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Date:   Thu, 29 Apr 2021 14:38:36 -0400
From:   Peter Xu <peterx@redhat.com>
To:     "Kirill A. Shutemov" <kirill@shutemov.name>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Simon Ser <contact@emersion.fr>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Will Deacon <will@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        David Herrmann <dh.herrmann@gmail.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Greg Kroah-Hartman <greg@kroah.com>,
        "tytso@mit.edu" <tytso@mit.edu>
Subject: Re: Sealed memfd & no-fault mmap
Message-ID: <20210429183836.GF8339@xz-x1>
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On Thu, Apr 29, 2021 at 06:48:07PM +0300, Kirill A. Shutemov wrote:
> > Side note: this will only ever work for non-shared mappings.
> 
> I think it's show-stopper for the use-case, no? IIUC, the mappings is used
> for communication between a compositor and a client and has to be shared.

Yes I had the same doubt..  Besides, we probably don't want to convert all
VM_FAULT_SIGBUS to fallback to anonymous pages, as I see that vmf_error()
converts mostly everything besides -ENOMEM to VM_FAULT_SIGBUS.  Thanks,

-- 
Peter Xu