From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BBA951E909B; Wed, 6 Nov 2024 12:43:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730897007; cv=none; b=m5frbaZMhLFZdLiMnQNBY44Pv24fpPrrNm6ofGx7doQSZm1/CJqFZJwc160HnOjSD/uTqA/FjqZUITxe9d3QYC8TAJdKIa2fqw3KZZIFGkAEt/+3sWcscudxj54AFoUncVmtunk2B+ahCIxxwEf+wBPzAiD6gYuYHS+mFh5U5Y4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730897007; c=relaxed/simple; bh=fTdNdLUKtvyJUG9nKbmIPUghjs1Q8Zzp9j+CrkL1N50=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=APFKhVy5aA+c58sQ9ot4jZCV1qCHDWL19UH3QEm3NEeKw1Jea5Z0FIhj2OC16r5ZbDMymlRh14xhVSEroWpU0T2CAK6e2QSOrS0jJNUOiORWiqLZxP0vTD7OOZ0Yi6bCDTq+kdODIDV6bwFQK5revhClU1dQp1+ZSsngQArmBV8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=j19miaAJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="j19miaAJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14A27C4CECD; Wed, 6 Nov 2024 12:43:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730897007; bh=fTdNdLUKtvyJUG9nKbmIPUghjs1Q8Zzp9j+CrkL1N50=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j19miaAJhklrW9k6lJpMW4RakNtg3yzSt7+fE+Z17FOo5lDd9IR/LpQv//rcj0AdH RenWMw9//a02fN+Y8Hl78p5MH0xS62aD2jQfDQdPE0WZ9r/Zu5RIUal3t5LRiCrvwV /w8glIa7JkvqQ1PVuFeulrUquD0gsv1OrfNjY8kI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lorenzo Stoakes , David Hildenbrand , Baoquan He , Alexander Viro , Jens Axboe , Jiri Olsa , Liu Shixin , "Matthew Wilcox (Oracle)" , "Uladzislau Rezki (Sony)" , Andrew Morton , Sasha Levin Subject: [PATCH 6.1 006/126] fs/proc/kcore: convert read_kcore() to read_kcore_iter() Date: Wed, 6 Nov 2024 13:03:27 +0100 Message-ID: <20241106120306.235846553@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120306.038154857@linuxfoundation.org> References: <20241106120306.038154857@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lorenzo Stoakes [ Upstream commit 46c0d6d0904a10785faabee53fe53ee1aa718fea ] 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. Link: https://lkml.kernel.org/r/ebe12c8d70eebd71f487d80095605f3ad0d1489c.1679511146.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes Reviewed-by: David Hildenbrand Reviewed-by: Baoquan He Cc: Alexander Viro Cc: Jens Axboe Cc: Jiri Olsa Cc: Liu Shixin Cc: Matthew Wilcox (Oracle) Cc: Uladzislau Rezki (Sony) Signed-off-by: Andrew Morton Stable-dep-of: 3d5854d75e31 ("fs/proc/kcore.c: allow translation of physical memory addresses") Signed-off-by: Sasha Levin --- 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 786e5e90f670c..2aff567abe1e3 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -25,7 +25,7 @@ #include #include #include -#include +#include #include #include #include @@ -309,9 +309,12 @@ 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; @@ -319,6 +322,7 @@ 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; @@ -357,12 +361,11 @@ 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; } @@ -399,15 +402,14 @@ 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; } @@ -449,14 +451,13 @@ 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; } @@ -498,7 +499,7 @@ 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; } @@ -509,14 +510,14 @@ 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; } @@ -532,7 +533,7 @@ 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; } @@ -542,17 +543,17 @@ 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; } @@ -560,7 +561,6 @@ 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); } @@ -604,7 +604,7 @@ 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, -- 2.43.0