Re: [PATCH v5 1/5] vmcore: Introduce ELF header in new memory feature

From: Vivek Goyal <vgoyal@redhat.com>
To: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>,
	Jan Willeke <willeke@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	linux-kernel@vger.kernel.org, kexec@lists.infradead.org
Subject: Re: [PATCH v5 1/5] vmcore: Introduce ELF header in new memory feature
Date: Fri, 14 Jun 2013 14:54:02 -0400	[thread overview]
Message-ID: <20130614185401.GL12023@redhat.com> (raw)
In-Reply-To: <1370624161-2298-2-git-send-email-holzheu@linux.vnet.ibm.com>

On Fri, Jun 07, 2013 at 06:55:57PM +0200, Michael Holzheu wrote:

[..]
> @@ -935,10 +967,17 @@ static int __init vmcore_init(void)
>  {
>  	int rc = 0;
>  
> -	/* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
> -	if (!(is_vmcore_usable()))
> -		return rc;
> +	/*
> +	 * If elfcorehdr= has not been passed in cmdline, try to get the
> +	 * header from 2nd kernel, then capture the dump.
> +	 */
> +	if (!(is_vmcore_usable())) {
> +		rc = elfcorehdr_alloc();
> +		if (rc)
> +			return rc;
> +	}

Hi Michael,

Patch description says that elfcorehdr_alloc() returns the addr and 
size of elf headers. But that does not seem to be the case here. Has
it been modified in later patches.

Also will it be better if we call elfcorehdr_alloc() always and then
check for is_vmcore_usable().

Something like.

elfcorehdr_addr = elfcorehdr_alloc()
if (elfcorehdr_addr < )
	return elfcorehdr_addr

if (!(is_vmcore_usable()))
	return error

Thanks
Vivek