[PATCH v15 00/10] arm64: Add kernel probes (kprobes) support

Catalin Marinas catalin.marinas at arm.com
Tue Jul 19 11:27:44 PDT 2016 

On Fri, Jul 08, 2016 at 12:35:44PM -0400, David Long wrote:
> From: "David A. Long" <dave.long at linaro.org>
> 
> This patchset is heavily based on Sandeepa Prabhu's ARM v8 kprobes patches,
> first seen in October 2013. This version attempts to address concerns
> raised by reviewers and also fixes problems discovered during testing.
> 
> This patchset adds support for kernel probes(kprobes), jump probes(jprobes)
> and return probes(kretprobes) support for ARM64.

Some more errors with this patchset applied and CONFIG_NET_TCPPROBE
enabled (it's fine with this option disabled though). I boot on a Juno
with NFS over UDP and then try to ssh into it (hence establish the first
TCP connection):

Unable to handle kernel NULL pointer dereference at virtual address 00000003
pgd = ffff000008ceb000
[00000003] *pgd=00000009fff6d003, *pud=00000009fff6c003, *pmd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc4+ #9
Hardware name: ARM Juno development board (r0) (DT)
task: ffff800976901900 ti: ffff800976910000 task.ti: ffff800976910000
PC is at enqueue_task_fair+0x818/0x1188
LR is at enqueue_task_fair+0x8a4/0x1188
pc : [<ffff0000080e73d8>] lr : [<ffff0000080e7464>] pstate: 600001c5
sp : ffff80097fec3a80
x29: ffff80097fec3a80 x28: 0000000000000001
x27: 00000000afb50401 x26: afb504000afb5041
x25: 0000000000000000 x24: 0000000000000001
x23: ffff000008bcbd90 x22: 0000000000000001
x21: ffff800975951900 x20: ffff800975951800
x19: ffff80097fec96e8 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000
x15: 0000000000000001 x14: 0000000000000001
x13: 0000000005da2e6c x12: 000000000044ab8d
x11: 0000000000000000 x10: 0000000000000001
x9 : 0000000000000000 x8 : 0000000991653ffc
x7 : 000000000000003e x6 : ffff80097fec9740
x5 : 0000000000000000 x4 : ffff0000087ef950
x3 : 0000000000000400 x2 : 000000000000005e
x1 : ffff80097fec9680 x0 : 0000000000000003

