{"id":784,"date":"2017-05-03T04:53:34","date_gmt":"2017-05-03T04:53:34","guid":{"rendered":"http:\/\/www.selinuxplus.com\/?p=784"},"modified":"2017-05-03T04:56:42","modified_gmt":"2017-05-03T04:56:42","slug":"systemtap-%e5%ad%a6%e4%b9%a0","status":"publish","type":"post","link":"http:\/\/www.selinuxplus.com\/?p=784","title":{"rendered":"systemtap \u5b66\u4e60"},"content":{"rendered":"<p>SystemTap \u63d0\u4f9b\u4e86\u4e00\u4e2a\u7b80\u5355\u7684\u547d\u4ee4\u884c\u63a5\u53e3\u548c\u5f3a\u5927\u7684\u811a\u672c\u8bed\u8a00\uff0c\u540c\u65f6\u9884\u5b9a\u4e49\u4e86\u4e30\u5bcc\u7684\u811a\u672c\u5e93\u3002\u57fa\u4e8e\u5185\u6838\u4e2d\u7684 kprobes\uff0cSystemTap \u5141\u8bb8\u7528\u6237\u81ea\u7531\u5730\u4ece\u8fd0\u884c\u4e2d\u7684\u5185\u6838\u6536\u96c6\u8c03\u8bd5\u4fe1\u606f\u548c\u6027\u80fd\u6570\u636e\uff0c\u6765\u7528\u4e8e\u4e4b\u540e\u7684\u5206\u6790\u548c\u5904\u7406\u3002\u7528\u6237\u53ef\u4ee5\u968f\u65f6\u5f00\u59cb\u6216\u8005\u505c\u6b62\u8fd9\u4e2a\u6536\u96c6\u8fc7\u7a0b\uff0c\u800c\u65e0\u9700\u6f2b\u957f\u7684\u4fee\u6539\u4ee3\u7801\u3001\u7f16\u8bd1\u5185\u6838\u548c\u91cd\u542f\u7cfb\u7edf\u8fd9\u4e2a\u5faa\u73af<br \/>\n&#8212;<strong> 0x01 SystemTap Features<\/strong><\/p>\n<blockquote><p>\u52a8\u6001\u7684\u6027\u80fd\u5206\u6790\u80fd\u529b\uff0c\u4e0d\u6253\u65ad\u5206\u6790\u76ee\u6807\u7684\u903b\u8f91\uff0c\u4e0d\u6539\u5199\u3001\u4fb5\u5165\u5206\u6790\u76ee\u6807\u7684\u4ee3\u7801\u3002<br \/>\n\u591a\u79cd\u591a\u6837\u7684probe events<br \/>\n\u4e5f\u53ef\u4ee5\u8c03\u8bd5\u5206\u6790\u529f\u80fd\u6027\u7684\u95ee\u9898<br \/>\n\u4f4e\u5f00\u9500\uff0c\u5b89\u5168\u6027\u9ad8\uff0c\u9002\u7528\u4e8e\u6b63\u5f0f\u4ea7\u54c1<br \/>\n\u6301\u7eed\u957f\u65f6\u95f4\u7684\u6027\u80fd\u5206\u6790<br \/>\n\u6309\u9700probe\uff0c\u53ef\u4ee5\u7528\u811a\u672c\u7f16\u5199\uff0c\u8fc7\u6ee4\u4fe1\u606f\u7684\u8f93\u51fa\u548c\u91c7\u96c6<br \/>\n\u6613\u7528\u6027\u8f83\u597d<\/p><\/blockquote>\n<p>&#8212;<strong> 0x02 SystemTap \u5229\u7528\u7684\u6280\u672fKprobes\/Kretprobe\/Uprobes\/Relayfs<\/strong><br \/>\nkernel\u5c42\u7684\u4e00\u4e2a\u63a5\u53e3\uff0c\u6ce8\u518c\u540e\u53ef\u4ee5\u975e\u4fb5\u5165\u7684\u52a8\u6001\u63d2\u5165\u7edd\u5927\u591a\u6570\uff08\u6ce81\uff09\u51fd\u6570\u5e76\u91c7\u96c6\u8c03\u8bd5\u4fe1\u606f\u548c\u6027\u80fd\u6570\u636e\u3002\u5f53\u63d2\u6869\u70b9\u88abhit\u65f6\uff0c\u4f1a\u6307\u5b9a\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684\u5904\u7406\u51fd\u6570\uff08handler\uff09\u6765\u5904\u7406\u65b0\u7684\u903b\u8f91\u3002<br \/>\nKprobes \u4ece 2.6.9 \u7248\u672c\u5f00\u59cb\u5c31\u6dfb\u52a0\u5230\u4e3b\u6d41\u7684 Linux \u5185\u6838\u4e2d\uff0c\u5e76\u4e14\u4e3a\u63a2\u6d4b\u5185\u6838\u63d0\u4f9b\u4e00\u822c\u6027\u670d\u52a1\u3002\u5b83\u63d0\u4f9b\u4e00\u4e9b\u4e0d\u540c\u7684\u670d\u52a1\uff0c\u4f46\u6700\u91cd\u8981\u7684\u4e24\u79cd\u670d\u52a1\u662f Kprobe \u548c Kretprobe\u3002Kprobes\u63d2\u6869\u7684\u6280\u672f\u5f88\u7b80\u5355\uff0c\u540c\u8c03\u8bd5\u5668\u548c\u52a8\u6001\u8865\u4e01\u6280\u672f\u7684\u539f\u7406\u5927\u81f4\u76f8\u540c\u3002\u9996\u5148\u4f1a\u62f7\u8d1d\u4e00\u4efd\u9700\u8981probe\u70b9\u7684\u6307\u4ee4\u5185\u5bb9\uff0c\u5e76\u4e14\u628a\u65e7\u7684\u4ee3\u7801\u6bb5\u66ff\u6362\u6210\u4e00\u4e2a\u65ad\u70b9\u6307\u4ee4(e.g., int3 on i386 and x86_64)\u3002\u5f53\u65ad\u70b9\u6307\u4ee4\u88ab\u89e6\u53d1\u540e\uff0c\u5904\u7406\u4e86\u65b0\u903b\u8f91\uff0c\u7136\u540e\u4f1a\u6062\u590d\u539f\u6765\u7684\u4ee3\u7801\u6bb5\u5185\u5bb9,\u63a5\u7740\u6267\u884c\u539f\u59cb\u7684\u6307\u4ee4\uff08\u4ece\u65ad\u70b9\u5f00\u59cb\uff09\u3002<br \/>\nKretprobes \u6709\u6240\u4e0d\u540c\uff0c\u5b83\u64cd\u4f5c\u8c03\u7528\u51fd\u6570\u7684\u8fd4\u56de\u7ed3\u679c\u3002\u6ce8\u610f\uff0c\u56e0\u4e3a\u4e00\u4e2a\u51fd\u6570\u53ef\u80fd\u6709\u591a\u4e2a\u8fd4\u56de\u70b9\uff0c\u6240\u4ee5\u542c\u8d77\u6765\u4e8b\u60c5\u6709\u4e9b\u590d\u6742\u3002\u4e0d\u8fc7\uff0c\u5b83\u5b9e\u9645\u4f7f\u7528\u4e00\u79cd\u79f0\u4e3a trampoline \u7684\u7b80\u5355\u6280\u672f\u3002\u60a8\u5c06\u5411\u51fd\u6570\u6761\u76ee\u6dfb\u52a0\u4e00\u5c0f\u6bb5\u4ee3\u7801\uff0c\u800c\u4e0d\u662f\u68c0\u67e5\u51fd\u6570\u4e2d\u7684\u6bcf\u4e2a\u8fd4\u56de\u70b9\u3002\u8fd9\u6bb5\u4ee3\u7801\u4f7f\u7528 trampoline \u5730\u5740\u66ff\u6362\u5806\u6808\u4e0a\u7684\u8fd4\u56de\u5730\u5740 \u2014\u2014 Kretprobe \u5730\u5740\u3002\u5f53\u8be5\u51fd\u6570\u5b58\u5728\u65f6\uff0c\u5b83\u6ca1\u6709\u8fd4\u56de\u5230\u8c03\u7528\u65b9\uff0c\u800c\u662f\u8c03\u7528 Kretprobe\uff08\u6267\u884c\u5b83\u7684\u529f\u80fd\uff09\uff0c\u7136\u540e\u4ece Kretprobe \u8fd4\u56de\u5230\u5b9e\u9645\u7684\u8c03\u7528\u65b9\u3002<br \/>\nRelayfs \u4e00\u79cd\u9ad8\u901f\u7684\u6570\u636e\u8f6c\u53d1\u6587\u4ef6\u7cfb\u7edf\u3002\u53ef\u4ee5\u4ecekernel\u5c42\u9ad8\u901f\uff0c\u76f4\u63a5\uff0c\u53ef\u9760\u7684\u628a\u6570\u636e\u8f6c\u53d1\u5230\u7528\u6237\u7a7a\u95f4\u8bfb\u3002<br \/>\n\u8bb8\u591atrace\/debug\u5de5\u5177\u90fd\u662f\u5229\u7528\u4e86relayfs\u673a\u5236\uff0ceg. Systemtap\/Lttng\/Debugfs<br \/>\n&#8212;<strong> 0x03 SystemTap working<\/strong><br \/>\n<a href=\"http:\/\/www.selinuxplus.com\/wp-content\/uploads\/2017\/05\/stap.png\"><img