drivers/net/wireless/iwlwifi: introduce missing kfree

Move orthogonal error handling code up before a kzalloc, so that it
doesn't have to free the allocated data.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 11e08c0..ca00cc8 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -308,18 +308,18 @@ static ssize_t iwl_dbgfs_nvm_read(struct file *file,
                return -ENODATA;
        }
 
+       ptr = priv->eeprom;
+       if (!ptr) {
+               IWL_ERR(priv, "Invalid EEPROM/OTP memory\n");
+               return -ENOMEM;
+       }
+
        /* 4 characters for byte 0xYY */
        buf = kzalloc(buf_size, GFP_KERNEL);
        if (!buf) {
                IWL_ERR(priv, "Can not allocate Buffer\n");
                return -ENOMEM;
        }
-
-       ptr = priv->eeprom;
-       if (!ptr) {
-               IWL_ERR(priv, "Invalid EEPROM/OTP memory\n");
-               return -ENOMEM;
-       }
        pos += scnprintf(buf + pos, buf_size - pos, "NVM Type: %s\n",
                        (priv->nvm_device_type == NVM_DEVICE_TYPE_OTP)
                        ? "OTP" : "EEPROM");