Re: [PATCH v3 resend 01/15] mm: add setup_initial_init_mm() helper

From: Souptick Joarder
Date: Tue Jun 08 2021 - 10:53:55 EST


On Tue, Jun 8, 2021 at 1:56 PM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>
> Add setup_initial_init_mm() helper to setup kernel text,
> data and brk.
>
> Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-csky@xxxxxxxxxxxxxxx
> Cc: uclinux-h8-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
> Cc: openrisc@xxxxxxxxxxxxxxxxxxxx
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
> Cc: linux-sh@xxxxxxxxxxxxxxx
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: x86@xxxxxxxxxx
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
> include/linux/mm.h | 3 +++
> mm/init-mm.c | 9 +++++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index c274f75efcf9..02aa057540b7 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -244,6 +244,9 @@ int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
>
> #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
>
> +void setup_initial_init_mm(void *start_code, void *end_code,
> + void *end_data, void *brk);
> +

Gentle query -> is there any limitation to add inline functions in
setup_arch() functions ?

> /*
> * Linux kernel virtual memory manager primitives.
> * The idea being to have a "virtual" mm in the same way
> diff --git a/mm/init-mm.c b/mm/init-mm.c
> index 153162669f80..b4a6f38fb51d 100644
> --- a/mm/init-mm.c
> +++ b/mm/init-mm.c
> @@ -40,3 +40,12 @@ struct mm_struct init_mm = {
> .cpu_bitmap = CPU_BITS_NONE,
> INIT_MM_CONTEXT(init_mm)
> };
> +
> +void setup_initial_init_mm(void *start_code, void *end_code,
> + void *end_data, void *brk)
> +{
> + init_mm.start_code = (unsigned long)start_code;
> + init_mm.end_code = (unsigned long)end_code;
> + init_mm.end_data = (unsigned long)end_data;
> + init_mm.brk = (unsigned long)brk;
> +}
> --
> 2.26.2
>
>