Process swapper/1 (pid: 0, stack limit = 0xffff800976910020)
Stack: (0xffff80097fec3a80 to 0xffff800976914000)
Call trace:
Exception stack(0xffff80097fec38c0 to 0xffff80097fec39e0)
38c0: ffff80097fec96e8 ffff800975951800 ffff80097fec3a80 ffff0000080e73d8
38e0: ffff800976ad2300 ffff800974a07e00 0000000000000003 ffff800974a00000
3900: 0000000000000000 ffff7e0025d28000 0000000000000013 0000000080010400
3920: ffff000008c9f000 0000000000000003 0000000100000000 000000000000000e
3940: ffff80097fec39a0 ffff0000081ae954 0000000000000000 0000000000000000
3960: 0000000000000003 ffff80097fec9680 000000000000005e 0000000000000400
3980: ffff0000087ef950 0000000000000000 ffff80097fec9740 000000000000003e
39a0: 0000000991653ffc 0000000000000000 0000000000000001 0000000000000000
39c0: 000000000044ab8d 0000000005da2e6c 0000000000000001 0000000000000001
[<ffff0000080e73d8>] enqueue_task_fair+0x818/0x1188
[<ffff0000080dbdd4>] activate_task+0x5c/0xa0
[<ffff0000080dc088>] ttwu_do_activate+0x50/0x88
[<ffff0000080dda60>] try_to_wake_up+0x228/0x2c0
[<ffff0000080ddbd0>] default_wake_function+0x10/0x18
[<ffff0000080f0ffc>] autoremove_wake_function+0x14/0x40
[<ffff0000080f0814>] __wake_up_common+0x5c/0xa0
[<ffff0000080f0e64>] __wake_up_sync_key+0x4c/0x78
[<ffff00000875a330>] tcp_prequeue+0x190/0x2e8
[<ffff00000875b8a4>] tcp_v4_rcv+0xa5c/0xb08
[<ffff000008736eac>] ip_local_deliver+0xa4/0x200
[<ffff0000087373e4>] ip_rcv+0x3dc/0x5f0
[<ffff000008707460>] __netif_receive_skb_core+0x5f8/0x7c8
[<ffff000008709990>] __netif_receive_skb+0x18/0x68
[<ffff000008709a04>] netif_receive_skb_internal+0x24/0xa8
[<ffff000008709a94>] netif_receive_skb+0xc/0x18
[<ffff00000858f9b0>] smsc911x_poll+0xf0/0x278
[<ffff00000870b0b0>] net_rx_action+0x1d8/0x2b0
[<ffff0000080be200>] __do_softirq+0x100/0x210
[<ffff0000080be5b8>] irq_exit+0x90/0xd8
[<ffff0000080fb2f8>] __handle_domain_irq+0x60/0xb8
[<ffff000008081578>] gic_handle_irq+0x58/0xb0
Exception stack(0xffff800976913df0 to 0xffff800976913f10)
3de0:                                   0000000000000000 ffff80097fec9680
3e00: 00008009772f9000 0000000002800000 0000000000000004 000000000115c074
3e20: 0000000000000015 000000000000012f 000000000000016d ffff80097fec872c
3e40: 0000000000000a12 0000000000000a12 071c71c71c71c71c 20230a2e746c7561
3e60: 524150203a4c4c41 0000000000000000 0000000000000000 0000000000000000
3e80: 0000000000000000 00000009972f2718 ffff8009763d7400 0000000000000000
3ea0: 0000000000000000 ffff000008c6bb20 00000009972ada50 ffff000008c05c1c
3ec0: ffff000008c05000 ffff000008c6bb20 ffff800976910000 ffff800976913f10
3ee0: ffff00000864ac08 ffff800976913f10 ffff00000864ac0c 0000000060000145
3f00: ffff000008c6bb20 ffff8009763d7400
[<ffff000008082720>] el1_irq+0xa0/0x10c
[<ffff00000864ac0c>] cpuidle_enter_state+0x1b4/0x238
[<ffff00000864acc8>] cpuidle_enter+0x18/0x20
[<ffff0000080f15c0>] call_cpuidle+0x18/0x30
[<ffff0000080f1838>] cpu_startup_entry+0x198/0x1f8
[<ffff00000808dc78>] secondary_start_kernel+0x158/0x198
[<00000000800831a8>] 0x800831a8
Code: f8606ae0 b4ffe5c0 f9447023 f9403e62 (f9400006)
Bad mode in Synchronous Abort handler detected on CPU1, code 0x8600000f -- IABT (current EL)
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G      D         4.7.0-rc4+ #9
Hardware name: ARM Juno development board (r0) (DT)
task: ffff800976901900 ti: ffff800976910000 task.ti: ffff800976910000
PC is at 0xffff80097fec3f40
LR is at irq_work_run_list+0x68/0xb8
pc : [<ffff80097fec3f40>] lr : [<ffff000008147978>] pstate: 000001c5
sp : ffff80097fec35f0
x29: ffff80097fec35f0 x28: ffff800976910000
x27: 00000000afb50401 x26: afb504000afb5041
x25: ffff80097fec0000 x24: ffff800976901900
x23: ffff000008005000 x22: 0000000000000000
x21: ffff000008ca0d53 x20: ffff000008ca0d52
x19: ffff80097fec4da8 x18: 0000000000000006
x17: 0000000000000000 x16: 0000000000000000
x15: ffff000008cacc95 x14: 3431303030303630
x13: ffff000008caf0aa x12: 0000000005f5e0ff
x11: 000000000000016d x10: 00000000000a3d60
x9 : ffff80097fec3480 x8 : 000000000000016e
x7 : 6628203236653330 x6 : 000000000000000a
x5 : ffff80097fec4da0 x4 : 00008009772f9000
x3 : ffff80097fec3f51 x2 : 0000000000000000
x1 : ffff80097fec3f40 x0 : ffff80097fec4da0

