linux-kernel - Re: [PATCH 16/16] kcov: update kcov to use mmap_prepare, mmap

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Message-ID: <20250908133013.GD616306@nvidia.com>
Date: Mon, 8 Sep 2025 10:30:13 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
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Subject: Re: [PATCH 16/16] kcov: update kcov to use mmap_prepare,
 mmap_complete

On Mon, Sep 08, 2025 at 12:10:47PM +0100, Lorenzo Stoakes wrote:
> Now we have the capacity to set up the VMA in f_op->mmap_prepare and then
> later, once the VMA is established, insert a mixed mapping in
> f_op->mmap_complete, do so for kcov.
> 
> We utilise the context desc->mmap_context field to pass context between
> mmap_prepare and mmap_complete to conveniently provide the size over which
> the mapping is performed.

Why?

+	    vma_desc_size(desc) != size) {
+  		res = -EINVAL;

Just call some vma_size()?

Jason