linux-kernel - Re: [PATCH] mm: Change return type to vm_fault

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: <CAFqt6zaxt=wXjvKV0qA+OwU1iUyoBdW2cJSLFqXupVWRpKdqEA@mail.gmail.com>
Date:   Tue, 29 May 2018 21:25:05 +0530
From:   Souptick Joarder <jrdr.linux@...il.com>
To:     Matthew Wilcox <willy@...radead.org>
Cc:     Al Viro <viro@...iv.linux.org.uk>, Hugh Dickins <hughd@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>,
        Ross Zwisler <ross.zwisler@...ux.intel.com>,
        zi.yan@...rutgers.edu,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Greg KH <gregkh@...uxfoundation.org>,
        Mark Rutland <mark.rutland@....com>, riel@...hat.com,
        pasha.tatashin@...cle.com, jschoenh@...zon.de,
        Kate Stewart <kstewart@...uxfoundation.org>,
        David Rientjes <rientjes@...gle.com>, tglx@...utronix.de,
        Peter Zijlstra <peterz@...radead.org>,
        Mel Gorman <mgorman@...e.de>, yang.s@...baba-inc.com,
        Minchan Kim <minchan@...nel.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        linux-kernel@...r.kernel.org, Linux-MM <linux-mm@...ck.org>
Subject: Re: [PATCH] mm: Change return type to vm_fault_t

On Tue, May 29, 2018 at 8:20 PM, Matthew Wilcox <willy@...radead.org> wrote:
> On Tue, May 29, 2018 at 08:01:26PM +0530, Souptick Joarder wrote:
>> Use new return type vm_fault_t for fault handler. For
>> now, this is just documenting that the function returns
>> a VM_FAULT value rather than an errno. Once all instances
>> are converted, vm_fault_t will become a distinct type.
>
> I don't believe you've checked this with sparse.
>
>> @@ -802,7 +802,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
>>                    bool *unlocked)
>>  {
>>       struct vm_area_struct *vma;
>> -     int ret, major = 0;
>> +     int major = 0;
>> +     vm_fault_t ret;
>>
>>       if (unlocked)
>>               fault_flags |= FAULT_FLAG_ALLOW_RETRY;
>
> ...
>         major |= ret & VM_FAULT_MAJOR;
>
> That should be throwing a warning.

Sorry, but I verified again and didn't see similar warnings.

steps followed -

apply the patch
make c=2 -j4 ( build for x86_64)
looking for warnings in files because of this patch.

The only error I am seeing "error: undefined identifier '__COUNTER__' "
which is pointing to BUG(). There are few warnings but those are not
related to this patch.

In my test tree the final patch to create new vm_fault_t type is
already applied.

Do you want me to verify in some other way ?