pkg/report: improve arm oops parsing

Stop treating stack memory dump as beginning of stack trace.
It's not getting anywhere, we are just getting more and more
special cases (see test 555).

8 files changed, 124 insertions, 81 deletions

diff --git a/pkg/report/linux.go b/pkg/report/linux.go
index 05929a293..dda9e81cd 100644
--- a/pkg/report/linux.go
+++ b/pkg/report/linux.go
@@ -535,21 +535,11 @@ func (ctx *linux) isCorrupted(title string, report []byte, format oopsFormat) (b
 		if len(frames) < 4 {
 			return true, "call trace is missed"
 		}
-		numLines := 15
 		corrupted := true
-		if bytes.Contains(frames[0], []byte("Stack:")) {
-			// Arm stacks contain 22 lines of memory dump before actual frames (see report 241).
-			numLines += 22
-			// More arm quirks: there are reports where "Stack:" denotes beginning of a stack,
-			// so we need to check them, but there are also reports where "Stack:" section is empty
-			// and it's immediately followed by "Backtrace:" which contains the real stack,
-			// so we can't mark the report as corrupted if "Stack:" is empty.
-			corrupted = false
-		}
 		frames = frames[1:]
 		// Check that at least one of the next few lines contains a frame.
 	outer:
-		for i := 0; i < numLines && i < len(frames); i++ {
+		for i := 0; i < 15 && i < len(frames); i++ {
 			for _, key1 := range linuxStackParams.stackStartRes {
 				// Next stack trace starts.
 				if key1.Match(frames[i]) {
@@ -720,7 +710,7 @@ var linuxStallAnchorFrames = []*regexp.Regexp{
 var (
 	linuxSymbolizeRe = regexp.MustCompile(`(?:\[\<(?:(?:0x)?[0-9a-f]+)\>\])?[ \t]+\(?(?:[0-9]+:)?([a-zA-Z0-9_.]+)\+0x([0-9a-f]+)/0x([0-9a-f]+)\)?`)
 	linuxRipFrame    = compile(`(?:IP|NIP|pc |PC is at):? (?:(?:[0-9]+:)?(?:{{PC}} +){0,2}{{FUNC}}|[0-9]+:0x[0-9a-f]+|(?:[0-9]+:)?{{PC}} +\[< *\(null\)>\] +\(null\)|[0-9]+: +\(null\))`)
-	linuxCallTrace   = compile(`(?:Call (?:T|t)race:)|(?:Stack: \(.* to .*\))|(?:Backtrace:)`)
+	linuxCallTrace   = compile(`(?:Call (?:T|t)race:)|(?:Backtrace:)`)
 )
 
 var linuxCorruptedTitles = []*regexp.Regexp{
@@ -738,7 +728,6 @@ var linuxStackParams = &stackParams{
 		// Match 'backtrace:', but exclude 'stack backtrace:'
 		regexp.MustCompile(`[^k] backtrace:`),
 		regexp.MustCompile(`Backtrace:`),
-		regexp.MustCompile(`Stack: \(.* to .*\)`), // arm is all unique
 	},
 	frameRes: []*regexp.Regexp{
 		compile("^ *(?:{{PC}} ){0,2}{{FUNC}}"),
diff --git a/pkg/report/testdata/linux/report/241 b/pkg/report/testdata/linux/report/241
index 93a86635c..1fc901e05 100644
--- a/pkg/report/testdata/linux/report/241
+++ b/pkg/report/testdata/linux/report/241
@@ -40,6 +40,7 @@ df80: 977bc000 00000000 000002e3 8027e954 00000000 00000000 00000000 00000036
 dfa0: 801011e4 80101000 00000000 00000000 00000015 00005406 20000040 00000000
 dfc0: 00000000 00000000 00000000 00000036 75fa97e4 00061b14 000005c6 000002e3
