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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 9B657C004E4 for ; Tue, 12 Jun 2018 00:40:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C698208B9 for ; Tue, 12 Jun 2018 00:40:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=tobin.cc header.i=@tobin.cc header.b="grkwpCPA"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="PoHOHuJU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C698208B9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=tobin.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934872AbeFLAjq (ORCPT ); Mon, 11 Jun 2018 20:39:46 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:49725 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934811AbeFLAje (ORCPT ); Mon, 11 Jun 2018 20:39:34 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 8B61321CA8; Mon, 11 Jun 2018 20:39:33 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Mon, 11 Jun 2018 20:39:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tobin.cc; h=cc :date:from:in-reply-to:message-id:references:subject:to :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=wVO0ELc2nMmioIWS8 aWaBXLUwnC2bh10GTjADlU81XU=; b=grkwpCPAfJXn68D6okPTD05ej1rfcAhW/ 7mg1KGLjndh8IDrbwUSFngJ9zYUPfDdHG2j71CpnRBquVxa82sz4I3aLx1VpYkTk SComzDaWsu4zyPxjBslWHQ3WnxzPjD9qIHFxflO9xPFCY0IpzytFuL7l1MBBsyTL pxWG2Ie+rgOlqR6nYL85dISfAsBHLgZrea/llVW0XdRvulCUFIG0aZuiBOwwVKOv SPLMI7WBcAGyBQXwZYzrVlO1eAzhFp9wIV9ptr357EgnEKcVk2mCSnd9BEy+SbsV OcH8GdZ7uVfwwM83F3x2NYTU2Re9TTIYWZWRRdujt01OK7znN/2vg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; bh=wVO0ELc2nMmioIWS8aWaBXLUwnC2bh10GTjADlU81XU=; b=PoHOHuJU uToei8C7q9HnYRWarl/dUJFjfNfDoNw++70ubG4Fq1z5KQllXubILIaFN8OApow5 6GddpDlNb5nCdQ/a7xwsSk/jDsv9NrFbrSN1vjPODe9UHSuRXZ/VDcV91s8ZI6Un EP7IhxE9yEC1tumg8ZSJtfZdFLjfsG6z05RmezTgF2BLmkZJ+3+s8SpVsiUFUSVi 7Ul6OmP3ffsWhMK9H65nE3OZxdEz+qWBOFr/NzLCFyMWezh8jzzf6/QawD7SmebQ 64pVKcGQADEMbNFTjKoqWFPEA9O3Ggu4rKaAtULzF6fOqF1LbodNC66ECmGdGMMw FHcP0liwPHVl3Q== X-ME-Proxy: X-ME-Proxy: X-ME-Proxy: X-ME-Proxy: X-ME-Proxy: X-ME-Proxy: X-ME-Sender: Received: from localhost (124-169-136-87.dyn.iinet.net.au [124.169.136.87]) by mail.messagingengine.com (Postfix) with ESMTPA id B3891E425A; Mon, 11 Jun 2018 20:39:32 -0400 (EDT) From: "Tobin C. Harding" To: "Theodore Ts'o" Cc: "Tobin C. Harding" , Linus Torvalds , Randy Dunlap , Steven Rostedt , Kees Cook , Anna-Maria Gleixner , Andrew Morton , Greg Kroah-Hartman , Arnd Bergmann , linux-kernel@vger.kernel.org Subject: [PATCH v7 2/4] random: Return nbytes filled from hw RNG Date: Tue, 12 Jun 2018 10:39:12 +1000 Message-Id: <1528763954-27731-3-git-send-email-me@tobin.cc> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1528763954-27731-1-git-send-email-me@tobin.cc> References: <1528763954-27731-1-git-send-email-me@tobin.cc> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently the function get_random_bytes_arch() has return value 'void'. If the hw RNG fails we currently fall back to using get_random_bytes(). This defeats the purpose of requesting random material from the hw RNG in the first place. There are currently no intree users of get_random_bytes_arch(). Only get random bytes from the hw RNG, make function return the number of bytes retrieved from the hw RNG. Signed-off-by: Tobin C. Harding Acked-by: Theodore Ts'o Reviewed-by: Steven Rostedt (VMware) --- drivers/char/random.c | 16 +++++++++------- include/linux/random.h | 2 +- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index ed679099afba..bd3d3fbea632 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1724,26 +1724,28 @@ EXPORT_SYMBOL(del_random_ready_callback); * key known by the NSA). So it's useful if we need the speed, but * only if we're willing to trust the hardware manufacturer not to * have put in a back door. + * + * Return number of bytes filled in. */ -void get_random_bytes_arch(void *buf, int nbytes) +int __must_check get_random_bytes_arch(void *buf, int nbytes) { + int left = nbytes; char *p = buf; - trace_get_random_bytes_arch(nbytes, _RET_IP_); - while (nbytes) { + trace_get_random_bytes_arch(left, _RET_IP_); + while (left) { unsigned long v; - int chunk = min(nbytes, (int)sizeof(unsigned long)); + int chunk = min_t(int, left, (int)sizeof(unsigned long)); if (!arch_get_random_long(&v)) break; memcpy(p, &v, chunk); p += chunk; - nbytes -= chunk; + left -= chunk; } - if (nbytes) - get_random_bytes(p, nbytes); + return nbytes - left; } EXPORT_SYMBOL(get_random_bytes_arch); diff --git a/include/linux/random.h b/include/linux/random.h index 2ddf13b4281e..f1c9bc5cd231 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -38,7 +38,7 @@ extern void get_random_bytes(void *buf, int nbytes); extern int wait_for_random_bytes(void); extern int add_random_ready_callback(struct random_ready_callback *rdy); extern void del_random_ready_callback(struct random_ready_callback *rdy); -extern void get_random_bytes_arch(void *buf, int nbytes); +extern int __must_check get_random_bytes_arch(void *buf, int nbytes); #ifndef MODULE extern const struct file_operations random_fops, urandom_fops; -- 2.7.4