Re: [PATCH v5] fs: clear file privilege bits when mmap writing

From: Al Viro
Date: Thu Dec 10 2015 - 16:57:16 EST

On Thu, Dec 10, 2015 at 01:45:09PM -0800, Kees Cook wrote:
> > but generally you need ->f_lock. And in situations where the bit can
> > go only off->on, check it lockless, skip the whole thing entirely if it's
> > already set and grab the spinlock otherwise.
> And I can take f_lock safely under mmap_sem?

Are you asking whether it's safe to take a spinlock under an rwsem?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at