[POWERPC] scanlog_init cleanup and minor fixes

scanlog_init() could use some love.

* properly return -ENODEV if this system doesn't support scan-log-dump
* don't printk if scan-log-dump not present; only older systems have it
* convert from create_proc_entry() to preferred proc_create()
* allocate zeroed data buffer
* fix potential memory leak of ent->data on failed create_proc_entry()
* simplify control flow

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/pseries/scanlog.c b/arch/powerpc/platforms/pseries/scanlog.c
index 8e1ef168e2ddfd67c111b0059e994f640ef17b57..e5b0ea87016495743f6dac0856da16d277a8fc03 100644 (file)
--- a/arch/powerpc/platforms/pseries/scanlog.c
+++ b/arch/powerpc/platforms/pseries/scanlog.c
@@ -195,31 +195,30 @@ const struct file_operations scanlog_fops = {
 static int __init scanlog_init(void)
 {
        struct proc_dir_entry *ent;
+       void *data;
+       int err = -ENOMEM;
 
        ibm_scan_log_dump = rtas_token("ibm,scan-log-dump");
-       if (ibm_scan_log_dump == RTAS_UNKNOWN_SERVICE) {
-               printk(KERN_ERR "scan-log-dump not implemented on this system\n");
-               return -EIO;
-       }
+       if (ibm_scan_log_dump == RTAS_UNKNOWN_SERVICE)
+               return -ENODEV;
 
-        ent = create_proc_entry("ppc64/rtas/scan-log-dump",  S_IRUSR, NULL);
-       if (ent) {
-               ent->proc_fops = &scanlog_fops;
-               /* Ideally we could allocate a buffer < 4G */
-               ent->data = kmalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
-               if (!ent->data) {
-                       printk(KERN_ERR "Failed to allocate a buffer\n");
-                       remove_proc_entry("scan-log-dump", ent->parent);
-                       return -ENOMEM;
-               }
-               ((unsigned int *)ent->data)[0] = 0;
-       } else {
-               printk(KERN_ERR "Failed to create ppc64/scan-log-dump proc entry\n");
-               return -EIO;
-       }
+       /* Ideally we could allocate a buffer < 4G */
+       data = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
+       if (!data)
+               goto err;
+
+       ent = proc_create("ppc64/rtas/scan-log-dump", S_IRUSR, NULL,
+                         &scanlog_fops);
+       if (!ent)
+               goto err;
+
+       ent->data = data;
        proc_ppc64_scan_log_dump = ent;
 
        return 0;
+err:
+       kfree(data);
+       return err;
 }
 
 static void __exit scanlog_cleanup(void)