[PATCH] acpi: gtdt: Fix the wrong checking of GTDT block

[Colin Ian King]

Hi there,

I can see the bug now, I think we need to combine your patch plus a fix
to the original code and then we get the best of both..



On 23/03/16 08:45, Vikas C Sajjan wrote:
> when "fwts gtdt" is executed, fwts throws below error even when the
> GTDT table looks fine in the "fwts acpidump".
> 
> gtdt: GTDT Generic Timer Description Table test
> 	  -------------------------------
> Test 1 of 1: GTDT Generic Timer Description Table test.
> FAILED [HIGH] GTDTShortBlock: Test 1, GTDT block is too short
> 	  -------------------------------
> 
> This patch removes the error checking,
> since (ptr + 20) is always less than end_ptr even for the valid
> GTDT block.
> 
> Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan at hpe.com>
> Signed-off-by: Sunil V L <sunil.vl at hpe.com>
> ---
>  src/acpi/gtdt/gtdt.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/src/acpi/gtdt/gtdt.c b/src/acpi/gtdt/gtdt.c
> index 421f17f..05ccea1 100644
> --- a/src/acpi/gtdt/gtdt.c
> +++ b/src/acpi/gtdt/gtdt.c
> @@ -75,13 +75,6 @@ static int gtdt_test1(fwts_framework *fw)
>  		case 0x00:
>  			/* GT Block Structure */
>  			block = (fwts_acpi_table_gtdt_block *)ptr;
> -			if (ptr + 20 < end_ptr) {

My code was wrong here, it should be checking to see if we don't run off
the end of the buffer with the following check:

			if (ptr + 20 > end_ptr)

I'll post a fix later on with your header sanity check plus a fix to my
broken comparison.


> -				passed = false;
> -				fwts_failed(fw, LOG_LEVEL_HIGH,
> -					"GTDTShortBlock",
> -					"GTDT block is too short");
> -				goto done;
> -			}
>  			if (block->length < 20) {
>  				passed = false;
>  				fwts_failed(fw, LOG_LEVEL_HIGH,
>