intel: i40e: fix confused code

This code is pretty confused. The variable name 'bytes_not_copied'
clearly indicates that the programmer knew the semantics of
copy_{to,from}_user, but then the return value is checked for being
negative and used as a -Exxx return value.

I'm not sure this is the proper fix, but at least we get rid of the
dead code which pretended to check for access faults.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
index d4b7af9..d1a91c8 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
@@ -103,8 +103,8 @@ static ssize_t i40e_dbg_dump_read(struct file *filp, char __user *buffer,
        len = min_t(int, count, (i40e_dbg_dump_data_len - *ppos));
 
        bytes_not_copied = copy_to_user(buffer, &i40e_dbg_dump_buf[*ppos], len);
-       if (bytes_not_copied < 0)
-               return bytes_not_copied;
+       if (bytes_not_copied)
+               return -EFAULT;
 
        *ppos += len;
        return len;
@@ -353,8 +353,8 @@ static ssize_t i40e_dbg_command_read(struct file *filp, char __user *buffer,
        bytes_not_copied = copy_to_user(buffer, buf, len);
        kfree(buf);
 
-       if (bytes_not_copied < 0)
-               return bytes_not_copied;
+       if (bytes_not_copied)
+               return -EFAULT;
 
        *ppos = len;
        return len;
@@ -981,12 +981,10 @@ static ssize_t i40e_dbg_command_write(struct file *filp,
        if (!cmd_buf)
                return count;
        bytes_not_copied = copy_from_user(cmd_buf, buffer, count);
-       if (bytes_not_copied < 0) {
+       if (bytes_not_copied) {
                kfree(cmd_buf);
-               return bytes_not_copied;
+               return -EFAULT;
        }
-       if (bytes_not_copied > 0)
-               count -= bytes_not_copied;
        cmd_buf[count] = '\0';
 
        cmd_buf_tmp = strchr(cmd_buf, '\n');
@@ -2034,8 +2032,8 @@ static ssize_t i40e_dbg_netdev_ops_read(struct file *filp, char __user *buffer,
        bytes_not_copied = copy_to_user(buffer, buf, len);
        kfree(buf);
 
-       if (bytes_not_copied < 0)
-               return bytes_not_copied;
+       if (bytes_not_copied)
+               return -EFAULT;
 
        *ppos = len;
        return len;
@@ -2068,10 +2066,8 @@ static ssize_t i40e_dbg_netdev_ops_write(struct file *filp,
        memset(i40e_dbg_netdev_ops_buf, 0, sizeof(i40e_dbg_netdev_ops_buf));
        bytes_not_copied = copy_from_user(i40e_dbg_netdev_ops_buf,
                                          buffer, count);
-       if (bytes_not_copied < 0)
-               return bytes_not_copied;
-       else if (bytes_not_copied > 0)
-               count -= bytes_not_copied;
+       if (bytes_not_copied)
+               return -EFAULT;
        i40e_dbg_netdev_ops_buf[count] = '\0';
 
        buf_tmp = strchr(i40e_dbg_netdev_ops_buf, '\n');