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V2EX  ›  redsonic  ›  全部回复第 20 页 / 共 60 页
回复总数  1195
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2018-01-31 20:25:30 +08:00
回复了 Plumes 创建的主题 宽带症候群 第 41 次《中国互联网络发展状况统计报告》出来了
@LGA1150 可以简单解释一下吗,谢谢
2018-01-31 20:09:48 +08:00
回复了 Plumes 创建的主题 宽带症候群 第 41 次《中国互联网络发展状况统计报告》出来了
@yexm0 我是通过只有北上广深有公开的城域网自治号估计的,不过上海联通这两年总体感觉是下降的,很多直连的 peer 都不行了。另外联通接的国外的 IX 是不是只有专线才走,看了一下上海城网 AS17621 到那 4 个 IX 都不通, 206.72.210.36 ,80.81.195.58 ,198.32.146.40 ,195.66.227.72 ,第一跳后面就没路由了。
2018-01-31 19:31:04 +08:00
回复了 Plumes 创建的主题 宽带症候群 第 41 次《中国互联网络发展状况统计报告》出来了
@965380535 估计北上广胃口越来越大了,联通真要有 9T 全给这三个城市也喂不饱。
2018-01-31 18:26:39 +08:00
回复了 Plumes 创建的主题 宽带症候群 第 41 次《中国互联网络发展状况统计报告》出来了
@965380535 是指 HE 的 tunnel 吗? 16 年和之前那会儿上海确实全天能跑满,后来就不行了,别的地方不知道。
2018-01-31 17:32:47 +08:00
回复了 Plumes 创建的主题 宽带症候群 第 41 次《中国互联网络发展状况统计报告》出来了
联通上海回程欧洲和北美全绕美国 LEVEL3 去了,晚上卡到和当年上海奠信一样可以上电视了。
2018-01-23 19:40:41 +08:00
回复了 wonpn 创建的主题 宽带症候群 最近套路云新加坡贼慢
@f2f2f
@19930618
不是这几天吧,去年底就开始绕了,越来越多的线路随后接着绕了。应该不是故障,感觉像是在调整什么。
2018-01-17 17:21:27 +08:00
回复了 Pai 创建的主题 机械键盘 ThinkPad25 周年纪念版小红点机械键盘
下面的三键太违和了,为啥不用传统 thinkpad 笔记本的那种。
2018-01-13 16:33:19 +08:00
回复了 mywaiting 创建的主题 分享发现 逛 Twitter 偶然发现的 CloudShell,竟然还是 Google 发的福利
有流量限制的吧,用多了会封号?
2018-01-12 17:44:05 +08:00
回复了 saran 创建的主题 问与答 更换网络身份的成本是多少
成本最高的是怎么办一个新身份证,其他都没太大意义。
2018-01-05 22:32:42 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
搜到霓虹那边关于 tsc 的一张表应该能判别哪些 cpu 会受到影响
http://www.02.246.ne.jp/~torutk/cxx/clock/cpucounter.html
2018-01-05 21:56:07 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
@yksoft1 开不开优化结果都一样
2018-01-05 21:18:44 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
@yksoft1 update: 刚才有疏忽,单核芯模式 core duo2 中招。dothan 应该都是单核心吧,所以中招。这样看老的 tsc 不准反而打掩护了。
2018-01-05 20:51:42 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
@yksoft1 我只启用一个核心,设置成实时优先级,mfence 和 lfence 都不起作用。dothan 我没有 没办法测试,不过手里的 core i 1 代 、2 代、4 代、5 代都中招。另外发现 core duo2 跑这个 PoC 要比中招的那几个慢非常多,trace 了一下几乎每个引用都慢很多,从这个角度看 core i 的访存设计可能真的和老 core duo2 差异蛮大的。dothan 应该就是 core duo1,不知道是不是这两代也有访存设计上的巨大差异。
2018-01-05 14:27:52 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
@yksoft1 我用 mingw-w64 编译又跑了一遍,老 core duo2 e6300 e6400 e6600 l7500 都猜不到,如果这个 PoC 没问题说明没有 invariant TSC 的 cpu 似乎很难通过侧信道攻击。
2018-01-05 01:43:52 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
@yksoft1 我是在 vs2013 里面编译的,64、32 位都卡在那,我在调调 readMemoryByte()。
还有你那个 rdtscp 定义成这样吗? 我试了一下老 core2 还是几乎猜不到。
unsigned long rdtscp()
{
unsigned int lo,hi;

__asm__ __volatile__
(
"mfence;rdtsc":"=a"(lo),"=d"(hi)
);
return (unsigned long)hi<<32|lo;
}
2018-01-05 00:33:11 +08:00
回复了 yksoft1 创建的主题 分享发现 Spectre 攻击的那个 PoC 有人复现了吗
linux 上面测试过了,结果贴在隔壁帖里了。老 cpu 可以用 rdtsc 代替 rdtscp,但几乎猜不中了。既然计时是侧信道泄漏的关键那 intel 只要弄个开关把计时模糊一下应该可以防止这类攻击。
另外 windows 的我编译了,运行时卡在 reading at malicious_x=FFFFF0E0 ......
