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SubjectRe: [PATCH] bitmap: bitmap_parse takes a kernel buffer instead of a user buffer
On Tue, 3 Oct 2006 08:16:27 -0700
Reinette Chatre <reinette.chatre@linux.intel.com> wrote:

> lib/bitmap.c:bitmap_parse() is a library function that received as input a user buffer. This seemed to have originated from the way the write_proc function of the /proc filesystem operates.
>
> This function will be useful for other uses as well; for example, taking input for /sysfs instead of /proc, so it was changed to accept kernel buffers. We have this use for the Linux UWB project, as part as the upcoming bandwidth allocator code.
>
> Only a few routines used this function and they were changed too.

Fair enough. But this:

>
> - err = cpumask_parse(buffer, count, new_value);
> + kbuf = kmalloc(count, GFP_KERNEL);
> + if (kbuf == NULL)
> + return -ENOMEM;
> + ret = copy_from_user(kbuf, buffer, count);
> + if (ret != 0) {
> + kfree(kbuf);
> + return -EFAULT;
> + }
> + err = cpumask_parse(kbuf, count, new_value);
> + kfree(kbuf);
> if (err)
> return err;
>
> ...
>
> - err = cpumask_parse(buffer, count, new_value);
> + kbuf = kmalloc(count, GFP_KERNEL);
> + if (kbuf == NULL)
> + return -ENOMEM;
> + ret = copy_from_user(kbuf, buffer, count);
> + if (ret != 0) {
> + kfree(kbuf);
> + return -EFAULT;
> + }
> + err = cpumask_parse(kbuf, count, new_value);
> + kfree(kbuf);
> if (err)
> return err;
>

is sending us a message ;)

How about adding a new bitmap_parse_user() (and cpumask_parse_user()) which
does the above?
-
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