[PATCH] reduce stack in wireless/airo.c

From: Randy.Dunlap (randy.dunlap@verizon.net)
Date: Sat Mar 22 2003 - 01:51:37 EST


Hi,

This reduces stack usage in drivers/net/wireless/airo.c by
dynamically allocating 2KB buffers in 2 places.

Patch is to 2.5.65. Please apply.

~Randy

patch_name: airo-stack.patch
patch_version: 2003-03-21.22:14:20
author: Randy.Dunlap <rddunlap@osdl.org>
description: reduce stack usage in drivers/net/wireless/airo::
                readrids() and writerids();
product: Linux
product_versions: 2.5.65
changelog: kmalloc() 2 KB buffers instead of declaring them on stack;
maintainer: Jean Tourrilhes <jt@hpl.hp.com>
diffstat: =
 drivers/net/wireless/airo.c | 80 ++++++++++++++++++++++++++++----------------
 1 files changed, 52 insertions(+), 28 deletions(-)

diff -Naur ./drivers/net/wireless/airo.c%RIDS ./drivers/net/wireless/airo.c
--- ./drivers/net/wireless/airo.c%RIDS Mon Mar 17 13:43:40 2003
+++ ./drivers/net/wireless/airo.c Fri Mar 21 22:14:01 2003
@@ -5894,6 +5894,7 @@
 #endif /* WIRELESS_EXT */
 
 #ifdef CISCO_EXT
+#define RIDS_SIZE 2048
 /*
  * This just translates from driver IOCTL codes to the command codes to
  * feed to the radio's host interface. Things can be added/deleted
@@ -5902,11 +5903,15 @@
  */
 static int readrids(struct net_device *dev, aironet_ioctl *comp) {
         unsigned short ridcode;
- unsigned char iobuf[2048];
+ unsigned char *iobuf;
         struct airo_info *ai = dev->priv;
+ int ret = 0;
 
         if (ai->flags & FLAG_FLASHING)
                 return -EIO;
+ iobuf = kmalloc(RIDS_SIZE, GFP_KERNEL);
+ if (!iobuf)
+ return -ENOMEM;
 
         switch(comp->command)
         {
@@ -5919,13 +5924,17 @@
         case AIROGEHTENC: ridcode = RID_ETHERENCAP; break;
         case AIROGWEPKTMP: ridcode = RID_WEP_TEMP;
                 /* Only super-user can read WEP keys */
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
+ if (!capable(CAP_NET_ADMIN)) {
+ ret = -EPERM;
+ goto rr_free;
+ }
                 break;
         case AIROGWEPKNV: ridcode = RID_WEP_PERM;
                 /* Only super-user can read WEP keys */
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
+ if (!capable(CAP_NET_ADMIN)) {
+ ret = -EPERM;
+ goto rr_free;
+ }
                 break;
         case AIROGSTAT: ridcode = RID_STATUS; break;
         case AIROGSTATSD32: ridcode = RID_STATSDELTA; break;
@@ -5933,23 +5942,25 @@
         case AIROGMICSTATS:
                 if (copy_to_user(comp->data, &ai->micstats,
                                  min((int)comp->len,(int)sizeof(ai->micstats))))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ goto rr_free;
         default:
- return -EINVAL;
- break;
+ ret = -EINVAL;
+ goto rr_free;
         }
 
- PC4500_readrid(ai,ridcode,iobuf,sizeof(iobuf));
+ PC4500_readrid(ai,ridcode,iobuf,RIDS_SIZE);
         /* get the count of bytes in the rid docs say 1st 2 bytes is it.
          * then return it to the user
          * 9/22/2000 Honor user given length
          */
 
         if (copy_to_user(comp->data, iobuf,
- min((int)comp->len, (int)sizeof(iobuf))))
- return -EFAULT;
- return 0;
+ min((int)comp->len, (int)RIDS_SIZE)))
+ ret = -EFAULT;
+rr_free:
+ kfree(iobuf);
+ return ret;
 }
 
 /*
@@ -5961,7 +5972,8 @@
         int ridcode, enabled;
         Resp rsp;
         static int (* writer)(struct airo_info *, u16 rid, const void *, int);
- unsigned char iobuf[2048];
+ unsigned char *iobuf;
+ int ret = 0;
 
         /* Only super-user can write RIDs */
         if (!capable(CAP_NET_ADMIN))
@@ -5970,6 +5982,10 @@
         if (ai->flags & FLAG_FLASHING)
                 return -EIO;
 
+ iobuf = kmalloc(RIDS_SIZE, GFP_KERNEL);
+ if (!iobuf)
+ return -ENOMEM;
+
         ridcode = 0;
         writer = do_writerid;
 
@@ -5991,8 +6007,8 @@
                  */
         case AIROPMACON:
                 if (enable_MAC(ai, &rsp) != 0)
- return -EIO;
- return 0;
+ ret = -EIO;
+ goto wr_free;
 
                 /*
                  * Evidently this code in the airo driver does not get a symbol
@@ -6000,32 +6016,38 @@
                  */
         case AIROPMACOFF:
                 disable_MAC(ai);
- return 0;
+ goto wr_free;
 
                 /* This command merely clears the counts does not actually store any data
                  * only reads rid. But as it changes the cards state, I put it in the
                  * writerid routines.
                  */
         case AIROPSTCLR:
- PC4500_readrid(ai,RID_STATSDELTACLEAR,iobuf,sizeof(iobuf));
+ PC4500_readrid(ai,RID_STATSDELTACLEAR,iobuf,RIDS_SIZE);
 
                 enabled = ai->micstats.enabled;
                 memset(&ai->micstats,0,sizeof(ai->micstats));
                 ai->micstats.enabled = enabled;
 
                 if (copy_to_user(comp->data, iobuf,
- min((int)comp->len, (int)sizeof(iobuf))))
- return -EFAULT;
- return 0;
+ min((int)comp->len, (int)RIDS_SIZE)))
+ ret = -EFAULT;
+ goto wr_free;
 
         default:
- return -EOPNOTSUPP; /* Blarg! */
+ ret = -EOPNOTSUPP; /* Blarg! */
+ goto wr_free;
+ }
+
+ if (comp->len > RIDS_SIZE) {
+ ret = -EINVAL;
+ goto wr_free;
         }
- if(comp->len > sizeof(iobuf))
- return -EINVAL;
 
- if (copy_from_user(iobuf,comp->data,comp->len))
- return -EFAULT;
+ if (copy_from_user(iobuf,comp->data,comp->len)) {
+ ret = -EFAULT;
+ goto wr_free;
+ }
 
         if (comp->command == AIROPCFG) {
                 ConfigRid *cfg = (ConfigRid *)iobuf;
@@ -6040,8 +6062,10 @@
         }
 
         if((*writer)(ai, ridcode, iobuf,comp->len))
- return -EIO;
- return 0;
+ ret = -EIO;
+wr_free:
+ kfree(iobuf);
+ return ret;
 }
 
 /*****************************************************************************

-
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This archive was generated by hypermail 2b29 : Sun Mar 23 2003 - 22:00:40 EST