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 Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 63210C433FE for ; Mon, 17 Oct 2022 13:43:37 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id ED0FC3CAFC9 for ; Mon, 17 Oct 2022 15:43:33 +0200 (CEST) Received: from in-7.smtp.seeweb.it (in-7.smtp.seeweb.it [217.194.8.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id F14C63CAFC9 for ; Mon, 17 Oct 2022 15:43:23 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-7.smtp.seeweb.it (Postfix) with ESMTPS id DA99A2005D2 for ; Mon, 17 Oct 2022 15:43:22 +0200 (CEST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C42B034104; Mon, 17 Oct 2022 13:43:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1666014201; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8qCEFZDHJuAapWtL/D5h9oGLMe2gEpPlN2Bx8PRN6+s=; b=Cxt49r27cj060t2uLtnWTIopWOFCBnpelr8TdolJZq/g33FlXX1Eikp4gBezFLXLzqAgIn acECkIsut8TOT+SZDSMRLZCYMTAoA0Jt39kz13xWG3mGmO+hugcZ4o3ZN2H6Ki+iOK/e92 cXw5BDHg4TNimnlOxMSjhUp1bw90zDg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1666014201; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8qCEFZDHJuAapWtL/D5h9oGLMe2gEpPlN2Bx8PRN6+s=; b=TqCqus+gecNP0n5CsQaJbbZzSG4uocbjPWkZ6gu6T8SLu4UV6nUclmdeb8wW/DGGz5wD0V 1qe6USG+SvfUYLBQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1949513398; Mon, 17 Oct 2022 13:43:21 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id UCUABflbTWOmYAAAMHmgww (envelope-from ); Mon, 17 Oct 2022 13:43:21 +0000 Date: Mon, 17 Oct 2022 15:45:03 +0200 From: Cyril Hrubis To: Tarun Sahu Message-ID: References: <20221016125731.249078-1-tsahu@linux.ibm.com> <20221016125731.249078-10-tsahu@linux.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221016125731.249078-10-tsahu@linux.ibm.com> X-Virus-Scanned: clamav-milter 0.102.4 at in-7.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH 09/29] Hugetlb: Migrating libhugetlbfs fork-cow X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: aneesh.kumar@linux.ibm.com, sbhat@linux.ibm.com, ltp@lists.linux.it, vaibhav@linux.ibm.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hi! > Migrating the libhugetlbfs/testcases/fork-cow.c test > > Test Description: This checks copy-on-write semantics, specifically the > semantics of a MAP_PRIVATE mapping across a fork(). Some versions of the > powerpc kernel had a bug in huge_ptep_set_wrprotect() which would fail to > flush the hash table after setting the write protect bit in the parent's > page tables, thus allowing the parent to pollute the child's mapping. > > Signed-off-by: Tarun Sahu > --- > runtest/hugetlb | 2 + > testcases/kernel/mem/.gitignore | 1 + > .../kernel/mem/hugetlb/hugefork/Makefile | 10 + > .../kernel/mem/hugetlb/hugefork/hugefork01.c | 220 ++++++++++++++++++ > 4 files changed, 233 insertions(+) > create mode 100644 testcases/kernel/mem/hugetlb/hugefork/Makefile > create mode 100644 testcases/kernel/mem/hugetlb/hugefork/hugefork01.c > > diff --git a/runtest/hugetlb b/runtest/hugetlb > index ec1fc2515..4c16e1e7c 100644 > --- a/runtest/hugetlb > +++ b/runtest/hugetlb > @@ -1,6 +1,8 @@ > hugefallocate01 hugefallocate01 > hugefallocate02 hugefallocate02 > > +hugefork01 hugefork01 > + > hugemmap01 hugemmap01 > hugemmap02 hugemmap02 > hugemmap04 hugemmap04 > diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore > index c0906f3d3..adea760c7 100644 > --- a/testcases/kernel/mem/.gitignore > +++ b/testcases/kernel/mem/.gitignore > @@ -1,6 +1,7 @@ > /cpuset/cpuset01 > /hugetlb/hugefallocate/hugefallocate01 > /hugetlb/hugefallocate/hugefallocate02 > +/hugetlb/hugefork/hugefork01 > /hugetlb/hugemmap/hugemmap01 > /hugetlb/hugemmap/hugemmap02 > /hugetlb/hugemmap/hugemmap04 > diff --git a/testcases/kernel/mem/hugetlb/hugefork/Makefile b/testcases/kernel/mem/hugetlb/hugefork/Makefile > new file mode 100644 > index 000000000..77ebb0aef > --- /dev/null > +++ b/testcases/kernel/mem/hugetlb/hugefork/Makefile > @@ -0,0 +1,10 @@ > +# SPDX-License-Identifier: GPL-2.0-or-later > +# Copyright (C) 2009, Cisco Systems Inc. > +# Ngie Cooper, July 2009 > + > +top_srcdir ?