linux-kernel - Re: [PATCH 1/3] mtd: nand: Add on-die ECC support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <553EBEDD.9050204@nod.at>
Date:	Tue, 28 Apr 2015 00:57:33 +0200
From:	Richard Weinberger <richard@....at>
To:	Brian Norris <computersforpeace@...il.com>
CC:	Ben Shelton <ben.shelton@...com>, linux-mtd@...ts.infradead.org,
	linux-kernel@...r.kernel.org, dwmw2@...radead.org,
	punnaiah.choudary.kalluri@...inx.com
Subject: Re: [PATCH 1/3] mtd: nand: Add on-die ECC support

Am 28.04.2015 um 00:53 schrieb Brian Norris:
> On Tue, Apr 28, 2015 at 12:42:18AM +0200, Richard Weinberger wrote:
>> Am 28.04.2015 um 00:36 schrieb Ben Shelton:
>>>>> When I build this without CONFIG_MTD_NAND_ECC_ON_DIE enabled, I get the
>>>>> following warning here:
>>>>>
>>>>> In file included from drivers/mtd/nand/nand_base.c:46:0:
>>>>> include/linux/mtd/nand_ondie.h: In function 'nand_read_subpage_on_die':
>>>>> include/linux/mtd/nand_ondie.h:28:1: warning: no return statement in function returning non-void [-Wreturn-type]
>>>>> include/linux/mtd/nand_ondie.h: In function 'nand_read_page_on_die':
>>>>> include/linux/mtd/nand_ondie.h:34:1: warning: no return statement in function returning non-void [-Wreturn-type]
>>>>>
>>>>> Perhaps return an error code here, even though you'll never get past the BUG()?
>>>>
>>>> What gcc is this?
>>>> gcc 4.8 here does not warn, I thought it is smart enough that this function does never
>>>> return. Can it be that your .config has CONFIG_BUG=n?
>>>> Anyway, this functions clearly needs a return statement. :)
>>>
>>> gcc 4.7.2, and you are correct that I had CONFIG_BUG off.  :)
>>
>> Yeah, just noticed that BUG() with CONFIG_BUG=n does not have
>> a nonreturn attribute. So, gcc cannot know...
> 
> But it's an obvious infinite loop... all of my toolchains (4.2, 4.5,
> 4.6, 4.8) are able to compile this without complaining (gcc -Wall):
> 
> int test() { do { } while (1); }

Not here. gcc 4.8 warns on that.
As soon I add __attribute__ ((noreturn)) it does not longer complain.

Thanks,
//richard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/