linux kernel driver debug
1. print
printk()
: never
pr_debug()
: always good
dev_dbg()
: prefered when you have a struct device
object
netdev_dbg()
: prefered when you have a struct netdevice
object
[something]_dbg()
: prefered when you have a that something object
see the implementation in source code:
/* If you are writing a driver, please use dev_dbg instead */
#if defined(CONFIG_DYNAMIC_DEBUG)
/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
#define pr_debug(fmt, ...) \
dynamic_pr_debug(fmt, ##__VA_ARGS__)
#elif defined(DEBUG)
#define pr_debug(fmt, ...) \
printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug(fmt, ...) \
no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif
It shows the CONFIG_DYNAMIC_DEBUG/DEBUG option can be used to enable or disable the print.
dynamic debug:
Benefits:
Almost no overhead when log code is not enabled.
Turn on/off debug log at runtime.
No need to recompile the kernel.
Control interface: uboot boot argus, debugfs
# mount -t debugfs none /sys/kernel/debug/
# cd /sys/kernel/debug/dynamic_debug/
# echo “file xxx.c +p” > control
# echo “file svcsock.c line 1603 +p” > control
# echo “file drivers/usb/core/* +p” > control
# echo “file xxx.c -p” > control
retrive the log information
dmesg
dmesg -C clear
dmesg -c show and then clear.
tail /var/log/syslog-f dynamic to show the log information in case the syslogd is running.
The debug log default size is 64K, you can configure it by menuconfig, note that the size is calculted by 2^n.
dmesg -n 5
Set console logging filter to KERN_WARNING or more severe.
dmesg -l warn
Only print the logs of KERN_WARNING in the kernel ring buffer.
Another option is dynamic debug by configuring the debugfs
enable it in kernel : CONFIG_DYNAMIC_DEBUG=y menuconfig
using pr_debug(), dev_dbg() ... in driver source code
e.g.
2. using file system proc/ memory large file or sequence file
3. using ioctrl to get/set specific data
Below shall enable the kernel debug. CONFIG_DEBUG_INFO =y
4. gdb list command to idenfiy the line of oops
e.g.
5. addr2line command to identify the line of oops
e.g. addr2line -fe vmlinux ce000678
6. objdump -dS .o
-d: display assembler conetents of executable sections
-S intermix source code with disassembly
linux kernel driver debug的更多相关文章
- CentOS VirtualBox启动虚拟及报错:VirtualBox error: Kernel driver not installed (rc=1908)
VirtualBox error: Kernel driver not installed (rc=1908) Hi all, Let me first say that this is my fin ...
- Fedora安装VirtualBox时出现错误Kernel driver not installed (rc=-1908)的解决办法
新建虚拟机后启动时出现如下错误: Kernel driver not installed (rc=-1908) The VirtualBox Linux kernel driver (vboxdrv) ...
- VirtualBox,Kernel driver not installed (rc=-1908)
http://hi.baidu.com/spt_form/item/316d6207b47b8ee03499020a VirtualBox,Kernel driver not installed (r ...
- 参考论坛:Mali kernel driver TX011-SW-99002-r5p1-00rel0 for firefly
最近手头有一块firefly_rk3288_reload的开发板,想实现在linux 下用openGL ES来做视频显示. 找到opengGL相关移植,参考论坛(http://bbs.t-firefl ...
- ubuntu中使用virtualbox遇到Kernel driver not installed (rc=-1908)错误
百度之后得到解决,再此做个笔记 错误提示 Kernel driver not installed (rc=-1908) The VirtualBox Linux kernel driver (vbox ...
- freeIPMI README && issue about OpenIPMI kernel driver
http://www.gnu.org/software/freeipmi/README FreeIPMI - Copyright (C) 2003-2013 FreeIPMI Core Team Fr ...
- Linux Kernel - Debug Guide (Linux内核调试指南 )
http://blog.csdn.net/blizmax6/article/details/6747601 linux内核调试指南 一些前言 作者前言 知识从哪里来 为什么撰写本文档 为什么需要汇编级 ...
- Linux kernel AACRAID Driver Compat IOCTL 本地安全绕过漏洞
漏洞名称: Linux kernel AACRAID Driver Compat IOCTL 本地安全绕过漏洞 CNNVD编号: CNNVD-201311-390 发布时间: 2013-11-29 更 ...
- Linux kernel support docker storage driver aufs
How to make docker use aufs in CentOS 7? - Server Faulthttps://serverfault.com/questions/650208/how- ...
随机推荐
- Springboot静态文件不更新的解决办法,以及Springboot实现热部署
Springboot静态文件不更新的解决办法,以及Springboot实现热部署 原文链接:https://www.cnblogs.com/blog5277/p/9271882.html 原文作者:博 ...
- 改写element-ui中的日期组件
如果你想实现一个自定义的日期组件规则如下:日期组件未点开前左右两边有前一天后一天控制箭头,且前一天后一天有数据时才显示箭头,没有数据时,快速切换箭头隐藏.当日期组件点开后,有数据的天为可点击状态,无数 ...
- Gson如何解析key值是数字的json数据
1.使用注解@SerializedName来解决这个问题 2.比如有如下json数据:(key值是数字"1112") { "1112": "抖音&qu ...
- English trip EM2-LP-4B At school Teacher:Will
课上内容(Lesson) 词汇(Key Word ) art 美术:艺术 business 商科 engineering 工程学 graphic design 平面造型学 history 历 ...
- [cf div 2 706E] Working routine
[cf div 2 706E] Working routine Vasiliy finally got to work, where there is a huge amount of tasks w ...
- 2015-10-12 jQuery4
十. 直接获取.编辑内容 1.获取内容 alert($("#d1").text()); //获取文本内容 alert($("#d1").html()); ...
- vscode settings.json
// 快捷键设置 keyiing.json // 将键绑定放入此文件中以覆盖默认值 [ /* // 转换大写 { "key" : "ctrl+shift+u", ...
- 如何解析超长的protobuf zhuan
在调用protobuf的ParseFromString(str)方法时,默认情况下,如果str的长度>64MB,会返回失败. 这里给出了解释,主要是出于安全因素的考虑. 可以通过SetTotal ...
- 协程----greenlet模块,gevent模块
1.协程初识,greenlet模块 2.gevent模块(需要pip安装) 一.协程初识,greenlet模块: 协程:是单线程下的并发,又称微线程,纤程.英文名Coroutine.一句话说明什么是线 ...
- Spring Boot 2.0尝鲜-动态 Banner
配置依赖 使用 Spring Boot 2.0 首先需要将项目依赖包替换为刚刚发布的 2.0 RELEASE,现在网站https://start.spring.io/也将 Spring Boot 2. ...