[PATCH] x86: kvm: propagate register_shrinker return code

[Arnd Bergmann <arnd@arndb.de>]

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>
---
 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;
 }
 
 /*
-- 
2.9.0