 dfe0: 75fa8b10 75fa8b00 00013291 000358c2 600d0030 00000015 00000000 00000000
+Backtrace:
 [<80b10c70>] (memset) from [<8062eec8>] (n_tty_set_termios+0x154/0x3c4)
 [<8062eec8>] (n_tty_set_termios) from [<80632588>] (tty_set_termios+0x1bc/0x230)
 [<80632588>] (tty_set_termios) from [<80632c94>] (set_termios+0x198/0x3f8)
diff --git a/pkg/report/testdata/linux/report/243 b/pkg/report/testdata/linux/report/243
index 44f0aa5d2..5566bd8fe 100644
--- a/pkg/report/testdata/linux/report/243
+++ b/pkg/report/testdata/linux/report/243
@@ -36,6 +36,7 @@ Stack: (0x97f07e00 to 0x97f08000)
 7fa0: 00000000 80101000 00000018 00000001 000b0118 00000001 7e964e40 00000000
 7fc0: 00000018 00000001 00000005 000000f0 000b0100 000b0010 000b011c 00000573
 7fe0: 7e964d30 7e964d20 00014039 000358c2 20000030 000b0118 00000000 00000000
+Backtrace:
 [<8015df40>] (migrate_task_rq_fair) from [<801559ec>] (set_task_cpu+0x4c/0xf8)
 [<801559ec>] (set_task_cpu) from [<80155eb8>] (try_to_wake_up+0x164/0x3a4)
 [<80155eb8>] (try_to_wake_up) from [<8015616c>] (wake_up_q+0x58/0x98)
diff --git a/pkg/report/testdata/linux/report/548 b/pkg/report/testdata/linux/report/548
index 55b4cfda3..0b49a242d 100644
--- a/pkg/report/testdata/linux/report/548
+++ b/pkg/report/testdata/linux/report/548
@@ -1,69 +1,27 @@
-TITLE: Unhandled fault in jffs2_parse_param
+TITLE: Unhandled fault in trace_hardirqs_off
 
-8<--- cut here ---
-Unhandled fault: page domain fault (0x01b) at 0x00000008
-pgd = 4c5c9ce0
-[00000008] *pgd=9671f835, *pte=00000000, *ppte=00000000
-Internal error: : 1b [#1] SMP ARM
-Dumping ftrace buffer:
-   (ftrace buffer empty)
-Modules linked in:
-CPU: 0 PID: 24993 Comm: syz-executor.0 Not tainted 5.10.2 #10
-Hardware name: ARM-Versatile Express
-PC is at jffs2_parse_param+0xa8/0x18c
-LR is at jffs2_parse_param+0x98/0x18c
-pc : [<8054b7c0>]    lr : [<8054b7b0>]    psr: 40000013
-sp : 94771e60  ip : 00000002  fp : 00000000
-r10: 9675f000  r9 : 00000000  r8 : 00000000
-r7 : 9258f200  r6 : 0002b400  r5 : 9676fb80  r4 : 00000001
-r3 : 00000000  r2 : 00040000  r1 : cb584000  r0 : 00000005
-Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
-Control: 10c5387d  Table: 95fd006a  DAC: 00000051
-Process syz-executor.0 (pid: 24993, stack limit = 0x9c3a9348)
-Stack: (0x94771e60 to 0x94772000)
-1e60: 00000000 00000000 00000000 00000000 000000ad 00000000 00000000 81104e88
-1e80: 00000014 8054b718 9676fb80 94771ec0 00000000 00000000 00000014 8037e608
-1ea0: 967f4280 802b75bc 9675f008 9675f008 00000014 9675f000 9676fb80 8037e7dc
-1ec0: 9675f000 00000002 967f4280 00000014 00000000 81104e88 00000072 9675f000
-1ee0: 9675f008 80e65d98 9676fb80 8037e8e0 9675f01d 81104e88 00800000 9676fb80
-1f00: 00000020 00000000 967f4740 811521c0 00800000 80360ff0 94771f74 8033ee34
-1f20: ffffff9c 00000000 00000000 81104e88 00000051 00000000 00000000 75e869c0
