figozhang / runninglinuxkernel_4.0

《奔跑吧Linux内核》配套实验平台和代码，白色入门酱香篇，蓝色进阶浓香篇

runninglinuxkernel_4.0 for 《奔跑吧Linux内核》 《奔跑吧Linux内核*入门篇》

国内git镜像

国内下载github比较慢，我们提供一个国内的git镜像。

$ git clone https://e.coding.net/benshushu/runninglinuxkernel_4.0.git -b rlk_basic

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国内首本Linux实验指导手册，将近400页，干货满满，融入企业实战项目的经验总结，让您快速入门！

加入奔跑吧Linux社区微信公众号（微信公众号：runninglinuxkernel），在微信公众号里输入“最新实验指导手册”，就会跳出下载地址啦。

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下载实验平台

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pdf版本的课件已经上传到人邮异步社区，ppt版本的课件仅限大专院校老师申请。培训机构或者企业内部培训，也可以 发邮件申请，需提供购买20本书的发票照片。

奔跑吧入门篇酱香篇配套代码

本分支是《奔跑吧Linux内核》入门酱香篇配套的实验环境和代码。

每当我看到Linux专家不用鼠标，直接在黑屏里噼噼啪啪的敲一通，一个程序就写好了， 我还在丑陋的VB/VC之类编程工具，我觉得我和大神们相差1000英里的距离

每次我看到Linux专家对Linux系统特别是Linux内核谈笑风生的时候，一大堆英文术语让我晕菜， 我觉得我和这些大神们的距离相差2000英里的距离。

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2. 配套全套实验代码： https://github.com/figozhang/runninglinuxkernel_4.0

3. 配套全套实验环境的vmware虚拟机镜像 （基于优麒麟Linux 18.04） 下载地址： 异步社区：https://www.epubit.com/book/detail/39321 百度网盘：https://pan.baidu.com/s/1XlJzdUBH_V7IwNRH1R4jrg 谷歌网盘：https://drive.google.com/open?id=1cTRQ73f0yzhTBoNt6rhHbkbbPTI8j_3P

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图书购买地址

• 当当：http://product.dangdang.com/26514293.html
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• 异步社区：https://www.epubit.com/book/detail/39321

收费视频

入门篇配套的免费视频基本上都是节选自奔跑吧旗舰篇视频，可能存在不完整或者不连贯。 若想收看完整的视频节目或者获得更好的学习效果，建议您订阅旗舰篇视频。 订阅地址：https://shop115683645.taobao.com/

runninglinuxkernel_4.0's Issues

Option frame-larger-than Warning

There are so many warning as shown below.

Is the below warning will be caused the kernel abnormal behavior ?

warning: the frame size of 2176 bytes is larger than 2048 bytes [-Wframe-larger-than=]

kernel don't run, waiting at "input: ImExPS/2 Generic Explorer Mouse as XXX"

Ubuntu 14.04.5
arm-linux-gnueabi-gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1)

qemu-system-arm -M vexpress-a9 -smp 4 -m 1024M -kernel arch/arm/boot/zImage  -append "rdinit=/linuxrc console=ttyAMA0 loglevel=8" -dtb arch/arm/boot/dts/vexpress-v2p-ca9.dtb -S -s -nographic

kernel waiting @

input: ImExPS/2 Generic Explorer Mouse as /devices/platform/smb/smb:motherboard/smb:motherboard:iofpga@7,00000000/10007000.kmi/serio1/input/input2

