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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 590AFC76186 for ; Thu, 18 Jul 2019 03:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 313A5205F4 for ; Thu, 18 Jul 2019 03:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563420371; bh=9TvNMRIVtFvr5+1q+DvEhMX7Rj3gXJ/+F85GI4B37T0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Urc/B3QSbimoARKQbeiqalQGSmLSLQxONZFlc22fcWsjK6OSlxj0o0+lg4pdtqmFR SDyGxaK79z4zktVn2rSSCpbzr9aDhVmyw/2QN9RKmsEsnP5SilCvW9MTzEfJ73t1H6 VFfOeW7u7welS2L4TuE8Lc9Autiwq5AXPCFTSD6U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727649AbfGRDEG (ORCPT ); Wed, 17 Jul 2019 23:04:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389558AbfGRDEF (ORCPT ); Wed, 17 Jul 2019 23:04:05 -0400 Received: from localhost (115.42.148.210.bf.2iij.net [210.148.42.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 419F621849; Thu, 18 Jul 2019 03:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563419044; bh=9TvNMRIVtFvr5+1q+DvEhMX7Rj3gXJ/+F85GI4B37T0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IpjIw/zmkry33RlNMlzx4vFTVXV+b7ozhp6PtdwT5ECkh5zB7EWx+4A0L8Kc6XLWR suWS75HL0ioHXuQUwTdn9ZOVtOJAAAnXjzLGodwB1E32cFtA179jbaUrc/+fcS5zuF dSSI5wE3wp5cyCZnl+HdUeVh8++kG0jMJYkA2dXY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman , Sasha Levin Subject: [PATCH 5.1 14/54] selftests/powerpc: Add test of fork with mapping above 512TB Date: Thu, 18 Jul 2019 12:01:09 +0900 Message-Id: <20190718030054.487588807@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190718030053.287374640@linuxfoundation.org> References: <20190718030053.287374640@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 16391bfc862342f285195013b73c1394fab28b97 ] This tests that when a process with a mapping above 512TB forks we correctly separate the parent and child address spaces. This exercises the bug in the context id handling fixed in the previous commit. Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- tools/testing/selftests/powerpc/mm/.gitignore | 3 +- tools/testing/selftests/powerpc/mm/Makefile | 4 +- .../powerpc/mm/large_vm_fork_separation.c | 87 +++++++++++++++++++ 3 files changed, 92 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/powerpc/mm/large_vm_fork_separation.c diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore index ba919308fe30..d503b8764a8e 100644 --- a/tools/testing/selftests/powerpc/mm/.gitignore +++ b/tools/testing/selftests/powerpc/mm/.gitignore @@ -3,4 +3,5 @@ subpage_prot tempfile prot_sao segv_errors -wild_bctr \ No newline at end of file +wild_bctr +large_vm_fork_separation \ No newline at end of file diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile index 43d68420e363..f1fbc15800c4 100644 --- a/tools/testing/selftests/powerpc/mm/Makefile +++ b/tools/testing/selftests/powerpc/mm/Makefile @@ -2,7 +2,8 @@ noarg: $(MAKE) -C ../ -TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors wild_bctr +TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors wild_bctr \ + large_vm_fork_separation TEST_GEN_FILES := tempfile top_srcdir = ../../../../.. @@ -13,6 +14,7 @@ $(TEST_GEN_PROGS): ../harness.c $(OUTPUT)/prot_sao: ../utils.c $(OUTPUT)/wild_bctr: CFLAGS += -m64 +$(OUTPUT)/large_vm_fork_separation: CFLAGS += -m64 $(OUTPUT)/tempfile: dd if=/dev/zero of=$@ bs=64k count=1 diff --git a/tools/testing/selftests/powerpc/mm/large_vm_fork_separation.c b/tools/testing/selftests/powerpc/mm/large_vm_fork_separation.c new file mode 100644 index 000000000000..2363a7f3ab0d --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/large_vm_fork_separation.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright 2019, Michael Ellerman, IBM Corp. +// +// Test that allocating memory beyond the memory limit and then forking is +// handled correctly, ie. the child is able to access the mappings beyond the +// memory limit and the child's writes are not visible to the parent. + +#include +#include +#include +#include +#include +#include + +#include "utils.h" + + +#ifndef MAP_FIXED_NOREPLACE +#define MAP_FIXED_NOREPLACE MAP_FIXED // "Should be safe" above 512TB +#endif + + +static int test(void) +{ + int p2c[2], c2p[2], rc, status, c, *p; + unsigned long page_size; + pid_t pid; + + page_size = sysconf(_SC_PAGESIZE); + SKIP_IF(page_size != 65536); + + // Create a mapping at 512TB to allocate an extended_id + p = mmap((void *)(512ul << 40), page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE, -1, 0); + if (p == MAP_FAILED) { + perror("mmap"); + printf("Error: couldn't mmap(), confirm kernel has 4TB support?\n"); + return 1; + } + + printf("parent writing %p = 1\n", p); + *p = 1; + + FAIL_IF(pipe(p2c) == -1 || pipe(c2p) == -1); + + pid = fork(); + if (pid == 0) { + FAIL_IF(read(p2c[0], &c, 1) != 1); + + pid = getpid(); + printf("child writing %p = %d\n", p, pid); + *p = pid; + + FAIL_IF(write(c2p[1], &c, 1) != 1); + FAIL_IF(read(p2c[0], &c, 1) != 1); + exit(0); + } + + c = 0; + FAIL_IF(write(p2c[1], &c, 1) != 1); + FAIL_IF(read(c2p[0], &c, 1) != 1); + + // Prevent compiler optimisation + barrier(); + + rc = 0; + printf("parent reading %p = %d\n", p, *p); + if (*p != 1) { + printf("Error: BUG! parent saw child's write! *p = %d\n", *p); + rc = 1; + } + + FAIL_IF(write(p2c[1], &c, 1) != 1); + FAIL_IF(waitpid(pid, &status, 0) == -1); + FAIL_IF(!WIFEXITED(status) || WEXITSTATUS(status)); + + if (rc == 0) + printf("success: test completed OK\n"); + + return rc; +} + +int main(void) +{ + return test_harness(test, "large_vm_fork_separation"); +} -- 2.20.1