Waiman Long ac7af1f57a kasan: don't call find_vm_area() in a PREEMPT_RT kernel ... 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 e30a0361b8 ("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 0cce06ba85 ("debugobjects,locking: Annotate debug_object_fill_pool() wait type violation"). Link: https://lkml.kernel.org/r/20250217204402.60533-1-longman@redhat.com Fixes: e30a0361b8 ("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>		2025-02-17 22:40:04 -08:00
..
common.c	slub: Introduce CONFIG_SLUB_RCU_DEBUG	2024-08-27 14:12:51 +02:00
generic.c	kasan: make kasan_record_aux_stack_noalloc() the default behaviour	2025-01-13 22:40:36 -08:00
hw_tags.c	kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()	2025-01-25 20:22:44 -08:00
init.c	mm: define general function pXd_init()	2024-11-11 17:22:27 -08:00
kasan_test_c.c	mm:kasan: fix sparse warnings: Should it be static?	2025-01-13 22:40:42 -08:00
kasan_test_rust.rs	rust: treewide: switch to the kernel Vec type	2024-10-15 23:10:32 +02:00
kasan.h	kasan: use correct kernel-doc format	2025-01-25 20:22:41 -08:00
Makefile	kasan: migrate copy_user_test to kunit	2024-11-11 00:26:44 -08:00
quarantine.c	kasan: revert eviction of stack traces in generic mode	2024-02-23 17:27:12 -08:00
report_generic.c	kasan: stop leaking stack trace handles	2024-01-05 10:17:45 -08:00
report_hw_tags.c	kasan: use internal prototypes matching gcc-13 builtins	2023-06-09 16:25:19 -07:00
report_sw_tags.c	kasan: use internal prototypes matching gcc-13 builtins	2023-06-09 16:25:19 -07:00
report_tags.c	kasan: simplify kasan_complete_mode_report_info for tag-based modes	2023-12-29 11:58:47 -08:00
report.c	kasan: don't call find_vm_area() in a PREEMPT_RT kernel	2025-02-17 22:40:04 -08:00
shadow.c	mm/vmalloc: combine all TLB flush operations of KASAN shadow virtual address into one operation	2024-11-05 16:56:21 -08:00
sw_tags.c	kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()	2025-01-25 20:22:46 -08:00
tags.c	kasan: simplify saving extra info into tracks	2023-12-29 11:58:46 -08:00