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| author | Mike Rapoport <rppt@linux.ibm.com> | 2021-10-21 10:09:29 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-10-21 18:30:49 -1000 |
| commit | 658aafc8139c23a6a23f6f4d9a0c4c95476838d4 (patch) | |
| tree | 4ef1a0cb67618f453b0cf065fe785f3e5c0fed1a /mm/memblock.c | |
| parent | 6c9a54551977ddf2d6e22c21354b4fb88946f96e (diff) | |
| download | lwn-658aafc8139c23a6a23f6f4d9a0c4c95476838d4.tar.gz lwn-658aafc8139c23a6a23f6f4d9a0c4c95476838d4.zip | |
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>
Diffstat (limited to 'mm/memblock.c')
| -rw-r--r-- | mm/memblock.c | 3 |
1 files changed, 3 insertions, 0 deletions
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) |