(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Wed, 14 Sep 2022 15:07:46 +0000 bugzilla-daemon@xxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=216489 > > Bug ID: 216489 > Summary: Machine freezes due to memory lock > Product: Memory Management > Version: 2.5 > Kernel Version: 5.19.8 > Hardware: AMD > OS: Linux > Tree: Mainline > Status: NEW > Severity: high > Priority: P1 > Component: Other > Assignee: akpm@xxxxxxxxxxxxxxxxxxxx > Reporter: dev@xxxxxxxxxxx > Regression: No > > Hi all, > With Kernel 5.19.x we noticed system freezes. This happens in virtual > environments as well as on real hardware. > On a real hardware machine we were able to catch the moment of freeze with > continuous profiling. Thanks. I forwarded this to Uladzislau and he offered to help. He said: : I can help with debugging. What i need is reproduce steps. Could you : please clarify if it is easy to hit and what kind of profiling triggers it? and : I do not think that Matthew Wilcox commits destroys it but... I see that : __vunmap() is invoked by the free_work() thus a caller is in atomic : context including IRQ context. > Specification of the machine where we captured the freeze: > Thinkpad T14 > CPU: AMD Ryzen 7 PRO 4750U > Kernel: 5.19.8-200.fc36.x86_64 > > Stacktrace of kworker/12:3 that is using all resources and causing the freeze: > > # Source Location Function Name Function Line > 0 arch/x86/include/asm/vdso/processor.h:13 rep_nop 11 > 1 arch/x86/include/asm/vdso/processor.h:18 cpu_relax 16 > 2 kernel/locking/qspinlock.c:514 native_queued_spin_lock_slowpath > 316 > 3 kernel/locking/qspinlock.c:316 native_queued_spin_lock_slowpath > N/A > 4 arch/x86/include/asm/paravirt.h:591 pv_queued_spin_lock_slowpath > 588 > 5 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock_slowpath 49 > 6 include/asm-generic/qspinlock.h:114 queued_spin_lock 107 > 7 include/linux/spinlock.h:185 do_raw_spin_lock 182 > 8 include/linux/spinlock_api_smp.h:134 __raw_spin_lock 130 > 9 kernel/locking/spinlock.c:154 _raw_spin_lock 152 > 10 include/linux/spinlock.h:349 spin_lock 347 > 11 mm/vmalloc.c:1805 find_vmap_area 1801 > 12 mm/vmalloc.c:2525 find_vm_area 2521 > 13 mm/vmalloc.c:2639 __vunmap 2628 > 14 mm/vmalloc.c:97 free_work 91 > 15 kernel/workqueue.c:2289 process_one_work 2181 > 16 kernel/workqueue.c:2436 worker_thread 2378 > 17 kernel/kthread.c:376 kthread 330 > 18 N/A ret_from_fork N/A > > The functions in the above shown stacktrace hardly change. There is only one > commit 993d0b287e2ef7bee2e8b13b0ce4d2b5066f278e which introduces changes to > find_vmap_area() for 5.19. > > With this change in mind we looked for stacktraces which make also use of this > new commit. And in a different kernel thread we do notice the use of > check_heap_object(): > > # Source Location Function Name Function Line > 0 arch/x86/include/asm/paravirt.h:704 arch_local_irq_enable 702 > 1 arch/x86/include/asm/irqflags.h:138 arch_local_irq_restore 135 > 2 kernel/sched/sched.h:1330 raw_spin_rq_unlock_irqrestore 1327 > 3 kernel/sched/sched.h:1327 raw_spin_rq_unlock_irqrestore N/A > 4 kernel/sched/sched.h:1611 rq_unlock_irqrestore 1607 > 5 kernel/sched/fair.c:8288 update_blocked_averages 8272 > 6 kernel/sched/fair.c:11133 run_rebalance_domains 11115 > 7 kernel/softirq.c:571 __do_softirq 528 > 8 kernel/softirq.c:445 invoke_softirq 433 > 9 kernel/softirq.c:650 __irq_exit_rcu 640 > 10 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt N/A > 11 N/A asm_sysvec_apic_timer_interrupt N/A > 12 include/linux/mmzone.h:1403 __nr_to_section 1395 > 13 include/linux/mmzone.h:1488 __pfn_to_section 1486 > 14 include/linux/mmzone.h:1539 pfn_valid 1524 > 15 arch/x86/mm/physaddr.c:65 __virt_addr_valid 47 > 16 mm/usercopy.c:188 check_heap_object 161 > 17 mm/usercopy.c:250 __check_object_size 212 > 18 mm/usercopy.c:212 __check_object_size N/A > 19 include/linux/thread_info.h:199 check_object_size 195 > 20 lib/strncpy_from_user.c:137 strncpy_from_user 113 > 21 fs/namei.c:150 getname_flags 129 > 22 fs/namei.c:2896 user_path_at_empty 2893 > 23 include/linux/namei.h:57 user_path_at 54 > 24 fs/open.c:446 do_faccessat 420 > 25 arch/x86/entry/common.c:50 do_syscall_x64 40 > 26 arch/x86/entry/common.c:80 do_syscall_64 73 > 27 N/A entry_SYSCALL_64_after_hwframe N/A > > We are neither experts in the mm subsystem nor can provide a fix, but wanted to > let you know about our findings. > > Cheers, > Florian > > -- > You may reply to this email to add a comment. > > You are receiving this mail because: > You are the assignee for the bug.
