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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 983A1C04FF3 for ; Mon, 24 May 2021 11:36:38 +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 145E26008E for ; Mon, 24 May 2021 11:36:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 145E26008E 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]:42086 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ll8su-0005qv-TU for qemu-devel@archiver.kernel.org; Mon, 24 May 2021 07:36:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60904) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ll8sA-000559-N7 for qemu-devel@nongnu.org; Mon, 24 May 2021 07:35:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32643) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ll8s8-0003ci-Nu for qemu-devel@nongnu.org; Mon, 24 May 2021 07:35:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621856147; 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=G+QD9yq11JG5TnEnibhU934eMSsOkyPks8c4YU+R/z0=; b=IQ5FlCy4GJ58vduPi1hxxSTu7VBOau6+0vpuWZnD39+iRXGClkUHOBGoFODPNDb5efaylc qa1tUOM+AX7AAZ/VunxTZTiIuRpGsq7b6gGoBQwDROPoxhFHVuzgDbT/nx92KreSctxDkN oAWqICR9jRj5YM2L+6P9xOQ/AdnJ/Ys= 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-73-EqimnvtWOeCT9NiyL5nZ-Q-1; Mon, 24 May 2021 07:35:45 -0400 X-MC-Unique: EqimnvtWOeCT9NiyL5nZ-Q-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 663CA180FD66; Mon, 24 May 2021 11:35:43 +0000 (UTC) Received: from redhat.com (ovpn-113-248.ams2.redhat.com [10.36.113.248]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 275EB5C541; Mon, 24 May 2021 11:35:40 +0000 (UTC) Date: Mon, 24 May 2021 12:35:38 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [RFC PATCH] linux-user: glib-ify is_proc_myself Message-ID: References: <20210524112323.2310-1-alex.bennee@linaro.org> MIME-Version: 1.0 In-Reply-To: <20210524112323.2310-1-alex.bennee@linaro.org> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: yamamoto@midokura.com, qemu-devel@nongnu.org, Laurent Vivier Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, May 24, 2021 at 12:23:23PM +0100, Alex Bennée wrote: > I'm not sure if this is neater than the original code but it does > remove a bunch of the !strcmp's in favour of glib's more natural bool > results. While we are at it make the function a bool return and fixup > the fake_open function prototypes. > > Signed-off-by: Alex Bennée > --- > linux-user/syscall.c | 30 ++++++++++++------------------ > 1 file changed, 12 insertions(+), 18 deletions(-) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index e739921e86..18e953de9d 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -7987,33 +7987,27 @@ static int open_self_auxv(void *cpu_env, int fd) > return 0; > } > > -static int is_proc_myself(const char *filename, const char *entry) > +static bool is_proc_myself(const char *filename, const char *entry) > { > - if (!strncmp(filename, "/proc/", strlen("/proc/"))) { > + if (g_str_has_prefix(filename, "/proc/")) { > filename += strlen("/proc/"); > - if (!strncmp(filename, "self/", strlen("self/"))) { > + if (g_str_has_prefix(filename, "self/")) { > filename += strlen("self/"); > - } else if (*filename >= '1' && *filename <= '9') { > - char myself[80]; > - snprintf(myself, sizeof(myself), "%d/", getpid()); > - if (!strncmp(filename, myself, strlen(myself))) { > - filename += strlen(myself); > - } else { > - return 0; > + } else if (g_ascii_isdigit(*filename)) { > + g_autofree char * myself = g_strdup_printf("%d/", getpid()); > + if (!g_str_has_prefix(filename, myself)) { > + return false; > } > - } else { > - return 0; > - } > - if (!strcmp(filename, entry)) { > - return 1; > + filename += strlen(myself); > } > + return g_str_has_prefix(filename, entry); > } > - return 0; > + return false; > } Diff is hard to compare, so this is what it looks like: static bool is_proc_myself(const char *filename, const char *entry) { if (g_str_has_prefix(filename, "/proc/")) { filename += strlen("/proc/"); if (g_str_has_prefix(filename, "self/")) { filename += strlen("self/"); } else if (g_ascii_isdigit(*filename)) { g_autofree char * myself = g_strdup_printf("%d/", getpid()); if (!g_str_has_prefix(filename, myself)) { return false; } filename += strlen(myself); } return g_str_has_prefix(filename, entry); } return false; } I think if we don't mind two heap allocs it can be simplified to: static int is_proc_myself(const char *filename, const char *entry) { g_autofree char *procself = g_strdup_printf("/proc/self/%s", entry); g_autofree char *procpid = g_strdup_printf("/proc/%d/%s", getpid(), entry); return g_str_equal(filename, procself) || g_str_equal(filename, procpid); } This makes me wonder if the code needs to cope with non-canonicalized filenames though. eg /proc///self/maps or /proc/./self/maps Is something further up ensuring canonicalization of 'filename' ? > > #if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN) || \ > defined(TARGET_SPARC) || defined(TARGET_M68K) || defined(TARGET_HPPA) > -static int is_proc(const char *filename, const char *entry) > +static bool is_proc(const char *filename, const char *entry) > { > return strcmp(filename, entry) == 0; > } > @@ -8097,7 +8091,7 @@ static int do_openat(void *cpu_env, int dirfd, const char *pathname, int flags, > struct fake_open { > const char *filename; > int (*fill)(void *cpu_env, int fd); > - int (*cmp)(const char *s1, const char *s2); > + bool (*cmp)(const char *s1, const char *s2); > }; > const struct fake_open *fake_open; > static const struct fake_open fakes[] = { > -- > 2.20.1 > > Regards, Daniel -- |: 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 :|