mtd: compat_ioctl cleanup

1) Move the MEMREADOOB/MEMWRITEOOB compat_ioctl wrappers from
fs/compat_ioctl.c into mtdchar.c .  Original request was here:

http://lkml.org/lkml/2009/4/1/295

2) Add missing COMPATIBLE_IOCTL lines, so that mtd-utils does not error
out when running in 64/32 compatibility mode.

LKML-Reference: <200904011650.22928.arnd@arndb.de>
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 171 insertions, 84 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index ad4b8618977d..51bb0b092003 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
 #include <linux/backing-dev.h>
+#include <linux/compat.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/compatmac.h>
@@ -355,6 +356,100 @@ static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 #endif
 
+static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
+        uint64_t start, uint32_t length, void __user *ptr,
+        uint32_t __user *retp)
+{
+        struct mtd_oob_ops ops;
+        uint32_t retlen;
+        int ret = 0;
+
+        if (!(file->f_mode & FMODE_WRITE))
+                return -EPERM;
+
+        if (length > 4096)
+                return -EINVAL;
+
+        if (!mtd->write_oob)
+                ret = -EOPNOTSUPP;
+        else
+                ret = access_ok(VERIFY_READ, ptr, length) ? 0 : EFAULT;
+
+        if (ret)
+                return ret;
+
+        ops.ooblen = length;
+        ops.ooboffs = start & (mtd->oobsize - 1);
+        ops.datbuf = NULL;
+        ops.mode = MTD_OOB_PLACE;
+
+        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
+                return -EINVAL;
+
+        ops.oobbuf = kmalloc(length, GFP_KERNEL);
+        if (!ops.oobbuf)
+                return -ENOMEM;
+
+        if (copy_from_user(ops.oobbuf, ptr, length)) {
+                kfree(ops.oobbuf);
+                return -EFAULT;
+        }
+
+        start &= ~((uint64_t)mtd->oobsize - 1);
+        ret = mtd->write_oob(mtd, start, &ops);
+
+        if (ops.oobretlen > 0xFFFFFFFFU)
+                ret = -EOVERFLOW;
+        retlen = ops.oobretlen;
+        if (copy_to_user(retp, &retlen, sizeof(length)))
+                ret = -EFAULT;
+
+        kfree(ops.oobbuf);
+        return ret;
+}
+
+static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
+        uint32_t length, void __user *ptr, uint32_t __user *retp)
+{
+        struct mtd_oob_ops ops;
+        int ret = 0;
+
+        if (length > 4096)
+                return -EINVAL;
+
+        if (!mtd->read_oob)
+                ret = -EOPNOTSUPP;
+        else
+                ret = access_ok(VERIFY_WRITE, ptr,
+                                length) ? 0 : -EFAULT;
+        if (ret)
+                return ret;
+
+        ops.ooblen = length;
+        ops.ooboffs = start & (mtd->oobsize - 1);
+        ops.datbuf = NULL;
+        ops.mode = MTD_OOB_PLACE;
+
+        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
+                return -EINVAL;
+
+        ops.oobbuf = kmalloc(length, GFP_KERNEL);
+        if (!ops.oobbuf)
+                return -ENOMEM;
+
+        start &= ~((uint64_t)mtd->oobsize - 1);
+        ret = mtd->read_oob(mtd, start, &ops);
+
+        if (put_user(ops.oobretlen, retp))
+                ret = -EFAULT;
+        else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
+                                            ops.oobretlen))
+                ret = -EFAULT;
+
+        kfree(ops.oobbuf);
+        return ret;
+}
+
 static int mtd_ioctl(struct inode *inode, struct file *file,
                      u_int cmd, u_long arg)
 {
@@ -487,100 +582,28 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
         case MEMWRITEOOB:
         {
                 struct mtd_oob_buf buf;
-                struct mtd_oob_ops ops;
-                struct mtd_oob_buf __user *user_buf = argp;
-                uint32_t retlen;
-
-                if(!(file->f_mode & FMODE_WRITE))
-                        return -EPERM;
-
-                if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
-                        return -EFAULT;
-
-                if (buf.length > 4096)
-                        return -EINVAL;
-
-                if (!mtd->write_oob)
-                        ret = -EOPNOTSUPP;
-                else
-                        ret = access_ok(VERIFY_READ, buf.ptr,
-                                        buf.length) ? 0 : EFAULT;
-
-                if (ret)
-                        return ret;
-
-                ops.ooblen = buf.length;
-                ops.ooboffs = buf.start & (mtd->oobsize - 1);
-                ops.datbuf = NULL;
-                ops.mode = MTD_OOB_PLACE;
-
-                if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
-                        return -EINVAL;
-
-                ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
-                if (!ops.oobbuf)
-                        return -ENOMEM;
-
-                if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
-                        kfree(ops.oobbuf);
-                        return -EFAULT;
-                }
-
-                buf.start &= ~(mtd->oobsize - 1);
-                ret = mtd->write_oob(mtd, buf.start, &ops);
+                struct mtd_oob_buf __user *buf_user = argp;
 
