Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * binfmt_misc.c
 *
 * Copyright (C) 1997 Richard Günther
 *
 * binfmt_misc detects binaries via a magic or filename extension and invokes
 * a specified wrapper. See Documentation/admin-guide/binfmt-misc.rst for more details.
 */
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched/mm.h>
#include <linux/magic.h>
#include <linux/binfmts.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/string_helpers.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/fs_context.h>
#include <linux/syscalls.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
 
#include "internal.h"
 
#ifdef DEBUG
# define USE_DEBUG 1
#else
# define USE_DEBUG 0
#endif
 
enum {
<------>VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
};
 
static LIST_HEAD(entries);
static int enabled = 1;
 
enum {Enabled, Magic};
#define MISC_FMT_PRESERVE_ARGV0 (1 << 31)
#define MISC_FMT_OPEN_BINARY (1 << 30)
#define MISC_FMT_CREDENTIALS (1 << 29)
#define MISC_FMT_OPEN_FILE (1 << 28)
 
typedef struct {
<------>struct list_head list;
<------>unsigned long flags;		/* type, status, etc. */
<------>int offset;			/* offset of magic */
<------>int size;			/* size of magic/mask */
<------>char *magic;			/* magic or filename extension */
<------>char *mask;			/* mask, NULL for exact match */
<------>const char *interpreter;	/* filename of interpreter */
<------>char *name;
<------>struct dentry *dentry;
<------>struct file *interp_file;
} Node;
 
static DEFINE_RWLOCK(entries_lock);
static struct file_system_type bm_fs_type;
static struct vfsmount *bm_mnt;
static int entry_count;
 
/*
 * Max length of the register string.  Determined by:
 *  - 7 delimiters
 *  - name:   ~50 bytes
 *  - type:   1 byte
 *  - offset: 3 bytes (has to be smaller than BINPRM_BUF_SIZE)
 *  - magic:  128 bytes (512 in escaped form)
 *  - mask:   128 bytes (512 in escaped form)
 *  - interp: ~50 bytes
 *  - flags:  5 bytes
 * Round that up a bit, and then back off to hold the internal data
 * (like struct Node).
 */
#define MAX_REGISTER_LENGTH 1920
 
/*
 * Check if we support the binfmt
 * if we do, return the node, else NULL
 * locking is done in load_misc_binary
 */
static Node *check_file(struct linux_binprm *bprm)
{
<------>char *p = strrchr(bprm->interp, '.');
<------>struct list_head *l;
 
<------>/* Walk all the registered handlers. */
<------>list_for_each(l, &entries) {
<------><------>Node *e = list_entry(l, Node, list);
<------><------>char *s;
<------><------>int j;
 
<------><------>/* Make sure this one is currently enabled. */
<------><------>if (!test_bit(Enabled, &e->flags))
<------><------><------>continue;
 
<------><------>/* Do matching based on extension if applicable. */
<------><------>if (!test_bit(Magic, &e->flags)) {
<------><------><------>if (p && !strcmp(e->magic, p + 1))
<------><------><------><------>return e;
<------><------><------>continue;
<------><------>}
 
<------><------>/* Do matching based on magic & mask. */
<------><------>s = bprm->buf + e->offset;
<------><------>if (e->mask) {
<------><------><------>for (j = 0; j < e->size; j++)
<------><------><------><------>if ((*s++ ^ e->magic[j]) & e->mask[j])
<------><------><------><------><------>break;
<------><------>} else {
<------><------><------>for (j = 0; j < e->size; j++)
<------><------><------><------>if ((*s++ ^ e->magic[j]))
<------><------><------><------><------>break;
<------><------>}
<------><------>if (j == e->size)
<------><------><------>return e;
<------>}
<------>return NULL;
}
 
/*
 * the loader itself
 */
static int load_misc_binary(struct linux_binprm *bprm)
{
<------>Node *fmt;
<------>struct file *interp_file = NULL;
<------>int retval;
 
<------>retval = -ENOEXEC;
<------>if (!enabled)
<------><------>return retval;
 
<------>/* to keep locking time low, we copy the interpreter string */
<------>read_lock(&entries_lock);
<------>fmt = check_file(bprm);
<------>if (fmt)
<------><------>dget(fmt->dentry);
<------>read_unlock(&entries_lock);
<------>if (!fmt)
<------><------>return retval;
 
<------>/* Need to be able to load the file after exec */
<------>retval = -ENOENT;
<------>if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
<------><------>goto ret;
 
