kasan: docs: update tests section

Update the "Tests" section in KASAN documentation:

 - Add an introductory sentence.

 - Add proper indentation for the list of ways to run KUnit tests.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/fb08845e25c8847ffda271fa19cda2621c04a65b.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/dev-tools/kasan.rst

@@ -420,19 +420,20 @@ saving and restoring the per-page KASAN tag via
 Tests
 ~~~~~
 
-KASAN tests consist of two parts:
+There are KASAN tests that allow verifying that KASAN works and can detect
+certain types of memory corruptions. The tests consist of two parts:
 
 1. Tests that are integrated with the KUnit Test Framework. Enabled with
 ``CONFIG_KASAN_KUNIT_TEST``. These tests can be run and partially verified
-automatically in a few different ways, see the instructions below.
+automatically in a few different ways; see the instructions below.
 
 2. Tests that are currently incompatible with KUnit. Enabled with
 ``CONFIG_KASAN_MODULE_TEST`` and can only be run as a module. These tests can
-only be verified manually, by loading the kernel module and inspecting the
+only be verified manually by loading the kernel module and inspecting the
 kernel log for KASAN reports.
 
-Each KUnit-compatible KASAN test prints a KASAN report if an error is detected.
-Then the test prints its number and status.
+Each KUnit-compatible KASAN test prints one of multiple KASAN reports if an
+error is detected. Then the test prints its number and status.
 
 When a test passes::
 
@@ -460,27 +461,24 @@ Or, if one of the tests failed::
 
         not ok 1 - kasan
 
-
 There are a few ways to run KUnit-compatible KASAN tests.
 
 1. Loadable module
 
-With ``CONFIG_KUNIT`` enabled, ``CONFIG_KASAN_KUNIT_TEST`` can be built as
-a loadable module and run on any architecture that supports KASAN by loading
-the module with insmod or modprobe. The module is called ``test_kasan``.
+   With ``CONFIG_KUNIT`` enabled, KASAN-KUnit tests can be built as a loadable
+   module and run by loading ``test_kasan.ko`` with ``insmod`` or ``modprobe``.
 
 2. Built-In
 
-With ``CONFIG_KUNIT`` built-in, ``CONFIG_KASAN_KUNIT_TEST`` can be built-in
-on any architecure that supports KASAN. These and any other KUnit tests enabled
-will run and print the results at boot as a late-init call.
+   With ``CONFIG_KUNIT`` built-in, KASAN-KUnit tests can be built-in as well.
+   In this case, the tests will run at boot as a late-init call.
 
 3. Using kunit_tool
 
-With ``CONFIG_KUNIT`` and ``CONFIG_KASAN_KUNIT_TEST`` built-in, it's also
-possible use ``kunit_tool`` to see the results of these and other KUnit tests
-in a more readable way. This will not print the KASAN reports of the tests that
-passed. Use `KUnit documentation <https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html>`_
-for more up-to-date information on ``kunit_tool``.
+   With ``CONFIG_KUNIT`` and ``CONFIG_KASAN_KUNIT_TEST`` built-in, it is also
+   possible to use ``kunit_tool`` to see the results of KUnit tests in a more
+   readable way. This will not print the KASAN reports of the tests that passed.
+   See `KUnit documentation <https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html>`_
+   for more up-to-date information on ``kunit_tool``.
 
 .. _KUnit: https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html