseq_unregister_current_thread()) { + fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n", + errno, strerror(errno)); + abort(); + } + return NULL; +} + +void test_membarrier_init_percpu_list(struct percpu_list *list) +{ + int i; + + memset(list, 0, sizeof(*list)); + for (i = 0; i < CPU_SETSIZE; i++) { + struct percpu_list_node *node; + + node = malloc(sizeof(*node)); + assert(node); + node->data = 0; + node->next = NULL; + list->c[i].head = node; + } +} + +void test_membarrier_free_percpu_list(struct percpu_list *list) +{ + int i; + + for (i = 0; i < CPU_SETSIZE; i++) + free(list->c[i].head); +} + +static int sys_membarrier(int cmd, int flags, int cpu_id) +{ + return syscall(__NR_membarrier, cmd, flags, cpu_id); +} + +/* + * The manager thread swaps per-cpu lists that worker threads see, + * and validates that there are no unexpected modifications. + */ +void *test_membarrier_manager_thread(void *arg) +{ + struct test_membarrier_thread_args *args = + (struct test_membarrier_thread_args *)arg; + struct percpu_list list_a, list_b; + intptr_t expect_a = 0, expect_b = 0; + int cpu_a = 0, cpu_b = 0; + + if (rseq_register_current_thread()) { + fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n", + errno, strerror(errno)); + abort(); + } + + /* Init lists. */ + test_membarrier_init_percpu_list(&list_a); + test_membarrier_init_percpu_list(&list_b); + + atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a); + + while (!atomic_load(&args->stop)) { + /* list_a is "active". */ + cpu_a = rand() % CPU_SETSIZE; + /* + * As list_b is "inactive", we should never see changes + * to list_b. + */ + if (expect_b != atomic_load(&list_b.c[cpu_b].head->data)) { + fprintf(stderr, "Membarrier test failed\n"); + abort(); + } + + /* Make list_b "active". */ + atomic_store(&args->percpu_list_ptr, (intptr_t)&list_b); + if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ, + MEMBARRIER_CMD_FLAG_CPU, cpu_a) && + errno != ENXIO /* missing CPU */) { + perror("sys_membarrier"); + abort(); + } + /* + * Cpu A should now only modify list_b, so the values + * in list_a should be stable. + */ + expect_a = atomic_load(&list_a.c[cpu_a].head->data); + + cpu_b = rand() % CPU_SETSIZE; + /* + * As list_a is "inactive", we should never see changes + * to list_a. + */ + if (expect_a != atomic_load(&list_a.c[cpu_a].head->data)) { + fprintf(stderr, "Membarrier test failed\n"); + abort(); + } + + /* Make list_a "active". */ + atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a); + if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ, + MEMBARRIER_CMD_FLAG_CPU, cpu_b) && + errno != ENXIO /* missing CPU*/) { + perror("sys_membarrier"); + abort(); + } + /* Remember a value from list_b. */ + expect_b = atomic_load(&list_b.c[cpu_b].head->data); + } + + test_membarrier_free_percpu_list(&list_a); + test_membarrier_free_percpu_list(&list_b); + + if (rseq_unregister_current_thread()) { + fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n", + errno, strerror(errno)); + abort(); + } + return NULL; +} + +/* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */ +#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV +void test_membarrier(void) +{ + const int num_threads = opt_threads; + struct test_membarrier_thread_args thread_args; + pthread_t worker_threads[num_threads]; + pthread_t manager_thread; + int i, ret; + + if (sys_membarrier(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ, 0, 0)) { + perror("sys_membarrier"); + abort(); + } + + thread_args.stop = 0; + thread_args.percpu_list_ptr = 0; + ret = pthread_create(&manager_thread, NULL, + test_membarrier_manager_thread, &thread_args); + if (ret) { + errno = ret; + perror("pthread_create"); + abort(); + } + + for (i = 0; i < num_threads; i++) { + ret = pthread_create(&worker_threads[i], NULL, + test_membarrier_worker_thread, &thread_args); + if (ret) { + errno = ret; + perror("pthread_create"); + abort(); + } + } + + + for (i = 0; i < num_threads; i++) { + ret = pthread_join(worker_threads[i], NULL); + if (ret) { + errno = ret; + perror("pthread_join"); + abort(); + } + } + + atomic_store(&thread_args.stop, 1); + ret = pthread_join(manager_thread, NULL); + if (ret) { + errno = ret; + perror("pthread_join"); + abort(); + } +} +#else /* RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV */ +void test_membarrier(void) +{ + fprintf(stderr, "rseq_offset_deref_addv is not implemented on this architecture. " + "Skipping membarrier test.\n"); +} +#endif + static void show_usage(int argc, char **argv) { printf("Usage : %s \n", @@ -1153,7 +1369,7 @@ static void show_usage(int argc, char **argv) printf(" [-r N] Number of repetitions per thread (default 5000)\n"); printf(" [-d] Disable rseq system call (no initialization)\n"); printf(" [-D M] Disable rseq for each M threads\n"); - printf(" [-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement\n"); + printf(" [-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement, membarrie(r)\n"); printf(" [-M] Push into buffer and memcpy buffer with memory barriers.\n"); printf(" [-v] Verbose output.\n"); printf(" [-h] Show this help.\n"); @@ -1268,6 +1484,7 @@ int main(int argc, char **argv) case 'i': case 'b': case 'm': + case 'r': break; default: show_usage(argc, argv); @@ -1320,6 +1537,10 @@ int main(int argc, char **argv) printf_verbose("counter increment\n"); test_percpu_inc(); break; + case 'r': + printf_verbose("membarrier\n"); + test_membarrier(); + break; } if (!opt_disable_rseq && rseq_unregister_current_thread()) abort(); diff --git a/tools/testing/selftests/rseq/run_param_test.sh b/tools/testing/selftests/rseq/run_param_test.sh index e426304..f51bc83 100755 --- a/tools/testing/selftests/rseq/run_param_test.sh +++ b/tools/testing/selftests/rseq/run_param_test.sh @@ -15,6 +15,7 @@ TEST_LIST=( "-T m" "-T m -M" "-T i" + "-T r" ) TEST_NAME=( @@ -25,6 +26,7 @@ TEST_NAME=( "memcpy" "memcpy with barrier" "increment" + "membarrier" ) IFS="$OLDIFS"