From 658aafc8139c23a6a23f6f4d9a0c4c95476838d4 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 21 Oct 2021 10:09:29 +0300 Subject: 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 Signed-off-by: Mike Rapoport Reviewed-by: Catalin Marinas Tested-by: Vladimir Zapolskiy Tested-by: Qian Cai Signed-off-by: Linus Torvalds --- mm/memblock.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm') diff --git a/mm/memblock.c b/mm/memblock.c index 103b052c016e..5096500b2647 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) -- cgit