kunit_driver_create() accepts a name for the driver, but does not copy
it, so if that name is either on the stack, or otherwise freed, we end
up with a use-after-free when the driver is cleaned up.

Instead, strdup() the name, and manage it as another KUnit allocation.
As there was no existing kunit_kstrdup(), we add one. Further, add a
kunit_ variant of strdup_const() and kfree_const(), so we don't need to
allocate and manage the string in the majority of cases where it's a
constant.

However, these are inline functions, and is_kernel_rodata() only works
for built-in code. This causes problems in two cases:
- If kunit is built as a module, __{start,end}_rodata is not defined.
- If a kunit test using these functions is built as a module, it will
  suffer the same fate.

This fixes a KASAN splat with overflow.overflow_allocation_test, when
built as a module.

Restrict the is_kernel_rodata() case to when KUnit is built as a module,
which fixes the first case, at the cost of losing the optimisation.

Also, make kunit_{kstrdup,kfree}_const non-inline, so that other modules
using them will not accidentally depend on is_kernel_rodata(). If KUnit
is built-in, they'll benefit from the optimisation, if KUnit is not,
they won't, but the string will be properly duplicated.

Fixes: d03c720e03bd ("kunit: Add APIs for managing devices")
Reported-by: Nico Pache <npache@redhat.com>
Closes: https://groups.google.com/g/kunit-dev/c/81V9b9QYON0
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Rae Moar <rmoar@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Tested-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The alloc/copy code pattern is better consolidated to single kstrdup (and
kstrndup) calls instead. This gets rid of deprecated[1] strncpy() uses as
well. Replace one other strncpy() use with the more idiomatic strscpy().

Link: https://github.com/KSPP/linux/issues/90 [1]
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Since arch_pick_mmap_layout() is an inline for non-MMU systems, disable
this test there.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406160505.uBge6TMY-lkp@intel.com/
Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

For tests that need to allocate using vm_mmap() (e.g. usercopy and
execve), provide the interface to have the allocation tracked by KUnit
itself. This requires bringing up a placeholder userspace mm.

This combines my earlier attempt at this with Mark Rutland's version[1].

Normally alloc_mm() and arch_pick_mmap_layout() aren't exported for
modules, so export these only for KUnit testing.

Link: https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ [1]
Co-developed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

make allmodconfig && make W=1 C=1 reports in lib/kunit:
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-example-test.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

There are multiple assertion formatting functions in the `assert.c`
file, which are not covered with tests yet. Implement the KUnit test
for these functions.

The test consists of 11 test cases for the following functions:

1) 'is_literal'
2) 'is_str_literal'
3) 'kunit_assert_prologue', test case for multiple assert types
4) 'kunit_assert_print_msg'
5) 'kunit_unary_assert_format'
6) 'kunit_ptr_not_err_assert_format'
7) 'kunit_binary_assert_format'
8) 'kunit_binary_ptr_assert_format'
9) 'kunit_binary_str_assert_format'
10) 'kunit_assert_hexdump'
11) 'kunit_mem_assert_format'

The test aims at maximizing the branch coverage for the assertion
formatting functions.

As you can see, it covers some of the static helper functions as
well, so mark the static functions in `assert.c` as 'VISIBLE_IF_KUNIT'
and conditionally export them with EXPORT_SYMBOL_IF_KUNIT. Add the
corresponding definitions to `assert.h`.

Build the assert test when CONFIG_KUNIT_TEST is enabled, similar to
how it is done for the string stream test.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Acked-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Commit c72a870926c2 added a mutex to prevent kunit tests from running
concurrently.  Unfortunately that mutex gets locked during module load
regardless of whether the module actually has any kunit tests.  This
causes a problem for kunit tests that might need to load other kernel
modules (e.g. gss_krb5_test loading the camellia module).

So check to see if there are actually any tests to run before locking
the kunit_run_lock mutex.

Fixes: c72a870926c2 ("kunit: add ability to run tests after boot using debugfs")
Reported-by: Nico Pache <npache@redhat.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Use KUNIT_DEFINE_ACTION_WRAPPER macro to define the 'kfree' and
'string_stream_destroy' wrappers for kunit_add_action.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Acked-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The NULL dereference tests in kunit_fault deliberately trigger a kernel
BUG(), and therefore print the associated stack trace, even when the
test passes. This is both annoying (as it bloats the test output), and
can confuse some test harnesses, which assume any BUG() is a failure.

Allow these tests to be specifically disabled (without disabling all
of KUnit's other tests), by placing them behind the
CONFIG_KUNIT_FAULT_TEST Kconfig option. This is enabled by default, but
can be set to 'n' to disable the test. An empty 'kunit_fault' suite is
left behind, which will automatically be marked 'skipped'.

As the fault tests already were disabled under UML (as they weren't
compatible with its fault handling), we can simply adapt those
conditions, and add a dependency on !UML for our new option.

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/928249cc-e027-4f7f-b43f-502f99a1ea63@roeck-us.net/
Fixes: 82b0beff3497 ("kunit: Add tests for fault")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Mickaël Salaün <mic@digikod.net>
Reviewed-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit_init_device() should unregister the device on bus register error,
but mistakenly it tries to unregister the bus.

Unregister the device instead of the bus.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Fixes: d03c720e03bd ("kunit: Add APIs for managing devices")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>