[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>

1 files changed, 18 insertions, 19 deletions

diff --git a/arch/powerpc/platforms/pseries/scanlog.c b/arch/powerpc/platforms/pseries/scanlog.c
index 8e1ef168e2dd..e5b0ea870164 100644
--- 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)