linux-kernel - Re: [PATCH v2 2/4] fs/proc/task_mmu: Implement IOCTL to get and clear soft dirty PTE bit

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: <YwcjTOgKD22TXwYk@kroah.com>
Date:   Thu, 25 Aug 2022 09:22:52 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Muhammad Usama Anjum <usama.anjum@...labora.com>
Cc:     Jonathan Corbet <corbet@....net>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Shuah Khan <shuah@...nel.org>,
        "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:PROC FILESYSTEM" <linux-fsdevel@...r.kernel.org>,
        "open list:MEMORY MANAGEMENT" <linux-mm@...ck.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@...r.kernel.org>, kernel@...labora.com
Subject: Re: [PATCH v2 2/4] fs/proc/task_mmu: Implement IOCTL to get and
 clear soft dirty PTE bit

On Thu, Aug 25, 2022 at 12:09:24PM +0500, Muhammad Usama Anjum wrote:
> - The flags can be specified in the flags field. Currently only one
>   PAGEMAP_SD_NO_REUSED_REGIONS is supported which can be specified to
>   ignore the VMA dirty flags.

You forgot to check that all other bits in that flag are set to 0
properly, otherwise you can never add a new bit to the field ever as you
can't expect userspace got it right and did not accidentaly set it
already.

There is kernel documentation on how to add a new ioctl, you might want
to read up on that first before resending this.

thanks,

greg k-h