= ../../../../.. > + > +include $(top_srcdir)/include/mk/testcases.mk > +include $(abs_srcdir)/../Makefile.inc > +include $(top_srcdir)/include/mk/generic_leaf_target.mk > + > diff --git a/testcases/kernel/mem/hugetlb/hugefork/hugefork01.c b/testcases/kernel/mem/hugetlb/hugefork/hugefork01.c > new file mode 100644 > index 000000000..096ff0c4d > --- /dev/null > +++ b/testcases/kernel/mem/hugetlb/hugefork/hugefork01.c > @@ -0,0 +1,220 @@ > +// SPDX-License-Identifier: LGPL-2.1-or-later > +/* > + * Copyright (C) 2008 David Gibson, IBM Corporation. > + * > + * Test Name: fork COW > + * > + * Test Description: This checks copy-on-write semantics, specifically the > + * semantics of a MAP_PRIVATE mapping across a fork(). Some versions of the > + * powerpc kernel had a bug in huge_ptep_set_wrprotect() which would fail to > + * flush the hash table after setting the write protect bit in the parent's > + * page tables, thus allowing the parent to pollute the child's mapping. > + * > + * HISTORY > + * Written by David Gibson > + * > + */ > + > +#define _GNU_SOURCE > + > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "hugetlb.h" > + > +#define RANDOM_CONSTANT 0x1234ABCD > +#define OTHER_CONSTANT 0xfeef5678 > + > +static int fd = -1; > +static char hfile[MAXPATHLEN]; > +static long hpage_size; > +static char *verbose; > + > +/* > + * The parent uses this to check if the child terminated badly. > + */ > +static void sigchld_handler(int signum, siginfo_t *si, void *uc) > +{ > + (void)signum; > + (void)uc; > + if (WEXITSTATUS(si->si_status) != 0) { > + tst_res(TFAIL, "Child failed: %d", WEXITSTATUS(si->si_status)); > + goto fail; > + } > + if (WIFSIGNALED(si->si_status)) { > + tst_res(TFAIL, "Child recived signal %s", > + strsignal(WTERMSIG(si->si_status))); > + goto fail; > + } > + return; > +fail: > + tst_brk(TBROK, "Once failed, No point in continuing the test"); You cannot call tst_* functions from a signal handler, these are not async-signal-safe. The only sensible thing to use the value filled in by the waitpid() call instead. > +} > + > +static void run_test(void) > +{ > + int status; > + void *syncarea; > + volatile unsigned int *p; > + volatile unsigned int *trigger, *child_readback; > + int parent_readback; > + pid_t pid; > + struct sigaction sa = { > + .sa_sigaction = sigchld_handler, > + .sa_flags = SA_SIGINFO, > + }; > + > + /* Get a shared normal page for synchronization */ > + if (verbose) > + tst_res(TINFO, "Mapping synchronization area.."); > + syncarea = SAFE_MMAP(NULL, getpagesize(), PROT_READ|PROT_WRITE, > + MAP_SHARED|MAP_ANONYMOUS, -1, 0); > + if (verbose) > + tst_res(TINFO, "done"); > + > + trigger = syncarea; > + *trigger = 0; > + > + child_readback = trigger + 1; > + *child_readback = 0; > + > + fd = SAFE_OPEN(hfile, O_RDWR | O_CREAT, 0600); > + SAFE_UNLINK(hfile); > + > + if (verbose) > + tst_res(TINFO, "Mapping hugepage area..."); > + p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); > + if (verbose) > + tst_res(TINFO, "mapped at %p", p); > + /* Touch