-1f40: 00000051 967f4740 00000000 00000015 9675f000 80361cc8 9675f000 8010cb7c
-1f60: 9197f748 00000000 20000000 00800000 94770000 822f19d0 82d8b198 81104e88
-1f80: 00800000 75e869c0 20000000 00000000 00000015 80100284 94770000 00000015
-1fa0: 20000040 80100260 75e869c0 20000000 00000000 20000000 200009c0 00800000
-1fc0: 75e869c0 20000000 00000000 00000015 200009c0 00000000 75e86980 20000040
-1fe0: 00000001 75e86938 00015750 0004ffc0 20000010 00000000 00000000 00000000
-[<8054b7c0>] (jffs2_parse_param) from [<8037e608>] (vfs_parse_fs_param+0xf8/0x23c)
-[<8037e608>] (vfs_parse_fs_param) from [<8037e7dc>] (vfs_parse_fs_string+0x90/0xd4)
-[<8037e7dc>] (vfs_parse_fs_string) from [<8037e8e0>] (generic_parse_monolithic+0xc0/0x114)
-[<8037e8e0>] (generic_parse_monolithic) from [<80360ff0>] (path_mount+0xb10/0x10c0)
-[<80360ff0>] (path_mount) from [<80361cc8>] (sys_mount+0x21c/0x36c)
-[<80361cc8>] (sys_mount) from [<80100260>] (__sys_trace_return+0x0/0x20)
-Exception stack(0x94771fa8 to 0x94771ff0)
-1fa0:                   75e869c0 20000000 00000000 20000000 200009c0 00800000
-1fc0: 75e869c0 20000000 00000000 00000015 200009c0 00000000 75e86980 20000040
-1fe0: 00000001 75e86938 00015750 0004ffc0
-Code: e5973000 e2169602 13e09000 e1a06506 (e5934008) 
----[ end trace 1e8bf21d99144682 ]---
-Kernel panic - not syncing: Fatal exception
-CPU1: stopping
-CPU: 1 PID: 0 Comm: swapper/1 Tainted: G      D           5.10.2 #10
-Hardware name: ARM-Versatile Express
-[<80118054>] (unwind_backtrace) from [<80110ce4>] (show_stack+0x20/0x24)
-[<80110ce4>] (show_stack) from [<80c16564>] (dump_stack+0x104/0x138)
-[<80c16564>] (dump_stack) from [<80115548>] (do_handle_IPI+0x3e8/0x45c)
-[<80115548>] (do_handle_IPI) from [<801155d8>] (ipi_handler+0x1c/0x28)
-[<801155d8>] (ipi_handler) from [<801aec5c>] (handle_percpu_devid_fasteoi_ipi+0x84/0x1a8)
-[<801aec5c>] (handle_percpu_devid_fasteoi_ipi) from [<801a59ec>] (__handle_domain_irq+0xb8/0x124)
-[<801a59ec>] (__handle_domain_irq) from [<806ab444>] (gic_handle_irq+0xb0/0xe8)
-[<806ab444>] (gic_handle_irq) from [<80100b6c>] (__irq_svc+0x6c/0x90)
-Exception stack(0x814fff60 to 0x814fffa8)
-ff60: 0048140c 00000000 814dc4c0 00000000 00000000 814fe000 00000000 00000001
-ff80: 81104ed4 81104f10 81067b90 814fffc0 00000000 814fffb0 8010c030 8010c034
-ffa0: 80000013 ffffffff
-[<80100b6c>] (__irq_svc) from [<8010c034>] (arch_cpu_idle+0x28/0x48)
-[<8010c034>] (arch_cpu_idle) from [<80c23ac4>] (default_idle_call+0x28/0xf0)
-[<80c23ac4>] (default_idle_call) from [<80181b30>] (do_idle+0x1cc/0x26c)
-[<80181b30>] (do_idle) from [<80181e88>] (cpu_startup_entry+0x18/0x1c)
-[<80181e88>] (cpu_startup_entry) from [<8010164c>] (__enable_mmu+0x0/0x14)
+[ 9080.453689][T11783] 8<--- cut here ---
+[ 9080.454760][T11783] Unhandled fault: page domain fault (0x01b) at 0x00000e30
+[ 9080.455761][T11783] pgd = e852c1e3