details

pulseaudio: set_sink_input_volume() failed
pulseaudio: Reason: Invalid argument
pulseaudio: set_sink_input_mute() failed
pulseaudio: Reason: Invalid argument
Booting Linux on physical CPU 0x0
Initializing cgroup subsys cpuset
Linux version 4.0.0+ (gatieme@Aspire) (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) ) #1 SMP Sun May 28 23:29:14 CST 2017
CPU: ARMv7 Processor [410fc090] revision 0 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine model: V2P-CA9
Memory policy: Data cache writealloc
On node 0 totalpages: 262144
free_area_init_node: node 0, pgdat c1037d40, node_mem_map eeffa000
  Normal zone: 1520 pages used for memmap
  Normal zone: 0 pages reserved
  Normal zone: 194560 pages, LIFO batch:31
  HighMem zone: 67584 pages, LIFO batch:15
PERCPU: Embedded 11 pages/cpu @eefbd000 s16064 r8192 d20800 u45056
pcpu-alloc: s16064 r8192 d20800 u45056 alloc=11*4096
pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 260624
Kernel command line: rdinit=/linuxrc console=ttyAMA0 loglevel=8
log_buf_len individual max cpu contribution: 4096 bytes
log_buf_len total cpu_extra contributions: 12288 bytes
log_buf_len min size: 16384 bytes
log_buf_len: 32768 bytes
early log buf free: 14948(91%)
PID hash table entries: 4096 (order: 2, 16384 bytes)
Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
Memory: 1022452K/1048576K available (11636K kernel code, 229K rwdata, 1820K rodata, 2908K init, 188K bss, 26124K reserved, 0K cma-reserved, 270336K highmem)
Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
    vmalloc : 0xf0000000 - 0xff000000   ( 240 MB)
    lowmem  : 0xc0000000 - 0xef800000   ( 760 MB)
    pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
    modules : 0xbf000000 - 0xbfe00000   (  14 MB)
      .text : 0xc0008000 - 0xc0d2c450   (13458 kB)
      .init : 0xc0d2d000 - 0xc1004000   (2908 kB)
      .data : 0xc1004000 - 0xc103d508   ( 230 kB)
       .bss : 0xc103d508 - 0xc106c518   ( 189 kB)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
Hierarchical RCU implementation.
	Additional per-CPU info printed with stalls.
	RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
NR_IRQS:16 nr_irqs:16 16
L2C: platform modifies aux control register: 0x02020000 -> 0x02420000
L2C: device tree omits to specify unified cache
L2C: DT/platform modifies aux control register: 0x02020000 -> 0x02420000
L2C-310 enabling early BRESP for Cortex-A9
L2C-310 full line of zeros enabled for Cortex-A9
L2C-310 dynamic clock gating disabled, standby mode disabled
L2C-310 cache controller enabled, 8 ways, 128 kB
L2C-310: CACHE_ID 0x410000c8, AUX_CTRL 0x46420001
smp_twd: clock not found -2
sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 178956969942ns
Console: colour dummy device 80x30
Calibrating local timer... 90.74MHz.
Calibrating delay loop... 540.67 BogoMIPS (lpj=2703360)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
CPU: Testing write buffer coherency: ok
CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
Setting up static identity map for 0x60b2d780 - 0x60b2d7d8
CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
Brought up 4 CPUs
SMP: Total of 4 processors activated (1167.87 BogoMIPS).
CPU: All CPU(s) started in SVC mode.
devtmpfs: initialized
VFP support v0.3: implementor 41 architecture 3 part 30 variant 9 rev 0
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic coherent allocations
cpuidle: using governor ladder
cpuidle: using governor menu
genirq: Setting trigger mode 1 for irq 18 failed (gic_set_type+0x0/0x100)
genirq: Setting trigger mode 1 for irq 19 failed (gic_set_type+0x0/0x100)
genirq: Setting trigger mode 1 for irq 20 failed (gic_set_type+0x0/0x100)
genirq: Setting trigger mode 1 for irq 21 failed (gic_set_type+0x0/0x100)
of_amba_device_create(): amba_device_add() failed (-19) for /memory-controller@100e0000
of_amba_device_create(): amba_device_add() failed (-19) for /memory-controller@100e1000
of_amba_device_create(): amba_device_add() failed (-19) for /watchdog@100e5000
of_amba_device_create(): amba_device_add() failed (-19) for /smb/motherboard/iofpga@7,00000000/sysctl@01000
of_amba_device_create(): amba_device_add() failed (-19) for /smb/motherboard/iofpga@7,00000000/wdt@0f000
No ATAGs?
