From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id AC1D31F5AE for ; Fri, 24 Jul 2020 12:43:11 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 99EAF389246A; Fri, 24 Jul 2020 12:43:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 99EAF389246A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1595594590; bh=A6c58HM+V5IBVu+4Pxf0kzmWuUMXX+tuDSxKXrM3x6U=; h=To:Subject:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=YbLe1EQoama3U+wiXLs/MO+OAgP0fF19Qzh4HLrzL+0P5Wko94a/xwVNwAd8Q9qOw OkqLv+il1/5hvP3/bmj4MyFP4P/WM0F+QATOPrD2pRSz+djP/QOuWBjZQ9aBiDFwYc jQCfUbM3ANEDdGcQWimRokXgWzjF8puv61B09faA= Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) by sourceware.org (Postfix) with ESMTP id 0281F3857C61 for ; Fri, 24 Jul 2020 12:43:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 0281F3857C61 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-457-XsVnU7xeOlqLDgTR_NGm7A-1; Fri, 24 Jul 2020 08:43:05 -0400 X-MC-Unique: XsVnU7xeOlqLDgTR_NGm7A-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C8BB219200C0; Fri, 24 Jul 2020 12:43:04 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-112-154.ams2.redhat.com [10.36.112.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F02937F8CC; Fri, 24 Jul 2020 12:43:03 +0000 (UTC) To: Adhemerval Zanella Subject: Re: [PATCH 16/16] linux: Move xmknoda{at} to compat symbols References: <20200723194641.1949404-1-adhemerval.zanella@linaro.org> <20200723194641.1949404-17-adhemerval.zanella@linaro.org> <87365h9pdo.fsf@oldenburg2.str.redhat.com> <8c431ddc-ffdd-84c7-fa0a-0657cc5b47cc@linaro.org> Date: Fri, 24 Jul 2020 14:43:02 +0200 In-Reply-To: <8c431ddc-ffdd-84c7-fa0a-0657cc5b47cc@linaro.org> (Adhemerval Zanella's message of "Fri, 24 Jul 2020 09:34:06 -0300") Message-ID: <87pn8l84o9.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Florian Weimer via Libc-alpha Reply-To: Florian Weimer Cc: Alistair Francis , Adhemerval Zanella via Libc-alpha Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" * Adhemerval Zanella: > On 24/07/2020 07:30, Florian Weimer wrote: >> * Adhemerval Zanella via Libc-alpha: >> >>> diff --git a/sysdeps/unix/sysv/linux/mknodat.c b/sysdeps/unix/sysv/linux/mknodat.c >>> new file mode 100644 >>> index 0000000000..d160fe520b >>> --- /dev/null >>> +++ b/sysdeps/unix/sysv/linux/mknodat.c >>> @@ -0,0 +1,41 @@ >> >>> +int >>> +__mknodat_common (int fd, const char *path, mode_t mode, dev_t *dev) >>> +{ >>> + /* We must convert the value to dev_t type used by the kernel. */ >>> + unsigned long long int k_dev = (*dev) & ((1ULL << 32) - 1); >>> + if (k_dev != *dev) >>> + return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); >>> + >>> + return INLINE_SYSCALL_CALL (mknodat, fd, path, mode, >>> + (unsigned int) k_dev); >>> +} >> >> This looks suspicious yo me. Why use a dev_t * argument? Why check >> against the unsigned long long int value, when the kernel receives an >> unsigned int value in the system call? > > Because glibc exports dev_t is 64-bit on all architectures (__DEV_T_TYPE), > while kernel current only accepts 32-bits. But then the type of k_dev should be unsigned int, I think. > But I used the dev_t * argument to make it more straightforward to > implement xmknod{at}. I can change to use a dev_t as well Yes please. Thanks, Florian