+[ 9080.456588][T11783] [00000e30] *pgd=e8c3e835
+[ 9080.459344][T11783] Internal error: : 1b [#1] PREEMPT SMP ARM
+[ 9080.461027][T11783] Dumping ftrace buffer:
+[ 9080.462253][T11783]    (ftrace buffer empty)
+[ 9080.463160][T11783] Modules linked in:
+[ 9080.464375][T11783] CPU: 1 PID: 11783 Comm: syz-executor.0 Not tainted 5.10.0-rc1+ #18
+[ 9080.465313][T11783] Hardware name: ARM-Versatile Express
+[ 9080.467190][T11783] PC is at __sanitizer_cov_trace_pc+0x4c/0x78
+[ 9080.468129][T11783] LR is at trace_hardirqs_off+0x6c/0x120
+[ 9080.468826][T11783] pc : [<802b4048>]    lr : [<802e1324>]    psr: 60000193
+[ 9080.469644][T11783] sp : 8bdfc010  ip : 8bdfc020  fp : 8bdfc01c
+[ 9080.470461][T11783] r10: 8591b080  r9 : 8bdfc000  r8 : 00000001
+[ 9080.471172][T11783] r7 : 80100a74  r6 : 844fbc1c  r5 : 60000193  r4 : 8bdfc000
+[ 9080.471940][T11783] r3 : 8bdfc000  r2 : 00000000  r1 : 00000000  r0 : 00000000
+[ 9080.472938][T11783] Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
+[ 9080.474920][T11783] Control: 10c5387d  Table: 8a14806a  DAC: 00000051
+[ 9080.475742][T11783] Process syz-executor.0 (pid: 11783, stack limit = 0xdf960dff)
+[ 9080.476792][T11783] Stack: (0x8bdfc010 to 0x00002000)
+[ 9080.477621][T11783] Backtrace: 
+[ 9080.479068][T11783] [<802b3ffc>] (__sanitizer_cov_trace_pc) from [<802e1324>] (trace_hardirqs_off+0x6c/0x120)
+[ 9080.480508][T11783] [<802e12b8>] (trace_hardirqs_off) from [<80100a74>] (__dabt_svc+0x54/0xa0)
+[ 9080.481456][T11783] Exception stack(0x8bdfc048 to 0x8bdfc090)
diff --git a/pkg/report/testdata/linux/report/551 b/pkg/report/testdata/linux/report/551
index 55b4cfda3..4f06665d6 100644
--- a/pkg/report/testdata/linux/report/551
+++ b/pkg/report/testdata/linux/report/551
@@ -34,6 +34,7 @@ Stack: (0x94771e60 to 0x94772000)
 1fa0: 20000040 80100260 75e869c0 20000000 00000000 20000000 200009c0 00800000
 1fc0: 75e869c0 20000000 00000000 00000015 200009c0 00000000 75e86980 20000040
 1fe0: 00000001 75e86938 00015750 0004ffc0 20000010 00000000 00000000 00000000
+Backtrace: 
 [<8054b7c0>] (jffs2_parse_param) from [<8037e608>] (vfs_parse_fs_param+0xf8/0x23c)
 [<8037e608>] (vfs_parse_fs_param) from [<8037e7dc>] (vfs_parse_fs_string+0x90/0xd4)
 [<8037e7dc>] (vfs_parse_fs_string) from [<8037e8e0>] (generic_parse_monolithic+0xc0/0x114)
diff --git a/pkg/report/testdata/linux/report/552 b/pkg/report/testdata/linux/report/552
index 4d542de34..a568c4400 100644
--- a/pkg/report/testdata/linux/report/552
+++ b/pkg/report/testdata/linux/report/552
@@ -37,6 +37,7 @@ ff80: 00000000 00000000 00000000 00000000 00000036 80100284 9e4fe000 00000036
 ffa0: 75e8ec9c 80100260 00000000 00000000 00000004 00005423 200000c0 00000000
 ffc0: 00000000 00000000 00000000 00000036 7e89e732 75e8f160 75e8eca0 75e8ec9c
 ffe0: 75e8eae8 75e8ead8 000152e8 0004ed10 60000010 00000004 00000000 00000000
