Re: [PATCH 1/3] mm/hugetlb_cma: fix incorrect hugetlb_cma_size assignment on malformed input

[Muchun Song]

> On Oct 28, 2026, at 19:33, Kaitao Cheng <kaitao.cheng@xxxxxxxxx> wrote:
> 
> From: Kaitao Cheng <chengkaitao@xxxxxxxxxx>
> 
> When hugetlb_cma contains a global size after node-specific entries,
> cmdline_parse_hugetlb_cma() enters the global branch and reparses the
> original parameter string. For hugetlb_cma=1:2G,4G, this interprets the
> initial node ID as a one-byte global size and clears the 2 GiB reservation
> recorded for node 1.
> 
> Global and node-specific formats cannot be mixed. Return -EINVAL when a
> global entry follows a node-specific entry, before updating any settings.
> This preserves the valid prefix, so the example retains node 1's 2 GiB
> reservation and reports the malformed option.
> 
> Fixes: 38e719ab2673 ("hugetlb: support node specified when using cma for gigantic hugepages")
> Closes: https://sashiko.dev/#/bug/linux-10f40d3e-3feb-4622-9da8-1fedecb2d0e2
> Signed-off-by: Kaitao Cheng <chengkaitao@xxxxxxxxxx>


Acked-by: Muchun Song <muchun.song@xxxxxxxxx>

Thanks