loading=\"lazy\" src=\"http:\/\/www.selinuxplus.com\/wp-content\/uploads\/2017\/05\/stap.png\" alt=\"stap\" width=\"500\" height=\"509\" class=\"aligncenter size-full wp-image-785\" srcset=\"http:\/\/www.selinuxplus.com\/wp-content\/uploads\/2017\/05\/stap.png 500w, http:\/\/www.selinuxplus.com\/wp-content\/uploads\/2017\/05\/stap-294x300.png 294w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><\/a><br \/>\n<strong>\u8bed\u6cd5\u5206\u6790\u9636\u6bb5\uff08parse\uff09<\/strong><br \/>\n\u4e3b\u8981\u662f\u68c0\u67e5\u8f93\u5165\u811a\u672c\u662f\u5426\u5b58\u5728\u8bed\u6cd5\u9519\u8bef\uff0c\u4f8b\u5982\u5927\u62ec\u53f7\u662f\u5426\u5339\u914d\u3001\u53d8\u91cf\u5b9a\u4e49\u662f\u5426\u89c4\u8303\u7b49<br \/>\n<strong>\u7ec6\u5316\uff08Elaborate\uff09<\/strong><br \/>\n\u7ec6\u5316\u662f\u5206\u6790\u8f93\u5165\u811a\u672c\u5e76\u89e3\u6790\u5bf9\u5185\u6838\u7684\u5f15\u7528\u6216\u7528\u6237\u7b26\u53f7\u4e0e tapsets \u7684\u5904\u7406\u9636\u6bb5\u3002Tapsets \u662f\u7528\u6765\u6269\u5c55\u811a\u672c\u80fd\u529b\u7684\u811a\u672c\u6216 C \u4ee3\u7801\u5e93\u3002\u7ec6\u5316\u5c06\u811a\u672c\u4e2d\u7684\u5916\u90e8\u5f15\u7528\u89e3\u6790\u4e3a\u7b26\u53f7\u4fe1\u606f\u5e76\u5bfc\u5165\u811a\u672c\u5b50\u7a0b\u5e8f\uff0c\u4e3a\u4e0b\u4e00\u6b65\u8f6c\u6362\u4e3a C \u7a0b\u5e8f\u505a\u51c6\u5907\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u5c31\u7c7b\u4f3c\u4e8e\u5c06\u5e93\u6587\u4ef6\u94fe\u63a5\u5230\u76ee\u6807\u6587\u4ef6\u3002\u5bf9\u5185\u6838\u6570\u636e\u5982\u51fd\u6570\u53c2\u6570\u3001\u5c40\u90e8\u548c\u5168\u5c40\u53d8\u91cf\u3001\u51fd\u6570\u4ee5\u53ca\u6e90\u5730\u5740\u90fd\u9700\u8981\u88ab\u89e3\u6790\u4e3a\u8fd0\u884c\u65f6\u5b9e\u9645\u7684\u5730\u5740\uff0c\u8fd9\u662f\u901a\u8fc7\u5bf9\u6784\u5efa\u5185\u6838\u65f6\u7f16\u8bd1\u5668\u4ea7\u751f\u7684 DWARF \u8c03\u8bd5\u4fe1\u606f\u8fdb\u884c\u5904\u7406\u6765\u5b9e\u73b0\u7684\u3002\u6240\u6709\u7684\u8c03\u8bd5\u6570\u636e\u90fd\u4f1a\u5728\u5185\u6838\u6a21\u5757\u8fd0\u884c\u4e4b\u524d\u88ab\u5904\u7406\u3002\u8c03\u8bd5\u6570\u636e\u5305\u542b\u8db3\u591f\u7684\u4fe1\u606f\u6765\u5b9a\u4f4d\u5185\u8054\u51fd\u6570\u3001\u5c40\u90e8\u53d8\u91cf\u3001\u7c7b\u578b\u4ee5\u53ca\u4e00\u4e9b\u901a\u5e38\u4e0d\u88ab\u5bfc\u51fa\u5230\u5185\u6838\u6a21\u5757\u7684\u58f0\u660e\u3002<br \/>\n\u4e0b\u9762\u603b\u7ed3\u4e00\u4e0b\u7ec6\u5316\u9636\u6bb5\u6240\u505a\u7684\u4e3b\u8981\u5de5\u4f5c\uff1a<\/p>\n<blockquote><p>\u83b7\u53d6\u7528\u6237\u7684\u63a2\u6d4b\u811a\u672c<br \/>\n\u9884\u5904\u7406\u5b8f<br \/>\n\u5305\u542b\u6240\u9700\u8981\u7684\u811a\u672c\u5e93<br \/>\n\u89e3\u6790\u4ee3\u7801\u4e2d\u5bf9\u7b26\u53f7\u7684\u5f15\u7528<br \/>\n\u67e5\u627e\u51fd\u6570\u5165\u53e3\u5730\u5740<br \/>\n\u67e5\u627e\u884c\u53f7\u4fe1\u606f<br \/>\n\u67e5\u627e\u5168\u5c40\u548c\u5c40\u90e8\u53d8\u91cf\u7684\u7c7b\u578b\u53ca\u5730\u5740<\/p><\/blockquote>\n<p><strong>\u8f6c\u6362\uff08Translate\uff09<\/strong><br \/>\n\u811a\u672c\u88ab\u7ec6\u5316\u540e\u5b83\u5c06\u4f1a\u88ab\u8f6c\u6362\u4e3a C \u8bed\u8a00\u4ee3\u7801\uff0c\u6bcf\u4e2a\u811a\u672c\u5b50\u7a0b\u5e8f\u90fd\u88ab\u6269\u5c55\u6210C\u8bed\u8a00\u4ee3\u7801\u5757\u5e76\u8fdb\u884c\u5b89\u5168\u68c0\u67e5\uff0c\u4f8b\u5982\u5bf9\u5faa\u73af\u7ed3\u6784\u8fdb\u884c\u9012\u589e\u68c0\u67e5\u4e86\u9632\u6b62\u65e0\u9650\u5faa\u73af\u3002\u7531\u591a\u4e2a\u63a2\u6d4b\u70b9\u5171\u4eab\u7684\u53d8\u91cf\u4f1a\u88ab\u6620\u5c04\u6210\u9002\u5f53\u7684\u9759\u6001\u58f0\u660e\uff0c\u5e76\u4ee5\u5757\u4e3a\u5355\u4f4d\u8fdb\u884c\u8bbf\u95ee\u4fdd\u62a4\u3002\u5728\u5185\u6838\u4e2d\u4f7f\u7528kprobes\u4e2d\u7684\u6ce8\u518cAPIs\u5bf9\u63a2\u6d4b\u70b9\u5904\u7406\u5668\uff08probe handlers\uff09\u8fdb\u884c\u6ce8\u518c\u3002\u5bf9\u4e8e\u5728\u5185\u6838\u4e2d\u7684\u63a2\u6d4b\u70b9\uff0c\u4f1a\u88ab\u63d2\u5165\u5230\u5185\u6838\u7684\u5185\u5b58\u7a7a\u95f4\u4e2d\uff1b\u5bf9\u4e8e\u7528\u6237\u7ea7\u522b\u63a2\u6d4b\u70b9\uff0c\u5b83\u5c06\u88ab\u63d2\u5165\u5230\u53ef\u6267\u884c\u4ee3\u7801\u4e2d\uff0c\u5f53\u5904\u7406\u5668\u5728\u5185\u6838\u4e2d\u8fd0\u884c\u65f6\u5c06\u5176\u8f7d\u5165\u5230\u7528\u6237\u7684\u5185\u5b58\u7a7a\u95f4\u3002<br \/>\n<strong>\u6784\u9020\uff08Build\uff09<br \/>\n<\/strong>\u8f6c\u6362\u5b8c\u6210\u540e\uff0c\u4ea7\u751f\u7684 C \u8bed\u8a00\u4ee3\u7801\u4f1a\u88ab\u7f16\u8bd1\u5e76\u4e0e\u8fd0\u884c\u65f6\u8fdb\u884c\u94fe\u63a5\u6210\u4e00\u4e2astand-alone \u5185\u6838\u6a21\u5757\u3002\u8be5\u6a21\u5757\u53ef\u88ab\u52a0\u5bc6\u6807\u8bb0\u4ee5\u7528\u4e8e\u5b89\u5168\u5f52\u6863\u6216\u8fdc\u7a0b\u4f7f\u7528\u3002<br \/>\n<strong>\u8fd0\u884c\uff08Execution\uff09<\/strong><br \/>\n\u751f\u6210\u6a21\u5757\u540e SystemTap \u9a71\u52a8\u7a0b\u5e8f\u4f1a\u4f7f\u7528 insmod \u5c06\u5185\u6838\u6a21\u5757\u8f7d\u5165\u3002\u8be5\u6a21\u5757\u4f1a\u8fdb\u884c\u521d\u59cb\u5316\u3001\u63d2\u5165\u63a2\u6d4b\u70b9\uff0c\u7136\u540e\u7b49\u5f85\u63a2\u6d4b\u70b9\u88ab\u89e6\u53d1\u3002\u63a2\u6d4b\u70b9\u88ab\u89e6\u53d1\u540e\u4f1a\u8c03\u7528\u76f8\u5173\u8054\u7684\u5904\u7406\u5668\u7a0b\u5e8f\u5e76\u6302\u8d77\u6267\u884c\u7ebf\u7a0b\uff0c\u5f53\u8be5\u63a2\u6d4b\u70b9\u6240\u6709\u7684\u5904\u7406\u5668\u90fd\u8fd0\u884c\u540e\uff0c\u7ebf\u7a0b\u91cd\u65b0\u8fd0\u884c\u3002\u5f53\u7528\u6237\u53d1\u9001\u4e2d\u65ad\u6216\u811a\u672c\u8c03\u7528 