+Backtrace: 
 [<8078e15c>] (io_serial_out) from [<8078fba0>] (serial8250_do_set_ldisc+0x10c/0x114)
 [<8078fba0>] (serial8250_do_set_ldisc) from [<8078fbec>] (serial8250_set_ldisc+0x44/0x4c)
 [<8078fbec>] (serial8250_set_ldisc) from [<80784f14>] (uart_set_ldisc+0x4c/0x5c)
diff --git a/pkg/report/testdata/linux/report/555 b/pkg/report/testdata/linux/report/555
new file mode 100644
index 000000000..0b49a242d
--- /dev/null
+++ b/pkg/report/testdata/linux/report/555
@@ -0,0 +1,27 @@
+TITLE: Unhandled fault in trace_hardirqs_off
+
+[ 9080.453689][T11783] 8<--- cut here ---
+[ 9080.454760][T11783] Unhandled fault: page domain fault (0x01b) at 0x00000e30
+[ 9080.455761][T11783] pgd = e852c1e3
+[ 9080.456588][T11783] [00000e30] *pgd=e8c3e835
+[ 9080.459344][T11783] Internal error: : 1b [#1] PREEMPT SMP ARM
+[ 9080.461027][T11783] Dumping ftrace buffer:
+[ 9080.462253][T11783]    (ftrace buffer empty)
+[ 9080.463160][T11783] Modules linked in:
+[ 9080.464375][T11783] CPU: 1 PID: 11783 Comm: syz-executor.0 Not tainted 5.10.0-rc1+ #18
+[ 9080.465313][T11783] Hardware name: ARM-Versatile Express
+[ 9080.467190][T11783] PC is at __sanitizer_cov_trace_pc+0x4c/0x78
+[ 9080.468129][T11783] LR is at trace_hardirqs_off+0x6c/0x120
+[ 9080.468826][T11783] pc : [<802b4048>]    lr : [<802e1324>]    psr: 60000193
+[ 9080.469644][T11783] sp : 8bdfc010  ip : 8bdfc020  fp : 8bdfc01c
+[ 9080.470461][T11783] r10: 8591b080  r9 : 8bdfc000  r8 : 00000001
+[ 9080.471172][T11783] r7 : 80100a74  r6 : 844fbc1c  r5 : 60000193  r4 : 8bdfc000
+[ 9080.471940][T11783] r3 : 8bdfc000  r2 : 00000000  r1 : 00000000  r0 : 00000000
+[ 9080.472938][T11783] Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
+[ 9080.474920][T11783] Control: 10c5387d  Table: 8a14806a  DAC: 00000051
+[ 9080.475742][T11783] Process syz-executor.0 (pid: 11783, stack limit = 0xdf960dff)
+[ 9080.476792][T11783] Stack: (0x8bdfc010 to 0x00002000)
+[ 9080.477621][T11783] Backtrace: 
+[ 9080.479068][T11783] [<802b3ffc>] (__sanitizer_cov_trace_pc) from [<802e1324>] (trace_hardirqs_off+0x6c/0x120)
+[ 9080.480508][T11783] [<802e12b8>] (trace_hardirqs_off) from [<80100a74>] (__dabt_svc+0x54/0xa0)
+[ 9080.481456][T11783] Exception stack(0x8bdfc048 to 0x8bdfc090)
diff --git a/pkg/report/testdata/linux/report/556 b/pkg/report/testdata/linux/report/556
new file mode 100644
index 000000000..84657d8a1
--- /dev/null
+++ b/pkg/report/testdata/linux/report/556
@@ -0,0 +1,65 @@
+TITLE: WARNING: ODEBUG bug in netdev_freemem
+
+[ 7978.980484][ T7864] ------------[ cut here ]------------
+[ 7978.984043][ T7864] WARNING: CPU: 0 PID: 7864 at lib/debugobjects.c:505 debug_print_object+0xb0/0xc4
+[ 7979.032914][ T7864] ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x28
+[ 7979.034400][ T7864] Modules linked in:
+[ 7979.054500][ T7864] Kernel panic - not syncing: panic_on_warn set ...
