Re: [PATCH 2/6] ERR_PTR: add ERR_OR_0_PTR

From: Al Viro
Date: Mon May 19 2008 - 02:34:23 EST

On Mon, May 19, 2008 at 07:55:04AM +0200, Christoph Hellwig wrote:
> On Mon, May 19, 2008 at 12:01:07AM +0200, Marcin Slusarz wrote:
> > Some codepaths call ERR_PTR with possibly 0 argument, which is not
> > a valid errno and rely on conversion from 0 to NULL pointer.
> > Add ERR_OR_0_PTR function which accepts errnos and 0 as an argument.
> Sorry, no. ERR_PTR(0) is perfectly valid, you just don't want to return
> the actualy value. E.g. we have a common idiom of:
> some_ptr = ERR_PTR(err);
> if (IS_ERR(some_ptr))
> goto out_handle_err;
> and obsfucating this with new syntactic sugar is not a good idea.

Um... Could somebody explain WTF is wrong with declaring that ERR_PTR(0)
is NULL? Sure, if we run into a target where converting non-constant
integer with value zero to void * does not result in null pointer, we'll
need to adjust ERR_PTR(). So. Fscking. What?
a) it's not a lot of adjustment, to start with
b) any such target will require much more work on porting anyway;
this part will be trivial.
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