Merge tag 'staging-5.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull IIO fixes and staging driver from Greg KH:
 "Here is a mix of a number of IIO driver fixes for 5.4-rc7, and a whole
  new staging driver.

  The IIO fixes resolve some reported issues, all are tiny.

  The staging driver addition is the vboxsf filesystem, which is the
  VirtualBox guest shared folder code. Hans has been trying to get
  filesystem reviewers to review the code for many months now, and
  Christoph finally said to just merge it in staging now as it is
  stand-alone and the filesystem people can review it easier over time
  that way.

  I know it's late for this big of an addition, but it is stand-alone.

  The code has been in linux-next for a while, long enough to pick up a
  few tiny fixes for it already so people are looking at it.

  All of these have been in linux-next with no reported issues"

* tag 'staging-5.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: Fix error return code in vboxsf_fill_super()
  staging: vboxsf: fix dereference of pointer dentry before it is null checked
  staging: vboxsf: Remove unused including <linux/version.h>
  staging: Add VirtualBox guest shared folder (vboxsf) support
  iio: adc: stm32-adc: fix stopping dma
  iio: imu: inv_mpu6050: fix no data on MPU6050
  iio: srf04: fix wrong limitation in distance measuring
  iio: imu: adis16480: make sure provided frequency is positive

1 files changed, 501 insertions, 0 deletions

diff --git a/drivers/staging/vboxsf/super.c b/drivers/staging/vboxsf/super.c
new file mode 100644
index 000000000000..0bf4d724aefd
--- /dev/null
+++ b/drivers/staging/vboxsf/super.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Virtual File System.
+ *
+ * Module initialization/finalization
+ * File system registration/deregistration
+ * Superblock reading
+ * Few utility functions
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/idr.h>
+#include <linux/fs_parser.h>
+#include <linux/magic.h>
+#include <linux/module.h>
+#include <linux/nls.h>
+#include <linux/statfs.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+#define VBOXSF_SUPER_MAGIC 0x786f4256 /* 'VBox' little endian */
+
+#define VBSF_MOUNT_SIGNATURE_BYTE_0 ('\000')
+#define VBSF_MOUNT_SIGNATURE_BYTE_1 ('\377')
+#define VBSF_MOUNT_SIGNATURE_BYTE_2 ('\376')
+#define VBSF_MOUNT_SIGNATURE_BYTE_3 ('\375')
+
+static int follow_symlinks;
+module_param(follow_symlinks, int, 0444);
+MODULE_PARM_DESC(follow_symlinks,
+		 "Let host resolve symlinks rather than showing them");
+
+static DEFINE_IDA(vboxsf_bdi_ida);
+static DEFINE_MUTEX(vboxsf_setup_mutex);
+static bool vboxsf_setup_done;
+static struct super_operations vboxsf_super_ops; /* forward declaration */
+static struct kmem_cache *vboxsf_inode_cachep;
+
+static char * const vboxsf_default_nls = CONFIG_NLS_DEFAULT;
+
+enum  { opt_nls, opt_uid, opt_gid, opt_ttl, opt_dmode, opt_fmode,
+	opt_dmask, opt_fmask };
+
+static const struct fs_parameter_spec vboxsf_param_specs[] = {
+	fsparam_string	("nls",		opt_nls),
+	fsparam_u32	("uid",		opt_uid),
+	fsparam_u32	("gid",		opt_gid),
+	fsparam_u32	("ttl",		opt_ttl),
+	fsparam_u32oct	("dmode",	opt_dmode),
+	fsparam_u32oct	("fmode",	opt_fmode),
+	fsparam_u32oct	("dmask",	opt_dmask),
+	fsparam_u32oct	("fmask",	opt_fmask),
+	{}
+};
+
+static const struct fs_parameter_description vboxsf_fs_parameters = {
+	.name  = "vboxsf",
+	.specs  = vboxsf_param_specs,
+};
+