+[ 7979.057839][ T7864] CPU: 0 PID: 7864 Comm: kworker/u4:4 Not tainted 5.10.0-rc1+ #19
+[ 7979.060934][ T7864] Hardware name: ARM-Versatile Express
+[ 7979.062695][ T7864] Workqueue: netns cleanup_net
+[ 7979.064032][ T7864] Backtrace: 
+[ 7979.066353][ T7864] [<8367729c>] (dump_backtrace) from [<83677618>] (show_stack+0x28/0x2c)
+[ 7979.070036][ T7864]  r9:ffffffff r8:800b0093 r7:00000080 r6:00000000 r5:841ff0ac r4:00000000
+[ 7979.071836][ T7864] [<836775f0>] (show_stack) from [<8368d44c>] (dump_stack+0x124/0x170)
+[ 7979.074734][ T7864]  r5:00000000 r4:847241a4
+[ 7979.076910][ T7864] [<8368d328>] (dump_stack) from [<83677f30>] (panic+0x1fc/0x5d8)
+[ 7979.080153][ T7864]  r10:845657dc r9:ffffffff r8:845657b4 r7:0000000a r6:00000000 r5:00000001
+[ 7979.081621][ T7864]  r4:8492fb80 r3:00000000
+[ 7979.083581][ T7864] [<83677d34>] (panic) from [<8014a7fc>] (__warn+0xe0/0x1a8)
+[ 7979.086255][ T7864]  r3:00000000 r2:00000000 r1:8b691e80 r0:83f8b770
+[ 7979.088904][ T7864]  r7:00000009
+[ 7979.090083][ T7864] [<8014a71c>] (__warn) from [<836783b8>] (warn_slowpath_fmt+0xac/0xec)
+[ 7979.091363][ T7864]  r7:8143e868 r6:000001f9 r5:84089c8c r4:84089c4c
+[ 7979.092601][ T7864] [<83678310>] (warn_slowpath_fmt) from [<8143e868>] (debug_print_object+0xb0/0xc4)
+[ 7979.096072][ T7864]  r8:83705e38 r7:8405b918 r6:8acfbf30 r5:85006060 r4:8454f4f8
+[ 7979.099174][ T7864] [<8143e7b8>] (debug_print_object) from [<8144001c>] (debug_check_no_obj_freed+0x1f8/0x244)
+[ 7979.102507][ T7864]  r8:00000122 r7:8b426228 r6:83705e38 r5:8934ec2c r4:8acfbf30
+[ 7979.105586][ T7864] [<8143fe24>] (debug_check_no_obj_freed) from [<8049290c>] (slab_free_freelist_hook+0xd8/0x16c)
+[ 7979.109889][ T7864]  r10:60000113 r9:8934e000 r8:8bd2bcbc r7:8bd2bcb8 r6:00000000 r5:8934e000
+[ 7979.112642][ T7864]  r4:85801900
+[ 7979.114443][ T7864] [<80492834>] (slab_free_freelist_hook) from [<8049631c>] (kfree+0xfc/0x4b8)
+[ 7979.118058][ T7864]  r10:8454ec94 r9:8454f124 r8:00000000 r7:85801900 r6:8040c948 r5:8934e000
+[ 7979.121083][ T7864]  r4:de744620
+[ 7979.122798][ T7864] [<80496220>] (kfree) from [<8040c948>] (kvfree+0x54/0x5c)
+[ 7979.125775][ T7864]  r10:8454ec94 r9:8454f124 r8:00000000 r7:00000000 r6:8934e000 r5:00000000
+[ 7979.128950][ T7864]  r4:8934e000
+[ 7979.130897][ T7864] [<8040c8f4>] (kvfree) from [<829b9504>] (netdev_freemem+0x24/0x28)
