memblock: exclude MEMBLOCK_NOMAP regions from kmemleak
Vladimir Zapolskiy reports:
Commit a7259df76702 ("memblock: make memblock_find_in_range method
private") invokes a kernel panic while running kmemleak on OF platforms
with nomaped regions:
Unable to handle kernel paging request at virtual address fff000021e00000
[...]
scan_block+0x64/0x170
scan_gray_list+0xe8/0x17c
kmemleak_scan+0x270/0x514
kmemleak_write+0x34c/0x4ac
The memory allocated from memblock is registered with kmemleak, but if
it is marked MEMBLOCK_NOMAP it won't have linear map entries so an
attempt to scan such areas will fault.
Ideally, memblock_mark_nomap() would inform kmemleak to ignore
MEMBLOCK_NOMAP memory, but it can be called before kmemleak interfaces
operating on physical addresses can use __va() conversion.
Make sure that functions that mark allocated memory as MEMBLOCK_NOMAP
take care of informing kmemleak to ignore such memory.
Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c6fb@linaro.org
Link: https://lore.kernel.org/all/c30ff0a2-d196-c50d-22f0-bd50696b1205@quicinc.com
Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private")
Reported-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memblock.c b/mm/memblock.c
index 103b052..5096500 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -932,6 +932,9 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
* covered by the memory map. The struct page representing NOMAP memory
* frames in the memory map will be PageReserved()
*
+ * Note: if the memory being marked %MEMBLOCK_NOMAP was allocated from
+ * memblock, the caller must inform kmemleak to ignore that memory
+ *
* Return: 0 on success, -errno on failure.
*/
int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)