Re: [PATCH 1/7] modules: Refactor within_module_core() and within_module_init()

From: Mike Rapoport
Date: Wed Jan 26 2022 - 16:36:31 EST


On Mon, Jan 24, 2022 at 09:22:15AM +0000, Christophe Leroy wrote:
> within_module_core() and within_module_init() are doing the exact same
> test, one on core_layout, the second on init_layout.
>
> In preparation of increasing the complexity of that verification,
> refactor it into a single function called within_module_layout().
>
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> ---
> include/linux/module.h | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index c9f1200b2312..33b4db8f5ca5 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -565,18 +565,27 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
> bool is_module_percpu_address(unsigned long addr);
> bool is_module_text_address(unsigned long addr);
>
> +static inline bool within_range(unsigned long addr, void *base, unsigned int size)
> +{
> + return addr >= (unsigned long)base && addr < (unsigned long)base + size;
> +}

There's also 'within' at least in arch/x86/mm/pat/set_memory.c and surely
tons of open-coded "address within" code.

Should it live in, say, include/linux/range.h?

> +
> +static inline bool within_module_layout(unsigned long addr,
> + const struct module_layout *layout)
> +{
> + return within_range(addr, layout->base, layout->size);
> +}
> +
> static inline bool within_module_core(unsigned long addr,
> const struct module *mod)
> {
> - return (unsigned long)mod->core_layout.base <= addr &&
> - addr < (unsigned long)mod->core_layout.base + mod->core_layout.size;
> + return within_module_layout(addr, &mod->core_layout);
> }
>
> static inline bool within_module_init(unsigned long addr,
> const struct module *mod)
> {
> - return (unsigned long)mod->init_layout.base <= addr &&
> - addr < (unsigned long)mod->init_layout.base + mod->init_layout.size;
> + return within_module_layout(addr, &mod->init_layout);
> }
>
> static inline bool within_module(unsigned long addr, const struct module *mod)
> --
> 2.33.1
>

--
Sincerely yours,
Mike.