From patchwork Wed Mar 22 14:55:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Stoakes X-Patchwork-Id: 13184197 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A0BCC6FD1F for ; Wed, 22 Mar 2023 14:55:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E65716B0075; Wed, 22 Mar 2023 10:55:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E16C16B0078; Wed, 22 Mar 2023 10:55:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8E176B007B; Wed, 22 Mar 2023 10:55:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id B9C7B6B0075 for ; Wed, 22 Mar 2023 10:55:39 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 28474C04C2 for ; Wed, 22 Mar 2023 14:55:39 +0000 (UTC) X-FDA: 80596833198.20.1C97634 Received: from mail-wm1-f49.google.com (mail-wm1-f49.google.com [209.85.128.49]) by imf11.hostedemail.com (Postfix) with ESMTP id 2BC0A40017 for ; Wed, 22 Mar 2023 14:55:36 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=VYs6ugG8; spf=pass (imf11.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.128.49 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1679496937; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=CnqbASwlTwT+hpjobkOVo9MU5RGxoqqRsLFO5z2uP7A=; b=rEpj6GamqX+cLXGQDR2GiqddhSWnINhyJEhzgkJw3TH6Raud/SVShKbY98UaecFnuOSzf7 nUgh7q30TgbA0kw4+9NALVNyUaSiOGBeyR3AZXDFlNlh0MWNk6EycmIj7T2qIVBF4zJaT5 dYtuC1b7adEfufD60DXkYpPRAkZhwm0= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=VYs6ugG8; spf=pass (imf11.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.128.49 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1679496937; a=rsa-sha256; cv=none; b=2meCvVoswK1xOPv1yG6+P1sVW4LV4viMfxF1UEJ90PONS1cCuVUhpmyF7r3JQFs8fANcdg 8tGvrwFph/pyVvr5NUmlVvfCQCT45Uw3J3qu4CJ0gkqxZ5LK9VIC5wJsIFqzv0WE/zKkmz b/ehxuXXBHi7kwvCCKks6WJ5ivdmM/Q= Received: by mail-wm1-f49.google.com with SMTP id p16so11719961wmq.5 for ; Wed, 22 Mar 2023 07:55:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679496935; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CnqbASwlTwT+hpjobkOVo9MU5RGxoqqRsLFO5z2uP7A=; b=VYs6ugG87mfTKeYAZszhJ4zHVIrm5oSCM3SiOaM9Rb9+Z4kqLzTtkkPo8FkMnjaQCi Au5clGPac1dlx+ijIXPxu1kRuLlDQGOIGWa8EaA80xeGft1ma8F76vHwldlxfSFH771D WrXTC3+cKYn5NAe7KlQKnRR/gAsZUgXpQRW+/c4MTlEJInNTG7CleO8s1pxN2sBuyD1N IIYWjMBNLIvRvfR4qduXhFYFHEKbVgFkPDvyGuEOozXYaBzCj51XyHEhZhfq4n5Avnqe 217YR8GkTStFxKUVA9XWDGV9JiUUt9MLAhCTJQfbektBiHj2p1bZYldccVgn1o6LyIGG LWRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679496935; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CnqbASwlTwT+hpjobkOVo9MU5RGxoqqRsLFO5z2uP7A=; b=RIwO6wHPrK0/6Y34HtDzvzgFoLljkvdqEWL6Rrkz5kIn1HyrtpSJun8JrJZzNfRFqT S2Ma0WevHOcndMO7IbIf7c/srvksIORryWCu/On+fi/Ig1hTPTu7lsHt+gWzyhKVLABj 6O4VeEIvjVByLJJd3u/B1g8O5VwLwnlD5SHSj7O5th+21pTBA+MhIdVCr0xMm/F4yP+M m73MIcMg0FooRuz6wV169GgngjwfmgaYhy1DqK1M6t3B8I1W0k03OfFJYGILrs3osAn9 zWzOZxjYc3oapC0gdPrujgk2Jbp545U7hy7sunWBNM5CrKiszJJdggKC1sHiKt5RNoG4 MSAg== X-Gm-Message-State: AO0yUKXlDWH3HkGqx4//44atlhAh4xxaVNbcO9p5zu50IfwlzlYWuz8X MHDv7G6eJIO5yasegJlhq1MWV9TslbQ= X-Google-Smtp-Source: AK7set+fXeYguHSdM/ECTto2wDq7Mo4z+CYXsMQV4PwwqbZd6DCt+5jTvUcB/xmS9G1k42Z3No87WA== X-Received: by 2002:a7b:c396:0:b0:3ee:19b4:a2e6 with SMTP id s22-20020a7bc396000000b003ee19b4a2e6mr5695693wmj.19.1679496935292; Wed, 22 Mar 2023 07:55:35 -0700 (PDT) Received: from lucifer.home ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.googlemail.com with ESMTPSA id n23-20020a7bcbd7000000b003ed243222adsm16812246wmi.42.2023.03.22.07.55.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Mar 2023 07:55:34 -0700 (PDT) From: Lorenzo Stoakes To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton Cc: Baoquan He , Uladzislau Rezki , Matthew Wilcox , David Hildenbrand , Liu Shixin , Jiri Olsa , Jens Axboe , Alexander Viro , Lorenzo Stoakes Subject: [PATCH v6 2/4] fs/proc/kcore: convert read_kcore() to read_kcore_iter() Date: Wed, 22 Mar 2023 14:55:26 +0000 Message-Id: X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 2BC0A40017 X-Stat-Signature: eqn4n7ejmuopsnmfzenz3e8137ay9ibf X-Rspam-User: X-HE-Tag: 1679496936-334675 X-HE-Meta: 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 u1oplkmY 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: For the time being we still use a bounce buffer for vread(), however in the next patch we will convert this to interact directly with the iterator and eliminate the bounce buffer altogether. Signed-off-by: Lorenzo Stoakes Reviewed-by: David Hildenbrand --- fs/proc/kcore.