[PATCH v10 03/10] powerpc: Always define MODULES_{VADDR,END}

[Christophe Leroy]

Le 30/03/2021 à 06:51, Jordan Niethe a écrit :
> If MODULES_{VADDR,END} are not defined set them to VMALLOC_START and
> VMALLOC_END respectively. This reduces the need for special cases. For
> example, powerpc's module_alloc() was previously predicated on
> MODULES_VADDR being defined but now is unconditionally defined.
> 
> This will be useful reducing conditional code in other places that need
> to allocate from the module region (i.e., kprobes).
> 
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
> v10: New to series
> ---
>   arch/powerpc/include/asm/pgtable.h | 5 +++++
>   arch/powerpc/kernel/module.c       | 5 +----

You probably also have changes to do in kernel/ptdump.c

In mm/book3s32/mmu.c and mm/kasan/kasan_init_32.c as well allthough that's harmless here.

>   2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
> index 4eed82172e33..014c2921f26a 100644
> --- a/arch/powerpc/include/asm/pgtable.h
> +++ b/arch/powerpc/include/asm/pgtable.h
> @@ -167,6 +167,11 @@ struct seq_file;
>   void arch_report_meminfo(struct seq_file *m);
>   #endif /* CONFIG_PPC64 */
>   
> +#ifndef MODULES_VADDR
> +#define MODULES_VADDR VMALLOC_START
> +#define MODULES_END VMALLOC_END
> +#endif
> +
>   #endif /* __ASSEMBLY__ */
>   
>   #endif /* _ASM_POWERPC_PGTABLE_H */
> diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
> index a211b0253cdb..f1fb58389d58 100644
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@ -14,6 +14,7 @@
>   #include <asm/firmware.h>
>   #include <linux/sort.h>
>   #include <asm/setup.h>
> +#include <linux/mm.h>
>   
>   static LIST_HEAD(module_bug_list);
>   
> @@ -87,13 +88,9 @@ int module_finalize(const Elf_Ehdr *hdr,
>   	return 0;
>   }
>   
> -#ifdef MODULES_VADDR
>   void *module_alloc(unsigned long size)
>   {
> -	BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> -

The above check is needed somewhere, if you remove it from here you have to perform the check 
somewhere else.

>   	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
>   				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
>   				    __builtin_return_address(0));
>   }
> -#endif
>