kcsan: selftest: Move test spinlock to static global
Running the TREE01 or TREE02 rcutorture scenarios results in the
following splat:
------------------------------------------------------------------------
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
? __this_cpu_preempt_check+0x1d/0x30
__lock_acquire+0x81/0xee0
? lock_is_held_type+0xf1/0x160
lock_acquire+0xce/0x230
? test_barrier+0x490/0x14c7
? lock_is_held_type+0xf1/0x160
? test_barrier+0x490/0x14c7
_raw_spin_lock+0x36/0x50
? test_barrier+0x490/0x14c7
? kcsan_init+0xf/0x80
test_barrier+0x490/0x14c7
? kcsan_debugfs_init+0x1f/0x1f
kcsan_selftest+0x47/0xa0
do_one_initcall+0x104/0x230
? rcu_read_lock_sched_held+0x5b/0xc0
? kernel_init+0x1c/0x200
do_initcall_level+0xa5/0xb6
do_initcalls+0x66/0x95
do_basic_setup+0x1d/0x23
kernel_init_freeable+0x254/0x2ed
? rest_init+0x290/0x290
kernel_init+0x1c/0x200
? rest_init+0x290/0x290
ret_from_fork+0x22/0x30
</TASK>
------------------------------------------------------------------------
This appears to be due to this line of code in kernel/kcsan/selftest.c:
KCSAN_CHECK_READ_BARRIER(spin_unlock(&spinlock)), which operates on a
spinlock allocated on the stack. This shot-in-the-dark patch makes the
spinlock instead be a static global, which suppresses the above splat.
Fixes: 510b49b8d4c9 ("kcsan: selftest: Add test case to check memory barrier instrumentation")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
1 file changed