<------>if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
<------><------>retval = remove_arg_zero(bprm);
<------><------>if (retval)
<------><------><------>goto ret;
<------>}
 
<------>if (fmt->flags & MISC_FMT_OPEN_BINARY)
<------><------>bprm->have_execfd = 1;
 
<------>/* make argv[1] be the path to the binary */
<------>retval = copy_string_kernel(bprm->interp, bprm);
<------>if (retval < 0)
<------><------>goto ret;
<------>bprm->argc++;
 
<------>/* add the interp as argv[0] */
<------>retval = copy_string_kernel(fmt->interpreter, bprm);
<------>if (retval < 0)
<------><------>goto ret;
<------>bprm->argc++;
 
<------>/* Update interp in case binfmt_script needs it. */
<------>retval = bprm_change_interp(fmt->interpreter, bprm);
<------>if (retval < 0)
<------><------>goto ret;
 
<------>if (fmt->flags & MISC_FMT_OPEN_FILE) {
<------><------>interp_file = file_clone_open(fmt->interp_file);
<------><------>if (!IS_ERR(interp_file))
<------><------><------>deny_write_access(interp_file);
<------>} else {
<------><------>interp_file = open_exec(fmt->interpreter);
<------>}
<------>retval = PTR_ERR(interp_file);
<------>if (IS_ERR(interp_file))
<------><------>goto ret;
 
<------>bprm->interpreter = interp_file;
<------>if (fmt->flags & MISC_FMT_CREDENTIALS)
<------><------>bprm->execfd_creds = 1;
 
<------>retval = 0;
ret:
<------>dput(fmt->dentry);
<------>return retval;
}
 
/* Command parsers */
 
/*
 * parses and copies one argument enclosed in del from *sp to *dp,
 * recognising the \x special.
 * returns pointer to the copied argument or NULL in case of an
 * error (and sets err) or null argument length.
 */
static char *scanarg(char *s, char del)
{
<------>char c;
 
<------>while ((c = *s++) != del) {
<------><------>if (c == '\\' && *s == 'x') {
<------><------><------>s++;
<------><------><------>if (!isxdigit(*s++))
<------><------><------><------>return NULL;
<------><------><------>if (!isxdigit(*s++))
<------><------><------><------>return NULL;
<------><------>}
<------>}
<------>s[-1] ='\0';
<------>return s;
}
 
static char *check_special_flags(char *sfs, Node *e)
{
<------>char *p = sfs;
<------>int cont = 1;
 
<------>/* special flags */
<------>while (cont) {
<------><------>switch (*p) {
<------><------>case 'P':
<------><------><------>pr_debug("register: flag: P (preserve argv0)\n");
<------><------><------>p++;
<------><------><------>e->flags |= MISC_FMT_PRESERVE_ARGV0;
<------><------><------>break;
<------><------>case 'O':
<------><------><------>pr_debug("register: flag: O (open binary)\n");
<------><------><------>p++;
<------><------><------>e->flags |= MISC_FMT_OPEN_BINARY;
<------><------><------>break;
<------><------>case 'C':
<------><------><------>pr_debug("register: flag: C (preserve creds)\n");
<------><------><------>p++;
<------><------><------>/* this flags also implies the
<------><------><------>   open-binary flag */
<------><------><------>e->flags |= (MISC_FMT_CREDENTIALS |
<------><------><------><------><------>MISC_FMT_OPEN_BINARY);
<------><------><------>break;
<------><------>case 'F':
<------><------><------>pr_debug("register: flag: F: open interpreter file now\n");
<------><------><------>p++;
<------><------><------>e->flags |= MISC_FMT_OPEN_FILE;
<------><------><------>break;
<------><------>default:
<------><------><------>cont = 0;
<------><------>}
<------>}
 
<------>return p;
}
 
/*
 * This registers a new binary format, it recognises the syntax
 * ':name:type:offset:magic:mask:interpreter:flags'
 * where the ':' is the IFS, that can be chosen with the first char
 */
static Node *create_entry(const char __user *buffer, size_t count)
{
<------>Node *e;
<------>int memsize, err;
<------>char *buf, *p;
<------>char del;
 
<------>pr_debug("register: received %zu bytes\n", count);
 
<------>/* some sanity checks */
<------>err = -EINVAL;
<------>if ((count < 11) || (count > MAX_REGISTER_LENGTH))
<------><------>goto out;
 
