linux-kernel - [PATCH] lkdtm: reduce stack size

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Date:	Sun, 01 Mar 2009 21:00:14 +0100
From:	Frank Seidel <fseidel@...e.de>
To:	linux kernel <linux-kernel@...r.kernel.org>
Cc:	akpm@...ux-foundation.org, Ankita Garg <ankita@...ibm.com>,
	Adrian Bunk <bunk@...nel.org>,
	Randy Dunlap <randy.dunlap@...cle.com>,
	Frank Seidel <fseidel@...e.de>,
	Frank Seidel <frank@...eidel.de>, kernalert.de@...il.com
Subject: [PATCH] lkdtm: reduce stack size

From: Frank Seidel <frank@...eidel.de>

Reduce stack memory footprint of lkdtm
(recursive_loop). From 1024 bytes on i386 down
to <10.

Signed-off-by: Frank Seidel <frank@...eidel.de>
---
 drivers/misc/lkdtm.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -225,14 +225,24 @@ static int lkdtm_parse_commandline(void)
 
 static int recursive_loop(int a)
 {
-	char buf[1024];
+	char *buf;
+	int ret;
+
+	buf = kmalloc(1024, GFP_KERNEL);
+	if (!buf) {
+		printk(KERN_ERR "lkdtm : couldn't allocate buffer\n");
+		return -ENOMEM;
+	}
 
 	memset(buf,0xFF,1024);
 	recur_count--;
 	if (!recur_count)
-		return 0;
+		ret = 0;
 	else
-        	return recursive_loop(a);
+		ret = recursive_loop(a);
+
+	kfree(buf);
+	return ret;
 }
 
 void lkdtm_handler(void)
--
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