+static int vboxsf_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct fs_parse_result result;
+	kuid_t uid;
+	kgid_t gid;
+	int opt;
+
+	opt = fs_parse(fc, &vboxsf_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_nls:
+		if (fc->purpose != FS_CONTEXT_FOR_MOUNT) {
+			vbg_err("vboxsf: Cannot reconfigure nls option\n");
+			return -EINVAL;
+		}
+		ctx->nls_name = param->string;
+		param->string = NULL;
+		break;
+	case opt_uid:
+		uid = make_kuid(current_user_ns(), result.uint_32);
+		if (!uid_valid(uid))
+			return -EINVAL;
+		ctx->o.uid = uid;
+		break;
+	case opt_gid:
+		gid = make_kgid(current_user_ns(), result.uint_32);
+		if (!gid_valid(gid))
+			return -EINVAL;
+		ctx->o.gid = gid;
+		break;
+	case opt_ttl:
+		ctx->o.ttl = msecs_to_jiffies(result.uint_32);
+		break;
+	case opt_dmode:
+		if (result.uint_32 & ~0777)
+			return -EINVAL;
+		ctx->o.dmode = result.uint_32;
+		ctx->o.dmode_set = true;
+		break;
+	case opt_fmode:
+		if (result.uint_32 & ~0777)
+			return -EINVAL;
+		ctx->o.fmode = result.uint_32;
+		ctx->o.fmode_set = true;
+		break;
+	case opt_dmask:
+		if (result.uint_32 & ~07777)
+			return -EINVAL;
+		ctx->o.dmask = result.uint_32;
+		break;
+	case opt_fmask:
+		if (result.uint_32 & ~07777)
+			return -EINVAL;
+		ctx->o.fmask = result.uint_32;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct shfl_string *folder_name, root_path;
+	struct vboxsf_sbi *sbi;
+	struct dentry *droot;
+	struct inode *iroot;
+	char *nls_name;
+	size_t size;
+	int err;
+
+	if (!fc->source)
+		return -EINVAL;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sbi->o = ctx->o;
+	idr_init(&sbi->ino_idr);
+	spin_lock_init(&sbi->ino_idr_lock);
+	sbi->next_generation = 1;
+	sbi->bdi_id = -1;
+
+	/* Load nls if not utf8 */
+	nls_name = ctx->nls_name ? ctx->nls_name : vboxsf_default_nls;
+	if (strcmp(nls_name, "utf8") != 0) {
+		if (nls_name == vboxsf_default_nls)
+			sbi->nls = load_nls_default();
+		else
+			sbi->nls = load_nls(nls_name);
+
+		if (!sbi->nls) {
+			vbg_err("vboxsf: Count not load '%s' nls\n", nls_name);
+			err = -EINVAL;
+			goto fail_free;
+		}
+	}
+
+	sbi->bdi_id = ida_simple_get(&vboxsf_bdi_ida, 0, 0, GFP_KERNEL);
+	if (sbi->bdi_id < 0) {
+		err = sbi->bdi_id;
+		goto fail_free;
+	}
+
+	err = super_setup_bdi_name(sb, "vboxsf-%s.%d", fc->source, sbi->bdi_id);
+	if (err)
+		goto fail_free;
+
+	/* Turn source into a shfl_string and map the folder */
+	size = strlen(fc->source) + 1;
+	folder_name = kmalloc(SHFLSTRING_HEADER_SIZE + size, GFP_KERNEL);
+	if (!folder_name) {
+		err = -ENOMEM;
+		goto fail_free;
+	}
+	folder_name->size = size;
+	folder_name->length = size - 1;
+	strlcpy(folder_name->string.utf8, fc->source, size);
+	err = vboxsf_map_folder(folder_name, &sbi->root);
+	kfree(folder_name);
+	if (err) {
+		vbg_err("vboxsf: Host rejected mount of '%s' with error %d\n",
+			fc->source, err);
+		goto fail_free;
+	}
+
+	root_path.length = 1;
+	root_path.size = 2;
+	root_path.string.utf8[0] = '/';
+	root_path.string.utf8[1] = 0;
+	err = vboxsf_stat(sbi, &root_path, &sbi->root_info);
+	if (err)
+		goto fail_unmap;
+
+	sb->s_magic = VBOXSF_SUPER_MAGIC;
+	sb->s_blocksize = 1024;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_op = &vboxsf_super_ops;
+	sb->s_d_op = &vboxsf_dentry_ops;
+
+	iroot = iget_locked(sb, 0);
+	if (!iroot) {
+		err = -ENOMEM;
+		goto fail_unmap;
+	}
+	vboxsf_init_inode(sbi, iroot, &sbi->root_info);
+	unlock_new_inode(iroot);