<------>err = -ENOMEM;
<------>memsize = sizeof(Node) + count + 8;
<------>e = kmalloc(memsize, GFP_KERNEL);
<------>if (!e)
<------><------>goto out;
 
<------>p = buf = (char *)e + sizeof(Node);
 
<------>memset(e, 0, sizeof(Node));
<------>if (copy_from_user(buf, buffer, count))
<------><------>goto efault;
 
<------>del = *p++;	/* delimeter */
 
<------>pr_debug("register: delim: %#x {%c}\n", del, del);
 
<------>/* Pad the buffer with the delim to simplify parsing below. */
<------>memset(buf + count, del, 8);
 
<------>/* Parse the 'name' field. */
<------>e->name = p;
<------>p = strchr(p, del);
<------>if (!p)
<------><------>goto einval;
<------>*p++ = '\0';
<------>if (!e->name[0] ||
<------>    !strcmp(e->name, ".") ||
<------>    !strcmp(e->name, "..") ||
<------>    strchr(e->name, '/'))
<------><------>goto einval;
 
<------>pr_debug("register: name: {%s}\n", e->name);
 
<------>/* Parse the 'type' field. */
<------>switch (*p++) {
<------>case 'E':
<------><------>pr_debug("register: type: E (extension)\n");
<------><------>e->flags = 1 << Enabled;
<------><------>break;
<------>case 'M':
<------><------>pr_debug("register: type: M (magic)\n");
<------><------>e->flags = (1 << Enabled) | (1 << Magic);
<------><------>break;
<------>default:
<------><------>goto einval;
<------>}
<------>if (*p++ != del)
<------><------>goto einval;
 
<------>if (test_bit(Magic, &e->flags)) {
<------><------>/* Handle the 'M' (magic) format. */
<------><------>char *s;
 
<------><------>/* Parse the 'offset' field. */
<------><------>s = strchr(p, del);
<------><------>if (!s)
<------><------><------>goto einval;
<------><------>*s = '\0';
<------><------>if (p != s) {
<------><------><------>int r = kstrtoint(p, 10, &e->offset);
<------><------><------>if (r != 0 || e->offset < 0)
<------><------><------><------>goto einval;
<------><------>}
<------><------>p = s;
<------><------>if (*p++)
<------><------><------>goto einval;
<------><------>pr_debug("register: offset: %#x\n", e->offset);
 
<------><------>/* Parse the 'magic' field. */
<------><------>e->magic = p;
<------><------>p = scanarg(p, del);
<------><------>if (!p)
<------><------><------>goto einval;
<------><------>if (!e->magic[0])
<------><------><------>goto einval;
<------><------>if (USE_DEBUG)
<------><------><------>print_hex_dump_bytes(
<------><------><------><------>KBUILD_MODNAME ": register: magic[raw]: ",
<------><------><------><------>DUMP_PREFIX_NONE, e->magic, p - e->magic);
 
<------><------>/* Parse the 'mask' field. */
<------><------>e->mask = p;
<------><------>p = scanarg(p, del);
<------><------>if (!p)
<------><------><------>goto einval;
<------><------>if (!e->mask[0]) {
<------><------><------>e->mask = NULL;
<------><------><------>pr_debug("register:  mask[raw]: none\n");
<------><------>} else if (USE_DEBUG)
<------><------><------>print_hex_dump_bytes(
<------><------><------><------>KBUILD_MODNAME ": register:  mask[raw]: ",
<------><------><------><------>DUMP_PREFIX_NONE, e->mask, p - e->mask);
 
<------><------>/*
<------><------> * Decode the magic & mask fields.
<------><------> * Note: while we might have accepted embedded NUL bytes from
<------><------> * above, the unescape helpers here will stop at the first one
<------><------> * it encounters.
<------><------> */
<------><------>e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX);
<------><------>if (e->mask &&
<------><------>    string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size)
<------><------><------>goto einval;
<------><------>if (e->size > BINPRM_BUF_SIZE ||
<------><------>    BINPRM_BUF_SIZE - e->size < e->offset)
<------><------><------>goto einval;
<------><------>pr_debug("register: magic/mask length: %i\n", e->size);
<------><------>if (USE_DEBUG) {
<------><------><------>print_hex_dump_bytes(
<------><------><------><------>KBUILD_MODNAME ": register: magic[decoded]: ",
<------><------><------><------>DUMP_PREFIX_NONE, e->magic, e->size);
 
