On Thu, Oct 1, 2020 at 3:41 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> Better
> loff_t dummy = 0;
> ...
> wr = __kernel_write(file, data, bytes, &dummy);
No, just fix __kernel_write() to work correctly.
The fact is, NULL _is_ the right pointer for ppos these days.
That commit by Christoph is buggy: it replaces new_sync_write() with a
buggy open-coded version.
Notice how new_sync_write does
kiocb.ki_pos = (ppos ? *ppos : 0);
,,,
if (ret > 0 && ppos)
*ppos = kiocb.ki_pos;
but the open-coded version doesn't.
So just fix that in linux-next. The *last* thing we want is to have
different semantics for the "same" kernel functions.
Linus
