linux-kernel - Re: [PATCH -V7 02/14] hugetlbfs: don't use ERR_PTR with VM

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: <alpine.DEB.2.00.1205302331380.25774@chino.kir.corp.google.com>
Date:	Wed, 30 May 2012 23:50:18 -0700 (PDT)
From:	David Rientjes <rientjes@...gle.com>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
cc:	linux-mm@...ck.org, kamezawa.hiroyu@...fujitsu.com,
	dhillf@...il.com, mhocko@...e.cz, akpm@...ux-foundation.org,
	hannes@...xchg.org, linux-kernel@...r.kernel.org,
	cgroups@...r.kernel.org, Andrea Arcangeli <aarcange@...hat.com>
Subject: Re: [PATCH -V7 02/14] hugetlbfs: don't use ERR_PTR with VM_FAULT*
 values

On Thu, 31 May 2012, Aneesh Kumar K.V wrote:

> > Yeah, but is there a reason for using VM_FAULT_HWPOISON_LARGE_MASK since 
> > that's the only VM_FAULT_* value that is greater than MAX_ERRNO?  The rest 
> > of your patch set doesn't require this, so I think this change should just 
> > be dropped.  (And PTR_ERR() still returns long, this wasn't fixed from my 
> > original review.)
> > 
> 
> The changes was done as per Andrew's request so that we don't have such hidden
> dependencies on the values of VM_FAULT_*. Yes it can be a seperate patch from
> the patchset. I have changed int to long as per your review.
> 

I think it confuscates the code, can't we just add something like 
BUILD_BUG_ON() to ensure that PTR_ERR() never uses values that are outside 
the bounds of MAX_ERRNO so we'll catch these at compile time if 
mm/hugetlb.c or anything else is ever extended to use such values?
--
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/