The callers of memblock_reserve() do not check the return value presuming that memblock_reserve() always succeeds, but there are cases where it may fail. Having numerous memblock reservations at early boot where memblock_can_resize is unset may exhaust the INIT_MEMBLOCK_REGIONS sized memblock.reserved regions array and an attempt to double this array via memblock_double_array() will fail and will return -1 to the caller. When this happens the system crashes anyway, but it's hard to identify the reason for the crash. Add a panic message to memblock_double_array() to aid debugging of the cases when too many regions are reserved before memblock can resize memblock.reserved array. Link: https://lore.kernel.org/linux-kernel/20230614131746.3670303-1-songshuaishuai@xxxxxxxxxxx/ Signed-off-by: Song Shuai <songshuaishuai@xxxxxxxxxxx> --- mm/memblock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memblock.c b/mm/memblock.c index 3feafea06ab2..1b8e902490e5 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -419,7 +419,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type, * of memory that aren't suitable for allocation */ if (!memblock_can_resize) - return -1; + panic("memblock: cannot resize %s array\n", type->name); /* Calculate new doubled size */ old_size = type->max * sizeof(struct memblock_region); -- 2.20.1