hw-breakpoint: debug architecture 0x0 unsupported.
Serial: AMBA PL011 UART driver
10009000.uart: ttyAMA0 at MMIO 0x10009000 (irq = 38, base_baud = 0) is a PL011 rev1
console [ttyAMA0] enabled
1000a000.uart: ttyAMA1 at MMIO 0x1000a000 (irq = 39, base_baud = 0) is a PL011 rev1
1000b000.uart: ttyAMA2 at MMIO 0x1000b000 (irq = 40, base_baud = 0) is a PL011 rev1
1000c000.uart: ttyAMA3 at MMIO 0x1000c000 (irq = 41, base_baud = 0) is a PL011 rev1
SCSI subsystem initialized
libata version 3.00 loaded.
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
Advanced Linux Sound Architecture Driver Initialized.
Switched to clocksource arm,sp804
NET: Registered protocol family 2
TCP established hash table entries: 8192 (order: 3, 32768 bytes)
TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP: reno registered
UDP hash table entries: 512 (order: 2, 16384 bytes)
UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
NET: Registered protocol family 1
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
hw perfevents: enabled with armv7_cortex_a9 PMU driver, 1 counters available
futex hash table entries: 1024 (order: 4, 65536 bytes)
squashfs: version 4.0 (2009/01/31) Phillip Lougher
jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
9p: Installing v9fs 9p2000 file system support
bounce: pool size: 64 pages
io scheduler noop registered (default)
clcd-pl11x 10020000.clcd: PL111 rev2 at 0x10020000
clcd-pl11x 10020000.clcd: /clcd@10020000 hardware, 1024x768@59 display
Console: switching to colour frame buffer device 128x48
clcd-pl11x 1001f000.clcd: PL111 rev2 at 0x1001f000
clcd-pl11x 1001f000.clcd: /smb/motherboard/iofpga@7,00000000/clcd@1f000 hardware, 640x480@59 display
40000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
NOR chip too large to fit in mapping. Attempting to cope...
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
erase region 0: offset=0x0,size=0x80000,blocks=256
Reducing visibility of 131072KiB chip to 65536KiB
40000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
NOR chip too large to fit in mapping. Attempting to cope...
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
erase region 0: offset=0x0,size=0x80000,blocks=256
Reducing visibility of 131072KiB chip to 65536KiB
Concatenating MTD devices:
(0): "40000000.flash"
(1): "40000000.flash"
into device "40000000.flash"
libphy: smsc911x-mdio: probed
smsc911x 4e000000.ethernet eth0: attached PHY driver [Generic PHY] (mii_bus:phy_addr=4e000000.etherne:01, irq=-1)
smsc911x 4e000000.ethernet eth0: MAC Address: 52:54:00:12:34:56
isp1760 4f000000.usb: bus width: 32, oc: digital
isp1760 4f000000.usb: NXP ISP1760 USB Host Controller
isp1760 4f000000.usb: new USB bus registered, assigned bus number 1
isp1760 4f000000.usb: Scratch test failed.
isp1760 4f000000.usb: can't setup: -19
isp1760 4f000000.usb: USB bus 1 deregistered
usbcore: registered new interface driver usb-storage
mousedev: PS/2 mouse device common for all mice
rtc-pl031 10017000.rtc: rtc core: registered pl031 as rtc0
Driver 'mmcblk' needs updating - please use bus_type methods
mmci-pl18x 10005000.mmci: Got CD GPIO
mmci-pl18x 10005000.mmci: Got WP GPIO
mmci-pl18x 10005000.mmci: No vqmmc regulator found
mmci-pl18x 10005000.mmci: mmc0: PL181 manf 41 rev0 at 0x10005000 irq 34,35 (pio)
ledtrig-cpu: registered to indicate activity on CPUs
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
input: AT Raw Set 2 keyboard as /devices/platform/smb/smb:motherboard/smb:motherboard:iofpga@7,00000000/10006000.kmi/serio0/input/input0
aaci-pl041 10004000.aaci: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 33
aaci-pl041 10004000.aaci: FIFO 512 entries
oprofile: using arm/armv7-ca9
TCP: cubic registered
NET: Registered protocol family 17
9pnet: Installing 9P2000 support
Registering SWP/SWPB emulation handler
rtc-pl031 10017000.rtc: setting system clock to 2017-05-28 16:06:41 UTC (1495987601)
ALSA device list:
  #0: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 33
Warning: unable to open an initial console.
Freeing unused kernel memory: 2908K (c0d2d000 - c1004000)
input: ImExPS/2 Generic Explorer Mouse as /devices/platform/smb/smb:motherboard/smb:motherboard:iofpga@7,00000000/10007000.kmi/serio1/input/input2

