There is a slim chance that free_heap_pages() may decide to merge a chunk
from the static region(PGC_reserved) with the about-to-be-free chunk.
So in order to avoid the above scenario, this commit updates free_heap_pages()
to check whether the predecessor and/or successor has PGC_reserved set,
when trying to merge the about-to-be-freed chunk with the predecessor
and/or successor.
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
---
v3 changes:
- no changes
---
v2 changes:
- new commit
---
xen/common/page_alloc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index be501582a3..1f3ad4bd28 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1483,6 +1483,7 @@ static void free_heap_pages(
/* Merge with predecessor block? */
if ( !mfn_valid(page_to_mfn(predecessor)) ||
!page_state_is(predecessor, free) ||
+ (predecessor->count_info & PGC_reserved) ||
(PFN_ORDER(predecessor) != order) ||
(phys_to_nid(page_to_maddr(predecessor)) != node) )
break;
@@ -1506,6 +1507,7 @@ static void free_heap_pages(
/* Merge with successor block? */
if ( !mfn_valid(page_to_mfn(successor)) ||
!page_state_is(successor, free) ||
+ (successor->count_info & PGC_reserved) ||
(PFN_ORDER(successor) != order) ||
(phys_to_nid(page_to_maddr(successor)) != node) )
break;
--
2.25.1
