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Date:   Tue, 18 Oct 2022 17:40:20 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Song Liu <songliubraving@meta.com>
Cc:     Christoph Hellwig <hch@lst.de>, Song Liu <song@kernel.org>,
        Linux-MM <linux-mm@kvack.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        X86 ML <x86@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
        Kernel Team <Kernel-team@fb.com>,
        "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
        "Hansen, Dave" <dave.hansen@intel.com>,
        "urezki@gmail.com" <urezki@gmail.com>
Subject: Re: [RFC v2 0/4] vmalloc_exec for modules and BPF programs
Message-ID: <20221018154020.GA24383@lst.de>
References: <20221007234315.2877365-1-song@kernel.org> <20221017072607.GA30977@lst.de> <E8A7DEAE-C1C6-4821-A3A3-FD4996414AFD@fb.com> <20221018145021.GC20131@lst.de> <9A9A2DFD-45FA-45EA-95FB-5FC0DC5A9E2E@fb.com>
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On Tue, Oct 18, 2022 at 03:05:24PM +0000, Song Liu wrote:
> Maybe we need something like vcopy_exec(x_mem, tmp_buf, size), where
> we explicitly check the allowed memory of x_mem is bigger or equal to
> size. And users of vmalloc_exec should only use vcopy_exec to update
> memory from vmalloc_exec. 
> 
> Does this make sense? Did I understand your concern correctly? 

It sounds sensible.  Make sure it iѕ properly documented and reviewed
by people that actually know this area.  I just know enough to ask
stupid question, not to very something is actually correct :)