Internal error: Oops - bad mode: 0 [#2] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G      D         4.7.0-rc4+ #9
Hardware name: ARM Juno development board (r0) (DT)
task: ffff800976901900 ti: ffff800976910000 task.ti: ffff800976910000
PC is at 0xffff80097fec3f40
LR is at irq_work_run_list+0x68/0xb8
pc : [<ffff80097fec3f40>] lr : [<ffff000008147978>] pstate: 000001c5
sp : ffff80097fec35f0
x29: ffff80097fec35f0 x28: ffff800976910000
x27: 00000000afb50401 x26: afb504000afb5041
x25: ffff80097fec0000 x24: ffff800976901900
x23: ffff000008005000 x22: 0000000000000000
x21: ffff000008ca0d53 x20: ffff000008ca0d52
x19: ffff80097fec4da8 x18: 0000000000000006
x17: 0000000000000000 x16: 0000000000000000
x15: ffff000008cacc95 x14: 3431303030303630
x13: ffff000008caf0aa x12: 0000000005f5e0ff
x11: 000000000000016d x10: 00000000000a3d60
x9 : ffff80097fec3480 x8 : 000000000000016e
x7 : 6628203236653330 x6 : 000000000000000a
x5 : ffff80097fec4da0 x4 : 00008009772f9000
x3 : ffff80097fec3f51 x2 : 0000000000000000
x1 : ffff80097fec3f40 x0 : ffff80097fec4da0

