Re: [PATCH V2] mm/cma: cma_declare_contiguous: correct err handling

From: Mike Rapoport
Date: Wed Feb 27 2019 - 10:36:39 EST


On Wed, Feb 27, 2019 at 02:34:55PM +0000, Peng Fan wrote:
> In case cma_init_reserved_mem failed, need to free the memblock allocated
> by memblock_reserve or memblock_alloc_range.
>
> Quote Catalin's comments:
> https://lkml.org/lkml/2019/2/26/482
> Kmemleak is supposed to work with the memblock_{alloc,free} pair and it
> ignores the memblock_reserve() as a memblock_alloc() implementation
> detail. It is, however, tolerant to memblock_free() being called on
> a sub-range or just a different range from a previous memblock_alloc().
> So the original patch looks fine to me. FWIW:
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>

Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

> ---
>
> V2:
> Per Mike's comments, add more information in commit log
> Add R-B
>
> mm/cma.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/cma.c b/mm/cma.c
> index c7b39dd3b4f6..f4f3a8a57d86 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -353,12 +353,14 @@ int __init cma_declare_contiguous(phys_addr_t base,
>
> ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
> if (ret)
> - goto err;
> + goto free_mem;
>
> pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
> &base);
> return 0;
>
> +free_mem:
> + memblock_free(base, size);
> err:
> pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
> return ret;
> --
> 2.16.4
>

--
Sincerely yours,
Mike.