1# User-Mode Exception Information 2 3During the running of the user mode, the following system exception may occur: 4 5``` 6##################excFrom: User!#################### 7prefetch_abort fault fsr:0x5, far:0x00000000 8Translation fault, section 9excType: prefetch abort 10processName = shell 11processID = 3 12process aspace = 0x01000000 -> 0x3f000000 13taskName = shell 14taskID = 4 15task user stack = 0x3707d000 -> 0x3717d000 16pc = 0x0 17ulr = 0x2000424 in /bin/shell ---> 0x424 18usp = 0x3717cd60fp = 0x3717cd64 19R0 = 0x1 20R1 = 0x0 21R2 = 0x0 22R3 = 0x1 23R4 = 0x3717cf58 24R5 = 0x0 25R6 = 0x3717cf54 26R7 = 0x200043c 27R8 = 0x84 28R9 = 0x229a7560 29R10 = 0x0 30R11 = 0x3717cd64 31R12 = 0x0 32CPSR = 0x40000030 33*******backtrace begin******* 34traceback 0 -- lr = 0x229123a4 fp = 0x0 lr in /lib/libc.so --> 0x213a4 35 36 PID PPID PGID UID Status CPUUSE CPUUSE10s CPUUSE1s Policy Priority MTID TaskTotal Mode PName 37 1 -1 1 0 Ready 0.0 0.0 0.0 RR 28 16 1 user init 38 2 -1 2 0 Pend 10.1 10.1 0.0 RR 0 0 14 kernel KProcess 39 3 1 3 0 Running 0.0 0.0 0.0 RR 28 4 1 user shell 40 41 TID PID Status StackSize WaterLine Policy Priority MEMUSE TaskName 42 16 1 Ready 0x3000 0x978 RR 31 0x8b0c init 43 0 2 Pend 0x1000 0x1d4 RR 5 0 ResourcesTask 44 2 2 Pend 0x4000 0x4ec RR 0 0 Swt_Task 45 3 2 Pend 0x4000 0x1d4 RR 1 0 system_wq 46 5 2 Pend 0x4000 0x1fc RR 9 0 SendToSer 47 6 2 PendTime 0x6000 0x204 RR 5 0 tcpip_thread 48 7 2 Pend 0x3000 0x1fc RR 5 0 sdmci_detect 49 8 2 Pend 0x4000 0x204 RR 5 0 USB_GIANT_Task 50 9 2 Pend 0x4000 0x204 RR 1 0 USB_NGIAN_ISOC_Task 51 10 2 Pend 0x4000 0x204 RR 2 0 USB_NGIAN_BULK_Task 52 11 2 Pend 0x4000 0x690 RR 5 0xbb0 USB_EXPLR_Task 53 12 2 Pend 0x4000 0x204 RR 5 0 USB_CXFER_Task 54 13 2 Pend 0x20000 0x1e4 RR 3 0xac20 eth_irq_Task 55 14 2 Pend 0x4000 0x1d4 RR 10 0 jffs2_gc_thread 56 15 2 Pend 0x2000 0x1f4 RR 4 0 hisi_frw 57 4 3 Running 0x3000 0x838 RR 31 0x1100 shell 58system memcheck over, all passed! 59``` 60 61The system exception includes the following information: 62 631. Basic information about the user-mode exception: 64 65 ``` 66 prefetch_abort fault fsr:0x5, far:0x00000000 67 Translation fault, section 68 excType: prefetch abort 69 processName = shell 70 processID = 3 71 process aspace = 0x01000000 -> 0x3f000000 72 taskName = shell 73 taskID = 4 74 task user stack = 0x3707d000 -> 0x3717d000 75 ``` 76 772. Register information: 78 79 ``` 80 pc = 0x0 81 ulr = 0x2000424 in /bin/shell ---> 0x424 82 usp = 0x3717cd60fp = 0x3717cd64 83 R0 = 0x1 84 R1 = 0x0 85 R2 = 0x0 86 R3 = 0x1 87 R4 = 0x3717cf58 88 R5 = 0x0 89 R6 = 0x3717cf54 90 R7 = 0x200043c 91 R8 = 0x84 92 R9 = 0x229a7560 93 R10 = 0x0 94 R11 = 0x3717cd64 95 R12 = 0x0 96 CPSR = 0x40000030 97 ``` 98 993. Call stack information: 100 101 ``` 102 *******backtrace begin******* 103 traceback 0 -- lr = 0x229123a4 fp = 0x0 lr in /lib/libc.so --> 0x213a4 104 ``` 105 1064. Basic information about processes and threads: 107 108 ``` 109 PID PPID PGID UID Status CPUUSE CPUUSE10s CPUUSE1s Policy Priority MTID TaskTotal Mode PName 110 1 -1 1 0 Ready 0.0 0.0 0.0 RR 28 16 1 user init 111 2 -1 2 0 Pend 10.1 10.1 0.0 RR 0 0 14 kernel KProcess 112 3 1 3 0 Running 0.0 0.0 0.0 RR 28 4 1 user shell 113 114 TID PID Status StackSize WaterLine Policy Priority MEMUSE TaskName 115 16 1 Ready 0x3000 0x978 RR 31 0x8b0c init 116 0 2 Pend 0x1000 0x1d4 RR 5 0 ResourcesTask 117 2 2 Pend 0x4000 0x4ec RR 0 0 Swt_Task 118 3 2 Pend 0x4000 0x1d4 RR 1 0 system_wq 119 5 2 Pend 0x4000 0x1fc RR 9 0 SendToSer 120 6 2 PendTime 0x6000 0x204 RR 5 0 tcpip_thread 121 7 2 Pend 0x3000 0x1fc RR 5 0 sdmci_detect 122 8 2 Pend 0x4000 0x204 RR 5 0 USB_GIANT_Task 123 9 2 Pend 0x4000 0x204 RR 1 0 USB_NGIAN_ISOC_Task 124 10 2 Pend 0x4000 0x204 RR 2 0 USB_NGIAN_BULK_Task 125 11 2 Pend 0x4000 0x690 RR 5 0xbb0 USB_EXPLR_Task 126 12 2 Pend 0x4000 0x204 RR 5 0 USB_CXFER_Task 127 13 2 Pend 0x20000 0x1e4 RR 3 0xac20 eth_irq_Task 128 14 2 Pend 0x4000 0x1d4 RR 10 0 jffs2_gc_thread 129 15 2 Pend 0x2000 0x1f4 RR 4 0 hisi_frw 130 4 3 Running 0x3000 0x838 RR 31 0x1100 shell 131 system memcheck over, all passed! 132 ``` 133 134 Based on the preceding information, you can analyze the causes of the user-mode exception. 135 136 137