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 556f310d6aa4..08b795fd80b4 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -24,7 +24,7 @@ #include #include #include -#include +#include #include #include #include @@ -308,9 +308,12 @@ static void append_kcore_note(char *notes, size_t *i, const char *name, } static ssize_t -read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) +read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) { + struct file *file = iocb->ki_filp; char *buf = file->private_data; + loff_t *fpos = &iocb->ki_pos; + size_t phdrs_offset, notes_offset, data_offset; size_t page_offline_frozen = 1; size_t phdrs_len, notes_len; @@ -318,6 +321,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) size_t tsz; int nphdr; unsigned long start; + size_t buflen = iov_iter_count(iter); size_t orig_buflen = buflen; int ret = 0; @@ -356,12 +360,11 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) }; tsz = min_t(size_t, buflen, sizeof(struct elfhdr) - *fpos); - if (copy_to_user(buffer, (char *)&ehdr + *fpos, tsz)) { + if (copy_to_iter((char *)&ehdr + *fpos, tsz, iter) != tsz) { ret = -EFAULT; goto out; } - buffer += tsz; buflen -= tsz; *fpos += tsz; } @@ -398,15 +401,14 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) } tsz = min_t(size_t, buflen, phdrs_offset + phdrs_len - *fpos); - if (copy_to_user(buffer, (char *)phdrs + *fpos - phdrs_offset, - tsz)) { + if (copy_to_iter((char *)phdrs + *fpos - phdrs_offset, tsz, + iter) != tsz) { kfree(phdrs); ret = -EFAULT; goto out; } kfree(phdrs); - buffer += tsz; buflen -= tsz; *fpos += tsz; } @@ -448,14 +450,13 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) min(vmcoreinfo_size, notes_len - i)); tsz = min_t(size_t, buflen, notes_offset + notes_len - *fpos); - if (copy_to_user(buffer, notes + *fpos - notes_offset, tsz)) { + if (copy_to_iter(notes + *fpos - notes_offset, tsz, iter) != tsz) { kfree(notes); ret = -EFAULT; goto out; } kfree(notes); - buffer += tsz; buflen -= tsz; *fpos += tsz; } @@ -497,7 +498,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) } if (!m) { - if (clear_user(buffer, tsz)) { + if (iov_iter_zero(tsz, iter) != tsz) { ret = -EFAULT; goto out; } @@ -508,14 +509,14 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) case KCORE_VMALLOC: vread(buf, (char *)start, tsz); /* we have to zero-fill user buffer even if no read */ - if (copy_to_user(buffer, buf, tsz)) { + if (copy_to_iter(buf, tsz, iter) != tsz) { ret = -EFAULT; goto out; } break; case KCORE_USER: /* User page is handled prior to normal kernel page: */ - if (copy_to_user(buffer, (char *)start, tsz)) { + if (copy_to_iter((char *)start, tsz, iter) != tsz) { ret = -EFAULT; goto out; } @@ -531,7 +532,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) */ if (!page || PageOffline(page) || is_page_hwpoison(page) || !pfn_is_ram(pfn)) { - if (clear_user(buffer, tsz)) { + if (iov_iter_zero(tsz, iter) != tsz) { ret = -EFAULT; goto out; } @@ -541,17 +542,17 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) case KCORE_VMEMMAP: case KCORE_TEXT: /* - * We use _copy_to_user() to bypass usermode hardening + * We use _copy_to_iter() to bypass usermode hardening * which would otherwise prevent this operation. */ - if (_copy_to_user(buffer, (char *)start, tsz)) { + if (_copy_to_iter((char *)start, tsz, iter) != tsz) { ret = -EFAULT; goto out; } break; default: pr_warn_once("Unhandled KCORE type: %d\n", m->type); - if (clear_user(buffer, tsz)) { + if (iov_iter_zero(tsz, iter) != tsz) { ret = -EFAULT; goto out; } @@ -559,7 +560,6 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) skip: buflen -= tsz; *fpos += tsz; - buffer += tsz; start += tsz; tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen); } @@ -603,7 +603,7 @@ static int release_kcore(struct inode *inode, struct file *file) } static const struct proc_ops kcore_proc_ops = { - .proc_read = read_kcore, + .proc_read_iter = read_kcore_iter, .proc_open = open_kcore, .proc_release = release_kcore, .proc_lseek = default_llseek,