ACK: [PATCH 3/5] bios: ebdadump: ensure mmap'd memory is readable before accessing it

[Alex Hung]

On 2017-07-12 05:53 AM, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> We need to check we don't get SIGSEGV or SIGBUS errors when reading
> the mmap'd data before we try and access it. Use the fwts_safe_memread
> check on the data to sanity check these mappings.
> 
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>   src/bios/ebdadump/ebdadump.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/src/bios/ebdadump/ebdadump.c b/src/bios/ebdadump/ebdadump.c
> index 437f225a..94f9376c 100644
> --- a/src/bios/ebdadump/ebdadump.c
> +++ b/src/bios/ebdadump/ebdadump.c
> @@ -66,7 +66,10 @@ static int ebdadump_test1(fwts_framework *fw)
>   		BIOS_ROM_START,
>   		len);
>   
> -	ebdadump_data(fw, mem, ebda_addr, len);
> +	if (fwts_safe_memread((void *)mem, len) != FWTS_OK)
> +		fwts_log_info(fw, "EBDA region at cannot be read");
> +	else
> +		ebdadump_data(fw, mem, ebda_addr, len);
>           (void)fwts_munmap(mem, len);
>   
>   	fwts_infoonly(fw);
> 


Acked-by: Alex Hung <alex.hung at canonical.com>