<------><------><------>if (e->mask) {
<------><------><------><------>int i;
<------><------><------><------>char *masked = kmalloc(e->size, GFP_KERNEL);
 
<------><------><------><------>print_hex_dump_bytes(
<------><------><------><------><------>KBUILD_MODNAME ": register:  mask[decoded]: ",
<------><------><------><------><------>DUMP_PREFIX_NONE, e->mask, e->size);
 
<------><------><------><------>if (masked) {
<------><------><------><------><------>for (i = 0; i < e->size; ++i)
<------><------><------><------><------><------>masked[i] = e->magic[i] & e->mask[i];
<------><------><------><------><------>print_hex_dump_bytes(
<------><------><------><------><------><------>KBUILD_MODNAME ": register:  magic[masked]: ",
<------><------><------><------><------><------>DUMP_PREFIX_NONE, masked, e->size);
 
<------><------><------><------><------>kfree(masked);
<------><------><------><------>}
<------><------><------>}
<------><------>}
<------>} else {
<------><------>/* Handle the 'E' (extension) format. */
 
<------><------>/* Skip the 'offset' field. */
<------><------>p = strchr(p, del);
<------><------>if (!p)
<------><------><------>goto einval;
<------><------>*p++ = '\0';
 
<------><------>/* Parse the 'magic' field. */
<------><------>e->magic = p;
<------><------>p = strchr(p, del);
<------><------>if (!p)
<------><------><------>goto einval;
<------><------>*p++ = '\0';
<------><------>if (!e->magic[0] || strchr(e->magic, '/'))
<------><------><------>goto einval;
<------><------>pr_debug("register: extension: {%s}\n", e->magic);
 
<------><------>/* Skip the 'mask' field. */
<------><------>p = strchr(p, del);
<------><------>if (!p)
<------><------><------>goto einval;
<------><------>*p++ = '\0';
<------>}
 
<------>/* Parse the 'interpreter' field. */
<------>e->interpreter = p;
<------>p = strchr(p, del);
<------>if (!p)
<------><------>goto einval;
<------>*p++ = '\0';
<------>if (!e->interpreter[0])
<------><------>goto einval;
<------>pr_debug("register: interpreter: {%s}\n", e->interpreter);
 
<------>/* Parse the 'flags' field. */
<------>p = check_special_flags(p, e);
<------>if (*p == '\n')
<------><------>p++;
<------>if (p != buf + count)
<------><------>goto einval;
 
<------>return e;
 
out:
<------>return ERR_PTR(err);
 
efault:
<------>kfree(e);
<------>return ERR_PTR(-EFAULT);
einval:
<------>kfree(e);
<------>return ERR_PTR(-EINVAL);
}
 
/*
 * Set status of entry/binfmt_misc:
 * '1' enables, '0' disables and '-1' clears entry/binfmt_misc
 */
static int parse_command(const char __user *buffer, size_t count)
{
<------>char s[4];
 
<------>if (count > 3)
<------><------>return -EINVAL;
<------>if (copy_from_user(s, buffer, count))
<------><------>return -EFAULT;
<------>if (!count)
<------><------>return 0;
<------>if (s[count - 1] == '\n')
<------><------>count--;
<------>if (count == 1 && s[0] == '0')
<------><------>return 1;
<------>if (count == 1 && s[0] == '1')
<------><------>return 2;
<------>if (count == 2 && s[0] == '-' && s[1] == '1')
<------><------>return 3;
<------>return -EINVAL;
}
 
/* generic stuff */
 
static void entry_status(Node *e, char *page)
{
<------>char *dp = page;
<------>const char *status = "disabled";
 
<------>if (test_bit(Enabled, &e->flags))
<------><------>status = "enabled";
 
<------>if (!VERBOSE_STATUS) {
<------><------>sprintf(page, "%s\n", status);
<------><------>return;
<------>}
 
<------>dp += sprintf(dp, "%s\ninterpreter %s\n", status, e->interpreter);
 
<------>/* print the special flags */
<------>dp += sprintf(dp, "flags: ");
<------>if (e->flags & MISC_FMT_PRESERVE_ARGV0)
<------><------>*dp++ = 'P';
<------>if (e->flags & MISC_FMT_OPEN_BINARY)
<------><------>*dp++ = 'O';
<------>if (e->flags & MISC_FMT_CREDENTIALS)
<------><------>*dp++ = 'C';
<------>if (e->flags & MISC_FMT_OPEN_FILE)
<------><------>*dp++ = 'F';
<------>*dp++ = '\n';
 
