mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
406 lines
9.7 KiB
406 lines
9.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
#include <linux/syscalls.h> |
|
#include <linux/export.h> |
|
#include <linux/fs.h> |
|
#include <linux/file.h> |
|
#include <linux/mount.h> |
|
#include <linux/namei.h> |
|
#include <linux/statfs.h> |
|
#include <linux/security.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/compat.h> |
|
#include "internal.h" |
|
|
|
static int flags_by_mnt(int mnt_flags) |
|
{ |
|
int flags = 0; |
|
|
|
if (mnt_flags & MNT_READONLY) |
|
flags |= ST_RDONLY; |
|
if (mnt_flags & MNT_NOSUID) |
|
flags |= ST_NOSUID; |
|
if (mnt_flags & MNT_NODEV) |
|
flags |= ST_NODEV; |
|
if (mnt_flags & MNT_NOEXEC) |
|
flags |= ST_NOEXEC; |
|
if (mnt_flags & MNT_NOATIME) |
|
flags |= ST_NOATIME; |
|
if (mnt_flags & MNT_NODIRATIME) |
|
flags |= ST_NODIRATIME; |
|
if (mnt_flags & MNT_RELATIME) |
|
flags |= ST_RELATIME; |
|
if (mnt_flags & MNT_NOSYMFOLLOW) |
|
flags |= ST_NOSYMFOLLOW; |
|
return flags; |
|
} |
|
|
|
static int flags_by_sb(int s_flags) |
|
{ |
|
int flags = 0; |
|
if (s_flags & SB_SYNCHRONOUS) |
|
flags |= ST_SYNCHRONOUS; |
|
if (s_flags & SB_MANDLOCK) |
|
flags |= ST_MANDLOCK; |
|
if (s_flags & SB_RDONLY) |
|
flags |= ST_RDONLY; |
|
return flags; |
|
} |
|
|
|
static int calculate_f_flags(struct vfsmount *mnt) |
|
{ |
|
return ST_VALID | flags_by_mnt(mnt->mnt_flags) | |
|
flags_by_sb(mnt->mnt_sb->s_flags); |
|
} |
|
|
|
static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf) |
|
{ |
|
int retval; |
|
|
|
if (!dentry->d_sb->s_op->statfs) |
|
return -ENOSYS; |
|
|
|
memset(buf, 0, sizeof(*buf)); |
|
retval = security_sb_statfs(dentry); |
|
if (retval) |
|
return retval; |
|
retval = dentry->d_sb->s_op->statfs(dentry, buf); |
|
if (retval == 0 && buf->f_frsize == 0) |
|
buf->f_frsize = buf->f_bsize; |
|
return retval; |
|
} |
|
|
|
int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid) |
|
{ |
|
struct kstatfs st; |
|
int error; |
|
|
|
error = statfs_by_dentry(dentry, &st); |
|
if (error) |
|
return error; |
|
|
|
*fsid = st.f_fsid; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(vfs_get_fsid); |
|
|
|
int vfs_statfs(const struct path *path, struct kstatfs *buf) |
|
{ |
|
int error; |
|
|
|
error = statfs_by_dentry(path->dentry, buf); |
|
if (!error) |
|
buf->f_flags = calculate_f_flags(path->mnt); |
|
return error; |
|
} |
|
EXPORT_SYMBOL(vfs_statfs); |
|
|
|
int user_statfs(const char __user *pathname, struct kstatfs *st) |
|
{ |
|
struct path path; |
|
int error; |
|
unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT; |
|
retry: |
|
error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
|
if (!error) { |
|
error = vfs_statfs(&path, st); |
|
path_put(&path); |
|
if (retry_estale(error, lookup_flags)) { |
|
lookup_flags |= LOOKUP_REVAL; |
|
goto retry; |
|
} |
|
} |
|
return error; |
|
} |
|
|
|
int fd_statfs(int fd, struct kstatfs *st) |
|
{ |
|
struct fd f = fdget_raw(fd); |
|
int error = -EBADF; |
|
if (f.file) { |
|
error = vfs_statfs(&f.file->f_path, st); |
|
fdput(f); |
|
} |
|
return error; |
|
} |
|
|
|
static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) |
|
{ |
|
struct statfs buf; |
|
|
|
if (sizeof(buf) == sizeof(*st)) |
|
memcpy(&buf, st, sizeof(*st)); |
|
else { |
|
if (sizeof buf.f_blocks == 4) { |
|
if ((st->f_blocks | st->f_bfree | st->f_bavail | |
|
st->f_bsize | st->f_frsize) & |
|
0xffffffff00000000ULL) |
|
return -EOVERFLOW; |
|
/* |
|
* f_files and f_ffree may be -1; it's okay to stuff |
