> I've discovered that the function free_vmap_stack() can trigger a warning. > It appears that free_vmap_stack() should handle interrupt context and > task context separately as vfree(). Hi Jeff, Thank you for reporting this. Yes, it appears free_vmap_stack() may get called from the interrupt context, and yet we call remove_vm_area() that takes locks. I will fix it in the next version similar to the way you suggested by adding an in_interrupt() case. Thank you, Pasha > [root@JeffXie ]# poweroff > [root@JeffXie ]# umount: devtmpfs busy - remounted read-only > [ 93.036872] EXT4-fs (vda): re-mounted > 2e1f057b-471f-4c08-a7b8-611457b221f2 ro. Quota mode: none. > The system is going down NOW! > Sent SIGTERM to all processes > Sent SIGKILL to all processes > Requesting system poweroff > [ 94.043540] ------------[ cut here ]------------ > [ 94.043977] WARNING: CPU: 0 PID: 0 at kernel/smp.c:786 > smp_call_function_many_cond+0x4e5/0x550 > [ 94.044744] Modules linked in: > [ 94.045024] CPU: 0 PID: 0 Comm: swapper/0 Not tainted > 6.8.0-00014-g82270db6e1f0 #91 > [ 94.045697] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), > BIOS 1.15.0-1 04/01/2014 > [ 94.046399] RIP: 0010:smp_call_function_many_cond+0x4e5/0x550 > [ 94.046914] Code: 48 8b 78 08 48 c7 c1 a0 84 16 81 4c 89 f6 e8 22 > 11 f6 ff 65 ff 0d 23 38 ec 7e 0f 85 a1 fc ff ff 0f 1f 44 00 00 e9 97 > fc ff ff <0f> 0b e9 61 > [ 94.048509] RSP: 0018:ffffc90000003e48 EFLAGS: 00010206 > [ 94.048965] RAX: ffffffff82cb3fd0 RBX: ffff88811862cbc0 RCX: 0000000000000003 > [ 94.049598] RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 > [ 94.050226] RBP: ffff8881052c5090 R08: 0000000000000000 R09: 0000000000000001 > [ 94.050861] R10: ffffffff82a060c0 R11: 0000000000008847 R12: ffff888102eb3500 > [ 94.051480] R13: ffff88811862b800 R14: ffff88811862cc38 R15: 0000000000000000 > [ 94.052109] FS: 0000000000000000(0000) GS:ffff888118600000(0000) > knlGS:0000000000000000 > [ 94.052812] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 94.053318] CR2: 00000000004759e0 CR3: 0000000002a2e000 CR4: 0000000000750ef0 > [ 94.053955] PKRU: 55555554 > [ 94.054203] Call Trace: > [ 94.054433] <IRQ> > [ 94.054632] ? __warn+0x84/0x140 > [ 94.054925] ? smp_call_function_many_cond+0x4e5/0x550 > [ 94.055362] ? report_bug+0x199/0x1b0 > [ 94.055697] ? handle_bug+0x3c/0x70 > [ 94.056010] ? exc_invalid_op+0x18/0x70 > [ 94.056350] ? asm_exc_invalid_op+0x1a/0x20 > [ 94.056728] ? smp_call_function_many_cond+0x4e5/0x550 > [ 94.057179] ? __pfx_do_kernel_range_flush+0x10/0x10 > [ 94.057622] on_each_cpu_cond_mask+0x24/0x40 > [ 94.057999] flush_tlb_kernel_range+0x98/0xb0 > [ 94.058390] free_unmap_vmap_area+0x2d/0x40 > [ 94.058768] remove_vm_area+0x3a/0x70 > [ 94.059094] free_vmap_stack+0x15/0x60 > [ 94.059427] rcu_core+0x2bf/0x980 > [ 94.059735] ? rcu_core+0x244/0x980 > [ 94.060046] ? kvm_clock_get_cycles+0x18/0x30 > [ 94.060431] __do_softirq+0xc2/0x292 > [ 94.060760] irq_exit_rcu+0x6a/0x90 > [ 94.061074] sysvec_apic_timer_interrupt+0x6e/0x90 > [ 94.061507] </IRQ> > [ 94.061704] <TASK> > [ 94.061903] asm_sysvec_apic_timer_interrupt+0x1a/0x20 > [ 94.062367] RIP: 0010:default_idle+0xf/0x20 > [ 94.062746] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 > 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 33 b4 2a > 00 fb f4 <fa> c3 cc c0 > [ 94.064342] RSP: 0018:ffffffff82a03e70 EFLAGS: 00000212 > [ 94.064805] RAX: ffff888118628608 RBX: ffffffff82a0c980 RCX: 0000000000000000 > [ 94.065429] RDX: 4000000000000000 RSI: ffffffff82725be8 RDI: 000000000000a14c > [ 94.066066] RBP: 0000000000000000 R08: 000000000000a14c R09: 0000000000000001 > [ 94.066705] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > [ 94.067311] R13: 0000000000000000 R14: ffffffff82a0c030 R15: 00000000000000ac > [ 94.067936] default_idle_call+0x2c/0xd0 > [ 94.068284] do_idle+0x1ce/0x210 > [ 94.068584] cpu_startup_entry+0x2a/0x30 > [ 94.068931] rest_init+0xc5/0xd0 > [ 94.069224] arch_call_rest_init+0xe/0x30 > [ 94.069597] start_kernel+0x58e/0x8d0 > [ 94.069929] x86_64_start_reservations+0x18/0x30 > [ 94.070353] x86_64_start_kernel+0xc6/0xe0 > [ 94.070725] secondary_startup_64_no_verify+0x16d/0x17b > [ 94.071189] </TASK> > [ 94.071392] ---[ end trace 0000000000000000 ]--- > [ 95.040718] e1000e: EEE TX LPI TIMER: 00000000 > [ 95.055005] ACPI: PM: Preparing to enter system sleep state S5 > [ 95.055619] reboot: Power down > > > ./scripts/faddr2line ./vmlinux smp_call_function_many_cond+0x4e5/0x550 > smp_call_function_many_cond+0x4e5/0x550: > smp_call_function_many_cond at kernel/smp.c:786 (discriminator 1) > > 756 static void smp_call_function_many_cond(const struct cpumask *mask, > 757 smp_call_func_t func, void *info, > 758 unsigned int scf_flags, > 759 smp_cond_func_t cond_func) > [...] > 781 * When @wait we can deadlock when we interrupt between > llist_add() and > 782 * arch_send_call_function_ipi*(); when !@wait we can > deadlock due to > 783 * csd_lock() on because the interrupt context uses the same csd > 784 * storage. > 785 */ > 786 WARN_ON_ONCE(!in_task()); > // <<< warning here > [...] > > > > -- > Thanks, > JeffXie
