linux-kernel - Re: [PATCH] xen/pvh: Do not fill kernel's e820 map in init_pvh

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Fri, 21 Apr 2017 11:37:51 +0200
From:   Juergen Gross <jgross@...e.com>
To:     Boris Ostrovsky <boris.ostrovsky@...cle.com>
Cc:     xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] xen/pvh: Do not fill kernel's e820 map in
 init_pvh_bootparams()

On 20/04/17 19:32, Boris Ostrovsky wrote:
> e820 map is updated with information from the zeropage (i.e.
> pvh_bootparams) by default_machine_specific_memory_setup().
> With the way things are done now, we end up with a duplicated
> e820 map.
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
> ---
> This patch is against for-linus-4.12 branch. Since this is not
> a critical issue I don't want to submit it to 4.11 at rc8 time
> (plus it will require rebasing for-linus-4.12).
> 
> 
>  arch/x86/xen/enlighten_pvh.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
> index 331d769..7ce319a9 100644
> --- a/arch/x86/xen/enlighten_pvh.c
> +++ b/arch/x86/xen/enlighten_pvh.c
> @@ -33,7 +33,6 @@ static void xen_pvh_arch_setup(void)
>  static void __init init_pvh_bootparams(void)
>  {
>  	struct xen_memory_map memmap;
> -	unsigned int i;
>  	int rc;
>  
>  	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
> @@ -60,12 +59,7 @@ static void __init init_pvh_bootparams(void)
>  	sanitize_e820_map(pvh_bootparams.e820_map,
>  			  ARRAY_SIZE(pvh_bootparams.e820_map),
>  			  &memmap.nr_entries);

Sorry, only saw it now: can't you just delete the sanitize_e820_map()
call, too?


Juergen

> -
>  	pvh_bootparams.e820_entries = memmap.nr_entries;
> -	for (i = 0; i < pvh_bootparams.e820_entries; i++)
> -		e820_add_region(pvh_bootparams.e820_map[i].addr,
> -				pvh_bootparams.e820_map[i].size,
> -				pvh_bootparams.e820_map[i].type);
>  
>  	pvh_bootparams.hdr.cmd_line_ptr =
>  		pvh_start_info.cmdline_paddr;
>