statfs: move compat syscalls from compat.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 140 insertions, 0 deletions

diff --git a/fs/statfs.c b/fs/statfs.c
index 13ae259d4879..4e4623c7a126 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -7,6 +7,7 @@
 #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)
@@ -239,3 +240,142 @@ SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
 
 	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)
+{
+	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;
+	}
+	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
+	    __put_user(kbuf->f_type, &ubuf->f_type) ||
+	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
+	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
+	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
+	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
+	    __put_user(kbuf->f_files, &ubuf->f_files) ||
+	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
+	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
+	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
+	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
+	    __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
+	    __put_user(kbuf->f_flags, &ubuf->f_flags) ||
+	    __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare)))
+		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)
+{
+	if (sizeof(ubuf->f_bsize) == 4) {
+		if ((kbuf->f_type | kbuf->f_bsize | kbuf->f_namelen |
+		     kbuf->f_frsize | kbuf->f_flags) & 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;
+	}
+	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
+	    __put_user(kbuf->f_type, &ubuf->f_type) ||
+	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
+	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
+	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
+	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
+	    __put_user(kbuf->f_files, &ubuf->f_files) ||
+	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
+	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
+	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
+	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
+	    __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
+	    __put_user(kbuf->f_flags, &ubuf->f_flags) ||
+	    __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare)))
+		return -EFAULT;
+	return 0;
+}
+
+COMPAT_SYSCALL_DEFINE3(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(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;
+}
+
+/*
+ * 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