exit \u65f6\uff0cSystemTap \u811a\u672c\u5c06\u4e2d\u6b62\u8fd0\u884c\u3002\u7136\u540e\u5378\u8f7d\u6a21\u5757\u5e76\u79fb\u9664\u63a2\u6d4b\u70b9\u3002<br \/>\n<strong>\u6570\u636e\u91c7\u96c6<\/strong><br \/>\nSystemTap \u9700\u8981\u5c06\u4ece\u5185\u6838\u4e2d\u83b7\u53d6\u7684\u6570\u636e\u4f20\u8f93\u5230\u7528\u6237\u7a7a\u95f4\uff0c\u5e76\u4e14\u9700\u8981\u5f88\u9ad8\u7684\u541e\u5410\u91cf\u3001\u4f4e\u5ef6\u8fdf\u4ee5\u53ca\u6700\u5c0f\u5316\u5bf9\u88ab\u76d1\u6d4b\u7cfb\u7edf\u6027\u80fd\u7684\u5f71\u54cd\u3002\u7f3a\u7701\u60c5\u51b5\u4e0b\uff0cSystemTap \u7684\u8f93\u51fa\u4f1a\u5728\u811a\u672c\u51fa\u53e3\u4ee5\u6279\u5904\u7406\u7684\u65b9\u5f0f\u5199\u5165 stdout\uff0c\u540c\u65f6\u8be5\u8f93\u51fa\u4f1a\u88ab\u81ea\u52a8\u4fdd\u5b58\u5230\u6587\u4ef6\u4e2d\u3002\u5728\u7528\u6237\u7a7a\u95f4\uff0cSystemTap \u53ef\u4ee5\u4ee5\u7b80\u5355\u7684\u6587\u672c\u65b9\u5f0f\u663e\u793a\u6570\u636e\uff0c\u6216\u4f7f\u7528\u56fe\u5f62\u7c7b\u7684\u5e94\u7528\u7a0b\u5e8f\u751f\u6210\u8ba1\u7b97\u673a\u53ef\u8bfb\u7684\u8868\u683c\u6570\u636e\u7b49\u3002<\/p>\n<p>&#8212;<strong> 0x04 \u8bed\u8a00\u57fa\u7840<\/strong><br \/>\n\u7f16\u5199\u51fd\u6570\u4f53\u548c\u63a2\u6d4b\u5904\u7406\u5668\u7684\u8bed\u6cd5\u5927\u90e8\u5206\u501f\u9274\u4e8e awk \u548c C \u8bed\u8a00\u3002SystemTap \u8fd8\u5141\u8bb8 C\u3001C++\u548c awk \u98ce\u683c\u7684\u6ce8\u91ca\u3002\u9664\u4e86$\u4e5f\u662f\u5408\u6cd5\u7684\u5b57\u7b26\u5916\uff0cSystemTap \u5b9a\u4e49\u6807\u8bc6\u7b26\u7684\u8bed\u6cd5\u4e0e C \u8bed\u8a00\u5b8c\u5168\u4e00\u6837\u3002\u6807\u8bc6\u7b26\u7528\u6765\u547d\u540d\u53d8\u91cf\u548c\u51fd\u6570\uff0c\u4ee5$\u5f00\u5934\u7684\u6807\u8bc6\u7b26\u88ab\u8ba4\u4e3a\u662f\u5bf9\u76ee\u6807\u7a0b\u5e8f\uff08\u5373\u88ab\u76d1\u6d4b\u7a0b\u5e8f\uff09\u4e2d\u53d8\u91cf\u7684\u5f15\u7528\u800c\u4e0d\u662f SystemTap \u811a\u672c\u4e2d\u7684\u53d8\u91cf\u3002SystemTap \u7684\u8bed\u8a00\u4e2d\u5305\u62ec\u5c11\u91cf\u7684\u6570\u636e\u7c7b\u578b\uff0c\u4f46\u662f\u6ca1\u6709\u7c7b\u578b\u58f0\u660e\uff1a\u53d8\u91cf\u7684\u7c7b\u578b\u662f\u4ece\u5b83\u7684\u4f7f\u7528\u4e2d\u63a8\u65ad\u51fa\u6765\u7684\u3002\u7c7b\u4f3c\u7684\uff0c\u5b57\u7b26\u4e32\u548c\u6570\u5b57\u4e4b\u95f4\u4e5f\u6ca1\u6709\u9690\u5f0f\u7684\u7c7b\u578b\u8f6c\u6362\u3002<br \/>\n\u8bed\u8a00\u4e2d\u5305\u542b\u4f20\u7edf\u7684if\uff0dthen\uff0delse \u8bed\u53e5\u4ee5\u53ca C\u8bed\u8a00\u548c awk \u4e2d\u7684\u8868\u8fbe\u5f0f\uff0c\u540c\u65f6\u8fd8\u652f\u6301\u7ed3\u6784\u5316\u63a7\u5236\u8bed\u53e5\u5982 