+[ 7979.133095][ T7864]  r5:00000004 r4:8934e000
+[ 7979.135298][ T7864] [<829b94e0>] (netdev_freemem) from [<82a07e90>] (netdev_release+0x44/0x50)
+[ 7979.136416][ T7864]  r5:00000004 r4:8934e370
+[ 7979.137612][ T7864] [<82a07e4c>] (netdev_release) from [<8172a1e0>] (device_release+0x44/0xdc)
+[ 7979.139005][ T7864]  r7:00000000 r6:8ae87c00 r5:82a07e4c r4:8934e370
+[ 7979.140174][ T7864] [<8172a19c>] (device_release) from [<814d43cc>] (kobject_put+0x158/0x2f4)
+[ 7979.141318][ T7864]  r6:8b31b200 r5:84733ce8 r4:8934e370
+[ 7979.142444][ T7864] [<814d4274>] (kobject_put) from [<829b9268>] (netdev_run_todo+0x460/0x5cc)
+[ 7979.143774][ T7864]  r8:8454edbc r7:00000002 r6:8934e338 r5:00000008 r4:00000001
+[ 7979.145048][ T7864] [<829b8e08>] (netdev_run_todo) from [<829cb45c>] (rtnl_unlock+0x14/0x18)
+[ 7979.146430][ T7864]  r10:8298b8ac r9:8bd2be2c r8:8b034ac0 r7:8bd2be18 r6:8bd2be94 r5:00000000
+[ 7979.147575][ T7864]  r4:8b034a94
+[ 7979.148702][ T7864] [<829cb448>] (rtnl_unlock) from [<829a4a0c>] (default_device_exit_batch+0x1bc/0x1e8)
+[ 7979.150083][ T7864] [<829a4850>] (default_device_exit_batch) from [<8298b8a4>] (ops_exit_list+0x7c/0x84)
+[ 7979.151527][ T7864]  r9:00000000 r8:ffffff90 r7:84806824 r6:8bd2be94 r5:829a2c14 r4:829a4850
+[ 7979.152783][ T7864] [<8298b828>] (ops_exit_list) from [<8298c9b0>] (cleanup_net+0x308/0x4f0)
+[ 7979.154073][ T7864]  r7:84804dd0 r6:84804dd0 r5:00000000 r4:84806824
+[ 7979.155446][ T7864] [<8298c6a8>] (cleanup_net) from [<801800f0>] (process_one_work+0x3dc/0xe0c)
+[ 7979.157001][ T7864]  r10:8bd2a000 r9:00000000 r8:00000000 r7:85820000 r6:85816400 r5:8b96e680
+[ 7979.158096][ T7864]  r4:84804d50
+[ 7979.159299][ T7864] [<8017fd14>] (process_one_work) from [<80180b90>] (worker_thread+0x70/0x7a8)
+[ 7979.160723][ T7864]  r10:84506d00 r9:85820038 r8:84804d50 r7:00000000 r6:85820000 r5:8b96e694
+[ 7979.161681][ T7864]  r4:8b96e680
+[ 7979.162720][ T7864] [<80180b20>] (worker_thread) from [<8018c338>] (kthread+0x1d0/0x20c)
+[ 7979.164104][ T7864]  r10:8ac55e34 r9:8b96e680 r8:80180b20 r7:00000000 r6:8bd2a000 r5:00000000
+[ 7979.165133][ T7864]  r4:8b96e600
+[ 7979.166266][ T7864] [<8018c168>] (kthread) from [<8010011c>] (ret_from_fork+0x14/0x38)
+[ 7979.167523][ T7864] Exception stack(0x8bd2bfb0 to 0x8bd2bff8)