Re: [Crash-utility] [PATCH] makedumpfile: fix max_mapnr issue on system has over 44-bit addressing
(2013/09/25 17:16), Jingbai Ma wrote:
<cut>
>
>> @@ -5153,10 +5160,11 @@ write_kdump_header(void)
>> * Write common header
>> */
>> strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
>> - dh->header_version = 5;
>> + dh->header_version = 6;
>> dh->block_size = info->page_size;
>> dh->sub_hdr_size = sizeof(kh) + size_note;
>> dh->sub_hdr_size = divideup(dh->sub_hdr_size, dh->block_size);
>> + /* dh->max_mapnr may be truncated here, full 64bit in kh.max_mapnr */
>> dh->max_mapnr = info->max_mapnr;
>
> dh->max_mapnr = MIN(info->max_mapnr, UINT_MAX) seems better for old
> versions of crash utitlity.
>
Although change this value to UINT_MAX doesn't help the old crash utility very much.
At least this special value will tell the user something happened.
Will fix it.
This is the largest page frame number old crash utilities can represent, not special
value.
By this, old crash utilities can read at least the pages less than UINT_MAX,
which is better than making dh->max_mapnr overflow; then dh->max_mapnr would
typically become
a small number.
--
Thanks.
HATAYAMA, Daisuke