[PATCH v2] rcu: Handle failure of memory allocation functions

[Li Qiong <liqiong@xxxxxxxxxxxx>]

Add warning when these functions (eg:kmalloc,vmalloc) fail, handle the
failure.

Signed-off-by: Li Qiong <liqiong@xxxxxxxxxxxx>
---
v2:
- check return value of kmem_cache_create().
---
 kernel/rcu/rcutorture.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7120165a9342..104d2658a366 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1990,7 +1990,13 @@ static void rcu_torture_mem_dump_obj(void)
 	static int z;
 
 	kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL);
+	if (WARN_ON_ONCE(!kcp))
+		return;
 	rhp = kmem_cache_alloc(kcp, GFP_KERNEL);
+	if (WARN_ON_ONCE(!rhp)) {
+		kmem_cache_destroy(kcp);
+		return;
+	}
 	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);
@@ -2007,6 +2013,8 @@ static void rcu_torture_mem_dump_obj(void)
 	kmem_cache_free(kcp, rhp);
 	kmem_cache_destroy(kcp);
 	rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
+	if (WARN_ON_ONCE(!rhp))
+		return;
 	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);
@@ -2014,6 +2022,8 @@ static void rcu_torture_mem_dump_obj(void)
 	mem_dump_obj(&rhp->func);
 	kfree(rhp);
 	rhp = vmalloc(4096);
+	if (WARN_ON_ONCE(!rhp))
+		return;
 	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);
-- 
2.25.1