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Date:   Tue, 26 Apr 2022 16:32:58 -0400
From:   Peter Xu <peterx@redhat.com>
To:     Axel Rasmussen <axelrasmussen@google.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Charan Teja Reddy <charante@codeaurora.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "Dmitry V . Levin" <ldv@altlinux.org>,
        Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>,
        Hugh Dickins <hughd@google.com>, Jan Kara <jack@suse.cz>,
        Jonathan Corbet <corbet@lwn.net>,
        Mel Gorman <mgorman@techsingularity.net>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@kernel.org>, Nadav Amit <namit@vmware.com>,
        Shuah Khan <shuah@kernel.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        zhangyi <yi.zhang@huawei.com>, linux-doc@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine
 grained access control
Message-ID: <YmhW+mOuQUWsByj4@xz-m1.local>
References: <20220422212945.2227722-1-axelrasmussen@google.com>
 <20220422212945.2227722-3-axelrasmussen@google.com>
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Axel,

On Fri, Apr 22, 2022 at 02:29:41PM -0700, Axel Rasmussen wrote:
> @@ -65,6 +66,8 @@ struct userfaultfd_ctx {
>  	unsigned int flags;
>  	/* features requested from the userspace */
>  	unsigned int features;
> +	/* whether or not to handle kernel faults */
> +	bool handle_kernel_faults;

Could you help explain why we need this bool?  I failed to figure out
myself on the difference against "!(ctx->flags & UFFD_USER_MODE_ONLY)".

Thanks,

-- 
Peter Xu