关于system call
在 FreeBSD 开发手册 中,有一部分内容介绍了关于系统调用。里面有这样一段话:
Linux is a UNIX like system. However, its kernel uses the same system-call convention of passing parameters in registers MS-DOS does. As with the UNIX convention, the function number is placed in EAX. The parameters, however, are not passed on the stack but in EBX, ECX, EDX, ESI, EDI, EBP:
open:
mov eax, 5
mov ebx, path
mov ecx, flags
mov edx, mode
int 80h
This convention has a great disadvantage over the UNIX way, at least as far as assembly language programming is concerned: Every time you make a kernel call you must push the registers, then pop them later. This makes your code bulkier and slower. Nevertheless, FreeBSD gives you a choice.
可能有人会问了,为什么说 UNIX way (将参数压栈) 更好呢?
阅读全文…SPF的好处
SPF并不总只是一种公德性的行为,有时它也会给你带来额外的好处,比如:
Dec 17 15:40:55 tarsier postfix/smtpd[63579]: NOQUEUE: reject: RCPT from unknown[60.177.46.2]: 550 support@geekcn.org: Sender address rejected: “geekcn.org [60.177.46.2] is not allowed to send mail for support@geekcn.org”; from=support@geekcn.org to=steve@geekcn.org proto=ESMTP helo=<geekcn.org>
参与评论是科幻还是灵异?北大自习室里鬼魂出没zt
From zoomq
你,通宵熬夜自习过吗?比如:期末考试将至,却发现选修的课程有一半没有去上过,及格的可能和国家足球队出线的可能性相当。又比如:距离 CET6级考试只有一周时间,却发现刘毅5000上一半的单词都不认识。再比如:导师下了死命令让你一个月之内交论文,却发现他给的参考文献80%以上是鸟语天书。你能怎么办?于是告别了温暖的被窝,摸进又黑又冷的自习教室,蜡烛、手电筒乃至应急灯的光明灭定。夜半时分,又困又饿又冷……身边漆黑一片,寂静无声,这个时候,害怕吗?或者突然就有什么东西出现……
阅读全文…诗艺zz
眼望岁月与流水汇成的长河
回想时间是另一条河,
要知道我们就像河流一去不复返
一张张脸孔水一样掠过。
要觉察到清醒是另一场梦
梦见自己并未做梦,而死亡
使我们的肉体充满恐惧,不过是那
被称为睡梦的夜夜归来的死亡。
设了一个套,把自己绕了进去,越缠越紧……
整理www.freebsd.org.cn,发现给自己设了个套,而且越缠越紧……文档的没有!!!!!:(:(:(
参与评论转换进行时
如果没有干扰,我相信有2.5天就能做完全部准备,需要时间……不过无论如何要在一周之内全部做完,这是我的底线。
参与评论黑了自己管的一台服务器……
接前文……以为彻底安全之后,苦思冥想,终于想起可以拿某台机器通过NFS走后门,果然洞开……进入后,写了个suid的binary进去,拿到root了!
阅读全文…干了一件超级傻事……
升级某台服务器的时候,一怒之下删除了所有port,删完发现自己敲下的命令是——
阅读全文…昨天买了两本书
一本是《概率统计》,机械工业出版社影印的,ISBN 7-111-12320-4/O·231,另一本是《模式分类》,也是机械工业出版社影印的,ISBN 7-111-13687-X/TP·3398。打算抽时间自学一下。
参与评论freefall is now running 6.0-STABLE
After it has runned 4.x series for a too long time, finally kensmith@ has stepped up to upgrade it.
Needless to say what this means, just upgrade all your boxes to FreeBSD 6.x. FreeBSD 6.0-RELEASE is the best release we have released in the recent years, and the best .0 release ever, as proven by many installations and developers’ code review.
参与评论