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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BE20C433ED for ; Fri, 7 May 2021 01:02:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AB1261289 for ; Fri, 7 May 2021 01:02:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233991AbhEGBDR (ORCPT ); Thu, 6 May 2021 21:03:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:42444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233982AbhEGBDQ (ORCPT ); Thu, 6 May 2021 21:03:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 78706611ED; Fri, 7 May 2021 01:02:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1620349336; bh=/Scj3jTXyxO/Ty9xjsH7YrSb6DO0PkfL0dEKyTTBGm0=; h=Date:From:To:Subject:In-Reply-To:From; b=qB3wfEh3Uyg94IaUJxw8dDffuOQ8ykJ6ZQ7GzNFAeMJl2dpFewxo0evSScp+HFyi2 MsLz199HOJ+Ewak8cdae5O7Guqph1uTKXyFtPRmznH23rVUQ29mM2RS6SBoBxor7nO pm4499PvNgtyNwy14o1UrWx9xNNVf+t2fEnoTlW4= Date: Thu, 06 May 2021 18:02:16 -0700 From: Andrew Morton To: adobriyan@gmail.com, akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 05/91] proc: mandate ->proc_lseek in "struct proc_ops" Message-ID: <20210507010216.Q_Od6LaA1%akpm@linux-foundation.org> In-Reply-To: <20210506180126.03e1baee7ca52bedb6cc6003@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Alexey Dobriyan Subject: proc: mandate ->proc_lseek in "struct proc_ops" Now that proc_ops are separate from file_operations and other operations it easy to check all instances to have ->proc_lseek hook and remove check in main code. Note: nonseekable_open() files naturally don't require ->proc_lseek. Garbage collect pde_lseek() function. [adobriyan@gmail.com: smoke test lseek()] Link: https://lkml.kernel.org/r/YG4OIhChOrVTPgdN@localhost.localdomain Link: https://lkml.kernel.org/r/YFYX0Bzwxlc7aBa/@localhost.localdomain Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton --- drivers/isdn/capi/kcapi_proc.c | 1 drivers/net/wireless/intersil/hostap/hostap_proc.c | 1 drivers/scsi/esas2r/esas2r_main.c | 1 fs/proc/inode.c | 14 +---------- include/linux/proc_fs.h | 1 tools/testing/selftests/proc/read.c | 4 ++- 6 files changed, 9 insertions(+), 13 deletions(-) --- a/drivers/isdn/capi/kcapi_proc.c~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/drivers/isdn/capi/kcapi_proc.c @@ -201,6 +201,7 @@ static ssize_t empty_read(struct file *f static const struct proc_ops empty_proc_ops = { .proc_read = empty_read, + .proc_lseek = default_llseek, }; // --------------------------------------------------------------------------- --- a/drivers/net/wireless/intersil/hostap/hostap_proc.c~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/drivers/net/wireless/intersil/hostap/hostap_proc.c @@ -227,6 +227,7 @@ static ssize_t prism2_aux_dump_proc_no_r static const struct proc_ops prism2_aux_dump_proc_ops = { .proc_read = prism2_aux_dump_proc_no_read, + .proc_lseek = default_llseek, }; --- a/drivers/scsi/esas2r/esas2r_main.c~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/drivers/scsi/esas2r/esas2r_main.c @@ -616,6 +616,7 @@ static const struct file_operations esas }; static const struct proc_ops esas2r_proc_ops = { + .proc_lseek = default_llseek, .proc_ioctl = esas2r_proc_ioctl, #ifdef CONFIG_COMPAT .proc_compat_ioctl = compat_ptr_ioctl, --- a/fs/proc/inode.c~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/fs/proc/inode.c @@ -273,25 +273,15 @@ void proc_entry_rundown(struct proc_dir_ spin_unlock(&de->pde_unload_lock); } -static loff_t pde_lseek(struct proc_dir_entry *pde, struct file *file, loff_t offset, int whence) -{ - typeof_member(struct proc_ops, proc_lseek) lseek; - - lseek = pde->proc_ops->proc_lseek; - if (!lseek) - lseek = default_llseek; - return lseek(file, offset, whence); -} - static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) { struct proc_dir_entry *pde = PDE(file_inode(file)); loff_t rv = -EINVAL; if (pde_is_permanent(pde)) { - return pde_lseek(pde, file, offset, whence); + return pde->proc_ops->proc_lseek(file, offset, whence); } else if (use_pde(pde)) { - rv = pde_lseek(pde, file, offset, whence); + rv = pde->proc_ops->proc_lseek(file, offset, whence); unuse_pde(pde); } return rv; --- a/include/linux/proc_fs.h~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/include/linux/proc_fs.h @@ -32,6 +32,7 @@ struct proc_ops { ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *); ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *); ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *); + /* mandatory unless nonseekable_open() or equivalent is used */ loff_t (*proc_lseek)(struct file *, loff_t, int); int (*proc_release)(struct inode *, struct file *); __poll_t (*proc_poll)(struct file *, struct poll_table_struct *); --- a/tools/testing/selftests/proc/read.c~proc-mandate-proc_lseek-in-struct-proc_ops +++ a/tools/testing/selftests/proc/read.c @@ -14,7 +14,7 @@ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ // Test -// 1) read of every file in /proc +// 1) read and lseek on every file in /proc // 2) readlink of every symlink in /proc // 3) recursively (1) + (2) for every directory in /proc // 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs @@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *fi fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); if (fd == -1) return; + /* struct proc_ops::proc_lseek is mandatory if file is seekable. */ + (void)lseek(fd, 0, SEEK_SET); rv = read(fd, buf, sizeof(buf)); assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); close(fd); _