cma_init_reserved_mem() checks base and size alignment with CMA_MIN_ALIGNMENT_BYTES. However, some users might call this during early boot when pageblock_order is 0. That means if base and size does not have pageblock_order alignment, it can cause functional failures during cma activate area.
So let's enforce pageblock_order to be non-zero during cma_init_reserved_mem(). Acked-by: David Hildenbrand <da...@redhat.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.l...@gmail.com> --- v2 -> v3: Separated the series into 2 as discussed in v2. [v2]: https://lore.kernel.org/linuxppc-dev/cover.1728585512.git.ritesh.l...@gmail.com/ mm/cma.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/cma.c b/mm/cma.c index 3e9724716bad..36d753e7a0bf 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -182,6 +182,15 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, if (!size || !memblock_is_region_reserved(base, size)) return -EINVAL; + /* + * CMA uses CMA_MIN_ALIGNMENT_BYTES as alignment requirement which + * needs pageblock_order to be initialized. Let's enforce it. + */ + if (!pageblock_order) { + pr_err("pageblock_order not yet initialized. Called during early boot?\n"); + return -EINVAL; + } + /* ensure minimal alignment required by mm core */ if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES)) return -EINVAL; -- 2.46.0
