cma_init_reserved_mem() checks base and size alignment with
CMA_MIN_ALIGNMENT_BYTES. However, some users might call this during
early boot when pageblock_order is 0. That means if base and size does
not have pageblock_order alignment, it can cause functional failures
during cma activate area.
So let's enforce pageblock_order to be non-zero during
cma_init_reserved_mem().
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
mm/cma.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/mm/cma.c b/mm/cma.c
index 3e9724716bad..36d753e7a0bf 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -182,6 +182,15 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
if (!size || !memblock_is_region_reserved(base, size))
return -EINVAL;
+ /*
+ * CMA uses CMA_MIN_ALIGNMENT_BYTES as alignment requirement which
+ * needs pageblock_order to be initialized. Let's enforce it.
+ */
+ if (!pageblock_order) {
+ pr_err("pageblock_order not yet initialized. Called during early boot?\n");
+ return -EINVAL;
+ }
+
/* ensure minimal alignment required by mm core */
if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES))
return -EINVAL;
--
2.46.0
