From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vineet.Gupta1@synopsys.com (Vineet Gupta)
Date: Wed, 6 Dec 2017 14:00:23 -0800
Subject: [PATCH] frv: fix build failure
In-Reply-To: <20171203223226.GA3741@sudip-laptop>
References: <1511302233-5008-1-git-send-email-sudipm.mukherjee@gmail.com>
 <1511457437.32422.6.camel@synopsys.com>
 <3a6fe86e-7a66-56df-3b1d-e2e8cd3e6eae@synopsys.com>
 <20171203223226.GA3741@sudip-laptop>
List-ID: <linux-snps-arc@lists.infradead.org>
Message-ID: <817df34a-f471-99d7-aaa1-94e0ee9d5ffa@synopsys.com>
To: linux-snps-arc@lists.infradead.org

On 12/03/2017 02:32 PM, Sudip Mukherjee wrote:
> On Mon, Nov 27, 2017@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@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?

To remove the divide by zero.

Or atleast have a __weak abort() defined in common code so all arches benefit from 
it !

-Vineet