+
+	droot = d_make_root(iroot);
+	if (!droot) {
+		err = -ENOMEM;
+		goto fail_unmap;
+	}
+
+	sb->s_root = droot;
+	sb->s_fs_info = sbi;
+	return 0;
+
+fail_unmap:
+	vboxsf_unmap_folder(sbi->root);
+fail_free:
+	if (sbi->bdi_id >= 0)
+		ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
+	if (sbi->nls)
+		unload_nls(sbi->nls);
+	idr_destroy(&sbi->ino_idr);
+	kfree(sbi);
+	return err;
+}
+
+static void vboxsf_inode_init_once(void *data)
+{
+	struct vboxsf_inode *sf_i = data;
+
+	mutex_init(&sf_i->handle_list_mutex);
+	inode_init_once(&sf_i->vfs_inode);
+}
+
+static struct inode *vboxsf_alloc_inode(struct super_block *sb)
+{
+	struct vboxsf_inode *sf_i;
+
+	sf_i = kmem_cache_alloc(vboxsf_inode_cachep, GFP_NOFS);
+	if (!sf_i)
+		return NULL;
+
+	sf_i->force_restat = 0;
+	INIT_LIST_HEAD(&sf_i->handle_list);
+
+	return &sf_i->vfs_inode;
+}
+
+static void vboxsf_free_inode(struct inode *inode)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->ino_idr_lock, flags);
+	idr_remove(&sbi->ino_idr, inode->i_ino);
+	spin_unlock_irqrestore(&sbi->ino_idr_lock, flags);
+	kmem_cache_free(vboxsf_inode_cachep, VBOXSF_I(inode));
+}
+
+static void vboxsf_put_super(struct super_block *sb)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(sb);
+
+	vboxsf_unmap_folder(sbi->root);
+	if (sbi->bdi_id >= 0)
+		ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
+	if (sbi->nls)
+		unload_nls(sbi->nls);
+
+	/*
+	 * vboxsf_free_inode uses the idr, make sure all delayed rcu free
+	 * inodes are flushed.
+	 */
+	rcu_barrier();
+	idr_destroy(&sbi->ino_idr);
+	kfree(sbi);
+}
+
+static int vboxsf_statfs(struct dentry *dentry, struct kstatfs *stat)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct shfl_volinfo shfl_volinfo;
+	struct vboxsf_sbi *sbi;
+	u32 buf_len;
+	int err;
+
+	sbi = VBOXSF_SBI(sb);
+	buf_len = sizeof(shfl_volinfo);
+	err = vboxsf_fsinfo(sbi->root, 0, SHFL_INFO_GET | SHFL_INFO_VOLUME,
+			    &buf_len, &shfl_volinfo);
+	if (err)
+		return err;
+
+	stat->f_type = VBOXSF_SUPER_MAGIC;
+	stat->f_bsize = shfl_volinfo.bytes_per_allocation_unit;
+
+	do_div(shfl_volinfo.total_allocation_bytes,
+	       shfl_volinfo.bytes_per_allocation_unit);
+	stat->f_blocks = shfl_volinfo.total_allocation_bytes;
+
+	do_div(shfl_volinfo.available_allocation_bytes,
+	       shfl_volinfo.bytes_per_allocation_unit);
+	stat->f_bfree  = shfl_volinfo.available_allocation_bytes;
+	stat->f_bavail = shfl_volinfo.available_allocation_bytes;
+
+	stat->f_files = 1000;
+	/*
+	 * Don't return 0 here since the guest may then think that it is not
+	 * possible to create any more files.
+	 */
+	stat->f_ffree = 1000000;
+	stat->f_fsid.val[0] = 0;
+	stat->f_fsid.val[1] = 0;
+	stat->f_namelen = 255;
+	return 0;
+}
+
+static struct super_operations vboxsf_super_ops = {
+	.alloc_inode	= vboxsf_alloc_inode,
+	.free_inode	= vboxsf_free_inode,
+	.put_super	= vboxsf_put_super,
+	.statfs		= vboxsf_statfs,
+};
+
+static int vboxsf_setup(void)
+{
+	int err;
+
+	mutex_lock(&vboxsf_setup_mutex);
+
+	if (vboxsf_setup_done)
+		goto success;
+
+	vboxsf_inode_cachep =
+		kmem_cache_create("vboxsf_inode_cache",
+				  sizeof(struct vboxsf_inode), 0,
+				  (SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD |
+				   SLAB_ACCOUNT),
+				  vboxsf_inode_init_once);
+	if (!vboxsf_inode_cachep) {
+		err = -ENOMEM;
+		goto fail_nomem;
+	}
+
+	err = vboxsf_connect();
+	if (err) {
+		vbg_err("vboxsf: err %d connecting to guest PCI-device\n", err);
