Re: [PATCH] frv: fix build failure

From: Sudip Mukherjee
Date: Sun Dec 03 2017 - 17:40:00 EST


On Mon, Nov 27, 2017 at 10:25:16AM -0800, Vineet Gupta wrote:
> +CC linux-arch, Arnd
>
> On 11/23/2017 09:17 AM, Alexey Brodkin wrote:
> >Hi Sudip,
> >
> >On Tue, 2017-11-21 at 22:10 +0000, Sudip Mukherjee wrote:

<snip>

> I understand the case/need for adding a weak/common abort() as a
> quick fix for handling such cases, but perhaps we should not and
> instead fix the rootcause. In this specific case, Claudiu mentioned
> that gcc was generating abort due to something like this (flagging a
> possible divide by zero due to
> -fno-isolate-erroneous-paths-dereference.
>
> a;
>
> fn1() {
> switch (a)
> case 0:
> return 1 / a;
> }
>
> Sudeep can you confirm that removing this hacking FRV build to not
> have this toggle fixes the abort issue.
>
> So the offending code needs to be fixed as in the end when that code
> path is taken system is hosed.

The above case that you mentioned is indeed the case here.
mpihelp_divrem() in lib/mpi/mpih-div.c has this same divide by zero case.

So, what should be the actual fix here?

--
Regards
Sudip