From d4f0e4daf0d867f80c78ca4f9ac03a562e229e72 Mon Sep 17 00:00:00 2001
From: Havard Skinnemoen <hskinnemoen@google.com>
Date: Thu, 26 Apr 2012 11:16:00 -0700
Subject: HID: hiddev: Use vzalloc to allocate hiddev_list

Everytime a HID device is opened, a new hiddev_list is allocated with
kzalloc. This requires 64KB of physically contiguous memory, which could
easily push a heavily loaded system over the edge.

Allocating the same amount of memory with vmalloc shouldn't be nearly as
demanding, so let's do that instead. The memory isn't used for DMA and
doesn't look particularly performance sensitive, so this should be safe.

Signed-off-by: Havard Skinnemoen <hskinnemoen@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index b1ec0e2..14599e2 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -34,6 +34,7 @@
 #include <linux/hid.h>
 #include <linux/hiddev.h>
 #include <linux/compat.h>
+#include <linux/vmalloc.h>
 #include "usbhid.h"
 
 #ifdef CONFIG_USB_DYNAMIC_MINORS
@@ -250,13 +251,13 @@ static int hiddev_release(struct inode * inode, struct file * file)
 		} else {
 			mutex_unlock(&list->hiddev->existancelock);
 			kfree(list->hiddev);
-			kfree(list);
+			vfree(list);
 			return 0;
 		}
 	}
 
 	mutex_unlock(&list->hiddev->existancelock);
-	kfree(list);
+	vfree(list);
 
 	return 0;
 }
@@ -278,7 +279,7 @@ static int hiddev_open(struct inode *inode, struct file *file)
 	hid = usb_get_intfdata(intf);
 	hiddev = hid->hiddev;
 
-	if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
+	if (!(list = vzalloc(sizeof(struct hiddev_list))))
 		return -ENOMEM;
 	mutex_init(&list->thread_lock);
 	list->hiddev = hiddev;
@@ -322,7 +323,7 @@ bail_unlock:
 	mutex_unlock(&hiddev->existancelock);
 bail:
 	file->private_data = NULL;
-	kfree(list);
+	vfree(list);
 	return res;
 }
 
-- 
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