C 看门狗内核模块未知符号看门狗寄存器设备

目前，我正试图开发一个内核模块来控制硬件看门狗，当它没有反馈时，关闭系统，就像看门狗应该做的那样。我知道已经有一个用户空间守护进程，可以从/dev/watchdog文件“控制”，但我需要一个内核模块。为了扩展这一点，我已经有了一个内核模块来接收GPIO输入，已经为此注册了一个IRQ，并且希望该IRQ能够提供给看门狗。因此，如果GPIO中断在X时间内未触发，系统将关闭

但是，我很难让看门狗头文件与我合作。我在这里阅读了关于watchdog内核api的小文档，但这似乎表明它可以正常工作

下面我粘贴了我的测试代码，以便让看门狗注册，然后是我遇到的错误

testWatchdog.c

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/watchdog.h>

static int __init watchdog_init(void)
{
    struct watchdog_device test;
    printk(KERN_INFO "WATCHDOG\n");
    watchdog_register_device(&test);
    test.ops->start(&test);
    test.ops->ping(&test);
    return 0;
}

static void __exit watchdog_exit(void)
{
    printk(KERN_INFO "GG!!!\n");
}

MODULE_LICENSE("GPL");

module_init(watchdog_init);
module_exit(watchdog_exit);

我的代码可以生成，但运行insmod时会出错

insmod:插入“/testWatchdog.ko”时出错：-1无效参数

运行dmesg后，我看到以下错误

未知符号监视程序\寄存器\设备（错误0）

如果有人能为我指出正确的方向，我将不胜感激。我对内核模块相当陌生，但我对此充满希望

更新： 出于某种原因，我决定重新运行这个insmod命令，并且我的输出已经更改。据我所知，我没有改变任何东西，但我可能更新了一个文件。不管怎样，当我现在尝试insmod时，我没有得到一个错误，但是我的内核说我正在做一个空指针解引用。这是我的错误的输出

[68964.787385] WATCHDOG
[68964.787405] BUG: unable to handle kernel NULL pointer dereference at 00000005
[68964.787409] IP: [<f84c7020>] watchdog_init+0x20/0x1000 [testWatchdog]
[68964.787420] *pdpt = 000000003676a001 *pde = 0000000000000000 
[68964.787423] Oops: 0000 [#1] SMP 
[68964.787427] Modules linked in: testWatchdog(OF+) vboxsf(OF) vesafb(F) microcode(F) vboxguest(OF) psmouse(F) serio_raw(F) i2c_piix4(F) mac_hid(F) vboxvideo(OF) rfcomm(F) bnep(F) parport_pc(F) bluetooth(F) ppdev(F) drm(F) binfmt_misc(F) lp(F) parport(F) pcnet32(F) ahci(F) libahci(F)
[68964.787446] Pid: 3180, comm: insmod Tainted: GF          O 3.8.0-34-generic #49~precise1-Ubuntu innotek GmbH VirtualBox/VirtualBox
[68964.787448] EIP: 0060:[<f84c7020>] EFLAGS: 00010296 CPU: 0
[68964.787451] EIP is at watchdog_init+0x20/0x1000 [testWatchdog]
[68964.787453] EAX: e1989e3c EBX: f84c4000 ECX: 00000000 EDX: 00000001
[68964.787455] ESI: 00001299 EDI: e1989f60 EBP: e1989eb8 ESP: e1989e38
[68964.787456]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[68964.787461] CR0: 8005003b CR2: 00000005 CR3: 34865000 CR4: 000006f0
[68964.787477] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[68964.787482] DR6: ffff0ff0 DR7: 00000400
[68964.787484] Process insmod (pid: 3180, ti=e1988000 task=f3f5e680 task.ti=e1988000)
[68964.787485] Stack:
[68964.787487]  f84c3024 c103fb63 00000000 e1989ed0 00000000 00000000 e1989eac c1040885
[68964.787492]  00000000 e1989e6c 00000000 f84c8000 00000001 00000000 80000000 e1989ed0
[68964.787496]  00000000 80000000 00000000 00000000 00000001 00000001 0003d5dc c10decd6
[68964.787501] Call Trace:
[68964.787528]  [<c103fb63>] ? cpa_flush_range+0x43/0xc0
[68964.787532]  [<c1040885>] ? change_page_attr_set_clr+0x225/0x250
[68964.787543]  [<c10decd6>] ? tracepoint_module_notify+0x26/0xc0
[68964.787546]  [<f84c7000>] ? 0xf84c6fff
[68964.787549]  [<c1040a7f>] ? set_memory_nx+0x5f/0x70
[68964.787552]  [<c1003054>] do_one_initcall+0x34/0x170
[68964.787555]  [<f84c7000>] ? 0xf84c6fff
[68964.787567]  [<c161b039>] do_init_module+0x80/0x1c6
[68964.787583]  [<c10af03b>] load_module+0x41b/0x5f0
[68964.787586]  [<c10acee0>] ? add_kallsyms+0x1e0/0x1e0
[68964.787611]  [<c12f92f2>] ? _copy_from_user+0x42/0x60
[68964.787615]  [<c10af296>] sys_init_module+0x86/0xa0
[68964.787620]  [<c163518d>] sysenter_do_call+0x12/0x28
[68964.787622] Code: <ff> 52 04 8b 55 d0 8d 45 84 ff 52 0c 31 c0 c9 c3 00 00 00 00 00 00
[68964.787642] EIP: [<f84c7020>] watchdog_init+0x20/0x1000 [testWatchdog] SS:ESP 0068:e1989e38
[68964.787646] CR2: 0000000000000005
[68964.787650] ---[ end trace fd9234fd8f14c123 ]---

