zhuizhuhaomeng Blog

「记录下来，一切都会更容易理解」

how does nginx http slice module work

我想分析一下 nginx_http_slice_module 的工作原理，因为自带的 OpenResty 不含该模块，因此需要自己编译。在深入代码分析之前，我们需要先了解 HTTP bytes range 的请求了解 HTTP bytes range 的原理可以在点击 mozilla rnage request 查看详细的信息。我们这里抽取一个请求响应的例子。 1 2 3 4 ...

Posted by zhuizhuhaomeng Blog on December 16, 2023

Add gnu BuildID for Go program

我们可以使用 file 命令查看 ELF 文件的 BuildID。比如： 1 2 $ file /usr/bin/ls /usr/bin/ls: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l...

Posted by zhuizhuhaomeng Blog on December 12, 2023

How to debug linux crash

总结 Linux 内核崩溃应该怎么调试呢？这篇文件挺好的，包含了分析的实例，https://wiki.whamcloud.com/display/LNet/Crash+course+on+Crash。总结下来，关键的步骤就是：要先配置 kdump 才能保存崩溃的现场。需要安装 kernel-debuginfo 需要安装 crash 程序（当然也要 gdb）使用...

Posted by zhuizhuhaomeng Blog on November 28, 2023

Examples of Linux find command

1 2 3 4 5 6 7 #!/bin/bash for name in `find / -maxdepth 1 -type d -regex "/[0-9]+t-[a-z]"`; do for d in `find /16t-a/trace-pkg-db -maxdepth 2 -type d -regex ".*/\(rpms\|debs\)"`; do f...

Posted by zhuizhuhaomeng Blog on November 11, 2023

An exmaple of ssl_certificate_by_lua

1. the lua code save the following code to file /usr/local/openresty/site/lualib/dynamic_cert.lua 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 ...

Posted by zhuizhuhaomeng Blog on October 27, 2023

HTTP error emulator

1. 模拟 HTTP 上游服务器不响应 (网关 504 超时) 以下 Go 程序作为源站 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 package main import ( ...

Posted by zhuizhuhaomeng Blog on October 24, 2023

DWARF op code

elf 中 debug 相关的节 .debug_abbrev - Abbreviations used in the .debug_info section .debug_aranges - Lookup table for mapping addresses to compilation units .debug_frame - Call frame information...

Posted by zhuizhuhaomeng Blog on October 20, 2023

systemctl examples

设置进程的调度属性 1 2 3 4 5 6 7 8 9 10 [Unit] Description=Machine Check Exception Logging Daemon [Service] ExecStart=/usr/sbin/mcelog --ignorenodev --daemon --foreground CPUSchedulingPolicy=fifo CPUSched...

Posted by zhuizhuhaomeng Blog on October 19, 2023

gdb 读取 tls 变量

As answered in Using GDB to read MSRs, this is possible with gdb 8, using the registers $fs_base and $gs_base.

Posted by zhuizhuhaomeng Blog on October 9, 2023

openssl 撤销证书

问题 lua-ngix-module 的测试用例中用到了撤销证书 t/cert/test.crl。在更新 t/cert/test.key 和 t/cert/test.crt 后忘记更新撤销证书列表导致用例失败。那么如何生成撤销证书列表呢？生成撤销证书列表生成撤销证书列表需要用到 CA 证书，但是因为这里是自签名证书，因此就 CA 就算自签名证书本身。下面的命令列表中给出了一些使...

Posted by zhuizhuhaomeng Blog on October 6, 2023