x86: kvm: propagate register_shrinker return code

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@arndb.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e577bacd4bd0..2b8eb4da4d08 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5466,30 +5466,34 @@ 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;
 }
 
 /*