Greg,
I was looking again to documentation, but didn't find a explanation about the show and store functions. I'm missing something ?
Yes, everything work if I simple use the buffer from store function, but I was looking for where it came from.
Like, It was from user space? So, I need to take care like simple_write_to_buffer does with user space memory ?
I said that because of file file_operations read and write, that I know that comes from user space. But kobj_attribute I didn't understand yet.
What I meant posting one piece of my code was just show what I doing in high level.
But, for some reason gmail sent in the middle of my writing.
static ssize_t id_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
char *buffer;
buffer = kcalloc(cnt, sizeof(char), GFP_KERNEL);
if (buffer) {
if (copy_from_user(buffer, buf, cnt) == cnt) {
if (strcmp(buffer, "Tanure") == 0)
return cnt;
}
}
}
return -EINVAL;
}
The copy_from_user returns 6 when I write my name in the file. So, 6 means that copy_from_user fails to copy 6 bytes from buf.
So there is my question, buf is a user pointer ? Or Can I just copy without problems ?
All this e-mails got me in trouble here. I got kicked from eudyptula challenge, what I still begging to be able to finish.
Thanks Greg for all the help.
--
Lucas Tanure +55 (19) 988176559
On Wed, Sep 3, 2014 at 9:56 PM, Greg KH <greg@xxxxxxxxx> wrote:
A: No.
Q: Should I include quotations after my reply?
http://daringfireball.net/2007/07/on_top
Why? What are you using "raw kobjects" for? You should almost never
On Wed, Sep 03, 2014 at 09:39:50PM -0300, Lucas Tanure wrote:
> Greg,
>
> I'm still trying to understand the sysfs.
need them.
Great, then it should "just work", right? :)
> I indeed read the documentation, I was using your "Sample kobject
> implementation" as base of my code.
Care to post your non-working code?
thanks,
greg k-h
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