On 10/01/2018 17:26, Arnd Bergmann wrote:
> Patch "mm,vmscan: mark register_shrinker() as __must_check" is
> queued for 4.16 in linux-mm and adds a warning about the unchecked
> call to register_shrinker:
>
> arch/x86/kvm/mmu.c:5485:2: warning: ignoring return value of 'register_shrinker', declared with attribute warn_unused_result [-Wunused-result]
>
> This changes the kvm_mmu_module_init() function to fail itself
> when the call to register_shrinker fails.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> arch/x86/kvm/mmu.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 89da688784fa..765c8e9df5d9 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -5465,30 +5465,34 @@ static void mmu_destroy_caches(void)
>
> int kvm_mmu_module_init(void)
> {
> + int ret = -ENOMEM;
> +
> kvm_mmu_clear_all_pte_masks();
>
> pte_list_desc_cache = kmem_cache_create("pte_list_desc",
> sizeof(struct pte_list_desc),
> 0, SLAB_ACCOUNT, NULL);
> if (!pte_list_desc_cache)
> - goto nomem;
> + goto out;
>
> mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
> sizeof(struct kvm_mmu_page),
> 0, SLAB_ACCOUNT, NULL);
> if (!mmu_page_header_cache)
> - goto nomem;
> + goto out;
>
> if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL))
> - goto nomem;
> + goto out;
>
> - register_shrinker(&mmu_shrinker);
> + ret = register_shrinker(&mmu_shrinker);
> + if (ret)
> + goto out;
>
> return 0;
>
> -nomem:
> +out:
> mmu_destroy_caches();
> - return -ENOMEM;
> + return ret;
> }
>
> /*
>
Queued, thanks.
Paolo
