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=-8.1 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,USER_AGENT_SANE_1 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 2C818C4BA24 for ; Thu, 27 Feb 2020 10:36:11 +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 EC0692468E for ; Thu, 27 Feb 2020 10:36:10 +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="Jd6OEZOT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC0692468E 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]:56948 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7GWY-0001xH-61 for qemu-devel@archiver.kernel.org; Thu, 27 Feb 2020 05:36:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46329) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7GSB-0005ou-1o for qemu-devel@nongnu.org; Thu, 27 Feb 2020 05:31:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j7GS7-0004HP-J8 for qemu-devel@nongnu.org; Thu, 27 Feb 2020 05:31:38 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:31209 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j7GS7-0004Fy-Cp for qemu-devel@nongnu.org; Thu, 27 Feb 2020 05:31:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582799494; h=from:from: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=RUE8shnfPzDdhihUcnfJnzAAfvwflL5lQ1zii1MF3wg=; b=Jd6OEZOTkA1V/qM97Utsp+tYv/h1QYD/fQWc/O8p+w0db/z4z+K3EZG5zqxFVae0C02Qjh Q3JoJc7kOKCyOoJLVwSLC5nIKKXfgTLgoaUnwe4FPz8zf8ltseQhpoMZNCd2llwJw1C+40 puITRvwgN+t75Z+xFbLrKYNMJcOKlxc= 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-464-mQefb3-cOba5iaNuYmj-1w-1; Thu, 27 Feb 2020 05:31:30 -0500 X-MC-Unique: mQefb3-cOba5iaNuYmj-1w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BA0371902EC8; Thu, 27 Feb 2020 10:31:29 +0000 (UTC) Received: from redhat.com (ovpn-112-43.ams2.redhat.com [10.36.112.43]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AF4AF65E98; Thu, 27 Feb 2020 10:31:21 +0000 (UTC) Date: Thu, 27 Feb 2020 10:31:18 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [RFC PATCH] linux-user/syscall: Use g_file_open_tmp() Message-ID: <20200227103118.GE1645630@redhat.com> References: <20200227100621.21844-1-philmd@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200227100621.21844-1-philmd@redhat.com> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Riku Voipio , qemu-devel@nongnu.org, Laurent Vivier Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Feb 27, 2020 at 11:06:21AM +0100, Philippe Mathieu-Daud=C3=A9 wrote= : > Use GLib g_file_open_tmp() instead of getenv + snprintf + mkstemp. >=20 > Signed-off-by: Philippe Mathieu-Daud=C3=A9 > --- > RFC because I'm not sure g_autoptr(GError) works this way. It does work. Any struct that's defined in GLib has support for g_autoptr(). If you aren't suyre though, just check for a G_DEFINE_AUTOPTR_CLEANUP_FUNC() macro usage that refers to the struct in question $ grep -r 'G_DEFINE_AUTOPTR_CLEANUP_FUNC(GError' /usr/include/glib-2.0 /usr/include/glib-2.0/glib/glib-autocleanups.h:G_DEFINE_AUTOPTR_CLEANUP_FUN= C(GError, g_error_free) > linux-user/syscall.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) >=20 > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 8d27d10807..0e44969e16 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -7282,17 +7282,14 @@ static int do_openat(void *cpu_env, int dirfd, co= nst char *pathname, int flags, > } > =20 > if (fake_open->filename) { > - const char *tmpdir; > - char filename[PATH_MAX]; > + g_autoptr(GError) gerr =3D NULL; > + g_autofree gchar *filename =3D NULL; > int fd, r; > =20 > /* create temporary file to map stat to */ > - tmpdir =3D getenv("TMPDIR"); > - if (!tmpdir) > - tmpdir =3D "/tmp"; > - snprintf(filename, sizeof(filename), "%s/qemu-open.XXXXXX", tmpd= ir); > - fd =3D mkstemp(filename); > + fd =3D g_file_open_tmp("qemu-open.XXXXXX", &filename, &gerr); g_file_open_tmp, calls g_get_tmp_name, which calls g_get_tmp_dir, which defaults to $TMPDIR, falling back to /tmp. So we're using the same dir as before. > if (fd < 0) { > + fprintf(stderr, "Error opening %s: %s\n", filename, gerr->me= ssage); This is wrong - the returned "filename" is only valid when g_file_open_tmp succeeds. So the use of "filename" here is likely a NULL. Given that the only place you use "filename" is in the error path, and that's not valid, we can simply eliminate it entirely, and pass NULL into g_file_open_tmp > return fd; > } > unlink(filename); Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberrange= :| |: https://libvirt.org -o- https://fstop138.berrange.com= :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange= :|