printk("globalvar register success\n"); sema_init(&globalvar.sem,1);//初始化信号量init_waitqueue_head(&globalvar.outq);//初始化等待队列globalvar.rd = globalvar.buffer;//读指针globalvar.wr = globalvar.buffer;//写指针globalvar.end = globalvar.buffer + MAXNUM;//缓冲区尾指针globalvar.f...
对于每个socket,拥有自己的send buffer和receive buffer。从Linux 2.6开始,两个缓冲区大小都由系统来自动调节(autotuning),但一般在default和max之间浮动。 # 获取socket的发送/接受缓冲区的大小:(后面的值是在Linux 2.6.38 x86_64上测试的结果) sysctl net.core.wmem_default #126976 sysctl net.core.wmem_max #...
int fd,size; char s [ ]=”Linux Programmer!\n”,buffer[80]; fd=open(“/tmp/temp”,O_WRONLY|O_CREAT); write(fd,s,sizeof(s)); close(fd); fd=open(“/tmp/temp”,O_RDONLY); size=read(fd,buffer,sizeof(buffer)); close(fd); printf(“%s”,buffer); } read 函数定义: ssize_t ...
复制 #include<unistd.h>#include<sys/types.h>#include<sys/stat.h>#include<fcntl.h>main(){int fd,size;char s[]=”Linux Programmer!\n”,buffer[80];fd=open(“/tmp/temp”,O_WRONLY|O_CREAT);write(fd,s,sizeof(s));close(fd);fd=open(“/tmp/temp”,O_RDONLY);size=read(fd,buffer,s...
linux 系统调用 write 的原子性 1. 问题描述 开始阅读 nginx 源码的时候就一直伴随着一个问题,那就是多进程的 nginx 模型是怎么保证多个进程同时写入一个文件不发生数据交错呢? 猜想中,主要有以下几种解决方案: 1. 最传统的,正在写文件的进程加锁,其他进程等待,但是这样的情况是绝对不允许的,效率太过低下 2....
The operating system transfers the write buffer to the disk controller (data is in the disk cache). The disk controller actually writes the data into a physical media (a magnetic disk, a Nand chip, …). 总结: 当我们到第3 步, 也就是write 操作系统返回的时候, 可以保证的是如果process 挂...
public virtual void Write (byte[] buffer, int index, int count); 參數 buffer Byte[] 含有要寫入之資料的位元組陣列。 index Int32 要從buffer 讀取並寫入到資料流之第一個位元組的索引。 count Int32 要從buffer 讀取並寫入到資料流的位元組數目。 例外狀況 ArgumentException 緩衝區長度減去 index...
After that, I checked online for existing exploits that achieved a PUAF primitive. At that time, I could not find any for iOS but that is when I stumbled upon Jann Horn's Mali issues. As a quick aside, I also skimmed his blog post aboutexploiting a simple Linux memory corruption bug,...
writev, instead, would gather together the contents of each buffer and put them out as a single write operation. Until version 2.3.44 of the kernel, however, Linux always emulated readv and writev with multiple calls to read and write. If your driver does not supply methods to handle the...
HTB 0x1:Linux:446pts No DIStractions:Miscellaneous:330pts Pirates of the Memorial:OSINT:332pts NITIC CTF (2020/07/19) NITIC CTF 1200 Points prime_factorization:PPC:200pts cha1n:Misc:200pts anim:Forensic:200pts Fortran:Reversing:200pts shift_only:Crypto:200pts 8^2:Web:100pts Dangerous Twitt...