the page for write in parent */ > + if (verbose) > + tst_res(TINFO, "Parent writes pre-fork..."); > + *p = RANDOM_CONSTANT; > + if (verbose) > + tst_res(TINFO, "%x", RANDOM_CONSTANT); > + > + SAFE_SIGACTION(SIGCHLD, &sa, NULL); > + > + pid = SAFE_FORK(); > + > + if (pid != 0) { > + /* Parent */ Useless comment again. > + if (verbose) > + tst_res(TINFO, "Parent writes post-fork..."); > + *p = ~RANDOM_CONSTANT; > + if (verbose) > + tst_res(TINFO, "~RANDOM_CONSTANT: %x", ~RANDOM_CONSTANT); > + *trigger = 1; We do have checkpoint library exactly for synchronization between parent and child make use of them, see TST_CHECKPOINT_*. > + while (*trigger != 2) > + ; > + > + if (verbose) > + tst_res(TINFO, "Parent reads.."); I would be inclined to remove these "Parent does xyz" and "Child does abc" messages from test once we make use of the CHECKPOINTs the synchronization is guaranteed to be right. > + parent_readback = *p; > + if (verbose) > + tst_res(TINFO, "Parent readback: %x", parent_readback); > + *trigger = 3; > + } else { > + /* Child */ Here as well. > + if (verbose) > + tst_res(TINFO, "Child starts.."); > + while (*trigger != 1) > + ; > + > + if (verbose) > + tst_res(TINFO, "Child reads..."); > + *child_readback = *p; > + if (verbose) { > + tst_res(TINFO, "child readback: %x", *child_readback); > + tst_res(TINFO, "Child writes..."); > + } > + *p = OTHER_CONSTANT; > + if (verbose) > + tst_res(TINFO, "OTHER_CONSTANT: %x", OTHER_CONSTANT); > + > + *trigger = 2; > + > + while (*trigger != 3) > + ; > + if (verbose) > + tst_res(TINFO, "Child exits..."); > + exit(0); > + } > + > + if (verbose) > + tst_res(TINFO, "child_readback = 0x%x, parent_readback = 0x%x\n", > + *child_readback, parent_readback); > + > + if (*child_readback != RANDOM_CONSTANT) { > + tst_res(TFAIL, "Child read back 0x%x instead of 0x%x", > + *child_readback, RANDOM_CONSTANT); > + goto fail; > + } > + if (parent_readback != ~RANDOM_CONSTANT) { > + tst_res(TFAIL, "Parent read back 0x%x instead of 0x%x", > + parent_readback, RANDOM_CONSTANT); > + goto fail; > + } > + > + SAFE_WAITPID(pid, &status, 0); > + > + tst_res(TPASS, "Successful"); > + SAFE_MUNMAP((void *)p, hpage_size); > + SAFE_MUNMAP(syncarea, getpagesize()); > + SAFE_CLOSE(fd); > + return; > +fail: > + tst_brk(TBROK, "Once failed, No point in continuing the test"); Here as well. > +} > + > +static void setup(void) > +{ > + int free_pages = SAFE_READ_MEMINFO("HugePages_Free:"); > + > + if (tst_hugepages < 2 || free_pages < 2) > + tst_brk(TCONF, "Not enough hugepages for testing."); > + > + if (!Hopt) > + Hopt = tst_get_tmpdir(); > + SAFE_MOUNT("none", Hopt, "hugetlbfs", 0, NULL); > + > + snprintf(hfile, sizeof(hfile), "%s/ltp_hugetlbfile%d", Hopt, getpid()); > + hpage_size = SAFE_READ_MEMINFO("Hugepagesize:")*1024; > +} > + > +static void cleanup(void) > +{ > + if (fd >= 0) > + SAFE_CLOSE(fd); > + umount2(Hopt, MNT_DETACH); Here as well. > +} > + > +static struct tst_test test = { > + .needs_root = 1, > + .needs_tmpdir = 1, > + .options = (struct tst_option[]) { > + {"v", &verbose, "Turns on verbose mode"}, > + {"H:", &Hopt, "Location of hugetlbfs, i.e. -H /var/hugetlbfs"}, > + {"s:", &nr_opt, "Set the number of the been allocated hugepages"}, > + {} > + }, > + .forks_child = 1, > + .setup = setup, > + .cleanup = cleanup, > + .test_all = run_test, > + .hugepages = {2, TST_REQUEST}, > +}; > -- > 2.31.1 > > > -- > Mailing list info: https://lists.linux.it/listinfo/ltp -- Cyril Hrubis chrubis@suse.cz -- Mailing list info: https://lists.linux.it/listinfo/ltp