[PATCH v2 1/3] lib/test_kasan: Add bitops tests

Marco Elver
2019-05-29T14:23:36Z

This adds bitops tests to the test_kasan module. In a follow-up patch,
support for bitops instrumentation will be added.

Signed-off-by: Marco Elver <elver@google.com>
---
Changes in v2:
* Use BITS_PER_LONG.
* Use heap allocated memory for test, as newer compilers (correctly)
warn on OOB stack access.
---
lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 72 insertions(+), 3 deletions(-)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 7de2702621dc..6562df0ca30d 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -11,16 +11,17 @@

#define pr_fmt(fmt) "kasan test: %s " fmt, __func__

+#include <linux/bitops.h>
#include <linux/delay.h>
+#include <linux/kasan.h>
#include <linux/kernel.h>
-#include <linux/mman.h>
#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/kasan.h>

/*
* Note: test functions are marked noinline so that their names appear in
@@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
strnlen(ptr, 1);
}

+static noinline void __init kasan_bitops(void)
+{
+ long *bits = kmalloc(sizeof(long), GFP_KERNEL | __GFP_ZERO);
+ if (!bits)
+ return;
+
+ pr_info("within-bounds in set_bit");
+ set_bit(0, bits);
+
+ pr_info("within-bounds in set_bit");
+ set_bit(BITS_PER_LONG - 1, bits);
+
+ pr_info("out-of-bounds in set_bit\n");
+ set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __set_bit\n");
+ __set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in clear_bit\n");
+ clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __clear_bit\n");
+ __clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in clear_bit_unlock\n");
+ clear_bit_unlock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __clear_bit_unlock\n");
+ __clear_bit_unlock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in change_bit\n");
+ change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __change_bit\n");
+ __change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_set_bit\n");
+ test_and_set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_set_bit\n");
+ __test_and_set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_set_bit_lock\n");
+ test_and_set_bit_lock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_clear_bit\n");
+ test_and_clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_clear_bit\n");
+ __test_and_clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_change_bit\n");
+ test_and_change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_change_bit\n");
+ __test_and_change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_bit\n");
+ (void)test_bit(BITS_PER_LONG, bits);
+
+#if defined(clear_bit_unlock_is_negative_byte)
+ pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
+ clear_bit_unlock_is_negative_byte(BITS_PER_LONG, bits);
+#endif
+ kfree(bits);
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -664,6 +732,7 @@ static int __init kmalloc_tests_init(void)
kasan_memchr();
kasan_memcmp();
kasan_strings();
+ kasan_bitops();

kasan_restore_multi_shot(multishot);

--
2.22.0.rc1.257.g3120a18244-goog