From patchwork Mon Jul 20 15:58:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11674247 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 11F5713B1 for ; Mon, 20 Jul 2020 16:27:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E671A22BF3 for ; Mon, 20 Jul 2020 16:27:47 +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="BpaEfKjb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732271AbgGTP7j (ORCPT ); Mon, 20 Jul 2020 11:59:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732260AbgGTP7h (ORCPT ); Mon, 20 Jul 2020 11:59:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FB04C0619D2; Mon, 20 Jul 2020 08:59:37 -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=UV4C0pnsKtW/E1uVrhnTBH7NG5CSb4x7/hRgSksNDcE=; b=BpaEfKjbynTc+h09t9IRtqHqOO X5oprzE301YxpiTvFrG6rxZ9/S7us41uFDB9MycC+P6dys/9EPja1DysXC2CgVwHXw6yNW5tWYBO7 2VkSeprDi5sSQMbH46cA0hz9X4z0g2vrjTVId5a9JM818MCKkNrldRVLYV7f4yu3TXgiioxD7Kl83 jc7NpYt6wnEEP1pDwvsuRCj1zehonKjP8kdUl1JQAiRButRrVzZtvUpV3i99mtBrF5yQ5/WE7grYg aO/CivXjIojfs5edt0WGwBCb0i1/zNg13U3i/FMx9b89EI04S1xha0omlWY5xBzno7iM5R75gcjcw OHfCTU/A==; Received: from [2001:4bb8:105:4a81:db56:edb1:dbf2:5cc3] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxYCS-0007r0-Fk; Mon, 20 Jul 2020 15:59:32 +0000 From: Christoph Hellwig To: Al Viro , Linus Torvalds Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH 16/24] fs: add a kern_symlink helper Date: Mon, 20 Jul 2020 17:58:54 +0200 Message-Id: <20200720155902.181712-17-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720155902.181712-1-hch@lst.de> References: <20200720155902.181712-1-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 Add a simple helper perform a symlink with a kernel space file name and use it in the early init code instead of relying on the implicit set_fs(KERNEL_DS) there. To do so push the getname from do_symlinkat into the callers. Remove the now unused ksys_symlink. Signed-off-by: Christoph Hellwig --- fs/internal.h | 2 -- fs/namei.c | 27 ++++++++++++++++++--------- include/linux/fs.h | 1 + include/linux/syscalls.h | 9 --------- init/initramfs.c | 2 +- 5 files changed, 20 insertions(+), 21 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index f0869d5dc4dbfa..46f727c0bd84e2 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -64,8 +64,6 @@ extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); -long do_symlinkat(const char __user *oldname, int newdfd, - const char __user *newname); /* * namespace.c diff --git a/fs/namei.c b/fs/namei.c index 9d80a5bce1051a..01e43676008644 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3991,20 +3991,21 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) } EXPORT_SYMBOL(vfs_symlink); -long do_symlinkat(const char __user *oldname, int newdfd, - const char __user *newname) +static int do_symlinkat(struct filename *from, int newdfd, + struct filename *newname) { int error; - struct filename *from; struct dentry *dentry; struct path path; unsigned int lookup_flags = 0; - from = getname(oldname); - if (IS_ERR(from)) + if (IS_ERR(from)) { + if (!IS_ERR(newname)) + putname(newname); return PTR_ERR(from); + } retry: - dentry = user_path_create(newdfd, newname, &path, lookup_flags); + dentry = filename_create(newdfd, newname, &path, lookup_flags); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_putname; @@ -4017,20 +4018,28 @@ long do_symlinkat(const char __user *oldname, int newdfd, lookup_flags |= LOOKUP_REVAL; goto retry; } + putname(newname); out_putname: - putname(from); + if (!IS_ERR(from)) + putname(from); return error; } +int __init kern_symlink(const char *oldname, const char *newname) +{ + return do_symlinkat(getname_kernel(oldname), AT_FDCWD, + getname_kernel(newname)); +} + SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, int, newdfd, const char __user *, newname) { - return do_symlinkat(oldname, newdfd, newname); + return do_symlinkat(getname(oldname), newdfd, getname(newname)); } SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname) { - return do_symlinkat(oldname, AT_FDCWD, newname); + return do_symlinkat(getname(oldname), AT_FDCWD, getname(newname)); } /** diff --git a/include/linux/fs.h b/include/linux/fs.h index fc3b09d473945f..7a7b3bf1b8aa53 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3680,5 +3680,6 @@ int __init kern_utimes(const char *filename, struct timespec64 *tv, int flags); int kern_mkdir(const char *pathname, umode_t mode); int kern_mknod(const char *filename, umode_t mode, unsigned int dev); int __init kern_link(const char *oldname, const char *newname); +int __init kern_symlink(const char *oldname, const char *newname); #endif /* _LINUX_FS_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 467cc4413874ed..474d5d165048c8 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1284,15 +1284,6 @@ static inline long ksys_rmdir(const char __user *pathname) return do_rmdir(AT_FDCWD, pathname); } -extern long do_symlinkat(const char __user *oldname, int newdfd, - const char __user *newname); - -static inline long ksys_symlink(const char __user *oldname, - const char __user *newname) -{ - return do_symlinkat(oldname, AT_FDCWD, newname); -} - extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small); static inline long ksys_ftruncate(unsigned int fd, loff_t length) diff --git a/init/initramfs.c b/init/initramfs.c index e484381c6c131b..4efd78427996da 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -389,7 +389,7 @@ static int __init do_symlink(void) { collected[N_ALIGN(name_len) + body_len] = '\0'; clean_path(collected, 0); - ksys_symlink(collected + N_ALIGN(name_len), collected); + kern_symlink(collected + N_ALIGN(name_len), collected); kern_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); do_utime(collected, mtime); state = SkipIt;