* Dave Hansen ([email protected]) wrote: > On 10/07/2013 01:21 PM, Robert C Jennings wrote: > > spd.partial[page_nr].offset = loff; > > spd.partial[page_nr].len = this_len; > > + spd.partial[page_nr].useraddr = index << PAGE_CACHE_SHIFT; > > len -= this_len; > > loff = 0; > > spd.nr_pages++; > > @@ -656,6 +702,7 @@ ssize_t default_file_splice_read(struct file *in, > > loff_t *ppos, > > this_len = min_t(size_t, vec[i].iov_len, res); > > spd.partial[i].offset = 0; > > spd.partial[i].len = this_len; > > + spd.partial[i].useraddr = (unsigned long)vec[i].iov_base; > > if (!this_len) { > > __free_page(spd.pages[i]); > > spd.pages[i] = NULL; > > @@ -1475,6 +1522,8 @@ static int get_iovec_page_array(const struct iovec > > __user *iov, > > > > partial[buffers].offset = off; > > partial[buffers].len = plen; > > + partial[buffers].useraddr = (unsigned long)base; > > + base = (void*)((unsigned long)base + PAGE_SIZE); > > > > off = 0; > > len -= plen; > > diff --git a/include/linux/splice.h b/include/linux/splice.h > > index 74575cb..56661e3 100644 > > --- a/include/linux/splice.h > > +++ b/include/linux/splice.h > > @@ -44,6 +44,7 @@ struct partial_page { > > unsigned int offset; > > unsigned int len; > > unsigned long private; > > + unsigned long useraddr; > > }; > > "useraddr" confuses me. You make it an 'unsigned long', yet two of the > three assignments are from "void __user *". The other assignment: > > spd.partial[page_nr].useraddr = index << PAGE_CACHE_SHIFT; > > 'index' looks to be the offset inside the file, not a user address, so > I'm confused what that is doing. > > Could you elaborate a little more on why 'useraddr' is suddenly needed > in these patches? How is "index << PAGE_CACHE_SHIFT" a virtual address? > Also, are we losing any of the advantages of sparse checking since > 'useraddr' is without the __user annotation? >
I'm working on cleaning this up. Trying to remove useraddr altogher through the use of the existing 'private' field just for the splice_to_user/pipe_to_user flow without upsetting other uses of the private field. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