<------>if (!test_bit(Magic, &e->flags)) {
<------><------>sprintf(dp, "extension .%s\n", e->magic);
<------>} else {
<------><------>dp += sprintf(dp, "offset %i\nmagic ", e->offset);
<------><------>dp = bin2hex(dp, e->magic, e->size);
<------><------>if (e->mask) {
<------><------><------>dp += sprintf(dp, "\nmask ");
<------><------><------>dp = bin2hex(dp, e->mask, e->size);
<------><------>}
<------><------>*dp++ = '\n';
<------><------>*dp = '\0';
<------>}
}
 
static struct inode *bm_get_inode(struct super_block *sb, int mode)
{
<------>struct inode *inode = new_inode(sb);
 
<------>if (inode) {
<------><------>inode->i_ino = get_next_ino();
<------><------>inode->i_mode = mode;
<------><------>inode->i_atime = inode->i_mtime = inode->i_ctime =
<------><------><------>current_time(inode);
<------>}
<------>return inode;
}
 
static void bm_evict_inode(struct inode *inode)
{
<------>Node *e = inode->i_private;
 
<------>if (e && e->flags & MISC_FMT_OPEN_FILE)
<------><------>filp_close(e->interp_file, NULL);
 
<------>clear_inode(inode);
<------>kfree(e);
}
 
static void kill_node(Node *e)
{
<------>struct dentry *dentry;
 
<------>write_lock(&entries_lock);
<------>list_del_init(&e->list);
<------>write_unlock(&entries_lock);
 
<------>dentry = e->dentry;
<------>drop_nlink(d_inode(dentry));
<------>d_drop(dentry);
<------>dput(dentry);
<------>simple_release_fs(&bm_mnt, &entry_count);
}
 
/* /<entry> */
 
static ssize_t
bm_entry_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
<------>Node *e = file_inode(file)->i_private;
<------>ssize_t res;
<------>char *page;
 
<------>page = (char *) __get_free_page(GFP_KERNEL);
<------>if (!page)
<------><------>return -ENOMEM;
 
<------>entry_status(e, page);
 
<------>res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page));
 
<------>free_page((unsigned long) page);
<------>return res;
}
 
static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
<------><------><------><------>size_t count, loff_t *ppos)
{
<------>struct dentry *root;
<------>Node *e = file_inode(file)->i_private;
<------>int res = parse_command(buffer, count);
 
<------>switch (res) {
<------>case 1:
<------><------>/* Disable this handler. */
<------><------>clear_bit(Enabled, &e->flags);
<------><------>break;
<------>case 2:
<------><------>/* Enable this handler. */
<------><------>set_bit(Enabled, &e->flags);
<------><------>break;
<------>case 3:
<------><------>/* Delete this handler. */
<------><------>root = file_inode(file)->i_sb->s_root;
<------><------>inode_lock(d_inode(root));
 
<------><------>if (!list_empty(&e->list))
<------><------><------>kill_node(e);
 
<------><------>inode_unlock(d_inode(root));
<------><------>break;
<------>default:
<------><------>return res;
<------>}
 
<------>return count;
}
 
static const struct file_operations bm_entry_operations = {
<------>.read		= bm_entry_read,
<------>.write		= bm_entry_write,
<------>.llseek		= default_llseek,
};
 
/* /register */
 
static ssize_t bm_register_write(struct file *file, const char __user *buffer,
<------><------><------>       size_t count, loff_t *ppos)
{
<------>Node *e;
<------>struct inode *inode;
<------>struct super_block *sb = file_inode(file)->i_sb;
<------>struct dentry *root = sb->s_root, *dentry;
<------>int err = 0;
<------>struct file *f = NULL;
 
<------>e = create_entry(buffer, count);
 
<------>if (IS_ERR(e))
<------><------>return PTR_ERR(e);
 
<------>if (e->flags & MISC_FMT_OPEN_FILE) {
<------><------>f = open_exec(e->interpreter);
<------><------>if (IS_ERR(f)) {
<------><------><------>pr_notice("register: failed to install interpreter file %s\n",
<------><------><------><------> e->interpreter);
<------><------><------>kfree(e);
<------><------><------>return PTR_ERR(f);
<------><------>}
<------><------>e->interp_file = f;
<------>}
 
<------>inode_lock(d_inode(root));
<------>dentry = lookup_one_len(e->name, root, strlen(e->name));
<------>err = PTR_ERR(dentry);
<------>if (IS_ERR(dentry))
<------><------>goto out;
 
