Re: [-mm PATCH 1/8] Memory controller resource counters (v2)

Balbir Singh
2007-07-06T21:46:45Z

Dave Hansen wrote:
> On Fri, 2007-07-06 at 14:03 -0700, Balbir Singh wrote:
>>>> +ssize_t res_counter_read(struct res_counter *cnt, int member,
>>>> + const char __user *userbuf, size_t nbytes, loff_t
>> *pos)
>>>> +{
>>>> + unsigned long *val;
>>>> + char buf[64], *s;
>>>> +
>>>> + s = buf;
>>>> + val = res_counter_member(cnt, member);
>>>> + s += sprintf(s, "%lu\n", *val);
>>>> + return simple_read_from_buffer((void __user *)userbuf, nbytes,
>>>> + pos, buf, s - buf);
>>>> +}
>>> Why do we need that cast?
>>>
>> u mean the __user? If I remember correctly it's a attribute for
>> sparse.
>
> The userbuf is already __user. This just appears to be making a 'const
> char *' into a 'void *'. I wondered what the reason for that part is.
>

Aah.. yes.. good point. I'll look into it.

> -- Dave
>
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