kmsan: add tests for KMSAN

The testing module triggers KMSAN warnings in different cases and checks
that the errors are properly reported, using console probes to capture the
tool's output.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexander Potapenko <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

lib/Kconfig.kmsan

@@ -47,4 +47,16 @@ config KMSAN_CHECK_PARAM_RETVAL
 	  may potentially report errors in corner cases when non-instrumented
 	  functions call instrumented ones.
 
+config KMSAN_KUNIT_TEST
+	tristate "KMSAN integration test suite" if !KUNIT_ALL_TESTS
+	default KUNIT_ALL_TESTS
+	depends on TRACEPOINTS && KUNIT
+	help
+	  Test suite for KMSAN, testing various error detection scenarios,
+	  and checking that reports are correctly output to console.
+
+	  Say Y here if you want the test to be built into the kernel and run
+	  during boot; say M if you want the test to build as a module; say N
+	  if you are unsure.
+
 endif

mm/kmsan/Makefile

@@ -22,3 +22,7 @@ CFLAGS_init.o := $(CC_FLAGS_KMSAN_RUNTIME)
 CFLAGS_instrumentation.o := $(CC_FLAGS_KMSAN_RUNTIME)
 CFLAGS_report.o := $(CC_FLAGS_KMSAN_RUNTIME)
 CFLAGS_shadow.o := $(CC_FLAGS_KMSAN_RUNTIME)
+
+obj-$(CONFIG_KMSAN_KUNIT_TEST) += kmsan_test.o
+KMSAN_SANITIZE_kmsan_test.o := y
+CFLAGS_kmsan_test.o += $(call cc-disable-warning, uninitialized)