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The following bug report was found when running a PREEMPT_RT debug kernel.
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 140605, name: kunit_try_catch
preempt_count: 1, expected: 0
Call trace:
rt_spin_lock+0x70/0x140
find_vmap_area+0x84/0x168
find_vm_area+0x1c/0x50
print_address_description.constprop.0+0x2a0/0x320
print_report+0x108/0x1f8
kasan_report+0x90/0xc8
Since commit e30a0361b851 ("kasan: make report_lock a raw spinlock"),
report_lock was changed to raw_spinlock_t to fix another similar
PREEMPT_RT problem. That alone isn't enough to cover other corner cases.
print_address_description() is always invoked under the report_lock. The
context under this lock is always atomic even on PREEMPT_RT.
find_vm_area() acquires vmap_node::busy.lock which is a spinlock_t,
becoming a sleeping lock on PREEMPT_RT and must not be acquired in atomic
context.
Don't invoke find_vm_area() on PREEMPT_RT and just print the address.
Non-PREEMPT_RT builds remain unchanged. Add a DEFINE_WAIT_OVERRIDE_MAP()
macro to tell lockdep that this lock nesting is allowed because the
PREEMPT_RT part (which is invalid) has been taken care of. This macro was
first introduced in commit 0cce06ba859a ("debugobjects,locking: Annotate
debug_object_fill_pool() wait type violation").
Link: https://lkml.kernel.org/r/20250217204402.60533-1-longman@redhat.com
Fixes: e30a0361b851 ("kasan: make report_lock a raw spinlock")
Signed-off-by: Waiman Long <longman@redhat.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mariano Pache <npache@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>