[PATCH v2 2/2] mm, kasan: add a ksize() test

[Alexander Potapenko]

Add a test that makes sure ksize() unpoisons the whole chunk.

Signed-off-by: Alexander Potapenko <gli...@google.com>
---
v2: - splitted v1 into two patches
---
 lib/test_kasan.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 82169fb..48e5a0b 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -344,6 +344,25 @@ static noinline void __init kasan_stack_oob(void)
        *(volatile char *)p;
 }
 
+static noinline void __init ksize_unpoisons_memory(void)
+{
+       char *ptr;
+       size_t size = 123, real_size = size;
+
+       pr_info("ksize() unpoisons the whole allocated chunk\n");
+       ptr = kmalloc(size, GFP_KERNEL);
+       if (!ptr) {
+               pr_err("Allocation failed\n");
+               return;
+       }
+       real_size = ksize(ptr);
+       /* This access doesn't trigger an error. */
+       ptr[size] = 'x';
+       /* This one does. */
+       ptr[real_size] = 'y';
+       kfree(ptr);
+}
+
 static int __init kmalloc_tests_init(void)
 {
        kmalloc_oob_right();
@@ -367,6 +386,7 @@ static int __init kmalloc_tests_init(void)
        kmem_cache_oob();
        kasan_stack_oob();
        kasan_global_oob();
+       ksize_unpoisons_memory();
        return -EAGAIN;
 }
 
-- 
2.8.0.rc3.226.g39d4020