Re: [PATCH v5 2/2] powerpc/64: Add module check for ELF ABI version

[Christophe Leroy]

Le 31/10/2022 à 13:07, Nicholas Piggin a écrit :
> Override the generic module ELF check to provide a check for the ELF ABI
> version. This becomes important if we allow big-endian ELF ABI V2 builds
> but it doesn't hurt to check now.
> 
> Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> [np: split patch, added changelog, adjust to Jessica's proposal]
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---
>   arch/powerpc/kernel/module.c | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
> index f6d6ae0a1692..d46bf9bfda26 100644
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@ -19,6 +19,23 @@
>   
>   static LIST_HEAD(module_bug_list);
>   
> +#ifdef CONFIG_PPC64

Can it go in arch/powerpc/kernel/module_64.c instead ?

> +bool module_elf_check_arch(Elf_Ehdr *hdr)
> +{
> +	unsigned long abi_level = hdr->e_flags & 0x3;
> +
> +	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) {
> +		if (abi_level != 2)
> +			return false;
> +	} else {
> +		if (abi_level >= 2)
> +			return false;
> +	}
> +
> +	return true;

Can be simpler:

	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
		return abi_level == 2;
	else
		return abi_level < 2;


> +}
> +#endif
> +
>   static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
>   				    const Elf_Shdr *sechdrs,
>   				    const char *name)