> On Aug 16, 2022, at 11:23 AM, Nadav Amit <na...@vmware.com> wrote:
>
> During my development, I enabled some Linux kernel checkers, specifically
> the “sleep in atomic” checker.
>
> I ran into unrelated issue that appears to be a result of commit
> 463713eb6164b6 ("VMCI: dma dg: add support for DMA datagrams receive”).
> IIUC, vmci_read_data() calls wait_event(), which is not allowed while IRQs
> are disabled, which they are during IRQ handling.
>
> I think "CONFIG_DEBUG_ATOMIC_SLEEP=y" is the one that triggers the warning
> below, which indicates a deadlock is possible.
>
> The splat below (after decoding) was experienced on Linux 5.19. Let me know
> if you need me to open a bug in bugzilla or whether this issue is already
> known.
Nathan reported this a few days ago, but we haven't gotten
around to it yet. Could you please file an internal bugzilla PR for
this?
Nathan,
Sorry we didn't respond to your email. Jorgen is no longer with
VMware and is not working on VMCI/VSOCKETS. We will take
a look at this.
Nadav,
Rajesh isn't with VMware now either, removing him from cc.
> [ 22.629691] BUG: sleeping function called from invalid context at
> drivers/misc/vmw_vmci/vmci_guest.c:145
> [ 22.633894] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 775,
> name: cloud-init
> [ 22.638232] preempt_count: 100, expected: 0
> [ 22.641887] RCU nest depth: 0, expected: 0
> [ 22.645461] 1 lock held by cloud-init/775:
> [ 22.649013] #0: ffff88810e057200 (&type->i_mutex_dir_key#6){++++}-{3:3},
> at: iterate_dir (fs/readdir.c:46)
> [ 22.653012] Preemption disabled at:
> [ 22.653017] __do_softirq (kernel/softirq.c:504 kernel/softirq.c:548)
> [ 22.660264] CPU: 3 PID: 775 Comm: cloud-init Not tainted 5.19.0+ #3
> [ 22.664004] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference
> Platform, BIOS VMW201.00V.20253199.B64.2208081742 08/08/2022
> [ 22.671600] Call Trace:
> [ 22.675165] <IRQ>
> [ 22.678681] dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
> [ 22.682303] dump_stack (lib/dump_stack.c:114)
> [ 22.685883] __might_resched.cold (kernel/sched/core.c:9822)
> [ 22.689500] __might_sleep (kernel/sched/core.c:9751 (discriminator 14))
> [ 22.692961] vmci_read_data (./include/linux/kernel.h:110
> drivers/misc/vmw_vmci/vmci_guest.c:145) vmw_vmci
> [ 22.696461] ? vmci_interrupt_bm (drivers/misc/vmw_vmci/vmci_guest.c:121)
> vmw_vmci
> [ 22.699920] ? __this_cpu_preempt_check (lib/smp_processor_id.c:67)
> [ 22.703305] ? wake_up_var (./include/linux/list.h:292
> ./include/linux/wait.h:129 kernel/sched/wait_bit.c:125
> kernel/sched/wait_bit.c:193)
> [ 22.706526] ? cpuusage_read (kernel/sched/wait_bit.c:192)
> [ 22.709682] ? mark_held_locks (kernel/locking/lockdep.c:4234)
> [ 22.712779] vmci_dispatch_dgs (drivers/misc/vmw_vmci/vmci_guest.c:332)
> vmw_vmci
> [ 22.715923] tasklet_action_common.constprop.0 (kernel/softirq.c:799)
> [ 22.719008] ? vmci_read_data (drivers/misc/vmw_vmci/vmci_guest.c:308)
> vmw_vmci
> [ 22.722018] tasklet_action (kernel/softirq.c:819)
> [ 22.724865] __do_softirq (kernel/softirq.c:571)
> [ 22.727650] __irq_exit_rcu (kernel/softirq.c:445 kernel/softirq.c:650)
> [ 22.730348] irq_exit_rcu (kernel/softirq.c:664)
> [ 22.732947] common_interrupt (arch/x86/kernel/irq.c:240 (discriminator
> 14))
> [ 22.735513] </IRQ>
> [ 22.737879] <TASK>
> [ 22.740141] asm_common_interrupt (./arch/x86/include/asm/idtentry.h:640)
> [ 22.742498] RIP: 0010:stack_trace_consume_entry (kernel/stacktrace.c:83)
> [ 22.744891] Code: be 80 01 00 00 48 c7 c7 40 82 cd 82 48 89 e5 e8 7d 38 53
> 00 5d c3 cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 e5 <41> 55
> 49 89 f5 41 54 53 48 89 fb 48 83 c7 10 e8 23 e0 36 00 48 8d
> All code
> ========
> 0: be 80 01 00 00 mov $0x180,%esi
> 5: 48 c7 c7 40 82 cd 82 mov $0xffffffff82cd8240,%rdi
> c: 48 89 e5 mov %rsp,%rbp
> f: e8 7d 38 53 00 call 0x533891
> 14: 5d pop %rbp
> 15: c3 ret
> 16: cc int3
> 17: cc int3
> 18: cc int3
> 19: cc int3
> 1a: cc int3
> 1b: cc int3
> 1c: cc int3
> 1d: cc int3
> 1e: cc int3
> 1f: cc int3
> 20: cc int3
> 21: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
> 26: 55 push %rbp
> 27: 48 89 e5 mov %rsp,%rbp
> 2a:* 41 55 push %r13 <-- trapping instruction
> 2c: 49 89 f5 mov %rsi,%r13
> 2f: 41 54 push %r12
> 31: 53 push %rbx
> 32: 48 89 fb mov %rdi,%rbx
> 35: 48 83 c7 10 add $0x10,%rdi
> 39: e8 23 e0 36 00 call 0x36e061
> 3e: 48 rex.W
> 3f: 8d .byte 0x8d
>
> Code starting with the faulting instruction
> ===========================================
> 0: 41 55 push %r13
> 2: 49 89 f5 mov %rsi,%r13
> 5: 41 54 push %r12
> 7: 53 push %rbx
> 8: 48 89 fb mov %rdi,%rbx
> b: 48 83 c7 10 add $0x10,%rdi
> f: e8 23 e0 36 00 call 0x36e037
> 14: 48 rex.W
> 15: 8d .byte 0x8d
> [ 22.750370] RSP: 0018:ffff8881250674d0 EFLAGS: 00000286
> [ 22.752906] RAX: ffffffff81676155 RBX: ffffffff81269600 RCX:
> ffffffff810e2106
> [ 22.755572] RDX: dffffc0000000000 RSI: ffffffff81676155 RDI:
> ffff8881250675a8
> [ 22.758217] RBP: ffff8881250674d0 R08: ffffffff810e20d4 R09:
> ffff88812f1a4000
> [ 22.760877] R10: ffff8881250674e0 R11: 0000000000000001 R12:
> ffff8881250675a8
> [ 22.763513] R13: 0000000000000000 R14: ffff88812f1a4000 R15:
> ffff88810f33c180
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