From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Wed, 9 May 2007 09:33:33 +0000 (-0700)
Subject: use simple_read_from_buffer in kernel/
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fstable%2Flinux-2.6.20.y.git;a=commitdiff_plain;h=85badbdf5120d246ce2bb3f1a7689a805f9c9006

use simple_read_from_buffer in kernel/

Cleanup using simple_read_from_buffer() for /dev/cpuset/tasks and
/proc/config.gz.

Cc: Paul Jackson <pj@sgi.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

Backported to Debian's 2.6.18 by dann frazier <dannf@debian.org>

diff -urpN linux-source-2.6.18.orig/kernel/configs.c linux-source-2.6.18/kernel/configs.c
--- linux-source-2.6.18.orig/kernel/configs.c	2006-09-19 21:42:06.000000000 -0600
+++ linux-source-2.6.18/kernel/configs.c	2007-08-27 22:30:10.774211736 -0600
@@ -61,18 +61,9 @@ static ssize_t
 ikconfig_read_current(struct file *file, char __user *buf,
 		      size_t len, loff_t * offset)
 {
-	loff_t pos = *offset;
-	ssize_t count;
-
-	if (pos >= kernel_config_data_size)
-		return 0;
-
-	count = min(len, (size_t)(kernel_config_data_size - pos));
-	if (copy_to_user(buf, kernel_config_data + MAGIC_SIZE + pos, count))
-		return -EFAULT;
-
-	*offset += count;
-	return count;
+	return simple_read_from_buffer(buf, len, offset,
+				       kernel_config_data + MAGIC_SIZE,
+				       kernel_config_data_size);
 }
 
 static struct file_operations ikconfig_file_ops = {
diff -urpN linux-source-2.6.18.orig/kernel/cpuset.c linux-source-2.6.18/kernel/cpuset.c
--- linux-source-2.6.18.orig/kernel/cpuset.c	2006-09-19 21:42:06.000000000 -0600
+++ linux-source-2.6.18/kernel/cpuset.c	2007-08-27 22:30:10.778211823 -0600
@@ -1743,12 +1743,7 @@ static ssize_t cpuset_tasks_read(struct 
 {
 	struct ctr_struct *ctr = file->private_data;
 
-	if (*ppos + nbytes > ctr->bufsz)
-		nbytes = ctr->bufsz - *ppos;
-	if (copy_to_user(buf, ctr->buf + *ppos, nbytes))
-		return -EFAULT;
-	*ppos += nbytes;
-	return nbytes;
+	return simple_read_from_buffer(buf, nbytes, ppos, ctr->buf, ctr->bufsz);
 }
 
 static int cpuset_tasks_release(struct inode *unused_inode, struct file *file)