[34-longterm 025/260] ext4: Fix compat EXT4_IOC_ADD_GROUP

Paul Gortmaker
2011-01-02T07:21:59Z

From: Ben Hutchings <ben@decadent.org.uk>

commit 4d92dc0f00a775dc2e1267b0e00befb783902fe7 upstream.

struct ext4_new_group_input needs to be converted because u64 has
only 32-bit alignment on some 32-bit architectures, notably i386.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
fs/ext4/ext4.h | 16 ++++++++++++++++
fs/ext4/ioctl.c | 25 +++++++++++++++++++++++--
2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0419018..2e31640 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -29,6 +29,9 @@
#include <linux/wait.h>
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
+#ifdef __KERNEL__
+#include <linux/compat.h>
+#endif

/*
* The fourth extended filesystem constants/structures
@@ -409,6 +412,18 @@ struct ext4_new_group_input {
__u16 unused;
};

+#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
+struct compat_ext4_new_group_input {
+ u32 group;
+ compat_u64 block_bitmap;
+ compat_u64 inode_bitmap;
+ compat_u64 inode_table;
+ u32 blocks_count;
+ u16 reserved_blocks;
+ u16 unused;
+};
+#endif
+
/* The struct ext4_new_group_input in kernel space, with free_blocks_count */
struct ext4_new_group_data {
__u32 group;
@@ -486,6 +501,7 @@ struct ext4_new_group_data {
#define EXT4_IOC32_GETRSVSZ _IOR('f', 5, int)
#define EXT4_IOC32_SETRSVSZ _IOW('f', 6, int)
#define EXT4_IOC32_GROUP_EXTEND _IOW('f', 7, unsigned int)
+#define EXT4_IOC32_GROUP_ADD _IOW('f', 8, struct compat_ext4_new_group_input)
#ifdef CONFIG_JBD2_DEBUG
#define EXT4_IOC32_WAIT_FOR_READONLY _IOR('f', 99, int)
#endif
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 66fa0b0..6ddec84 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -373,8 +373,29 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case EXT4_IOC32_SETRSVSZ:
cmd = EXT4_IOC_SETRSVSZ;
break;
- case EXT4_IOC_GROUP_ADD:
- break;
+ case EXT4_IOC32_GROUP_ADD: {
+ struct compat_ext4_new_group_input __user *uinput;
+ struct ext4_new_group_input input;
+ mm_segment_t old_fs;
+ int err;
+
+ uinput = compat_ptr(arg);
+ err = get_user(input.group, &uinput->group);
+ err |= get_user(input.block_bitmap, &uinput->block_bitmap);
+ err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
+ err |= get_user(input.inode_table, &uinput->inode_table);
+ err |= get_user(input.blocks_count, &uinput->blocks_count);
+ err |= get_user(input.reserved_blocks,
+ &uinput->reserved_blocks);
+ if (err)
+ return -EFAULT;
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
+ (unsigned long) &input);
+ set_fs(old_fs);
+ return err;
+ }
case EXT4_IOC_MOVE_EXT:
break;
default:
--
1.7.3.3