for\u548c while \u5faa\u73af\uff0c\u4f46\u4e0d\u652f\u6301\u975e\u7ed3\u6784\u5316\u64cd\u4f5c\u5982\u6807\u53f7\u548c goto \u8bed\u53e5\u3002\u4e3a\u652f\u6301\u5173\u8054\u6570\u7ec4\uff0cSystemTap \u8bed\u8a00\u5305\u542b\u4e86\u8fed\u4ee3\u5668\u548c delete \u8bed\u53e5\u3002\u8fed\u4ee3\u5668\u8bed\u53e5\u5141\u8bb8\u7a0b\u5e8f\u5458\u6307\u5b9a\u6267\u884c\u6570\u7ec4\u4e2d\u6240\u6709\u6210\u5458\u7684\u64cd\u4f5c\uff0cdelete \u64cd\u4f5c\u53ef\u4ee5\u79fb\u9664\u6570\u7ec4\u4e2d\u4e00\u4e2a\u6216\u5168\u90e8\u6210\u5458\u3002C \u8bed\u8a00\u4e2d\u5178\u578b\u7684\u7b97\u672f\u3001\u4f4d\u3001\u8d4b\u503c\u53ca\u4e00\u5143\u64cd\u4f5c\u5728 SystemTap\u4e2d\u90fd\u53ef\u4ee5\u4f7f\u7528\uff0c\u4f46\u90fd\u662f\u64cd\u4f5c\u5728 64 \u4f4d\u6570\u5b57\u4e0a\u7684\uff0c\u8d4b\u503c\u548c\u6bd4\u8f83\u8fd0\u7b97\u7b26\u53ef\u4ee5\u91cd\u8f7d\u4e3a\u5b57\u7b26\u4e32\u4f7f\u7528\u3002<br \/>\n<strong>Events<\/strong><br \/>\n\u63a2\u6d4b\u70b9\u6307\u5b9a\u4e86\u5728\u5185\u6838\u7684\u4ec0\u4e48\u4f4d\u7f6e\u8fdb\u884c\u63a2\u6d4b\uff0c\u63a2\u6d4b\u70b9\u8fd8\u53ef\u4ee5\u5b9a\u4e49\u5728\u4e0e\u76ee\u6807\u7a0b\u5e8f\u4e0a\u67d0\u4e2a\u70b9\u6ca1\u6709\u8054\u7cfb\u7684\u62bd\u8c61\u4e8b\u4ef6\u4e0a\uff0c\u4f46\u8fd9\u65f6\u8f6c\u6362\u5668\u5c31\u4e0d\u80fd\u83b7\u5f97\u592a\u591a\u5173\u4e8e\u63a2\u6d4b\u70b9\u7684\u7b26\u53f7\u4fe1\u606f\u3002<\/p>\n<pre class=\"lang:default decode:true \" >begin The startup of the systemtap session.\r\nend The end of the systemtap session.\r\nkernel.function(\"sys_open\") The entry to the function named sys_open in the kernel.\r\nsyscall.close.return The return from the close system call.\r\nmodule(\"ext3\").statement(0xdeadbeef) The addressed instruction in the ext3 filesystem driver.\r\ntimer.ms(200) A timer that fires every 200 milliseconds.\r\ntimer.profile A timer that fires periodically on every CPU.\r\nperf.hw.cache_misses A particular number of CPU cache misses have occurred.\r\nprocfs(\"status\").read A process trying to read a synthetic <\/pre>\n<p><strong>Handlers<\/strong><br \/>\n\u63a2\u6d4b\u70b9\u540d\u79f0\u540e\u7d27\u8ddf\u7684\u4e00\u7ec4\u5927\u62ec\u53f7\u5185\u5b9a\u4e49\u4e86\u6bcf\u6b21\u5185\u6838\u8fd0\u884c\u5230\u8be5\u63a2\u6d4b\u70b9\u65f6\u9700\u8981\u8fdb\u884c\u7684\u64cd\u4f5c\uff0c\u6bd4\u5982\u53ef\u4ee5\u6307\u5b9a\u8f93\u51fa\u6570\u636e\u8fc7\u6ee4\u7684\u6761\u4ef6\uff0c\u6216\u8005\u66f4\u4e3a\u590d\u6742\u7684\u63a7\u5236\u903b\u8f91\u3002\u8fd9\u4e9b\u64cd\u4f5c\u5b8c\u6210\u540e\u518d\u8fd4\u56de\u63a2\u6d4b\u70b9\uff0c\u7ee7\u7eed\u4e0b\u9762\u7684\u6307\u4ee4\u3002<br \/>\n<strong>Helper functions<\/strong><\/p>\n<pre class=\"lang:default decode:true \" >tid() The id of the current thread.