ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/fs/fsopen.c b/marvell/linux/fs/fsopen.c
new file mode 100644
index 0000000..043ffa8
--- /dev/null
+++ b/marvell/linux/fs/fsopen.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Filesystem access-by-fd.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/anon_inodes.h>
+#include <linux/namei.h>
+#include <linux/file.h>
+#include <uapi/linux/mount.h>
+#include "internal.h"
+#include "mount.h"
+
+/*
+ * Allow the user to read back any error, warning or informational messages.
+ */
+static ssize_t fscontext_read(struct file *file,
+ char __user *_buf, size_t len, loff_t *pos)
+{
+ struct fs_context *fc = file->private_data;
+ struct fc_log *log = fc->log;
+ unsigned int logsize = ARRAY_SIZE(log->buffer);
+ ssize_t ret;
+ char *p;
+ bool need_free;
+ int index, n;
+
+ ret = mutex_lock_interruptible(&fc->uapi_mutex);
+ if (ret < 0)
+ return ret;
+
+ if (log->head == log->tail) {
+ mutex_unlock(&fc->uapi_mutex);
+ return -ENODATA;
+ }
+
+ index = log->tail & (logsize - 1);
+ p = log->buffer[index];
+ need_free = log->need_free & (1 << index);
+ log->buffer[index] = NULL;
+ log->need_free &= ~(1 << index);
+ log->tail++;
+ mutex_unlock(&fc->uapi_mutex);
+
+ ret = -EMSGSIZE;
+ n = strlen(p);
+ if (n > len)
+ goto err_free;
+ ret = -EFAULT;
+ if (copy_to_user(_buf, p, n) != 0)
+ goto err_free;
+ ret = n;
+
+err_free:
+ if (need_free)
+ kfree(p);
+ return ret;
+}
+
+static int fscontext_release(struct inode *inode, struct file *file)
+{
+ struct fs_context *fc = file->private_data;
+
+ if (fc) {
+ file->private_data = NULL;
+ put_fs_context(fc);
+ }
+ return 0;
+}
+
+const struct file_operations fscontext_fops = {
+ .read = fscontext_read,
+ .release = fscontext_release,
+ .llseek = no_llseek,
+};
+
+/*
+ * Attach a filesystem context to a file and an fd.
+ */
+static int fscontext_create_fd(struct fs_context *fc, unsigned int o_flags)
+{
+ int fd;
+
+ fd = anon_inode_getfd("[fscontext]", &fscontext_fops, fc,
+ O_RDWR | o_flags);
+ if (fd < 0)
+ put_fs_context(fc);
+ return fd;
+}
+
+static int fscontext_alloc_log(struct fs_context *fc)
+{
+ fc->log = kzalloc(sizeof(*fc->log), GFP_KERNEL);
+ if (!fc->log)
+ return -ENOMEM;
+ refcount_set(&fc->log->usage, 1);
+ fc->log->owner = fc->fs_type->owner;
+ return 0;
+}
+
+/*
+ * Open a filesystem by name so that it can be configured for mounting.
+ *
+ * We are allowed to specify a container in which the filesystem will be
+ * opened, thereby indicating which namespaces will be used (notably, which
+ * network namespace will be used for network filesystems).
+ */
+SYSCALL_DEFINE2(fsopen, const char __user *, _fs_name, unsigned int, flags)
+{
+ struct file_system_type *fs_type;
+ struct fs_context *fc;
+ const char *fs_name;
+ int ret;
+
+ if (!ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (flags & ~FSOPEN_CLOEXEC)
+ return -EINVAL;
+
+ fs_name = strndup_user(_fs_name, PAGE_SIZE);
+ if (IS_ERR(fs_name))
+ return PTR_ERR(fs_name);
+
+ fs_type = get_fs_type(fs_name);
+ kfree(fs_name);
+ if (!fs_type)
+ return -ENODEV;
+
+ fc = fs_context_for_mount(fs_type, 0);
+ put_filesystem(fs_type);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ fc->phase = FS_CONTEXT_CREATE_PARAMS;
+
+ ret = fscontext_alloc_log(fc);
+ if (ret < 0)
+ goto err_fc;
+
+ return fscontext_create_fd(fc, flags & FSOPEN_CLOEXEC ? O_CLOEXEC : 0);
+
+err_fc:
+ put_fs_context(fc);
+ return ret;
+}
+
+/*
+ * Pick a superblock into a context for reconfiguration.
