From patchwork Mon May 24 08:58:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergiy Kibrik X-Patchwork-Id: 12275703 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 2A20DC04FF3 for ; Mon, 24 May 2021 09:00:45 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 D93EA611EE for ; Mon, 24 May 2021 09:00:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D93EA611EE Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=epam.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.131701.246014 (Exim 4.92) (envelope-from ) id 1ll6Rm-0005lU-ED; Mon, 24 May 2021 09:00:26 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 131701.246014; Mon, 24 May 2021 09:00:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ll6Rm-0005kd-8Z; Mon, 24 May 2021 09:00:26 +0000 Received: by outflank-mailman (input) for mailman id 131701; Mon, 24 May 2021 08:59:07 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ll6QV-0004xC-GZ for xen-devel@lists.xenproject.org; Mon, 24 May 2021 08:59:07 +0000 Received: from pb-smtp1.pobox.com (unknown [64.147.108.70]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 22e90eb8-1801-4bd7-b845-4aed584d810b; Mon, 24 May 2021 08:59:05 +0000 (UTC) Received: from pb-smtp1.pobox.com (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id 76323C5336; Mon, 24 May 2021 04:59:05 -0400 (EDT) (envelope-from sakib@darkstar.site) Received: from pb-smtp1.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id 6CD61C5335; Mon, 24 May 2021 04:59:05 -0400 (EDT) (envelope-from sakib@darkstar.site) Received: from localhost (unknown [95.67.114.216]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp1.pobox.com (Postfix) with ESMTPSA id AC917C5334; Mon, 24 May 2021 04:59:04 -0400 (EDT) (envelope-from sakib@darkstar.site) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 22e90eb8-1801-4bd7-b845-4aed584d810b DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:date:message-id:mime-version:content-transfer-encoding; s=sasl; bh=N3y2IUOrV3tiaMzNDcpoZJubh8fsBaImgmUzGyl9YYg=; b=k0bv mGxaD3or+1r/4ZAdUHMIq/qVK51+Ra3roGoCKfOuK9Wie1Y71IwuuawCq24jMbxl fzQyLGFDR06/M/NX+7VtjR+XfpPgW/8L/3FxGmuyoWTQb50z7LIhqSbfR0DOeJ+U 8jE2ZpsrrGf1o/OLi279T0EI7Xhys9CteC615EI= From: Sergiy Kibrik To: xen-devel@lists.xenproject.org Cc: Ian Jackson , Wei Liu , Sergiy Kibrik Subject: [XEN PATCH v1] libxl: use getrandom() syscall for random data extraction Date: Mon, 24 May 2021 08:58:58 +0000 Message-Id: <20210524085858.1902-1-Sergiy_Kibrik@epam.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Pobox-Relay-ID: 4A7FC54E-BC6E-11EB-928E-D152C8D8090B-90055647!pb-smtp1.pobox.com Simplify libxl__random_bytes() routine by using a newer dedicated syscall. This allows not only to substantially reduce its footprint, but syscall also considered to be safer and generally better solution: https://lwn.net/Articles/606141/ getrandom() available on Linux, FreeBSD and NetBSD. Signed-off-by: Sergiy Kibrik --- tools/libxl/libxl_utils.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-) diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c index b039143b8a..f3e56a4026 100644 --- a/tools/libxl/libxl_utils.c +++ b/tools/libxl/libxl_utils.c @@ -16,6 +16,7 @@ #include "libxl_osdeps.h" /* must come before any other headers */ #include +#include #include "libxl_internal.h" #include "_paths.h" @@ -1226,26 +1227,10 @@ void libxl_string_copy(libxl_ctx *ctx, char **dst, char * const*src) */ int libxl__random_bytes(libxl__gc *gc, uint8_t *buf, size_t len) { - static const char *dev = "/dev/urandom"; - int fd; - int ret; - - fd = open(dev, O_RDONLY); - if (fd < 0) { - LOGE(ERROR, "failed to open \"%s\"", dev); + ssize_t ret = getrandom(buf, len, 0); + if (ret != len) return ERROR_FAIL; - } - ret = libxl_fd_set_cloexec(CTX, fd, 1); - if (ret) { - close(fd); - return ERROR_FAIL; - } - - ret = libxl_read_exactly(CTX, fd, buf, len, dev, NULL); - - close(fd); - - return ret; + return 0; } int libxl__prepare_sockaddr_un(libxl__gc *gc,