From patchwork Mon Jul 6 07:28:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 278493 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 55466C433DF for ; Mon, 6 Jul 2020 07:30:26 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 250ED206CD for ; Mon, 6 Jul 2020 07:30:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ii8JoFWK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 250ED206CD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34972 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jsLa5-0004m6-Af for qemu-devel@archiver.kernel.org; Mon, 06 Jul 2020 03:30:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47266) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jsLYW-0003Oe-BP for qemu-devel@nongnu.org; Mon, 06 Jul 2020 03:28:48 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26308 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jsLYU-0004Iu-9z for qemu-devel@nongnu.org; Mon, 06 Jul 2020 03:28:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594020525; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:content-type:content-type:in-reply-to:in-reply-to: references:references; bh=sl4lnePHTVMyRzh87za++kiW+h7Hwz5DLgCYMcy9GQQ=; b=ii8JoFWKK5BlYjzdMi6W41kIvmSrAtuEXN5cuUxnSbO8/84WnBHndJE3N1synKbcrDbPGE Hr315sAJpnZ0rD4XT8Z5sdu8UwOQeTTbuofrqiCO3NYclCXW3dTzjRWdBOF+2Avfd78y1v NaX3y1/7Q3yndm4ldFQ8y5SaT7ySsmI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-375-m7SLHQaIOGO8X9RdE7hMWw-1; Mon, 06 Jul 2020 03:28:42 -0400 X-MC-Unique: m7SLHQaIOGO8X9RdE7hMWw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B46A0EC1A1; Mon, 6 Jul 2020 07:28:41 +0000 (UTC) Received: from thuth.com (ovpn-112-144.ams2.redhat.com [10.36.112.144]) by smtp.corp.redhat.com (Postfix) with ESMTP id B87095D9CC; Mon, 6 Jul 2020 07:28:40 +0000 (UTC) From: Thomas Huth To: Peter Maydell Subject: [PULL 2/6] fuzz: do not use POSIX shm for coverage bitmap Date: Mon, 6 Jul 2020 09:28:31 +0200 Message-Id: <20200706072835.23582-3-thuth@redhat.com> In-Reply-To: <20200706072835.23582-1-thuth@redhat.com> References: <20200706072835.23582-1-thuth@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=thuth@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/06 01:39:15 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexander Bulekov , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Alexander Bulekov We used shm_open with mmap to share libfuzzer's coverage bitmap with child (runner) processes. The same functionality can be achieved with MAP_SHARED | MAP_ANONYMOUS, since we do not care about naming or permissioning the shared memory object. Signed-off-by: Alexander Bulekov Message-Id: <20200622165040.15121-1-alxndr@bu.edu> Reviewed-by: Darren Kenny Reviewed-by: Stefan Hajnoczi Signed-off-by: Thomas Huth --- tests/qtest/fuzz/fork_fuzz.c | 40 ++++++++++++------------------------ 1 file changed, 13 insertions(+), 27 deletions(-) diff --git a/tests/qtest/fuzz/fork_fuzz.c b/tests/qtest/fuzz/fork_fuzz.c index 2bd0851903..6ffb2a7937 100644 --- a/tests/qtest/fuzz/fork_fuzz.c +++ b/tests/qtest/fuzz/fork_fuzz.c @@ -17,39 +17,25 @@ void counter_shm_init(void) { - char *shm_path = g_strdup_printf("/qemu-fuzz-cntrs.%d", getpid()); - int fd = shm_open(shm_path, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR); - g_free(shm_path); - - if (fd == -1) { - perror("Error: "); - exit(1); - } - if (ftruncate(fd, &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START) == -1) { - perror("Error: "); - exit(1); - } - /* Copy what's in the counter region to the shm.. */ - void *rptr = mmap(NULL , - &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START, - PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); - memcpy(rptr, + /* Copy what's in the counter region to a temporary buffer.. */ + void *copy = malloc(&__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START); + memcpy(copy, &__FUZZ_COUNTERS_START, &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START); - munmap(rptr, &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START); - - /* And map the shm over the counter region */ - rptr = mmap(&__FUZZ_COUNTERS_START, - &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START, - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, 0); - - close(fd); - - if (!rptr) { + /* Map a shared region over the counter region */ + if (mmap(&__FUZZ_COUNTERS_START, + &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, + 0, 0) == MAP_FAILED) { perror("Error: "); exit(1); } + + /* Copy the original data back to the counter-region */ + memcpy(&__FUZZ_COUNTERS_START, copy, + &__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START); + free(copy); }