Subject: Re: [BUG resend next-20230818] error: 'prepare_elf_headers' defined but not used

From: Baoquan He <[email-masked]>
Date: Sat, 19 Aug 2023 21:04:33 +0800

On 08/18/23 at 07:28pm, Paul E. McKenney wrote:
> Hello!
> 
> This morning's rcutorture testing on next-20230818 complained about
> prepare_elf_headers() being defined but unused on several rcutorture
> scenarios.  The patch below makes rcutorture happy, but might or might
> not be a proper fix.
> 
> This is a resend adding a few more people on CC, given a possible
> relationship to 9f1f399ca999 ("x86/crash: add x86 crash hotplug support").
> 
> Thoughts?
> 

Thanks for reporting this, Paul.
> 
> ------------------------------------------------------------------------
> 
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 1d0f824559fce..926c39e22387b 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -127,7 +127,8 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
>  	crash_save_cpu(regs, safe_smp_processor_id());
>  }
>  
> -#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
> +#if (defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)) && defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)

Hi Eric,

Now prepare_elf_headers() is needed for kexec_file_load and crash
hotplug support of kexec_load, change it like this?

#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_HOTPLUG)