\r\npid() The process (task group) id of the current thread.\r\nuid() The id of the current user.\r\nexecname() The name of the current process.\r\ncpu() The current cpu number.\r\ngettimeofday_s() Number of seconds since epoch.\r\nget_cycles() Snapshot of hardware cycle counter.\r\npp() A string describing the probe point being currently handled.\r\nppfunc() If known, the the function name in which this probe was placed.\r\n$$vars If available, a pretty-printed listing of all local variables in scope.\r\nprint_backtrace() If possible, print a kernel backtrace.\r\nprint_ubacktrace() If possible, print a user-space backtrace<\/pre>\n<p><strong>Tapset<\/strong><br \/>\n\u5f53\u6211\u4eec\u8bca\u65ad\u7cfb\u7edf\u7ea7\u7684\u95ee\u9898\u65f6\uff0c\u901a\u5e38\u9700\u8981\u8ddf\u8e2a\u64cd\u4f5c\u7cfb\u7edf\u548c\u5e94\u7528\u7a0b\u5e8f\u7684\u4e0d\u540c\u5b50\u7cfb\u7edf\u3002\u4e3a\u4f7f\u6211\u4eec\u66f4\u65b9\u4fbf\u7684\u8fdb\u884c\u8bca\u65ad\uff0cSystemTap \u5305\u542b\u4e86\u4e00\u4e2a\u4e3a\u591a\u4e2a\u5b50\u7cfb\u7edf\u7f16\u5199\u597d\u7684\u76d1\u6d4b\u6a21\u5757\u5e93\uff0c\u5373 tapsets\uff0c\u7528\u6237\u53ef\u4ee5\u5728\u811a\u672c\u4e2d\u4f7f\u7528\u5df2\u7ecf\u53d1\u5e03\u7684tapsets\u3002Tapset \u7684\u4e3b\u8981\u601d\u60f3\u662f\uff1a\u4e00\u4e2a\u7ed9\u5b9a\u5b50\u7cfb\u7edf\u7684\u4e13\u5bb6\u77e5\u9053\u54ea\u4e9b\u65b9\u9762\u5bf9\u4e8e\u6df1\u5165\u7406\u89e3\u8be5\u5b50\u7cfb\u7edf\u662f\u91cd\u8981\u7684\uff1b\u8be5\u4e13\u5bb6\u4f1a\u5c06\u91cd\u8981\u7684\u6570\u636e\u4ee5 tapset \u7684\u5f62\u5f0f\uff0c\u901a\u8fc7\u5728\u63a2\u6d4b\u70b9\u4e2d\u8c03\u7528\u4e00\u4e2a\u6216\u591a\u4e2a\u51fd\u6570\u8fdb\u884c\u8f93\u51fa\u3002\u8fd9\u6837\uff0c\u6211\u4eec\u4e0d\u9700\u8981\u6210\u4e3a\u5185\u6838\u6240\u6709\u9886\u57df\u4e2d\u7684\u4e13\u5bb6\uff0c\u4f46\u4ecd\u7136\u53ef\u4ee5\u4ece\u7cfb\u7edf\u4e2d\u83b7\u5f97\u91cd\u8981\u7684\u6570\u636e\u3002Tapsets\u5df2\u7ecf\u8986\u76d6\u5305\u542b\u7684\u5b50\u7cfb\u7edf: systemcalls, process, scheduler, filesystem, networking etc.<\/p>\n<p>&#8212;<strong> 0x05 Systemtap\u5b89\u5168\u7279\u6027<\/strong><br \/>\n\u4f7f\u7528\u7684toolchain\u7ecf\u8fc7\u4e86\u5f88\u597d\u7684\u6d4b\u8bd5\uff0c\u6ca1\u6709\u7528\u65b0\u7684compiler or interpreter<br \/>\n\u4f7f\u7528\u4e86\u7ecf\u8fc7\u5b8c\u5584\u6d4b\u8bd5\u7684\u5185\u6838\u7279\u6027<br \/>\n\u53e6\u5916systemtap\u8bed\u8a00\u672c\u8eab\u7684\u5b89\u5168\u7279\u6027\u6709\uff1a<\/p>\n<blockquote><p>No