On 12/09/2016 09:08 PM, Boris Ostrovsky wrote:
On 12/09/2016 10:50 AM, Ross Lagerwall wrote:
When relocating the p2m/initrd, take special care not to relocate it so
that is overlaps with the current location of the p2m/initrd. This is
needed since the full extent of the current location is not marked as a
reserved region in the e820 (and it shouldn't be since it is about to be
moved).
This was seen to happen to a dom0 with a large initial p2m and a small
reserved region in the middle of the initial p2m.
/*
- * Find a free area in physical memory not yet reserved and compliant with
- * E820 map.
+ * Find a free area in physical memory not yet reserved, compliant with the
+ * E820 map and not overlapping with the pre-allocated area.
* Used to relocate pre-allocated areas like initrd or p2m list which are in
* conflict with the to be used E820 map.
* In case no area is found, return 0. Otherwise return the physical address
* of the area which is already reserved for convenience.
*/
-phys_addr_t __init xen_find_free_area(phys_addr_t size)
+phys_addr_t __init xen_find_free_area(phys_addr_t size, phys_addr_t cur_start,
+ phys_addr_t cur_size)
{
unsigned mapcnt;
phys_addr_t addr, start;
@@ -652,7 +653,8 @@ phys_addr_t __init xen_find_free_area(phys_addr_t size)
continue;
start = entry->addr;
for (addr = start; addr < start + size; addr += PAGE_SIZE) {
- if (!memblock_is_reserved(addr))
+ if (!memblock_is_reserved(addr) &&
+ (addr < cur_start || addr >= cur_start + cur_size))
continue;
start = addr + PAGE_SIZE;
if (start + size > entry->addr + entry->size)
Wouldn't this in fact make it even more likely to return pointer to the
currently allocated chunk?
If we are in [cur_start, cur_start+cur_size) then we assign this address
to 'start' and may well return it, no?
If addr is in [cur_start, cur_start + cur_size) then start is set to
addr + PAGE_SIZE and we go round the inner loop again. If the new addr
is still in [cur_start, cur_start + cur_size) then we set start to addr
+ PAGE_SIZE and go round again... I can't see why it would return it
It is treated the same as if addr is in a reserved memblock.
--
Ross Lagerwall
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