kasan: docs: update usage section

Update the "Usage" section in KASAN documentation:

 - Add inline code snippet markers.

 - Reword the part about stack traces for clarity.

 - Other minor clean-ups.

Link: https://lkml.kernel.org/r/48427809cd4b8b5d6bc00926cbe87e2b5081df17.1615559068.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/dev-tools/kasan.rst

@@ -41,22 +41,21 @@ and riscv architectures, and tag-based KASAN modes are supported only for arm64.
 Usage
 -----
 
-To enable KASAN configure kernel with::
+To enable KASAN, configure the kernel with::
 
-	  CONFIG_KASAN = y
+	  CONFIG_KASAN=y
 
-and choose between CONFIG_KASAN_GENERIC (to enable generic KASAN),
-CONFIG_KASAN_SW_TAGS (to enable software tag-based KASAN), and
-CONFIG_KASAN_HW_TAGS (to enable hardware tag-based KASAN).
+and choose between ``CONFIG_KASAN_GENERIC`` (to enable generic KASAN),
+``CONFIG_KASAN_SW_TAGS`` (to enable software tag-based KASAN), and
+``CONFIG_KASAN_HW_TAGS`` (to enable hardware tag-based KASAN).
 
-For software modes, you also need to choose between CONFIG_KASAN_OUTLINE and
-CONFIG_KASAN_INLINE. Outline and inline are compiler instrumentation types.
-The former produces smaller binary while the latter is 1.1 - 2 times faster.
+For software modes, also choose between ``CONFIG_KASAN_OUTLINE`` and
+``CONFIG_KASAN_INLINE``. Outline and inline are compiler instrumentation types.
+The former produces a smaller binary while the latter is 1.1-2 times faster.
 
-For better error reports that include stack traces, enable CONFIG_STACKTRACE.
-
-To augment reports with last allocation and freeing stack of the physical page,
-it is recommended to enable also CONFIG_PAGE_OWNER and boot with page_owner=on.
+To include alloc and free stack traces of affected slab objects into reports,
+enable ``CONFIG_STACKTRACE``. To include alloc and free stack traces of affected
+physical pages, enable ``CONFIG_PAGE_OWNER`` and boot with ``page_owner=on``.
 
 Error reports
 ~~~~~~~~~~~~~