ACPI / APEI: Release resources if gen_pool_add() fails

Destroy ghes_estatus_pool and release memory allocated via vmalloc() on
errors in ghes_estatus_pool_init() in order to avoid memory leaks.

 [ bp: do the labels properly and with descriptive names and massage. ]

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1563173924-47479-1-git-send-email-zhangliguang@linux.alibaba.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/apei/ghes.c

@@ -153,6 +153,7 @@ static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
 int ghes_estatus_pool_init(int num_ghes)
 {
 	unsigned long addr, len;
+	int rc;
 
 	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
 	if (!ghes_estatus_pool)
@@ -164,15 +165,27 @@ int ghes_estatus_pool_init(int num_ghes)
 	ghes_estatus_pool_size_request = PAGE_ALIGN(len);
 	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
 	if (!addr)
-		return -ENOMEM;
+		goto err_pool_alloc;
 
 	/*
 	 * New allocation must be visible in all pgd before it can be found by
 	 * an NMI allocating from the pool.
 	 */
 	vmalloc_sync_all();
 
-	return gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
+	rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
+	if (rc)
+		goto err_pool_add;
+
+	return 0;
+
+err_pool_add:
+	vfree((void *)addr);
+
+err_pool_alloc:
+	gen_pool_destroy(ghes_estatus_pool);
+
+	return -ENOMEM;
 }
 
 static int map_gen_v2(struct ghes *ghes)