2018-01-04 23:25:23 +08:00
回复了 dndx 创建的主题 分享发现 x86 CPU bug 更详细的技术细节流出
@jaleo 自主可控就不需要后门了,直接前门
2018-01-04 23:03:42 +08:00
回复了 dndx 创建的主题 分享发现 x86 CPU bug 更详细的技术细节流出
@VYSE linux 上实测带有 invariant tsc 的新处理器全中招,老的 core2 在__rdtscp 处非法指令,换成 rdtsc 能跑过,但基本不中招。牙膏厂只要弄个开关把 tsc 弄得模糊点应该可以应付过去 spectre 攻击。

新赛扬,core i:
# /tmp/spectre-attack
Putting 'The Magic Words are Squeamish Ossifrage.' in memory
Reading 40 bytes:
Reading at malicious_x = 0xffffffffffdfeb98... Success: 0x54=’ T ’ score=17 (second best: 0x05 score=6)
Reading at malicious_x = 0xffffffffffdfeb99... Success: 0x68=’ h ’ score=17 (second best: 0x05 score=6)
Reading at malicious_x = 0xffffffffffdfeb9a... Success: 0x65=’ e ’ score=2
Reading at malicious_x = 0xffffffffffdfeb9b... Success: 0x20=’ ’ score=2
Reading at malicious_x = 0xffffffffffdfeb9c... Success: 0x4D=’ M ’ score=2
Reading at malicious_x = 0xffffffffffdfeb9d... Success: 0x61=’ a ’ score=19 (second best: 0x00 score=6)
Reading at malicious_x = 0xffffffffffdfeb9e... Success: 0x67=’ g ’ score=2
Reading at malicious_x = 0xffffffffffdfeb9f... Success: 0x69=’ i ’ score=2
Reading at malicious_x = 0xffffffffffdfeba0... Success: 0x63=’ c ’ score=125 (second best: 0x00 score=61)
Reading at malicious_x = 0xffffffffffdfeba1... Success: 0x20=’ ’ score=2
Reading at malicious_x = 0xffffffffffdfeba2... Success: 0x57=’ W ’ score=2
Reading at malicious_x = 0xffffffffffdfeba3... Success: 0x6F=’ o ’ score=2
Reading at malicious_x = 0xffffffffffdfeba4... Success: 0x72=’ r ’ score=2
Reading at malicious_x = 0xffffffffffdfeba5... Success: 0x64=’ d ’ score=2
Reading at malicious_x = 0xffffffffffdfeba6... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfeba7... Success: 0x20=’ ’ score=97 (second best: 0x05 score=46)
Reading at malicious_x = 0xffffffffffdfeba8... Success: 0x61=’ a ’ score=2
Reading at malicious_x = 0xffffffffffdfeba9... Success: 0x72=’ r ’ score=2
Reading at malicious_x = 0xffffffffffdfebaa... Success: 0x65=’ e ’ score=107 (second best: 0x00 score=50)
Reading at malicious_x = 0xffffffffffdfebab... Success: 0x20=’ ’ score=2
Reading at malicious_x = 0xffffffffffdfebac... Success: 0x53=’ S ’ score=2
Reading at malicious_x = 0xffffffffffdfebad... Success: 0x71=’ q ’ score=2
Reading at malicious_x = 0xffffffffffdfebae... Success: 0x75=’ u ’ score=2
Reading at malicious_x = 0xffffffffffdfebaf... Success: 0x65=’ e ’ score=2
Reading at malicious_x = 0xffffffffffdfebb0... Success: 0x61=’ a ’ score=513 (second best: 0x00 score=255)
Reading at malicious_x = 0xffffffffffdfebb1... Success: 0x6D=’ m ’ score=2
Reading at malicious_x = 0xffffffffffdfebb2... Success: 0x69=’ i ’ score=2
Reading at malicious_x = 0xffffffffffdfebb3... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfebb4... Success: 0x68=’ h ’ score=13 (second best: 0x00 score=5)
Reading at malicious_x = 0xffffffffffdfebb5... Success: 0x20=’ ’ score=2
Reading at malicious_x = 0xffffffffffdfebb6... Success: 0x4F=’ O ’ score=17 (second best: 0x00 score=7)
Reading at malicious_x = 0xffffffffffdfebb7... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfebb8... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfebb9... Success: 0x69=’ i ’ score=93 (second best: 0x00 score=45)
Reading at malicious_x = 0xffffffffffdfebba... Success: 0x66=’ f ’ score=2
