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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49B11C43334 for ; Thu, 23 Jun 2022 17:40:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234550AbiFWRkb (ORCPT ); Thu, 23 Jun 2022 13:40:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234841AbiFWRiV (ORCPT ); Thu, 23 Jun 2022 13:38:21 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92D1649911; Thu, 23 Jun 2022 10:08:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4ED74B82499; Thu, 23 Jun 2022 17:08:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FAFBC3411B; Thu, 23 Jun 2022 17:08:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656004129; bh=F2C+a+8dtvviJkoaai/uJj0g+utQmcXAR8Ws3qofBw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lAo5eO5h0YPyc6i0xgUAETmTr/x98815/Z2VXdyXPvMiw7RCMAsd+YCUESZee4Dc3 1RjqW3V78GRxrAoPUwMKwvpufi6K+LAJG6paZGZzgTSfj64ROUD3u3k+x4+OQto4h3 OTf1aIxvzu1zpYc+PlVtycwiDLZWccxCIfyO1yaA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Al Viro , "Jason A. Donenfeld" Subject: [PATCH 4.14 180/237] random: convert to using fops->write_iter() Date: Thu, 23 Jun 2022 18:43:34 +0200 Message-Id: <20220623164348.328200521@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164343.132308638@linuxfoundation.org> References: <20220623164343.132308638@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jens Axboe commit 22b0a222af4df8ee9bb8e07013ab44da9511b047 upstream. Now that the read side has been converted to fix a regression with splice, convert the write side as well to have some symmetry in the interface used (and help deprecate ->write()). Signed-off-by: Jens Axboe [Jason: cleaned up random_ioctl a bit, require full writes in RNDADDENTROPY since it's crediting entropy, simplify control flow of write_pool(), and incorporate suggestions from Al.] Cc: Al Viro Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 67 ++++++++++++++++++++++++++------------------------ 1 file changed, 35 insertions(+), 32 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1251,39 +1251,31 @@ static unsigned int random_poll(struct f return crng_ready() ? POLLIN | POLLRDNORM : POLLOUT | POLLWRNORM; } -static int write_pool(const char __user *ubuf, size_t len) +static ssize_t write_pool(struct iov_iter *iter) { - size_t block_len; - int ret = 0; u8 block[BLAKE2S_BLOCK_SIZE]; + ssize_t ret = 0; + size_t copied; - while (len) { - block_len = min(len, sizeof(block)); - if (copy_from_user(block, ubuf, block_len)) { - ret = -EFAULT; - goto out; - } - len -= block_len; - ubuf += block_len; - mix_pool_bytes(block, block_len); + if (unlikely(!iov_iter_count(iter))) + return 0; + + for (;;) { + copied = copy_from_iter(block, sizeof(block), iter); + ret += copied; + mix_pool_bytes(block, copied); + if (!iov_iter_count(iter) || copied != sizeof(block)) + break; cond_resched(); } -out: memzero_explicit(block, sizeof(block)); - return ret; + return ret ? ret : -EFAULT; } -static ssize_t random_write(struct file *file, const char __user *ubuf, - size_t len, loff_t *ppos) +static ssize_t random_write_iter(struct kiocb *kiocb, struct iov_iter *iter) { - int ret; - - ret = write_pool(ubuf, len); - if (ret) - return ret; - - return (ssize_t)len; + return write_pool(iter); } static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter) @@ -1315,9 +1307,8 @@ static ssize_t random_read_iter(struct k static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) { - int size, ent_count; int __user *p = (int __user *)arg; - int retval; + int ent_count; switch (cmd) { case RNDGETENTCNT: @@ -1334,20 +1325,32 @@ static long random_ioctl(struct file *f, return -EINVAL; credit_init_bits(ent_count); return 0; - case RNDADDENTROPY: + case RNDADDENTROPY: { + struct iov_iter iter; + struct iovec iov; + ssize_t ret; + int len; + if (!capable(CAP_SYS_ADMIN)) return -EPERM; if (get_user(ent_count, p++)) return -EFAULT; if (ent_count < 0) return -EINVAL; - if (get_user(size, p++)) + if (get_user(len, p++)) + return -EFAULT; + ret = import_single_range(WRITE, p, len, &iov, &iter); + if (unlikely(ret)) + return ret; + ret = write_pool(&iter); + if (unlikely(ret < 0)) + return ret; + /* Since we're crediting, enforce that it was all written into the pool. */ + if (unlikely(ret != len)) return -EFAULT; - retval = write_pool((const char __user *)p, size); - if (retval < 0) - return retval; credit_init_bits(ent_count); return 0; + } case RNDZAPENTCNT: case RNDCLEARPOOL: /* No longer has any effect. */ @@ -1373,7 +1376,7 @@ static int random_fasync(int fd, struct const struct file_operations random_fops = { .read_iter = random_read_iter, - .write = random_write, + .write_iter = random_write_iter, .poll = random_poll, .unlocked_ioctl = random_ioctl, .fasync = random_fasync, @@ -1382,7 +1385,7 @@ const struct file_operations random_fops const struct file_operations urandom_fops = { .read_iter = urandom_read_iter, - .write = random_write, + .write_iter = random_write_iter, .unlocked_ioctl = random_ioctl, .fasync = random_fasync, .llseek = noop_llseek,