<------>err = -EEXIST;
<------>if (d_really_is_positive(dentry))
<------><------>goto out2;
 
<------>inode = bm_get_inode(sb, S_IFREG | 0644);
 
<------>err = -ENOMEM;
<------>if (!inode)
<------><------>goto out2;
 
<------>err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count);
<------>if (err) {
<------><------>iput(inode);
<------><------>inode = NULL;
<------><------>goto out2;
<------>}
 
<------>e->dentry = dget(dentry);
<------>inode->i_private = e;
<------>inode->i_fop = &bm_entry_operations;
 
<------>d_instantiate(dentry, inode);
<------>write_lock(&entries_lock);
<------>list_add(&e->list, &entries);
<------>write_unlock(&entries_lock);
 
<------>err = 0;
out2:
<------>dput(dentry);
out:
<------>inode_unlock(d_inode(root));
 
<------>if (err) {
<------><------>if (f)
<------><------><------>filp_close(f, NULL);
<------><------>kfree(e);
<------><------>return err;
<------>}
<------>return count;
}
 
static const struct file_operations bm_register_operations = {
<------>.write		= bm_register_write,
<------>.llseek		= noop_llseek,
};
 
/* /status */
 
static ssize_t
bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
<------>char *s = enabled ? "enabled\n" : "disabled\n";
 
<------>return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s));
}
 
static ssize_t bm_status_write(struct file *file, const char __user *buffer,
<------><------>size_t count, loff_t *ppos)
{
<------>int res = parse_command(buffer, count);
<------>struct dentry *root;
 
<------>switch (res) {
<------>case 1:
<------><------>/* Disable all handlers. */
<------><------>enabled = 0;
<------><------>break;
<------>case 2:
<------><------>/* Enable all handlers. */
<------><------>enabled = 1;
<------><------>break;
<------>case 3:
<------><------>/* Delete all handlers. */
<------><------>root = file_inode(file)->i_sb->s_root;
<------><------>inode_lock(d_inode(root));
 
<------><------>while (!list_empty(&entries))
<------><------><------>kill_node(list_first_entry(&entries, Node, list));
 
<------><------>inode_unlock(d_inode(root));
<------><------>break;
<------>default:
<------><------>return res;
<------>}
 
<------>return count;
}
 
static const struct file_operations bm_status_operations = {
<------>.read		= bm_status_read,
<------>.write		= bm_status_write,
<------>.llseek		= default_llseek,
};
 
/* Superblock handling */
 
static const struct super_operations s_ops = {
<------>.statfs		= simple_statfs,
<------>.evict_inode	= bm_evict_inode,
};
 
static int bm_fill_super(struct super_block *sb, struct fs_context *fc)
{
<------>int err;
<------>static const struct tree_descr bm_files[] = {
<------><------>[2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO},
<------><------>[3] = {"register", &bm_register_operations, S_IWUSR},
<------><------>/* last one */ {""}
<------>};
 
<------>err = simple_fill_super(sb, BINFMTFS_MAGIC, bm_files);
<------>if (!err)
<------><------>sb->s_op = &s_ops;
<------>return err;
}
 
static int bm_get_tree(struct fs_context *fc)
{
<------>return get_tree_single(fc, bm_fill_super);
}
 
static const struct fs_context_operations bm_context_ops = {
<------>.get_tree	= bm_get_tree,
};
 
static int bm_init_fs_context(struct fs_context *fc)
{
<------>fc->ops = &bm_context_ops;
<------>return 0;
}
 
static struct linux_binfmt misc_format = {
<------>.module = THIS_MODULE,
<------>.load_binary = load_misc_binary,
};
 
static struct file_system_type bm_fs_type = {
<------>.owner		= THIS_MODULE,
<------>.name		= "binfmt_misc",
<------>.init_fs_context = bm_init_fs_context,
<------>.kill_sb	= kill_litter_super,
};
MODULE_ALIAS_FS("binfmt_misc");
 
static int __init init_misc_binfmt(void)
{
<------>int err = register_filesystem(&bm_fs_type);
<------>if (!err)
<------><------>insert_binfmt(&misc_format);
<------>return err;
}
 
static void __exit exit_misc_binfmt(void)
{
<------>unregister_binfmt(&misc_format);
<------>unregister_filesystem(&bm_fs_type);
}
 
core_initcall(init_misc_binfmt);
module_exit(exit_misc_binfmt);
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);