Reading at malicious_x = 0xffffffffffdfebbb... Success: 0x72=’ r ’ score=2
Reading at malicious_x = 0xffffffffffdfebbc... Success: 0x61=’ a ’ score=2
Reading at malicious_x = 0xffffffffffdfebbd... Success: 0x67=’ g ’ score=2
Reading at malicious_x = 0xffffffffffdfebbe... Success: 0x65=’ e ’ score=2
Reading at malicious_x = 0xffffffffffdfebbf... Success: 0x2E=’.’ score=251 (second best: 0x00 score=122)

老 core2,每次结果不一样,因为 tsc 不准,这是猜对最多的一次:
#./spectre-attack 10
Putting 'The Magic Words are Squeamish Ossifrage.' in memory
Reading 40 bytes:
Reading at malicious_x = 0xffffffffffdfeb78... Success: 0x54=’ T ’ score=2
Reading at malicious_x = 0xffffffffffdfeb79... Success: 0x68=’ h ’ score=2
Reading at malicious_x = 0xffffffffffdfeb7a... Success: 0x65=’ e ’ score=6
Reading at malicious_x = 0xffffffffffdfeb7b... Success: 0x20=’ ’ score=2
Reading at malicious_x = 0xffffffffffdfeb7c... Success: 0x4D=’ M ’ score=1
Reading at malicious_x = 0xffffffffffdfeb7d... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb7e... Success: 0x67=’ g ’ score=1
Reading at malicious_x = 0xffffffffffdfeb7f... Success: 0x69=’ i ’ score=1
Reading at malicious_x = 0xffffffffffdfeb80... Success: 0x63=’ c ’ score=2
Reading at malicious_x = 0xffffffffffdfeb81... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb82... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb83... Success: 0x6F=’ o ’ score=1
Reading at malicious_x = 0xffffffffffdfeb84... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb85... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb86... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfeb87... Success: 0x66=’ f ’ score=1
Reading at malicious_x = 0xffffffffffdfeb88... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb89... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8a... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8b... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8c... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8d... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8e... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb8f... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb90... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb91... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb92... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb93... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb94... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb95... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb96... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb97... Success: 0x73=’ s ’ score=2
Reading at malicious_x = 0xffffffffffdfeb98... Success: 0x00=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb99... Success: 0x69=’ i ’ score=2
Reading at malicious_x = 0xffffffffffdfeb9a... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb9b... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb9c... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb9d... Success: 0xFF=’?’ score=0
Reading at malicious_x = 0xffffffffffdfeb9e... Success: 0x65=’ e ’ score=1
Reading at malicious_x = 0xffffffffffdfeb9f... Success: 0xFF=’?’ score=0
2018-01-04 18:20:14 +08:00
回复了 dndx 创建的主题 分享发现 x86 CPU bug 更详细的技术细节流出
@BlueFly 好像还没有,但国家队应该有了,发现这个漏洞的研究员好像都签了保密协议。
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