Pull KUnit updates from Shuah Khan:
 "Several fixes, cleanups, and enhancements to tests and framework:

   - introduce _NULL and _NOT_NULL macros to pointer error checks

   - rework kunit_resource allocation policy to fix memory leaks when
     caller doesn't specify free() function to be used when allocating
     memory using kunit_add_resource() and kunit_alloc_resource() funcs.

   - add ability to specify suite-level init and exit functions"

* tag 'linux-kselftest-kunit-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (41 commits)
  kunit: tool: Use qemu-system-i386 for i386 runs
  kunit: fix executor OOM error handling logic on non-UML
  kunit: tool: update riscv QEMU config with new serial dependency
  kcsan: test: use new suite_{init,exit} support
  kunit: tool: Add list of all valid test configs on UML
  kunit: take `kunit_assert` as `const`
  kunit: tool: misc cleanups
  kunit: tool: minor cosmetic cleanups in kunit_parser.py
  kunit: tool: make parser stop overwriting status of suites w/ no_tests
  kunit: tool: remove dead parse_crash_in_log() logic
  kunit: tool: print clearer error message when there's no TAP output
  kunit: tool: stop using a shell to run kernel under QEMU
  kunit: tool: update test counts summary line format
  kunit: bail out of test filtering logic quicker if OOM
  lib/Kconfig.debug: change KUnit tests to default to KUNIT_ALL_TESTS
  kunit: Rework kunit_resource allocation policy
  kunit: fix debugfs code to use enum kunit_status, not bool
  kfence: test: use new suite_{init/exit} support, add .kunitconfig
  kunit: add ability to specify suite-level init and exit functions
  kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)
  ...

Use the newly added suite_{init,exit} support for suite-wide init and
cleanup. This avoids the unsupported method by which the test used to do
suite-wide init and cleanup (avoiding issues such as missing TAP
headers, and possible future conflicts).

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Per PREEMPT_DYNAMIC, checking CONFIG_PREEMPT doesn't tell you the actual
preemption model of the live kernel. Use the newly-introduced accessors
instead.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20211112185203.280040-4-valentin.schneider@arm.com

Some architectures do not define clear_bit_unlock_is_negative_byte().
Only test it when it is actually defined (similar to other usage, such
as in lib/test_kasan.c).

Link: https://lkml.kernel.org/r/202112050757.x67rHnFU-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

The barrier tests in selftest and the kcsan_test module only need the
spinlock and mutex to test correct barrier instrumentation. Therefore,
these were initially placed on the stack.

However, lockdep asserts that locks are in static storage, and will
generate this warning:

 | INFO: trying to register non-static key.
 | The code is fine but needs lockdep annotation, or maybe
 | you didn't initialize this object before use?
 | turning off the locking correctness validator.
 | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-rc1+ #3208
 | Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
 | Call Trace:
 |  <TASK>
 |  dump_stack_lvl+0x88/0xd8
 |  dump_stack+0x15/0x1b
 |  register_lock_class+0x6b3/0x840
 |  ...
 |  test_barrier+0x490/0x14c7
 |  kcsan_selftest+0x47/0xa0
 |  ...

To fix, move the test locks into static storage.

Fixing the above also revealed that lock operations are strengthened on
first use with lockdep enabled, due to lockdep calling out into
non-instrumented files (recall that kernel/locking/lockdep.c is not
instrumented with KCSAN).

Only kcsan_test checks for over-instrumentation of *_lock() operations,
where we can simply "warm up" the test locks to avoid the test case
failing with lockdep.

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Adds test cases to check that memory barriers are instrumented
correctly, and detection of missing memory barriers is working as
intended if CONFIG_KCSAN_STRICT=y.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Due to reordering accesses with weak memory modeling, any access can now
appear as "(reordered)".

Match any permutation of accesses if CONFIG_KCSAN_WEAK_MEMORY=y, so that
we effectively match an access if it is denoted "(reordered)" or not.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

The scoping of an access simply denotes the scope in which it may be
reordered. However, in reports, it'll be less confusing to say the
access is "reordered". This is more accurate when the race occurred.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Support generating the string representation of scoped read-write
accesses for completeness. They will become required in planned changes.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

If an explicit access address is set, as is done for scoped accesses,
always start the stack trace from that location. get_stack_skipnr() is
changed into sanitize_stack_entries(), which if given an address, scans
the stack trace for a matching function and then replaces that entry
with the explicitly provided address.

The previous reports for scoped accesses were all over the place, which
could be quite confusing. We now always point at the start of the scope.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>