[PATCH -next v2] bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem

[PATCH -next v2] bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem

[Liu Shixin]

The vmemmap pages is marked by kmemleak when allocated from memblock.
Remove it from kmemleak when free the page. Otherwise, when we reuse the
page, kmemleak may report such an error and then stop working.

 kmemleak: Cannot insert 0xffff98fb6eab3d40 into the object search tree (overlaps existing)
 kmemleak: Kernel memory leak detector disabled
 kmemleak: Object 0xffff98fb6be00000 (size 335544320):
 kmemleak:   comm "swapper", pid 0, jiffies 4294892296
 kmemleak:   min_count = 0
 kmemleak:   count = 0
 kmemleak:   flags = 0x1
 kmemleak:   checksum = 0
 kmemleak:   backtrace:

Fixes: f41f2ed43ca5 (mm: hugetlb: free the vmemmap pages associated with each HugeTLB page)
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
 mm/bootmem_info.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
index f18a631e7479..b1efebfcf94b 100644
--- a/mm/bootmem_info.c
+++ b/mm/bootmem_info.c
@@ -12,6 +12,7 @@
 #include <linux/memblock.h>
 #include <linux/bootmem_info.h>
 #include <linux/memory_hotplug.h>
+#include <linux/kmemleak.h>
 
 void get_page_bootmem(unsigned long info, struct page *page, unsigned long type)
 {
@@ -33,6 +34,7 @@ void put_page_bootmem(struct page *page)
 		ClearPagePrivate(page);
 		set_page_private(page, 0);
 		INIT_LIST_HEAD(&page->lru);
+		kmemleak_free_part(page_to_virt(page), PAGE_SIZE);
 		free_reserved_page(page);
 	}
 }
-- 
2.25.1

Re: [PATCH -next v2] bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem

[Muchun Song]

> On Aug 19, 2022, at 17:40, Liu Shixin <liushixin2@huawei.com> wrote:
> 
> The vmemmap pages is marked by kmemleak when allocated from memblock.
> Remove it from kmemleak when free the page. Otherwise, when we reuse the
> page, kmemleak may report such an error and then stop working.
> 
> kmemleak: Cannot insert 0xffff98fb6eab3d40 into the object search tree (overlaps existing)
> kmemleak: Kernel memory leak detector disabled
> kmemleak: Object 0xffff98fb6be00000 (size 335544320):
> kmemleak:   comm "swapper", pid 0, jiffies 4294892296
> kmemleak:   min_count = 0
> kmemleak:   count = 0
> kmemleak:   flags = 0x1
> kmemleak:   checksum = 0
> kmemleak:   backtrace:
> 
> Fixes: f41f2ed43ca5 (mm: hugetlb: free the vmemmap pages associated with each HugeTLB page)
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>

Thanks for fixing this.

Reviewed-by: Muchun Song <songmuchun@bytedance.com>