Hmm.... ping...
On Tue, May 2, 2017 at 9:26 PM, Wei Yang <[email protected]> wrote:
> Hi, Borislav and all
>
> Do you agree with my analysis or you have other comments?
>
> On Tue, Mar 14, 2017 at 11:56:39AM +0800, Wei Yang wrote:
>>On Mon, Mar 13, 2017 at 07:50:21PM +0100, Borislav Petkov wrote:
>>>On Fri, Feb 17, 2017 at 10:30:33PM +0800, Wei Yang wrote:
>>>> In case (last_start <= step_size), start is for sure to be 0. So, it is
>>>
>>
>>Hmm, I may write it more specific:
>>
>>"start" is for sure to be set to 0 with round_down(last_start - 1, step_size).
>>
>>>Well, lemme see:
>>>
>>>[ 0.000000] memory_map_top_down: entry, [0x100000:0x7ffdf000)
>>>[ 0.000000] memory_map_top_down: addr: 0x7fc00000, real_end: 0x7fe00000
>>>[ 0.000000] memory_map_top_down: last_start: 0x40000000 <= step_size: 0x2000000000, start: 0x40000000
>>> ^^^^^^^^^^
>>>It doesn't look like 0 to me.
>>>
>>>---
>>>diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
>>>index 2193799ca800..d3b02a416df3 100644
>>>--- a/arch/x86/mm/init.c
>>>+++ b/arch/x86/mm/init.c
>>>@@ -527,8 +531,13 @@ static void __init memory_map_top_down(unsigned long map_start,
>>> start = round_down(last_start - 1, step_size);
>>> if (start < map_start)
>>> start = map_start;
>>>- } else
>>>+ } else {
>>>+ pr_info("%s: last_start: 0x%lx <= step_size: 0x%lx, start: 0x%lx\n",
>>>+ __func__, last_start, step_size, start);
>>>+
>>
>>If you change this log with the following
>>
>> pr_err("%s: last_start: 0x%lx <= step_size: 0x%lx, start: 0x%lx\n",
>> __func__, last_start, step_size,
>> round_down(last_start - 1, step_size));
>>
>>You could see after calculation, start is 0 when (last_start <= step_size).
>>
>>--
>>Wei Yang
>>Help you, Help me
>
>
>
> --
> Wei Yang
> Help you, Help me