|
* that into 32 bits |
|
*/ |
|
if (st->f_files != -1 && |
|
(st->f_files & 0xffffffff00000000ULL)) |
|
return -EOVERFLOW; |
|
if (st->f_ffree != -1 && |
|
(st->f_ffree & 0xffffffff00000000ULL)) |
|
return -EOVERFLOW; |
|
} |
|
|
|
buf.f_type = st->f_type; |
|
buf.f_bsize = st->f_bsize; |
|
buf.f_blocks = st->f_blocks; |
|
buf.f_bfree = st->f_bfree; |
|
buf.f_bavail = st->f_bavail; |
|
buf.f_files = st->f_files; |
|
buf.f_ffree = st->f_ffree; |
|
buf.f_fsid = st->f_fsid; |
|
buf.f_namelen = st->f_namelen; |
|
buf.f_frsize = st->f_frsize; |
|
buf.f_flags = st->f_flags; |
|
memset(buf.f_spare, 0, sizeof(buf.f_spare)); |
|
} |
|
if (copy_to_user(p, &buf, sizeof(buf))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) |
|
{ |
|
struct statfs64 buf; |
|
if (sizeof(buf) == sizeof(*st)) |
|
memcpy(&buf, st, sizeof(*st)); |
|
else { |
|
buf.f_type = st->f_type; |
|
buf.f_bsize = st->f_bsize; |
|
buf.f_blocks = st->f_blocks; |
|
buf.f_bfree = st->f_bfree; |
|
buf.f_bavail = st->f_bavail; |
|
buf.f_files = st->f_files; |
|
buf.f_ffree = st->f_ffree; |
|
buf.f_fsid = st->f_fsid; |
|
buf.f_namelen = st->f_namelen; |
|
buf.f_frsize = st->f_frsize; |
|
buf.f_flags = st->f_flags; |
|
memset(buf.f_spare, 0, sizeof(buf.f_spare)); |
|
} |
|
if (copy_to_user(p, &buf, sizeof(buf))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) |
|
{ |
|
struct kstatfs st; |
|
int error = user_statfs(pathname, &st); |
|
if (!error) |
|
error = do_statfs_native(&st, buf); |
|
return error; |
|
} |
|
|
|
SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) |
|
{ |
|
struct kstatfs st; |
|
int error; |
|
if (sz != sizeof(*buf)) |
|
return -EINVAL; |
|
error = user_statfs(pathname, &st); |
|
if (!error) |
|
error = do_statfs64(&st, buf); |
|
return error; |
|
} |
|
|
|
SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) |
|
{ |
|
struct kstatfs st; |
|
int error = fd_statfs(fd, &st); |
|
if (!error) |
|
error = do_statfs_native(&st, buf); |
|
return error; |
|
} |
|
|
|
SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) |
|
{ |
|
struct kstatfs st; |
|
int error; |
|
|
|
if (sz != sizeof(*buf)) |
|
return -EINVAL; |
|
|
|
error = fd_statfs(fd, &st); |
|
if (!error) |
|
error = do_statfs64(&st, buf); |
|
return error; |
|
} |
|
|
|
static int vfs_ustat(dev_t dev, struct kstatfs *sbuf) |
|
{ |
|
struct super_block *s = user_get_super(dev, false); |
|
int err; |
|
if (!s) |
|
return -EINVAL; |
|
|
|
err = statfs_by_dentry(s->s_root, sbuf); |
|
drop_super(s); |
|
return err; |
|
} |
|
|
|
SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf) |
|
{ |
|
struct ustat tmp; |
|
struct kstatfs sbuf; |
|
int err = vfs_ustat(new_decode_dev(dev), &sbuf); |
|
if (err) |
|
return err; |
|
|
|
memset(&tmp,0,sizeof(struct ustat)); |
|
tmp.f_tfree = sbuf.f_bfree; |
|
if (IS_ENABLED(CONFIG_ARCH_32BIT_USTAT_F_TINODE)) |
|
tmp.f_tinode = min_t(u64, sbuf.f_ffree, UINT_MAX); |
|
else |
|
tmp.f_tinode = sbuf.f_ffree; |
|
|
|
return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf) |
|
{ |
|
struct compat_statfs buf; |
|
if (sizeof ubuf->f_blocks == 4) { |
|
if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | |
|
kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) |
|
return -EOVERFLOW; |
|
/* f_files and f_ffree may be -1; it's okay |
|
* to stuff that into 32 bits */ |
|
if (kbuf->f_files != 0xffffffffffffffffULL |
|
&& (kbuf->f_files & 0xffffffff00000000ULL)) |
|
return -EOVERFLOW; |
|
if (kbuf->f_ffree != 0xffffffffffffffffULL |
|
