Re: [PATCH 3/4] mm: move dup_mmap() to mm

From: Pedro Falcato
Date: Fri Apr 25 2025 - 05:13:50 EST


On Thu, Apr 24, 2025 at 10:15:28PM +0100, Lorenzo Stoakes wrote:
> This is a key step in our being able to abstract and isolate VMA allocation
> and destruction logic.
>
> This function is the last one where vm_area_free() and vm_area_dup() are
> directly referenced outside of mmap, so having this in mm allows us to
> isolate these.
>
> We do the same for the nommu version which is substantially simpler.
>
> We place the declaration for dup_mmap() in mm/internal.h and have
> kernel/fork.c import this in order to prevent improper use of this
> functionality elsewhere in the kernel.
>
> While we're here, we remove the useless #ifdef CONFIG_MMU check around
> mmap_read_lock_maybe_expand() in mmap.c, mmap.c is compiled only if
> CONFIG_MMU is set.
>
> Suggested-by: Pedro Falcato <pfalcato@xxxxxxx>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

Reviewed-by: Pedro Falcato <pfalcato@xxxxxxx>

Have I told you how awesome you are? Thank you so much for the series!

--
Pedro