Re: [RESEND, PATCH v2] lib: overflow-test: add KUnit test of check_*_overflow functions

25 Jun 2020

On Thu, Jun 18, 2020 at 8:06 PM Kees Cook keescook@chromium.org wrote:
Apologies for just jumping in the middle of this late. Vitor just
brought something to my attention.
...
On Thu, Jun 18, 2020 at 11:08:14AM -0300, Vitor Massaru Iha wrote:
...
This adds the conversion of the runtime tests of check_*_overflow functions,
from `lib/test_overflow.c`to KUnit tests.
The log similar to the one seen in dmesg running test_overflow.c can be
seen in `test.log`.
Signed-off-by: Vitor Massaru Iha vitor@massaru.org
Tested-by: David Gow davidgow@google.com

v2:

moved lib/test_overflow.c to lib/overflow-test.c;

I still don't want a dash in the filename, as this creates a difference
between the source name and the module name. While I still prefer
overflow_kunit.c, I can get over it and accept overflow_test.c :)
...
* back to original license;
* fixed style code;
* keeps __initconst and added _refdata on overflow_test_cases variable;
* keeps macros intact making asserts with the variable err;
* removed duplicate test_s8_overflow();


fixed typos on commit message;


lib/Kconfig.debug                        | 20 +++++++--
 lib/Makefile                             |  2 +-
 lib/{test_overflow.c => overflow-test.c} | 54 +++++++++---------------
 3 files changed, 38 insertions(+), 38 deletions(-)
 rename lib/{test_overflow.c => overflow-test.c} (96%)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d74ac0fd6b2d..fb8a3955e969 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2000,9 +2000,6 @@ config TEST_UUID
 config TEST_XARRAY
      tristate "Test the XArray code at runtime"
-config TEST_OVERFLOW

tristate "Test check_*_overflow() functions at runtime"




config TEST_RHASHTABLE
      tristate "Perform selftest on resizable hash table"
      help
@@ -2155,6 +2152,23 @@ config SYSCTL_KUNIT_TEST
    If unsure, say N.


+config OVERFLOW_KUNIT_TEST

tristate "KUnit test for overflow" if !KUNIT_ALL_TESTS


depends on KUNIT


default KUNIT_ALL_TESTS


help


  This builds the overflow KUnit tests.



  KUnit tests run during boot and output the results to the debug log


  in TAP format (http://testanything.org/). Only useful for kernel devs


  running KUnit test harness and are not for inclusion into a production


  build.



  For more information on KUnit and unit tests in general please refer


  to the KUnit documentation in Documentation/dev-tools/kunit/.



  If unsure, say N.




config LIST_KUNIT_TEST
      tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
      depends on KUNIT
diff --git a/lib/Makefile b/lib/Makefile
index b1c42c10073b..3b725c9f92d4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -75,7 +75,6 @@ obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
 obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
 obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
-obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_SORT) += test_sort.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
@@ -318,3 +317,4 @@ obj-$(CONFIG_OBJAGG) += objagg.o
 # KUnit tests
 obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
 obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
+obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow-test.o
diff --git a/lib/test_overflow.c b/lib/overflow-test.c
similarity index 96%
rename from lib/test_overflow.c
rename to lib/overflow-test.c
index 7a4b6f6c5473..d40ef06b1ade 100644
--- a/lib/test_overflow.c
+++ b/lib/overflow-test.c
@@ -4,14 +4,11 @@
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <kunit/test.h>
 #include <linux/device.h>
 #include <linux/init.h>
-#include <linux/kernel.h>
 #include <linux/mm.h>
-#include <linux/module.h>
 #include <linux/overflow.h>
-#include <linux/slab.h>
-#include <linux/types.h>
 #include <linux/vmalloc.h>
#define DEFINE_TEST_ARRAY(t)                 \
@@ -270,7 +267,7 @@ DEFINE_TEST_FUNC(u64, "%llu");
 DEFINE_TEST_FUNC(s64, "%lld");
 #endif
-static int __init test_overflow_calculation(void)
+static void __init overflow_calculation_test(struct kunit *test)
 {
      int err = 0;
@@ -285,10 +282,10 @@ static int __init test_overflow_calculation(void)
      err |= test_s64_overflow();
 #endif

return err;




KUNIT_EXPECT_FALSE(test, err);



}
Ah! Well, yes, I guess that is one way to do it. :) I'm just curious:
why the change away from doing EXPECTs on individual tests?
...
-static int __init test_overflow_shift(void)
+static void __init overflow_shift_test(struct kunit *test)
 {
      int err = 0;
@@ -479,7 +476,7 @@ static int __init test_overflow_shift(void)
      err |= TEST_ONE_SHIFT(0, 31, s32, 0, false);
      err |= TEST_ONE_SHIFT(0, 63, s64, 0, false);

return err;




KUNIT_EXPECT_FALSE(test, err);