+ */
+SYSCALL_DEFINE3(fspick, int, dfd, const char __user *, path, unsigned int, flags)
+{
+ struct fs_context *fc;
+ struct path target;
+ unsigned int lookup_flags;
+ int ret;
+
+ if (!ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if ((flags & ~(FSPICK_CLOEXEC |
+ FSPICK_SYMLINK_NOFOLLOW |
+ FSPICK_NO_AUTOMOUNT |
+ FSPICK_EMPTY_PATH)) != 0)
+ return -EINVAL;
+
+ lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
+ if (flags & FSPICK_SYMLINK_NOFOLLOW)
+ lookup_flags &= ~LOOKUP_FOLLOW;
+ if (flags & FSPICK_NO_AUTOMOUNT)
+ lookup_flags &= ~LOOKUP_AUTOMOUNT;
+ if (flags & FSPICK_EMPTY_PATH)
+ lookup_flags |= LOOKUP_EMPTY;
+ ret = user_path_at(dfd, path, lookup_flags, &target);
+ if (ret < 0)
+ goto err;
+
+ ret = -EINVAL;
+ if (target.mnt->mnt_root != target.dentry)
+ goto err_path;
+
+ fc = fs_context_for_reconfigure(target.dentry, 0, 0);
+ if (IS_ERR(fc)) {
+ ret = PTR_ERR(fc);
+ goto err_path;
+ }
+
+ fc->phase = FS_CONTEXT_RECONF_PARAMS;
+
+ ret = fscontext_alloc_log(fc);
+ if (ret < 0)
+ goto err_fc;
+
+ path_put(&target);
+ return fscontext_create_fd(fc, flags & FSPICK_CLOEXEC ? O_CLOEXEC : 0);
+
+err_fc:
+ put_fs_context(fc);
+err_path:
+ path_put(&target);
+err:
+ return ret;
+}
+
+/*
+ * Check the state and apply the configuration. Note that this function is
+ * allowed to 'steal' the value by setting param->xxx to NULL before returning.
+ */
+static int vfs_fsconfig_locked(struct fs_context *fc, int cmd,
+ struct fs_parameter *param)
+{
+ struct super_block *sb;
+ int ret;
+
+ ret = finish_clean_context(fc);
+ if (ret)
+ return ret;
+ switch (cmd) {
+ case FSCONFIG_CMD_CREATE:
+ if (fc->phase != FS_CONTEXT_CREATE_PARAMS)
+ return -EBUSY;
+ if (!mount_capable(fc))
+ return -EPERM;
+ fc->phase = FS_CONTEXT_CREATING;
+ ret = vfs_get_tree(fc);
+ if (ret)
+ break;
+ sb = fc->root->d_sb;
+ ret = security_sb_kern_mount(sb);
+ if (unlikely(ret)) {
+ fc_drop_locked(fc);
+ break;
+ }
+ up_write(&sb->s_umount);
+ fc->phase = FS_CONTEXT_AWAITING_MOUNT;
+ return 0;
+ case FSCONFIG_CMD_RECONFIGURE:
+ if (fc->phase != FS_CONTEXT_RECONF_PARAMS)
+ return -EBUSY;
+ fc->phase = FS_CONTEXT_RECONFIGURING;
+ sb = fc->root->d_sb;
+ if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {
+ ret = -EPERM;
+ break;
+ }
+ down_write(&sb->s_umount);
+ ret = reconfigure_super(fc);
+ up_write(&sb->s_umount);
+ if (ret)
+ break;
+ vfs_clean_context(fc);
+ return 0;
+ default:
+ if (fc->phase != FS_CONTEXT_CREATE_PARAMS &&
+ fc->phase != FS_CONTEXT_RECONF_PARAMS)
+ return -EBUSY;
+
+ return vfs_parse_fs_param(fc, param);
+ }
+ fc->phase = FS_CONTEXT_FAILED;
+ return ret;
+}
+
+/**
+ * sys_fsconfig - Set parameters and trigger actions on a context
+ * @fd: The filesystem context to act upon
+ * @cmd: The action to take
+ * @_key: Where appropriate, the parameter key to set
+ * @_value: Where appropriate, the parameter value to set
+ * @aux: Additional information for the value
+ *
+ * This system call is used to set parameters on a context, including
+ * superblock settings, data source and security labelling.
+ *
+ * Actions include triggering the creation of a superblock and the
+ * reconfiguration of the superblock attached to the specified context.
+ *
+ * When setting a parameter, @cmd indicates the type of value being proposed
+ * and @_key indicates the parameter to be altered.
+ *
+ * @_value and @aux are used to specify the value, should a value be required:
+ *
+ * (*) fsconfig_set_flag: No value is specified. The parameter must be boolean
+ * in nature. The key may be prefixed with "no" to invert the
+ * setting. @_value must be NULL and @aux must be 0.
+ *
+ * (*) fsconfig_set_string: A string value is specified. The parameter can be
+ * expecting boolean, integer, string or take a path. A conversion to an
+ * appropriate type will be attempted (which may include looking up as a
+ * path). @_value points to a NUL-terminated string and @aux must be 0.
+ *
+ * (*) fsconfig_set_binary: A binary blob is specified. @_value points to the
+ * blob and @aux indicates its size. The parameter must be expecting a
+ * blob.
+ *
+ * (*) fsconfig_set_path: A non-empty path is specified. The parameter must be
+ * expecting a path object. @_value points to a NUL-terminated string that
+ * is the path and @aux is a file descriptor at which to start a relative
+ * lookup or AT_FDCWD.
+ *
+ * (*) fsconfig_set_path_empty: As fsconfig_set_path, but with AT_EMPTY_PATH
+ * implied.
+ *
+ * (*) fsconfig_set_fd: An open file descriptor is specified. @_value must be
+ * NULL and @aux indicates the file descriptor.