dynamic memory allocation<br \/>\nTypes and type conversions limited<br \/>\nLimited pointer operations<\/p><\/blockquote>\n<p>\u5185\u5d4c\u7684\u5b89\u5168\u68c0\u67e5\uff1a<\/p>\n<blockquote><p>Infinite loops and recursion<br \/>\nInvalid variable access<br \/>\nDivision by zero<br \/>\nRestricted access to kernel memory<br \/>\nArray bound checks<br \/>\nVersion compatibility checks<\/p><\/blockquote>\n<p>Limitations<\/p>\n<blockquote><p>Off kernel. Generating kernel modules<br \/>\nRunning kernel modules. Requires privilege to load, mistakes are fatal, mitigated by protected stap language<br \/>\nNo early boot tracing<br \/>\nReview kernel codes detailedly, or have to understand tapsets clearly<br \/>\nSingle step break<\/p><\/blockquote>\n<p>&#8212;<strong> 0x06 \u5907\u6ce8<\/strong><br \/>\n1.\u5b9e\u9645\u4e0a\uff0csystemtap\u4e5f\u4e0d\u662f\u6240\u6709\u7684kernel\u51fd\u6570\u90fd\u53ef\u4ee5\u63d2\u6869\uff0c\u6709\u4e2ablacklist\u5c4f\u853d\u4e86systemstap\u63d2\u6869\u53ef\u80fd\u4f1a\u5f15\u8d77\u95ee\u9898\u7684\u51fd\u6570\u5217\u8868<br \/>\n2.\u5c3d\u7ba1\u8be5\u8bed\u8a00\u5141\u8bb8\u5f00\u53d1\u590d\u6742\u7684\u811a\u672c\uff0c\u4f46\u6bcf\u4e2a\u63a2\u9488\u53ea\u80fd\u6267\u884c 1000 \u6761\u8bed\u53e5\uff08\u8fd9\u4e2a\u6570\u91cf\u662f\u53ef\u914d\u7f6e\u7684\uff09<br \/>\n3 <a href=\"http:\/\/sourceware.org\/systemtap\/tutorial.pdf\" title=\"systemtap tutorial\">systemtap tutorial<\/a><br \/>\n4 <a href=\"https:\/\/www.ibm.com\/developerworks\/cn\/linux\/l-systemtap\/\" title=\"l-systemtap\">l-systemtap<\/a><br \/>\n5 <a href=\"https:\/\/www.ibm.com\/developerworks\/community\/blogs\/5144904d-5d75-45ed-9d2b-cf1754ee936a\/entry\/stap-intro?lang=en\" title=\"systemtap-intro\">systemtap-intro<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>SystemTap \u63d0\u4f9b\u4e86\u4e00\u4e2a\u7b80\u5355\u7684\u547d\u4ee4\u884c\u63a5\u53e3\u548c\u5f3a&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[45,6],"tags":[169],"_links":{"self":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/784"}],"collection":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=784"}],"version-history":[{"count":6,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/784\/revisions"}],"predecessor-version":[{"id":791,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/784\/revisions\/791"}],"wp:attachment":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=784"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=784"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=784"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}