+		vbg_err("vboxsf: make sure you are inside a VirtualBox VM\n");
+		vbg_err("vboxsf: and check dmesg for vboxguest errors\n");
+		goto fail_free_cache;
+	}
+
+	err = vboxsf_set_utf8();
+	if (err) {
+		vbg_err("vboxsf_setutf8 error %d\n", err);
+		goto fail_disconnect;
+	}
+
+	if (!follow_symlinks) {
+		err = vboxsf_set_symlinks();
+		if (err)
+			vbg_warn("vboxsf: Unable to show symlinks: %d\n", err);
+	}
+
+	vboxsf_setup_done = true;
+success:
+	mutex_unlock(&vboxsf_setup_mutex);
+	return 0;
+
+fail_disconnect:
+	vboxsf_disconnect();
+fail_free_cache:
+	kmem_cache_destroy(vboxsf_inode_cachep);
+fail_nomem:
+	mutex_unlock(&vboxsf_setup_mutex);
+	return err;
+}
+
+static int vboxsf_parse_monolithic(struct fs_context *fc, void *data)
+{
+	char *options = data;
+
+	if (options && options[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 &&
+		       options[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 &&
+		       options[2] == VBSF_MOUNT_SIGNATURE_BYTE_2 &&
+		       options[3] == VBSF_MOUNT_SIGNATURE_BYTE_3) {
+		vbg_err("vboxsf: Old binary mount data not supported, remove obsolete mount.vboxsf and/or update your VBoxService.\n");
+		return -EINVAL;
+	}
+
+	return generic_parse_monolithic(fc, data);
+}
+
+static int vboxsf_get_tree(struct fs_context *fc)
+{
+	int err;
+
+	err = vboxsf_setup();
+	if (err)
+		return err;
+
+	return vfs_get_super(fc, vfs_get_independent_super, vboxsf_fill_super);
+}
+
+static int vboxsf_reconfigure(struct fs_context *fc)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(fc->root->d_sb);
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct inode *iroot;
+
+	iroot = ilookup(fc->root->d_sb, 0);
+	if (!iroot)
+		return -ENOENT;
+
+	/* Apply changed options to the root inode */
+	sbi->o = ctx->o;
+	vboxsf_init_inode(sbi, iroot, &sbi->root_info);
+
+	return 0;
+}
+
+static void vboxsf_free_fc(struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+
+	kfree(ctx->nls_name);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations vboxsf_context_ops = {
+	.free			= vboxsf_free_fc,
+	.parse_param		= vboxsf_parse_param,
+	.parse_monolithic	= vboxsf_parse_monolithic,
+	.get_tree		= vboxsf_get_tree,
+	.reconfigure		= vboxsf_reconfigure,
+};
+
+static int vboxsf_init_fs_context(struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	current_uid_gid(&ctx->o.uid, &ctx->o.gid);
+
+	fc->fs_private = ctx;
+	fc->ops = &vboxsf_context_ops;
+	return 0;
+}
+
+static struct file_system_type vboxsf_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= "vboxsf",
+	.init_fs_context	= vboxsf_init_fs_context,
+	.parameters		= &vboxsf_fs_parameters,
+	.kill_sb		= kill_anon_super
+};
+
+/* Module initialization/finalization handlers */
+static int __init vboxsf_init(void)
+{
+	return register_filesystem(&vboxsf_fs_type);
+}
+
+static void __exit vboxsf_fini(void)
+{
+	unregister_filesystem(&vboxsf_fs_type);
+
+	mutex_lock(&vboxsf_setup_mutex);
+	if (vboxsf_setup_done) {
+		vboxsf_disconnect();
+		/*
+		 * Make sure all delayed rcu free inodes are flushed
+		 * before we destroy the cache.
+		 */
+		rcu_barrier();
+		kmem_cache_destroy(vboxsf_inode_cachep);
+	}
+	mutex_unlock(&vboxsf_setup_mutex);
+}
+
+module_init(vboxsf_init);
+module_exit(vboxsf_fini);
+
+MODULE_DESCRIPTION("Oracle VM VirtualBox Module for Host File System Access");
+MODULE_AUTHOR("Oracle Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_FS("vboxsf");