}
/*
@@ -555,7 +552,7 @@ DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
 DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
 DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
-static int __init test_overflow_allocation(void)
+static void __init overflow_allocation_test(struct kunit *test)
 {
      const char device_name[] = "overflow-test";
      struct device *dev;
@@ -563,10 +560,8 @@ static int __init test_overflow_allocation(void)
  /* Create dummy device for devm_kmalloc()-family tests. */
  dev = root_device_register(device_name);


if (IS_ERR(dev)) {


        pr_warn("Cannot register test device\n");


        return 1;


}




if (IS_ERR(dev))


        kunit_warn(test, "Cannot register test device\n");

err |= test_kmalloc(NULL);
err |= test_kmalloc_node(NULL);



@@ -585,30 +580,21 @@ static int __init test_overflow_allocation(void)
  device_unregister(dev);



return err;




KUNIT_EXPECT_FALSE(test, err);



}
-static int __init test_module_init(void)
-{

int err = 0;



err |= test_overflow_calculation();


err |= test_overflow_shift();


err |= test_overflow_allocation();



if (err) {


        pr_warn("FAIL!\n");


        err = -EINVAL;


} else {


        pr_info("all tests passed\n");


}



+static struct kunit_case __refdata overflow_test_cases[] = {
Erm, __refdata? This seems like it should be __initdata.
...

KUNIT_CASE(overflow_calculation_test),


KUNIT_CASE(overflow_shift_test),


KUNIT_CASE(overflow_allocation_test),


{}



+};

return err;



-}
+static struct kunit_suite overflow_test_suite = {
And this.
...

.name = "overflow",


.test_cases = overflow_test_cases,



+};
-static void __exit test_module_exit(void)
-{ }
+kunit_test_suites(&overflow_test_suite);
I suspect the problem causing the need for __refdata there is the lack
of __init markings on the functions in kunit_test_suites()?
That is correct, Kees.
This problem goes all the way back to the initial KUnit RFC. I forget
who first brought it up, but there was an issue that KUnit runs in
init and consequently has access to __init stuff, but we weren't sure
that we want to mark *everything* in KUnit as __init. This was for a
number of reasons: one of these reasons was that we were considering
allowing KUnit to run at different times; with Alan's KUNIT_DEBUGFS
patches, this is now a reality. Thus, in some configurations, KUnit
can run its tests after kernel init is done, but also not as a module.
Sorry for not seeing this before.
...
(Or maybe this is explained somewhere else I've missed it.)
For example, would this work? (I haven't tested it all.)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 59f3144f009a..aad746d59d2f 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -233,9 +233,9 @@ size_t kunit_suite_num_test_cases(struct kunit_suite *suite);
 unsigned int kunit_test_case_num(struct kunit_suite *suite,
                                 struct kunit_case *test_case);
-int __kunit_test_suites_init(struct kunit_suite **suites);
+int __init __kunit_test_suites_init(struct kunit_suite **suites);
-void __kunit_test_suites_exit(struct kunit_suite **suites);
+void __exit __kunit_test_suites_exit(struct kunit_suite **suites);
/**

kunit_test_suites() - used to register one or more &struct kunit_suite

@@ -263,8 +263,9 @@ void __kunit_test_suites_exit(struct kunit_suite **suites);

everything else is definitely initialized.

*/
 #define kunit_test_suites(suites_list...)                              \

  static struct kunit_suite *suites[] = {suites_list, NULL};      \


  static int kunit_test_suites_init(void)                         \




  static struct kunit_suite *suites[] __initdata =                \


          {suites_list, NULL};                                    \


  static int __init kunit_test_suites_init(void)                  \
  {                                                               \
          return __kunit_test_suites_init(suites);                \
  }                                                               \



diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index c36037200310..bfb0f563721b 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -381,7 +381,7 @@ static void kunit_init_suite(struct kunit_suite *suite)
        kunit_debugfs_create_suite(suite);
 }
-int __kunit_test_suites_init(struct kunit_suite **suites)
+int __init __kunit_test_suites_init(struct kunit_suite **suites)
 {
        unsigned int i;
@@ -393,7 +393,7 @@ int __kunit_test_suites_init(struct kunit_suite **suites)
 }
 EXPORT_SYMBOL_GPL(__kunit_test_suites_init);
-static void kunit_exit_suite(struct kunit_suite *suite)
+static void __exit kunit_exit_suite(struct kunit_suite *suite)
 {
        kunit_debugfs_destroy_suite(suite);
 }
...
-module_init(test_module_init);
-module_exit(test_module_exit);
 MODULE_LICENSE("Dual MIT/GPL");
base-commit: 7bf200b3a4ac10b1b0376c70b8c66ed39eae7cdd
prerequisite-patch-id: e827b6b22f950b9f69620805a04e4a264cf4cc6a
--
2.26.2
Thanks again for the conversion!
--
Kees Cook

    

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Re: [RESEND, PATCH v2] lib: overflow-test: add KUnit test of check_*_overflow functions