[ feature request] modules related dir for basic rootfs

Due to we need to study linux kernel by linux kernel modules.
So I regard that we should add lib/modules/$(version) in the rootfs for newbee.
if not, it will cause rmmod failed!
And also there is no shared mount point for module install. maybe we can used virt-9p for that.

红黑树实验用例，rmmod rb_test.ko 时发生异常

源码路径如下：
runninglinuxkernel_4.0/rlk_lab/rlk_basic/chapter_2/lab3/kernel_module/

使用该源码编译出 rb_test.ko，拷贝至 kmodules 文件夹下，通过 ./run.sh arm32 启动 qemu 后，执行 insmod rb_test.ko 无问题，但执行 rmmod rb_test.ko 报错如下：

/mnt # insmod rb_test.ko 
[   33.857806] key=0
[   33.859100] key=2
[   33.859175] key=4
[   33.859309] key=6
[   33.859386] key=8
[   33.859535] key=10
[   33.859624] key=12
[   33.859736] key=14
[   33.859804] key=16
[   33.859860] key=18
/mnt # rmmod rb_test.ko 
[   39.756729] Unable to handle kernel paging request at virtual address 6b6b6b73
[   39.759282] pgd = c4b4c000
[   39.759520] [6b6b6b73] *pgd=00000000
[   39.760576] Internal error: Oops: 5 [#1] SMP ARM
[   39.760934] Modules linked in: rb_test(O-)
[   39.761669] CPU: 1 PID: 778 Comm: rmmod Tainted: G           O    4.0.0+ #1
[   39.761957] Hardware name: ARM-Versatile Express
[   39.762247] task: c5df1b80 ti: c4530000 task.ti: c4530000
[   39.762929] PC is at rb_next+0x54/0xb0
[   39.763477] LR is at my_exit+0x5c/0x78 [rb_test]
[   39.763767] pc : [<c05a88c8>]    lr : [<bf000214>]    psr: 20000013
[   39.763767] sp : c4533f10  ip : 00000000  fp : 002183a4
[   39.764324] r10: 00000000  r9 : c4530000  r8 : c0014ec4
[   39.764547] r7 : 00000081  r6 : 00000000  r5 : 00747365  r4 : 745f6272
[   39.764719] r3 : 6b6b6b6b  r2 : 6b6b6b6b  r1 : 00000010  r0 : c44f7000
[   39.765112] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   39.765444] Control: 10c5387d  Table: 64b4c06a  DAC: 00000015
[   39.765640] Process rmmod (pid: 778, stack limit = 0xc4530210)
[   39.765823] Stack: (0xc4533f10 to 0xc4534000)
[   39.766191] 3f00:                                     c63bbee0 6b6b6b6b 745f6272 bf00020c
[   39.766533] 3f20: 00000001 c44f7000 c44f7000 c44f7000 be996abc c01149e0 00000880 be996abc
[   39.766908] 3f40: 745f6272 00747365 c4455b80 00004000 0000000c 00000000 fffffffe c4454280
[   39.767160] 3f60: 00000000 c10c1bb4 c4455b80 00000001 00000000 001e1bfc 00ffff9c 00000000
[   39.767608] 3f80: 00000000 c024a10c bf0003d4 00000000 bf00027c 00000880 be996abc 00000000
[   39.768052] 3fa0: 00000017 c0014d40 745f6272 00747365 be996abc 00000880 00000007 00000000
[   39.768239] 3fc0: 745f6272 00747365 00000000 00000081 00000001 00000000 00000000 002183a4
[   39.768417] 3fe0: be996ab8 be996aa8 0002d680 00012130 60000010 be996abc 00000000 00000000
[   39.768899] [<c05a88c8>] (rb_next) from [<bf000214>] (my_exit+0x5c/0x78 [rb_test])
[   39.769365] [<bf000214>] (my_exit [rb_test]) from [<c01149e0>] (SyS_delete_module+0x1d0/0x238)
[   39.769765] [<c01149e0>] (SyS_delete_module) from [<c0014d40>] (ret_fast_syscall+0x0/0x34)
[   39.770376] Code: e59d3004 e5933008 e58d3004 e59d3004 (e5933008) 
[   39.771142] ---[ end trace 464d93677bdf49e3 ]---
Segmentation fault

追踪至异常源码处，node 是 data 的红黑树结点指针，循环中 kfree 将 data 释放后，data 中的 node 也就释放了，在下一次循环时就使用了非法地址。

  static void __exit my_exit(void)
  {
          struct mytype *data;
          struct rb_node *node;
          for (node = rb_first(&mytree); node; node = rb_next(node)) {
                  data = rb_entry(node, struct mytype, node);
                  if (data) {
                          rb_erase(&data->node, &mytree);
                          kfree(data);
                  }
          }
  }

