Re: [patch v2] epoll use a single inode ...

From: Davide Libenzi
Date: Mon Mar 05 2007 - 19:12:30 EST


On Mon, 5 Mar 2007, Linus Torvalds wrote:

> On Mon, 5 Mar 2007, Davide Libenzi wrote:
> > @@ -763,15 +767,17 @@
> > * using the inode number.
> > */
> > error = -ENOMEM;
> > - sprintf(name, "[%lu]", inode->i_ino);
> > this.name = name;
> > - this.len = strlen(name);
> > - this.hash = inode->i_ino;
> > + this.len = sprintf(name, "[%p]", ep);
> > + this.hash = 0;
>
> Please don't expose kernel pointers to user space.
>
> It's much better to do something like
>
> static unsigned int epoll_inode;
>
> this.len = sprintf(name, "[%u]", ++epoll_inode);
>
> if you just need some pseudo-unique name to distinguish two epoll things
> from each other (vs from a dup'ed fd).

Heh, this is what Al was saying ;)
I'm fine with that, but how about counter cycles (going back to zero)?
Should we care to handle them correctly?



- Davide


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