Re: Finding user/kernel pointer bugs [no html]

From: Greg KH
Date: Thu Jun 10 2004 - 14:34:50 EST


On Thu, Jun 10, 2004 at 08:14:00PM +0100, viro@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx wrote:
> On Thu, Jun 10, 2004 at 12:10:04PM -0700, Greg KH wrote:
> > @@ -170,8 +170,11 @@
> > static int DIV_TO_REG(int val)
> > {
> > int answer = 0;
> > - while ((val >>= 1))
> > + val >>= 1;
> > + while (val) {
> > answer++;
> > + val >>= 1;
> > + }
> > return answer;
>
> That's less readable than the original...

Hm, so we should ignore the sparse warning about the original then?

> > - data_ptrs = (u8 **) kmalloc(rdwr_arg.nmsgs * sizeof(u8 *),
> > - GFP_KERNEL);
> > + data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
>
> While we are at it, what's the type of ->nmsgs?

include/linux/i2c-dev.h states it is __u32. Any problems with that?

thanks,

greg k-h
-
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