请帮忙确认下是否有上述问题，thanks!

repo address may be wrong

➜ tiny git clone https://github.com/figozhang/runninglinuxkernel_4.0.git tig: Not a git repository ➜ tiny git clone [email protected]:figozhang/runninglinuxkernel_4.0.git tig: Not a git repository ➜ tiny

网盘版本缺少run.sh

Hi,

我下载了网盘版本，但是发现缺少了run.sh脚本。
github的repo是有run.sh

我想，这个不同会容易造成困惑(如果不仔细比较的话)。

试验5-8出错

只修改了device的名称

/ # mknod /dev/mydemo_err0 c 252 0
/ # cd mnt
/mnt # insmod miscerr.ko
[ 77.235510] succeeded register char device: mydemo_err
/mnt # cat /dev/mydemo_err0 &
/mnt # [ 93.227125] demodrv_open: major=252, minor=0, device=mydemo_err0
[ 93.233195] demodrv_read:mydemo_err0 pid=778, going to sleep, private_data_0

/mnt #
/mnt #
/mnt # echo "i am study linux now" > /dev/mydemo_err0
[ 131.945397] demodrv_open: major=252, minor=0, device=mydemo_err0
[ 131.948193] wait up read queue, private_data_0
[ 131.948609] demodrv_write:mydemo_err0 pid=772, actual_write =21, ppos=0, ret=0
[ 131.950152] Unable to handle kernel paging request at virtual address c789f6c0
[ 131.950673] pgd = c47d4000
[ 131.950852] [c789f6c0] *pgd=00000000
[ 131.952042] Internal error: Oops: 5 [#1] SMP ARM
[ 131.952779] Modules linked in: miscerr(O)
[ 131.954508] CPU: 0 PID: 772 Comm: sh Tainted: G O 4.0.0+ #2
[ 131.955054] Hardware name: ARM-Versatile Express
[ 131.956382] task: c4ab0b00 ti: c47d0000 task.ti: c47d0000
[ 131.957525] PC is at kfree+0x178/0x704
[ 131.957849] LR is at __kfifo_free+0x1c/0x64
[ 131.958290] pc : [] lr : [] psr: 20000013
[ 131.958290] sp : c47d3c68 ip : 00000000 fp : beb48fbe
[ 131.958923] r10: 00000000 r9 : c47d0000 r8 : c0014ec4
[ 131.959194] r7 : 0000003f r6 : 00000000 r5 : 0021da88 r4 : c05c0fb8
[ 131.959539] r3 : c789f6c0 r2 : c789f6c0 r1 : 00000019 r0 : 6b6b6b6b
[ 131.960074] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 131.960416] Control: 10c5387d Table: 647d406a DAC: 00000015
[ 131.960762] Process sh (pid: 772, stack limit = 0xc47d0210)
[ 131.961111] Stack: (0xc47d3c68 to 0xc47d4000)
[ 131.961506] 3c60: c4c3a280 6b6b6b6b 0a9b0a9b c0239350 00000000 c4c3a280
[ 131.962103] 3c80: c10f5188 c10f5188 60000013 c00c80f8 00000400 20000013 c10c378c c10c378c
[ 131.962595] 3ca0: 20000013 c10c378c 000003e0 c10c378c bcbcfdb1 00000000 0021dab8 bf000504
[ 131.963136] 3cc0: 00000000 c10f5188 c10f5188 c10f5188 c10f5188 60000013 00000004 c10f5188
[ 131.964751] 3ce0: 60000013 c10f5188 00000002 00000004 c62f4078 60000013 00000000 01000000
[ 131.967115] 3d00: c10f5188 c4ab0b00 00000000 00000000 00000000 c4ab0b00 00000000 00000042
[ 131.968103] 3d20: beb48fbe c007cc94 00000004 01000000 c5438c00 c4ab0b00 c4ba5ad0 00000002
[ 131.968833] 3d40: c47d0000 00000002 c4ab0b00 00000000 00000000 00000000 c4ab0ee4 00000004
[ 131.969416] 3d60: c5438c00 00000000 c4ab0ee4 00000004 c5438c00 c62feff8 05248000 c10b6ff8
