From patchwork Thu Sep 3 14:22:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11753871 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 85A9014E3 for ; Thu, 3 Sep 2020 14:47:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C16820716 for ; Thu, 3 Sep 2020 14:47:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="LdRJc175" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728596AbgICOrV (ORCPT ); Thu, 3 Sep 2020 10:47:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728896AbgICOYh (ORCPT ); Thu, 3 Sep 2020 10:24:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48D4AC06123B; Thu, 3 Sep 2020 07:22:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=DsUb6hfLeJUvA4GCxVVSz23IH1puKspKytCSglE7c2s=; b=LdRJc175F5A1pOcbnm1cLKFZlU ZWU8Ms6njxu8IGdDsuP6Xtf6gGdB1TXoO8O+jnMnwBOYHipnKu3MNZF9yCeopFU5o/EM+3MKdnvTN rupIWrHI6Ls/BCx4j3hhdamcbq8phYVNK5ud8/ptEEHdTR4iXZ1wNf8vFGgvvU0UEeuso2FSGiZuj AynpHzCxr7W78ExmgJvcBrkBdEyg+UodTDeIECsS7lDH9dIjMypmt8ilvWKv8hLTmI+ag7zWapcr8 8prZMxYcoHUeZOkvoj/M4W9Xnt0H0kpSyMSyGCsfvZp3iEMfeWTGg/4D8rkCU6pza8Y0gTXauR8Sc 1tjzf3NA==; Received: from [2001:4bb8:184:af1:c70:4a89:bc61:2] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDq8W-0004aY-QY; Thu, 03 Sep 2020 14:22:49 +0000 From: Christoph Hellwig To: Linus Torvalds , Al Viro , Michael Ellerman , x86@kernel.org Cc: Alexey Dobriyan , Luis Chamberlain , Kees Cook , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Matthew Wilcox (Oracle)" Subject: [PATCH 04/14] sysctl: Convert to iter interfaces Date: Thu, 3 Sep 2020 16:22:32 +0200 Message-Id: <20200903142242.925828-5-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903142242.925828-1-hch@lst.de> References: <20200903142242.925828-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: "Matthew Wilcox (Oracle)" Using the read_iter/write_iter interfaces allows for in-kernel users to set sysctls without using set_fs(). Also, the buffer is a string, so give it the real type of 'char *', not void *. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christoph Hellwig --- fs/proc/proc_sysctl.c | 46 ++++++++++++++++++-------------------- include/linux/bpf-cgroup.h | 2 +- kernel/bpf/cgroup.c | 2 +- 3 files changed, 24 insertions(+), 26 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 6c1166ccdaea57..a4a3122f8a584a 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -540,13 +541,14 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, return err; } -static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, - size_t count, loff_t *ppos, int write) +static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter, + int write) { - struct inode *inode = file_inode(filp); + struct inode *inode = file_inode(iocb->ki_filp); struct ctl_table_header *head = grab_header(inode); struct ctl_table *table = PROC_I(inode)->sysctl_entry; - void *kbuf; + size_t count = iov_iter_count(iter); + char *kbuf; ssize_t error; if (IS_ERR(head)) @@ -569,32 +571,30 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, error = -ENOMEM; if (count >= KMALLOC_MAX_SIZE) goto out; + kbuf = kzalloc(count + 1, GFP_KERNEL); + if (!kbuf) + goto out; if (write) { - kbuf = memdup_user_nul(ubuf, count); - if (IS_ERR(kbuf)) { - error = PTR_ERR(kbuf); - goto out; - } - } else { - kbuf = kzalloc(count, GFP_KERNEL); - if (!kbuf) - goto out; + error = -EFAULT; + if (!copy_from_iter_full(kbuf, count, iter)) + goto out_free_buf; + kbuf[count] = '\0'; } error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count, - ppos); + &iocb->ki_pos); if (error) goto out_free_buf; /* careful: calling conventions are nasty here */ - error = table->proc_handler(table, write, kbuf, &count, ppos); + error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos); if (error) goto out_free_buf; if (!write) { error = -EFAULT; - if (copy_to_user(ubuf, kbuf, count)) + if (copy_to_iter(kbuf, count, iter) < count) goto out_free_buf; } @@ -607,16 +607,14 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, return error; } -static ssize_t proc_sys_read(struct file *filp, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter) { - return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); + return proc_sys_call_handler(iocb, iter, 0); } -static ssize_t proc_sys_write(struct file *filp, const char __user *buf, - size_t count, loff_t *ppos) +static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter) { - return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); + return proc_sys_call_handler(iocb, iter, 1); } static int proc_sys_open(struct inode *inode, struct file *filp) @@ -853,8 +851,8 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat, static const struct file_operations proc_sys_file_operations = { .open = proc_sys_open, .poll = proc_sys_poll, - .read = proc_sys_read, - .write = proc_sys_write, + .read_iter = proc_sys_read, + .write_iter = proc_sys_write, .llseek = default_llseek, }; diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 64f367044e25f4..82b26a1386d85e 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -136,7 +136,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, struct ctl_table *table, int write, - void **buf, size_t *pcount, loff_t *ppos, + char **buf, size_t *pcount, loff_t *ppos, enum bpf_attach_type type); int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level, diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index e21de4f1754c2c..6ec088a96302f9 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1226,7 +1226,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = { */ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, struct ctl_table *table, int write, - void **buf, size_t *pcount, loff_t *ppos, + char **buf, size_t *pcount, loff_t *ppos, enum bpf_attach_type type) { struct bpf_sysctl_kern ctx = {