Process swapper/1 (pid: 0, stack limit = 0xffff800976910020)
Stack: (0xffff80097fec35f0 to 0xffff800976914000)
Call trace:
[<ffff80097fec3f40>] 0xffff80097fec3f40
[<ffff0000081479ec>] irq_work_run+0x24/0x40
[<ffff00000808e208>] handle_IPI+0x148/0x168
[<ffff0000080815b0>] gic_handle_irq+0x90/0xb0
Exception stack(0xffff80097fec3680 to 0xffff80097fec37a0)
3680: ffff80097fec36b0 ffff80097fec3960 ffff80097fec37d0 ffff0000087d0468
36a0: 0000000060000145 ffff80097fec3720 ffff000008ca70e8 0000000000000001
36c0: 0000000000000080 0000000000000080 0000000000000000 ffff80097fec4da0
36e0: 000000000000000a 6628203236653330 000000000000016e ffff80097fec3480
3700: 00000000000a3d60 000000000000016d 0000000005f5e0ff ffff000008caf0aa
3720: 3431303030303630 ffff000008cacc95 0000000000000000 0000000000000000
3740: 0000000000000006 ffff000008ca7000 ffff80097fec3960 0000000000000000
3760: ffff0000089fd908 ffff800976910000 ffff800976901900 0000000000000000
3780: afb504000afb5041 00000000afb50401 0000000000000001 ffff80097fec37d0
[<ffff000008082720>] el1_irq+0xa0/0x10c
[<ffff00000809800c>] __do_kernel_fault.part.1+0x74/0x88
[<ffff0000087d277c>] do_page_fault+0x37c/0x380
[<ffff0000087d27c4>] do_translation_fault+0x44/0x50
[<ffff00000808137c>] do_mem_abort+0x44/0xa0
Exception stack(0xffff80097fec38c0 to 0xffff80097fec39e0)
38c0: ffff80097fec96e8 ffff800975951800 ffff80097fec3a80 ffff0000080e73d8
38e0: ffff800976ad2300 ffff800974a07e00 0000000000000003 ffff800974a00000
3900: 0000000000000000 ffff7e0025d28000 0000000000000013 0000000080010400
3920: ffff000008c9f000 0000000000000003 0000000100000000 000000000000000e
3940: ffff80097fec39a0 ffff0000081ae954 0000000000000000 0000000000000000
3960: 0000000000000003 ffff80097fec9680 000000000000005e 0000000000000400
3980: ffff0000087ef950 0000000000000000 ffff80097fec9740 000000000000003e
39a0: 0000000991653ffc 0000000000000000 0000000000000001 0000000000000000
39c0: 000000000044ab8d 0000000005da2e6c 0000000000000001 0000000000000001
[<ffff000008082568>] el1_da+0x18/0x70
[<ffff0000080dbdd4>] activate_task+0x5c/0xa0
[<ffff0000080dc088>] ttwu_do_activate+0x50/0x88
[<ffff0000080dda60>] try_to_wake_up+0x228/0x2c0
[<ffff0000080ddbd0>] default_wake_function+0x10/0x18
[<ffff0000080f0ffc>] autoremove_wake_function+0x14/0x40
[<ffff0000080f0814>] __wake_up_common+0x5c/0xa0
[<ffff0000080f0e64>] __wake_up_sync_key+0x4c/0x78
[<ffff00000875a330>] tcp_prequeue+0x190/0x2e8
[<ffff00000875b8a4>] tcp_v4_rcv+0xa5c/0xb08
[<ffff000008736eac>] ip_local_deliver+0xa4/0x200
[<ffff0000087373e4>] ip_rcv+0x3dc/0x5f0
[<ffff000008707460>] __netif_receive_skb_core+0x5f8/0x7c8
[<ffff000008709990>] __netif_receive_skb+0x18/0x68
[<ffff000008709a04>] netif_receive_skb_internal+0x24/0xa8
[<ffff000008709a94>] netif_receive_skb+0xc/0x18
[<ffff00000858f9b0>] smsc911x_poll+0xf0/0x278
[<ffff00000870b0b0>] net_rx_action+0x1d8/0x2b0
[<ffff0000080be200>] __do_softirq+0x100/0x210
[<ffff0000080be5b8>] irq_exit+0x90/0xd8
[<ffff0000080fb2f8>] __handle_domain_irq+0x60/0xb8
[<ffff000008081578>] gic_handle_irq+0x58/0xb0
Exception stack(0xffff800976913df0 to 0xffff800976913f10)
3de0:                                   0000000000000000 ffff80097fec9680
3e00: 00008009772f9000 0000000002800000 0000000000000004 000000000115c074
3e20: 0000000000000015 000000000000012f 000000000000016d ffff80097fec872c
3e40: 0000000000000a12 0000000000000a12 071c71c71c71c71c 20230a2e746c7561
3e60: 524150203a4c4c41 0000000000000000 0000000000000000 0000000000000000
3e80: 0000000000000000 00000009972f2718 ffff8009763d7400 0000000000000000
3ea0: 0000000000000000 ffff000008c6bb20 00000009972ada50 ffff000008c05c1c
3ec0: ffff000008c05000 ffff000008c6bb20 ffff800976910000 ffff800976913f10
3ee0: ffff00000864ac08 ffff800976913f10 ffff00000864ac0c 0000000060000145
3f00: ffff000008c6bb20 ffff8009763d7400
[<ffff000008082720>] el1_irq+0xa0/0x10c
[<ffff00000864ac0c>] cpuidle_enter_state+0x1b4/0x238
[<ffff00000864acc8>] cpuidle_enter+0x18/0x20
[<ffff0000080f15c0>] call_cpuidle+0x18/0x30
[<ffff0000080f1838>] cpu_startup_entry+0x198/0x1f8
[<ffff00000808dc78>] secondary_start_kernel+0x158/0x198
[<00000000800831a8>] 0x800831a8
Code: 08aa2d08 ffff0000 08ca0d50 ffff0000 (7fec3f40)

-- 
Catalin

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