[PATCH tip/core/rcu 2/2] rcutorture: Add crude tests for mem_dump_obj()

[paulmck@xxxxxxxxxx]

From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>

This commit adds a few crude tests for mem_dump_obj() to rcutorture
runs.  Just to prevent bitrot, you understand!

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/rcu/rcutorture.c | 39 +++++++++++++++++++++++++++++++++++++++
 mm/slab_common.c        |  2 ++
 mm/util.c               |  1 +
 3 files changed, 42 insertions(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 99657ff..8e93f2e 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1861,6 +1861,45 @@ rcu_torture_stats(void *arg)
 		torture_shutdown_absorb("rcu_torture_stats");
 	} while (!torture_must_stop());
 	torture_kthread_stopping("rcu_torture_stats");
+
+	{
+		struct rcu_head *rhp;
+		struct kmem_cache *kcp;
+		static int z;
+
+		kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL);
+		rhp = kmem_cache_alloc(kcp, GFP_KERNEL);
+		pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z);
+		pr_alert("mem_dump_obj(ZERO_SIZE_PTR):");
+		mem_dump_obj(ZERO_SIZE_PTR);
+		pr_alert("mem_dump_obj(NULL):");
+		mem_dump_obj(NULL);
+		pr_alert("mem_dump_obj(%px):", &rhp);
+		mem_dump_obj(&rhp);
+		pr_alert("mem_dump_obj(%px):", rhp);
+		mem_dump_obj(rhp);
+		pr_alert("mem_dump_obj(%px):", &rhp->func);
+		mem_dump_obj(&rhp->func);
+		pr_alert("mem_dump_obj(%px):", &z);
+		mem_dump_obj(&z);
+		kmem_cache_free(kcp, rhp);
+		kmem_cache_destroy(kcp);
+		rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
+		pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
+		pr_alert("mem_dump_obj(kmalloc %px):", rhp);
+		mem_dump_obj(rhp);
+		pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func);
+		mem_dump_obj(&rhp->func);
+		kfree(rhp);
+		rhp = vmalloc(4096);
+		pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
+		pr_alert("mem_dump_obj(vmalloc %px):", rhp);
+		mem_dump_obj(rhp);
+		pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func);
+		mem_dump_obj(&rhp->func);
+		vfree(rhp);
+	}
+
 	return 0;
 }
 
diff --git a/mm/slab_common.c b/mm/slab_common.c
index cec9536..4c6107e 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -545,6 +545,7 @@ bool kmem_valid_obj(void *object)
 	page = virt_to_head_page(object);
 	return PageSlab(page);
 }
+EXPORT_SYMBOL_GPL(kmem_valid_obj);
 
 /**
  * kmem_dump_obj - Print available slab provenance information
@@ -601,6 +602,7 @@ void kmem_dump_obj(void *object)
 		pr_info("    %pS\n", kp.kp_stack[i]);
 	}
 }
+EXPORT_SYMBOL_GPL(kmem_dump_obj);
 #endif
 
 #ifndef CONFIG_SLOB
diff --git a/mm/util.c b/mm/util.c
index 2d497fe..c37e24d 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -1014,4 +1014,5 @@ void mem_dump_obj(void *object)
 	}
 	pr_cont(" non-slab/vmalloc memory.\n");
 }
+EXPORT_SYMBOL_GPL(mem_dump_obj);
 #endif
-- 
2.9.5