Re: [PATCH v2 05/12] modules, execmem: drop module_alloc

[Song Liu]

On Fri, Jun 16, 2023 at 1:51 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
>
> From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
>
> Define default parameters for address range for code allocations using
> the current values in module_alloc() and make execmem_text_alloc() use
> these defaults when an architecure does not supply its specific
> parameters.
>
> With this, execmem_text_alloc() implements memory allocation in a way
> compatible with module_alloc() and can be used as a replacement for
> module_alloc().
>
> Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

Acked-by: Song Liu <song@xxxxxxxxxx>

> ---
>  include/linux/execmem.h      |  8 ++++++++
>  include/linux/moduleloader.h | 12 ------------
>  kernel/module/main.c         |  7 -------
>  mm/execmem.c                 | 12 ++++++++----
>  4 files changed, 16 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> index 68b2bfc79993..b9a97fcdf3c5 100644
> --- a/include/linux/execmem.h
> +++ b/include/linux/execmem.h
> @@ -4,6 +4,14 @@
>
>  #include <linux/types.h>
>
> +#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
> +               !defined(CONFIG_KASAN_VMALLOC)
> +#include <linux/kasan.h>
> +#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
> +#else
> +#define MODULE_ALIGN PAGE_SIZE
> +#endif
> +
>  /**
>   * struct execmem_range - definition of a memory range suitable for code and
>   *                       related data allocations
> diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
> index b3374342f7af..4321682fe849 100644
> --- a/include/linux/moduleloader.h
> +++ b/include/linux/moduleloader.h
> @@ -25,10 +25,6 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
>  /* Additional bytes needed by arch in front of individual sections */
>  unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section);
>
> -/* Allocator used for allocating struct module, core sections and init
> -   sections.  Returns NULL on failure. */
> -void *module_alloc(unsigned long size);
> -
>  /* Determines if the section name is an init section (that is only used during
>   * module loading).
>   */
> @@ -113,12 +109,4 @@ void module_arch_cleanup(struct module *mod);
>  /* Any cleanup before freeing mod->module_init */
>  void module_arch_freeing_init(struct module *mod);
>
> -#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
> -               !defined(CONFIG_KASAN_VMALLOC)
> -#include <linux/kasan.h>
> -#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
> -#else
> -#define MODULE_ALIGN PAGE_SIZE
> -#endif
> -
>  #endif
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 43810a3bdb81..b445c5ad863a 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -1600,13 +1600,6 @@ static void free_modinfo(struct module *mod)
>         }
>  }
>
> -void * __weak module_alloc(unsigned long size)
> -{
> -       return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> -                       GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> -                       NUMA_NO_NODE, __builtin_return_address(0));
> -}
> -
>  bool __weak module_init_section(const char *name)
>  {
>         return strstarts(name, ".init");
> diff --git a/mm/execmem.c b/mm/execmem.c
> index 2fe36dcc7bdf..a67acd75ffef 100644
> --- a/mm/execmem.c
> +++ b/mm/execmem.c
> @@ -59,9 +59,6 @@ void *execmem_text_alloc(size_t size)
>         unsigned long fallback_end = execmem_params.modules.text.fallback_end;
>         bool kasan = execmem_params.modules.flags & EXECMEM_KASAN_SHADOW;
>
> -       if (!execmem_params.modules.text.start)
> -               return module_alloc(size);
> -
>         return execmem_alloc(size, start, end, align, pgprot,
>                              fallback_start, fallback_end, kasan);
>  }
> @@ -108,8 +105,15 @@ void __init execmem_init(void)
>  {
>         struct execmem_params *p = execmem_arch_params();
>
> -       if (!p)
> +       if (!p) {
> +               p = &execmem_params;
> +               p->modules.text.start = VMALLOC_START;
> +               p->modules.text.end = VMALLOC_END;
> +               p->modules.text.pgprot = PAGE_KERNEL_EXEC;
> +               p->modules.text.alignment = 1;
> +
>                 return;
> +       }
>
>         if (!execmem_validate_params(p))
>                 return;
> --
> 2.35.1
>