Re: [PATCH] driver core: Add the ability to unbind drivers to devices from userspace

[Jon Smirl <jonsmirl@gmail.com>]

On 7/25/05, Greg KH <greg@kroah.com> wrote:
> > I'll put one together to trim leading/trailing white space from the
> > buffer before it is passed into the attribute functions. Now that I
> > think about this I believe the attributes should have always had the
> > leading/trailing white space removed. If we don't do it in the sysfs
> > code then every driver has to do it.
> 
> Ok, sounds good.

How does this look? This is a count based interface but a lot of
attributes don't work unless I add the terminating zero. This
interface should be documented: count or zero terminated, white space
stripped or not, etc. Are these strings ASCII, UTF8, Unicode?

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -6,6 +6,7 @@
 #include <linux/fsnotify.h>
  #include <linux/kobject.h>
 #include <linux/namei.h>
+#include <linux/ctype.h>
 #include <asm/uaccess.h>
 #include <asm/semaphore.h>
 
@@ -207,6 +208,28 @@ flush_write_buffer(struct dentry * dentr
  	struct attribute * attr = to_attr(dentry);
  	struct kobject * kobj = to_kobj(dentry->d_parent);
  	struct sysfs_ops * ops = buffer->ops;
+	char *x, *y, *z;
+
+	/* locate leading white space */
+	x = buffer->page;
+	while( isspace(*x) && (x - buffer->page < count))
+		x++;
+
+	/* locate trailng white space */
+	z = y = x;
+	while (y - buffer->page < count) {
+		y++;
+		z = y;
+		while( isspace(*y) && (y - buffer->page < count)) {
+			y++;
+		}
+	}
+	count = z - x;
+
+	/* strip the white space */
+	if (buffer->page != x)
+		memmove(buffer->page, x, count);
+	buffer->page[count] = '\0';
 
  	return ops->store(kobj,attr,buffer->page,count);
 }


-- 
Jon Smirl
jonsmirl@gmail.com
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