[ 131.970017] 3d80: 00000000 00000000 00000000 00000000 05248000 c10b6ffc 00000000 00000000
[ 131.970820] 3da0: c4c3a280 c5c03cc0 00000080 c4c3a280 80010d00 c4c3a280 c4c3a280 c5c03cc0
[ 131.971726] 3dc0: c4c3a280 bf0001a8 c4c3a280 c63ca740 c789f6c0 0000000f c789f6c0 c789f6c0
[ 131.972422] 3de0: c789f6c0 0000000f c63ca740 c63ca740 c63ca740 c63ca740 00000007 00000000
[ 131.974227] 3e00: 60000013 00000000 c10f17a8 c10f17a8 6b6b6b6b c05c0fb8 c10f17a8 c10f17a8
[ 131.974868] 3e20: c4c3a280 6b6b6b6b c5d37540 c5c03cc0 c5d37548 6b6b6b6b 0000000b c05c0fb8
[ 131.976320] 3e40: c63ca740 c4c3a2c4 0000000b bf0001c4 c5438c00 c452c448 00000000 c4c3a2c4
[ 131.976861] 3e60: c4c3a2c4 c4c3a280 00000001 c0250b0c 00000000 00000000 00000002 c5438c00
[ 131.977718] 3e80: 00000001 c5d37508 00000000 00000000 00000000 00000000 00000000 c5d37540
[ 131.978780] 3ea0: 00000001 00000008 c5bf8270 c5438c08 00000008 0004001e c452c448 c5438c00
[ 131.979130] 3ec0: c5438c08 c5438c94 c5438c00 c028967c 00000000 00000000 00000001 c5438c00
[ 131.979624] 3ee0: c5438c00 c452c448 c5cf4c10 c5bf8270 00000002 c0250e30 c55da000 c5438c00
[ 131.980088] 3f00: 00000000 c5438c00 c5d37508 c007d16c 01e601e6 01e601e6 c5d37500 0000000b
[ 131.980496] 3f20: 00000004 c47d3f10 c4ab0ef8 c5438c00 c5438c00 00000000 c4ab0ee4 00000004
[ 131.981302] 3f40: 00000000 c5438c00 c4ab0ee4 00000004 00000000 c5438c00 c4ab0ee4 00000000
[ 131.981866] 3f60: 00000000 c4ab0ef8 00000000 c4ab0b00 c5438c00 c5438c00 00200200 c001c8e0
[ 131.982384] 3f80: c5438c00 c0014ec4 00000004 c47d3fb0 00000015 00000002 c47d0000 c47d3fb0
[ 131.985925] 3fa0: 00000017 c0014d40 0000000b c0014d84 00000001 00000001 0021c828 00000001
[ 131.986431] 3fc0: 0000000b 0021da88 00000000 0000003f 0021cc28 00000000 001ca858 beb48fbe
[ 131.986848] 3fe0: 00000000 beb489fc 000707d0 00011bbc 20000010 0000000b 00000000 00000000
[ 131.987406] [] (kfree) from [] (__kfifo_free+0x1c/0x64)
[ 131.988871] [] (__kfifo_free) from [] (demodrv_release+0x40/0x50 [miscerr])
[ 131.989336] [] (demodrv_release [miscerr]) from [] (__fput+0x1fc/0x3f0)
[ 131.989831] [] (__fput) from [] (____fput+0x20/0x2c)
[ 131.990178] [] (____fput) from [] (task_work_run+0x2ec/0x334)
[ 131.990626] [] (task_work_run) from [] (do_work_pending+0x13c/0x174)
[ 131.991237] [] (do_work_pending) from [] (work_pending+0xc/0x20)
[ 131.992238] Code: e1a032c3 e1a03103 e59d2168 e0823003 (e5932000)
[ 131.993084] ---[ end trace a12670f987276c82 ]---

[入门篇]印刷错误

109页

实验3：为虚拟设备编写驱动

代码

static char *device_buffer;

这里device_buffer是一个野指针，没有任何定义在后续的read和write就直接使用了

然后错误2是在demodrv_read函数中，

need_read = max_free > count ? lbuf : max_free;

没有找到lbuf的定义，推测是不是该为count?

百度网盘连接失效？

执行rmmod发生Segmentation fault

/mnt # rmmod modhello
Segmentation fault

网盘上的repo遇到这个问题，码云上的repo我也测试了，也是这个问题

hello_exit的退出函数里，只有一句printk