[68964.787385]看门狗
[68964.787405]错误：无法处理00000005处的内核空指针解引用
[68964.787409]IP:[]看门狗初始化+0x20/0x1000[测试看门狗]
[68964.787420]*pdpt=00000000 3676A001*pde=0000000000000000
[68964.787423]Oops:0000[#1]SMP
[68964.787427]模块链接：testWatchdog（OF+）vboxsf（OF）vesafb（F）微码（F）vboxguest（OF）psmouse（F）serio_raw（F）i2c_piix4（F）mac_hid（F）vboxvideo（F）rfcomm（F）bnep（F）parport（F）pc（F）蓝牙（F）ppdev（F）drm（F）binfmt(Miscu（F）lp（F）parport（F）pcnet32（F）ahci（F）libahci（F）libahci（F）
[68964.787446]Pid:3180，通信：insmod污染：GF O 3.8.0-34-generic#49~precise1 Ubuntu innotek GmbH VirtualBox/VirtualBox
[68964.787448]EIP:0060:[]EFLAGS:00010296 CPU:0
[68964.787451]EIP位于watchdog_init+0x20/0x1000[testWatchdog]
[68964.787453]EAX:e1989e3c EBX:f84c4000 ECX:00000000 EDX:00000001
[68964.787455]ESI:00001299 EDI:e1989f60 EBP:e1989eb8 ESP:e1989e38
[68964.787456]DS:007b ES:007b FS:00d8 GS:00e0 SS:0068
[68964.787461]CR0:8005003b CR2:00000005 CR3:34865000 CR4:000006f0
[68964.787477]DR0:00000000 DR1:00000000 DR2:00000000 DR3:00000000
[68964.787482]DR6:ffff0ff0 DR7:00000400
[68964.787484]过程insmod（pid:3180，ti=e1988000任务=f3f5e680任务。ti=e1988000）
[68964.787485]堆栈：
[68964.787487]f84c3024 c103fb63 00000000 e1989ed0 00000000 00000000 e1989eac c1040885
[68964.787492]00000000 e1989e6c 00000000 f84c8000 00000001 00000000 8000000 e1989ed0
[68964.787496]00000000 8000000000000000 00000000 1000000000001 0003d5dc c10decd6
[68964.787501]呼叫跟踪：
[68964.787528]  [] ? cpa\u冲洗\u范围+0x43/0xc0
[68964.787532]  [] ? 更改页面属性设置clr+0x225/0x250
[68964.787543]  [] ? 跟踪点模块通知+0x26/0xc0
[68964.787546]  [] ? 0xf84c6fff
[68964.787549]  [] ? 设置内存\u nx+0x5f/0x70
[68964.787552][]执行一次初始化调用+0x34/0x170
[68964.787555]  [] ? 0xf84c6fff
[68964.787567][]执行初始化模块+0x80/0x1c6
[68964.787583][]加载_模块+0x41b/0x5f0
[68964.787586]  [] ? 添加_kallsyms+0x1e0/0x1e0
[68964.787611]  [] ? _从用户+0x42/0x60复制用户
[68964.787615][]系统初始化模块+0x86/0xa0
[68964.787620][]系统输入\u do\u调用+0x12/0x28
[68964.787622]代码：52 04 8b 55 d0 8d 45 84 ff 52 0c 31 c0 c9 c3 00 00
[68964.787642]EIP:[]看门狗初始化+0x20/0x1000[测试看门狗]SS:ESP 0068:e1989e38
[68964.787646]CR2:0000000000005
[68964.787650]--[end trace fd9234fd8f14c123]---