+ */
+SYSCALL_DEFINE5(fsconfig,
+ int, fd,
+ unsigned int, cmd,
+ const char __user *, _key,
+ const void __user *, _value,
+ int, aux)
+{
+ struct fs_context *fc;
+ struct fd f;
+ int ret;
+
+ struct fs_parameter param = {
+ .type = fs_value_is_undefined,
+ };
+
+ if (fd < 0)
+ return -EINVAL;
+
+ switch (cmd) {
+ case FSCONFIG_SET_FLAG:
+ if (!_key || _value || aux)
+ return -EINVAL;
+ break;
+ case FSCONFIG_SET_STRING:
+ if (!_key || !_value || aux)
+ return -EINVAL;
+ break;
+ case FSCONFIG_SET_BINARY:
+ if (!_key || !_value || aux <= 0 || aux > 1024 * 1024)
+ return -EINVAL;
+ break;
+ case FSCONFIG_SET_PATH:
+ case FSCONFIG_SET_PATH_EMPTY:
+ if (!_key || !_value || (aux != AT_FDCWD && aux < 0))
+ return -EINVAL;
+ break;
+ case FSCONFIG_SET_FD:
+ if (!_key || _value || aux < 0)
+ return -EINVAL;
+ break;
+ case FSCONFIG_CMD_CREATE:
+ case FSCONFIG_CMD_RECONFIGURE:
+ if (_key || _value || aux)
+ return -EINVAL;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ f = fdget(fd);
+ if (!f.file)
+ return -EBADF;
+ ret = -EINVAL;
+ if (f.file->f_op != &fscontext_fops)
+ goto out_f;
+
+ fc = f.file->private_data;
+ if (fc->ops == &legacy_fs_context_ops) {
+ switch (cmd) {
+ case FSCONFIG_SET_BINARY:
+ case FSCONFIG_SET_PATH:
+ case FSCONFIG_SET_PATH_EMPTY:
+ case FSCONFIG_SET_FD:
+ ret = -EOPNOTSUPP;
+ goto out_f;
+ }
+ }
+
+ if (_key) {
+ param.key = strndup_user(_key, 256);
+ if (IS_ERR(param.key)) {
+ ret = PTR_ERR(param.key);
+ goto out_f;
+ }
+ }
+
+ switch (cmd) {
+ case FSCONFIG_SET_FLAG:
+ param.type = fs_value_is_flag;
+ break;
+ case FSCONFIG_SET_STRING:
+ param.type = fs_value_is_string;
+ param.string = strndup_user(_value, 256);
+ if (IS_ERR(param.string)) {
+ ret = PTR_ERR(param.string);
+ goto out_key;
+ }
+ param.size = strlen(param.string);
+ break;
+ case FSCONFIG_SET_BINARY:
+ param.type = fs_value_is_blob;
+ param.size = aux;
+ param.blob = memdup_user_nul(_value, aux);
+ if (IS_ERR(param.blob)) {
+ ret = PTR_ERR(param.blob);
+ goto out_key;
+ }
+ break;
+ case FSCONFIG_SET_PATH:
+ param.type = fs_value_is_filename;
+ param.name = getname_flags(_value, 0, NULL);
+ if (IS_ERR(param.name)) {
+ ret = PTR_ERR(param.name);
+ goto out_key;
+ }
+ param.dirfd = aux;
+ param.size = strlen(param.name->name);
+ break;
+ case FSCONFIG_SET_PATH_EMPTY:
+ param.type = fs_value_is_filename_empty;
+ param.name = getname_flags(_value, LOOKUP_EMPTY, NULL);
+ if (IS_ERR(param.name)) {
+ ret = PTR_ERR(param.name);
+ goto out_key;
+ }
+ param.dirfd = aux;
+ param.size = strlen(param.name->name);
+ break;
+ case FSCONFIG_SET_FD:
+ param.type = fs_value_is_file;
+ ret = -EBADF;
+ param.file = fget(aux);
+ if (!param.file)
+ goto out_key;
+ break;
+ default:
+ break;
+ }
+
+ ret = mutex_lock_interruptible(&fc->uapi_mutex);
+ if (ret == 0) {
+ ret = vfs_fsconfig_locked(fc, cmd, ¶m);
+ mutex_unlock(&fc->uapi_mutex);
+ }
+
+ /* Clean up the our record of any value that we obtained from
+ * userspace. Note that the value may have been stolen by the LSM or
+ * filesystem, in which case the value pointer will have been cleared.
+ */
+ switch (cmd) {
+ case FSCONFIG_SET_STRING:
+ case FSCONFIG_SET_BINARY:
+ kfree(param.string);
+ break;
+ case FSCONFIG_SET_PATH:
+ case FSCONFIG_SET_PATH_EMPTY:
+ if (param.name)
+ putname(param.name);
+ break;
+ case FSCONFIG_SET_FD:
+ if (param.file)
+ fput(param.file);
+ break;
+ default:
+ break;
+ }
+out_key:
+ kfree(param.key);
+out_f:
+ fdput(f);
+ return ret;
+}