[PATCH 2/6] mm: kfence: check kfence pool size at building time

From: Muchun Song
Date: Tue Mar 28 2023 - 05:59:22 EST


Check kfence pool size at building time to expose problem ASAP.

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
mm/kfence/core.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index de62a84d4830..6781af1dfa66 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -841,10 +841,9 @@ static int kfence_init_late(void)
return -ENOMEM;
__kfence_pool = page_to_virt(pages);
#else
- if (nr_pages > MAX_ORDER_NR_PAGES) {
- pr_warn("KFENCE_NUM_OBJECTS too large for buddy allocator\n");
- return -EINVAL;
- }
+ BUILD_BUG_ON_MSG(get_order(KFENCE_POOL_SIZE) > MAX_ORDER,
+ "CONFIG_KFENCE_NUM_OBJECTS is too large for buddy allocator");
+
__kfence_pool = alloc_pages_exact(KFENCE_POOL_SIZE, GFP_KERNEL);
if (!__kfence_pool)
return -ENOMEM;
--
2.11.0