[PATCH v7 3/4] kasan: add tests for call_rcu stack recording

[Walter Wu]

Test call_rcu() call stack recording and verify whether it correctly
is printed in KASAN report.

Signed-off-by: Walter Wu <walter-zh...@mediatek.com>
Reviewed-and-tested-by: Dmitry Vyukov <dvyu...@google.com>
Reviewed-by: Andrey Konovalov <andreyk...@google.com>
Cc: Andrey Ryabinin <aryabi...@virtuozzo.com>
Cc: Alexander Potapenko <gli...@google.com>
Cc: Matthias Brugger <matthias....@gmail.com>
---

Changes since v6:
- renamed the variable name in testcase

---
 lib/test_kasan.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index e3087d90e00d..19c72c1501ef 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -792,6 +792,35 @@ static noinline void __init vmalloc_oob(void)
 static void __init vmalloc_oob(void) {}
 #endif
 
+static struct kasan_rcu_info {
+       int i;
+       struct rcu_head rcu;
+} *global_rcu_ptr;
+
+static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
+{
+       struct kasan_rcu_info *fp = container_of(rp,
+                                               struct kasan_rcu_info, rcu);
+
+       kfree(fp);
+       fp->i = 1;
+}
+
+static noinline void __init kasan_rcu_uaf(void)
+{
+       struct kasan_rcu_info *ptr;
+
+       pr_info("use-after-free in kasan_rcu_reclaim\n");
+       ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
+       if (!ptr) {
+               pr_err("Allocation failed\n");
+               return;
+       }
+
+       global_rcu_ptr = rcu_dereference_protected(ptr, NULL);
+       call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim);
+}
+
 static int __init kmalloc_tests_init(void)
 {
        /*
@@ -839,6 +868,7 @@ static int __init kmalloc_tests_init(void)
        kasan_bitops();
        kmalloc_double_kzfree();
        vmalloc_oob();
+       kasan_rcu_uaf();
 
        kasan_restore_multi_shot(multishot);
 
-- 
2.18.0