&& (kbuf->f_ffree & 0xffffffff00000000ULL)) |
|
return -EOVERFLOW; |
|
} |
|
memset(&buf, 0, sizeof(struct compat_statfs)); |
|
buf.f_type = kbuf->f_type; |
|
buf.f_bsize = kbuf->f_bsize; |
|
buf.f_blocks = kbuf->f_blocks; |
|
buf.f_bfree = kbuf->f_bfree; |
|
buf.f_bavail = kbuf->f_bavail; |
|
buf.f_files = kbuf->f_files; |
|
buf.f_ffree = kbuf->f_ffree; |
|
buf.f_namelen = kbuf->f_namelen; |
|
buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; |
|
buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; |
|
buf.f_frsize = kbuf->f_frsize; |
|
buf.f_flags = kbuf->f_flags; |
|
if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
/* |
|
* The following statfs calls are copies of code from fs/statfs.c and |
|
* should be checked against those from time to time |
|
*/ |
|
COMPAT_SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct compat_statfs __user *, buf) |
|
{ |
|
struct kstatfs tmp; |
|
int error = user_statfs(pathname, &tmp); |
|
if (!error) |
|
error = put_compat_statfs(buf, &tmp); |
|
return error; |
|
} |
|
|
|
COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, buf) |
|
{ |
|
struct kstatfs tmp; |
|
int error = fd_statfs(fd, &tmp); |
|
if (!error) |
|
error = put_compat_statfs(buf, &tmp); |
|
return error; |
|
} |
|
|
|
static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) |
|
{ |
|
struct compat_statfs64 buf; |
|
|
|
if ((kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) |
|
return -EOVERFLOW; |
|
|
|
memset(&buf, 0, sizeof(struct compat_statfs64)); |
|
buf.f_type = kbuf->f_type; |
|
buf.f_bsize = kbuf->f_bsize; |
|
buf.f_blocks = kbuf->f_blocks; |
|
buf.f_bfree = kbuf->f_bfree; |
|
buf.f_bavail = kbuf->f_bavail; |
|
buf.f_files = kbuf->f_files; |
|
buf.f_ffree = kbuf->f_ffree; |
|
buf.f_namelen = kbuf->f_namelen; |
|
buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; |
|
buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; |
|
buf.f_frsize = kbuf->f_frsize; |
|
buf.f_flags = kbuf->f_flags; |
|
if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs64))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf) |
|
{ |
|
struct kstatfs tmp; |
|
int error; |
|
|
|
if (sz != sizeof(*buf)) |
|
return -EINVAL; |
|
|
|
error = user_statfs(pathname, &tmp); |
|
if (!error) |
|
error = put_compat_statfs64(buf, &tmp); |
|
return error; |
|
} |
|
|
|
COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) |
|
{ |
|
return kcompat_sys_statfs64(pathname, sz, buf); |
|
} |
|
|
|
int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf) |
|
{ |
|
struct kstatfs tmp; |
|
int error; |
|
|
|
if (sz != sizeof(*buf)) |
|
return -EINVAL; |
|
|
|
error = fd_statfs(fd, &tmp); |
|
if (!error) |
|
error = put_compat_statfs64(buf, &tmp); |
|
return error; |
|
} |
|
|
|
COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) |
|
{ |
|
return kcompat_sys_fstatfs64(fd, sz, buf); |
|
} |
|
|
|
/* |
|
* This is a copy of sys_ustat, just dealing with a structure layout. |
|
* Given how simple this syscall is that apporach is more maintainable |
|
* than the various conversion hacks. |
|
*/ |
|
COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u) |
|
{ |
|
struct compat_ustat tmp; |
|
struct kstatfs sbuf; |
|
int err = vfs_ustat(new_decode_dev(dev), &sbuf); |
|
if (err) |
|
return err; |
|
|
|
memset(&tmp, 0, sizeof(struct compat_ustat)); |
|
tmp.f_tfree = sbuf.f_bfree; |
|
tmp.f_tinode = sbuf.f_ffree; |
|
if (copy_to_user(u, &tmp, sizeof(struct compat_ustat))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
#endif
|
|
|