在您的.config文件config\u WATCHDOG\u CORE=y中，在my/usr/src/（uname-r）-generic/.config文件config\u WATCHDOG\u CORE=y中，请查看此驱动程序。恐慌是因为

test

没有用正确的数据初始化就通过了。谢谢你，我才开始意识到我有多傻。出于某种原因，我认为看门狗寄存器设备就像一个空结构的初始化。现在更有意义了。

[68964.787385] WATCHDOG
[68964.787405] BUG: unable to handle kernel NULL pointer dereference at 00000005
[68964.787409] IP: [<f84c7020>] watchdog_init+0x20/0x1000 [testWatchdog]
[68964.787420] *pdpt = 000000003676a001 *pde = 0000000000000000 
[68964.787423] Oops: 0000 [#1] SMP 
[68964.787427] Modules linked in: testWatchdog(OF+) vboxsf(OF) vesafb(F) microcode(F) vboxguest(OF) psmouse(F) serio_raw(F) i2c_piix4(F) mac_hid(F) vboxvideo(OF) rfcomm(F) bnep(F) parport_pc(F) bluetooth(F) ppdev(F) drm(F) binfmt_misc(F) lp(F) parport(F) pcnet32(F) ahci(F) libahci(F)
[68964.787446] Pid: 3180, comm: insmod Tainted: GF          O 3.8.0-34-generic #49~precise1-Ubuntu innotek GmbH VirtualBox/VirtualBox
[68964.787448] EIP: 0060:[<f84c7020>] EFLAGS: 00010296 CPU: 0
[68964.787451] EIP is at watchdog_init+0x20/0x1000 [testWatchdog]
[68964.787453] EAX: e1989e3c EBX: f84c4000 ECX: 00000000 EDX: 00000001
[68964.787455] ESI: 00001299 EDI: e1989f60 EBP: e1989eb8 ESP: e1989e38
[68964.787456]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[68964.787461] CR0: 8005003b CR2: 00000005 CR3: 34865000 CR4: 000006f0
[68964.787477] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[68964.787482] DR6: ffff0ff0 DR7: 00000400
[68964.787484] Process insmod (pid: 3180, ti=e1988000 task=f3f5e680 task.ti=e1988000)
[68964.787485] Stack:
[68964.787487]  f84c3024 c103fb63 00000000 e1989ed0 00000000 00000000 e1989eac c1040885
[68964.787492]  00000000 e1989e6c 00000000 f84c8000 00000001 00000000 80000000 e1989ed0
[68964.787496]  00000000 80000000 00000000 00000000 00000001 00000001 0003d5dc c10decd6
[68964.787501] Call Trace:
[68964.787528]  [<c103fb63>] ? cpa_flush_range+0x43/0xc0
[68964.787532]  [<c1040885>] ? change_page_attr_set_clr+0x225/0x250
[68964.787543]  [<c10decd6>] ? tracepoint_module_notify+0x26/0xc0
[68964.787546]  [<f84c7000>] ? 0xf84c6fff
[68964.787549]  [<c1040a7f>] ? set_memory_nx+0x5f/0x70
[68964.787552]  [<c1003054>] do_one_initcall+0x34/0x170
[68964.787555]  [<f84c7000>] ? 0xf84c6fff
[68964.787567]  [<c161b039>] do_init_module+0x80/0x1c6
[68964.787583]  [<c10af03b>] load_module+0x41b/0x5f0
[68964.787586]  [<c10acee0>] ? add_kallsyms+0x1e0/0x1e0
[68964.787611]  [<c12f92f2>] ? _copy_from_user+0x42/0x60
[68964.787615]  [<c10af296>] sys_init_module+0x86/0xa0
[68964.787620]  [<c163518d>] sysenter_do_call+0x12/0x28
[68964.787622] Code: <ff> 52 04 8b 55 d0 8d 45 84 ff 52 0c 31 c0 c9 c3 00 00 00 00 00 00
[68964.787642] EIP: [<f84c7020>] watchdog_init+0x20/0x1000 [testWatchdog] SS:ESP 0068:e1989e38
[68964.787646] CR2: 0000000000000005
[68964.787650] ---[ end trace fd9234fd8f14c123 ]---