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Date: Tue, 1 Mar 2016 13:00:11 +0100
From: Torsten Duwe <duwe@lst.de>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@ozlabs.org, bsingharora@gmail.com,
 linux-kernel@vger.kernel.org, rostedt@goodmis.org,
 kamalesh@linux.vnet.ibm.com, pmladek@suse.com, jeyu@redhat.com,
 jkosina@suse.cz, live-patching@vger.kernel.org, mbenes@suse.cz
Subject: Re: [PATCH v2 2/8] powerpc/module: Only try to generate the
 ftrace_caller() stub once
Message-ID: <20160301120011.GB10342@lst.de>
References: <1456737989-8755-1-git-send-email-mpe@ellerman.id.au>
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On Mon, Feb 29, 2016 at 08:26:23PM +1100, Michael Ellerman wrote:
[...]
> diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
> index 2c01665eb410..dd095496d225 100644
> --- a/arch/powerpc/kernel/module_32.c
> +++ b/arch/powerpc/kernel/module_32.c
> @@ -294,11 +294,19 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
>  			return -ENOEXEC;
>  		}
>  	}
> +
> +	return 0;
> +}
> +
>  #ifdef CONFIG_DYNAMIC_FTRACE
> -	module->arch.tramp =
> -		do_plt_call(module->core_layout.base,
> -			    (unsigned long)ftrace_caller,
> -			    sechdrs, module);
> -#endif
> +int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs)
> +{
> +	module->arch.tramp = do_plt_call(module->core_layout.base,
> +					 (unsigned long)ftrace_caller,
> +					 sechdrs, module);
> +	if (!mod->arch.tramp)

That should probably read (!module->arch.tramp).

> +		return -ENOENT;
> +
>  	return 0;
>  }
> +#endif