[PATCH] Reduce stack usage in time.c

[Yum Rayan <yum.rayan@gmail.com>]

Attempt to reduce stack usage in time.c (linux-2.6.12-rc1-mm3). Stack
usage was noted using checkstack.pl. Specifically:

Before patch
------------
sys_adjtimex - 128

After patch
-----------
sys_adjtimex - none (register usage only)

Signed-off-by: Yum Rayan <yum.rayan@gmail.com>

--- a/kernel/time.c	2005-03-25 22:11:06.000000000 -0800
+++ b/kernel/time.c	2005-03-30 16:59:51.000000000 -0800
@@ -413,17 +413,27 @@
 
 asmlinkage long sys_adjtimex(struct timex __user *txc_p)
 {
-	struct timex txc;		/* Local copy of parameter */
-	int ret;
+	struct timex *txc;		/* Local copy of parameter */
+	int retval;
+
+	txc = kmalloc(sizeof(struct timex), GFP_KERNEL);
+	if (!txc)
+		return -ENOMEM;
 
 	/* Copy the user data space into the kernel copy
 	 * structure. But bear in mind that the structures
 	 * may change
 	 */
-	if(copy_from_user(&txc, txc_p, sizeof(struct timex)))
-		return -EFAULT;
-	ret = do_adjtimex(&txc);
-	return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
+	if(copy_from_user(txc, txc_p, sizeof(struct timex))) {
+		retval = -EFAULT;
+		goto free_txc;
+	}
+	retval = do_adjtimex(txc);
+	if (copy_to_user(txc_p, txc, sizeof(struct timex)))
+		retval = -EFAULT;
+free_txc:
+	kfree(txc);
+	return retval;
 }
 
 inline struct timespec current_kernel_time(void)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/