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

From: tip-bot2 for Paul E. McKenney
Date: Sun Apr 11 2021 - 09:47:18 EST


The following commit has been merged into the core/rcu branch of tip:

Commit-ID: 0d3dd2c8eadb7d4404b8788f552fb2b824fe2c7e
Gitweb: https://git.kernel.org/tip/0d3dd2c8eadb7d4404b8788f552fb2b824fe2c7e
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate: Mon, 07 Dec 2020 21:23:36 -08:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 08 Mar 2021 14:18:46 -08:00

rcutorture: Add crude tests for mem_dump_obj()

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