-                if (ops.oobretlen > 0xFFFFFFFFU)
-                        ret = -EOVERFLOW;
-                retlen = ops.oobretlen;
-                if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
+                /* NOTE: writes return length to buf_user->length */
+                if (copy_from_user(&buf, argp, sizeof(buf)))
                         ret = -EFAULT;
-
-                kfree(ops.oobbuf);
+                else
+                        ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
+                                buf.ptr, &buf_user->length);
                 break;
-
         }
 
         case MEMREADOOB:
         {
                 struct mtd_oob_buf buf;
-                struct mtd_oob_ops ops;
-
-                if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
-                        return -EFAULT;
-
-                if (buf.length > 4096)
-                        return -EINVAL;
-
-                if (!mtd->read_oob)
-                        ret = -EOPNOTSUPP;
-                else
-                        ret = access_ok(VERIFY_WRITE, buf.ptr,
-                                        buf.length) ? 0 : -EFAULT;
-                if (ret)
-                        return ret;
-
-                ops.ooblen = buf.length;
-                ops.ooboffs = buf.start & (mtd->oobsize - 1);
-                ops.datbuf = NULL;
-                ops.mode = MTD_OOB_PLACE;
+                struct mtd_oob_buf __user *buf_user = argp;
 
-                if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
-                        return -EINVAL;
-
-                ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
-                if (!ops.oobbuf)
-                        return -ENOMEM;
-
-                buf.start &= ~(mtd->oobsize - 1);
-                ret = mtd->read_oob(mtd, buf.start, &ops);
-
-                if (put_user(ops.oobretlen, (uint32_t __user *)argp))
-                        ret = -EFAULT;
-                else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
-                                                    ops.oobretlen))
+                /* NOTE: writes return length to buf_user->start */
+                if (copy_from_user(&buf, argp, sizeof(buf)))
                         ret = -EFAULT;
-
-                kfree(ops.oobbuf);
+                else
+                        ret = mtd_do_readoob(mtd, buf.start, buf.length,
+                                buf.ptr, &buf_user->start);
                 break;
         }
 
@@ -771,6 +794,67 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
         return ret;
 } /* memory_ioctl */
 
+#ifdef CONFIG_COMPAT
+
+struct mtd_oob_buf32 {
+        u_int32_t start;
+        u_int32_t length;
+        compat_caddr_t ptr;     /* unsigned char* */
+};
+
+#define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
+#define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
+
+static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
+        unsigned long arg)
+{
+        struct mtd_file_info *mfi = file->private_data;
+        struct mtd_info *mtd = mfi->mtd;
+        void __user *argp = (void __user *)arg;
+        int ret = 0;
+
+        lock_kernel();
+
+        switch (cmd) {
+        case MEMWRITEOOB32:
+        {
+                struct mtd_oob_buf32 buf;
+                struct mtd_oob_buf32 __user *buf_user = argp;
+
+                if (copy_from_user(&buf, argp, sizeof(buf)))
+                        ret = -EFAULT;
+                else
+                        ret = mtd_do_writeoob(file, mtd, buf.start,
+                                buf.length, compat_ptr(buf.ptr),
+                                &buf_user->length);
+                break;
+        }
+
+        case MEMREADOOB32:
+        {
+                struct mtd_oob_buf32 buf;
+                struct mtd_oob_buf32 __user *buf_user = argp;
+
+                /* NOTE: writes return length to buf->start */
+                if (copy_from_user(&buf, argp, sizeof(buf)))
+                        ret = -EFAULT;
+                else
+                        ret = mtd_do_readoob(mtd, buf.start,
+                                buf.length, compat_ptr(buf.ptr),
+                                &buf_user->start);
+                break;
+        }
+        default:
+                ret = -ENOIOCTLCMD;
+        }
+
+        unlock_kernel();
+
+        return ret;
+}
+
+#endif /* CONFIG_COMPAT */
+
 /*
  * try to determine where a shared mapping can be made
  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
@@ -830,6 +914,9 @@ static const struct file_operations mtd_fops = {
         .read           = mtd_read,
         .write          = mtd_write,
         .ioctl          = mtd_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl   = mtd_compat_ioctl,
+#endif
         .open           = mtd_open,
         .release        = mtd_close,
         .mmap           = mtd_mmap,