[PATCH] reduce stack in wanrouter/wanmain.c::device_new_if()

["Randy.Dunlap" <rddunlap@osdl.org>]

Hi,

This patch reduces stack usage in device_new_if() by almost 0x500 bytes
(on x86).

I didn't see an email address for Gideon Hack listed anywhere....

Comments on the patch?

Thanks,
--
~Randy


patch_name:	wan-stack.patch
patch_version:	2003-04-02.20:59:49
author:		Randy.Dunlap <rddunlap@osdl.org>
description:	reduce stack in net/wanrouter/wanmain.c::device_new_if()
		from 0x520 to 0x24;
product:	Linux
product_versions: 2.5.66
changelog:	allocate and free the <wanif_conf_t> data;
maintainer:	Gideon Hack (no email address listed)
diffstat:	=
 net/wanrouter/wanmain.c |   52 +++++++++++++++++++++++++++++++-----------------
 1 files changed, 34 insertions(+), 18 deletions(-)


diff -Naur ./net/wanrouter/wanmain.c%WANSTK ./net/wanrouter/wanmain.c
--- ./net/wanrouter/wanmain.c%WANSTK	2003-03-24 14:01:11.000000000 -0800
+++ ./net/wanrouter/wanmain.c	2003-04-02 20:49:58.000000000 -0800
@@ -660,7 +660,7 @@
 
 static int device_new_if (wan_device_t *wandev, wanif_conf_t *u_conf)
 {
-	wanif_conf_t conf;
+	wanif_conf_t *cnf;
 	netdevice_t *dev=NULL;
 #ifdef CONFIG_WANPIPE_MULTPPP
 	struct ppp_device *pppdev=NULL;
@@ -670,37 +670,51 @@
 	if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
 		return -ENODEV;
 
-	if (copy_from_user(&conf, u_conf, sizeof(wanif_conf_t)))
-		return -EFAULT;
+	cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
+	if (!cnf)
+		return -ENOBUFS;
+
+	if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t))) {
+		err = -EFAULT;
+		goto conffree;
+	}
 
-	if (conf.magic != ROUTER_MAGIC)
-		return -EINVAL;
+	if (cnf->magic != ROUTER_MAGIC) {
+		err = -EINVAL;
+		goto conffree;
+	}
 
-	if (conf.config_id == WANCONFIG_MPPP) {
+	if (cnf->config_id == WANCONFIG_MPPP) {
 #ifdef CONFIG_WANPIPE_MULTPPP
 		pppdev = kmalloc(sizeof(struct ppp_device), GFP_KERNEL);
-		if (pppdev == NULL)
-			return -ENOBUFS;
+		if (pppdev == NULL) {
+			err = -ENOBUFS;
+			goto conffree;
+		}
 		memset(pppdev, 0, sizeof(struct ppp_device));
 		pppdev->dev = kmalloc(sizeof(netdevice_t), GFP_KERNEL);
 		if (pppdev->dev == NULL) {
 			kfree(pppdev);
-			return -ENOBUFS;
+			err = -ENOBUFS;
+			goto conffree;
 		}
 		memset(pppdev->dev, 0, sizeof(netdevice_t));
-		err = wandev->new_if(wandev, (netdevice_t *)pppdev, &conf);
+		err = wandev->new_if(wandev, (netdevice_t *)pppdev, cnf);
 		dev = pppdev->dev;
 #else
 		printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 				wandev->name);
-		return -EPROTONOSUPPORT;
+		err = -EPROTONOSUPPORT;
+		goto conffree;
 #endif
 	} else {
 		dev = kmalloc(sizeof(netdevice_t), GFP_KERNEL);
-		if (dev == NULL)
-			return -ENOBUFS;
+		if (dev == NULL) {
+			err = -ENOBUFS;
+			goto conffree;
+		}
 		memset(dev, 0, sizeof(netdevice_t));
-		err = wandev->new_if(wandev, dev, &conf);
+		err = wandev->new_if(wandev, dev, cnf);
 	}
 
 	if (!err) {
@@ -739,7 +753,8 @@
 				++wandev->ndev;
 
 				unlock_adapter_irq(&wandev->lock, &smp_flags);
-				return 0;	/* done !!! */
+				err = 0;	/* done !!! */
+				goto conffree;
 			}
 		}
 		if (wandev->del_if)
@@ -752,18 +767,19 @@
 		dev->priv = NULL;
 	}
 
-
 #ifdef CONFIG_WANPIPE_MULTPPP
-	if (conf.config_id == WANCONFIG_MPPP)
+	if (cnf->config_id == WANCONFIG_MPPP)
 		kfree(pppdev);
 	else
 		kfree(dev);
 #else
 	/* Sync PPP is disabled */
-	if (conf.config_id != WANCONFIG_MPPP)
+	if (cnf->config_id != WANCONFIG_MPPP)
 		kfree(dev);
 #endif
 
+ conffree:
+	kfree(cnf);
 	return err;
 }
 
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