{"id":2086,"date":"2010-12-01T17:32:56","date_gmt":"2010-12-01T09:32:56","guid":{"rendered":"http:\/\/edsionte.com\/techblog\/?p=2086"},"modified":"2010-12-21T15:48:52","modified_gmt":"2010-12-21T07:48:52","slug":"%e5%9c%a8%e5%86%85%e6%a0%b8%e4%b8%ad%e6%b7%bb%e5%8a%a0%e7%b3%bb%e7%bb%9f%e8%b0%83%e7%94%a8","status":"publish","type":"post","link":"http:\/\/edsionte.com\/techblog\/archives\/2086","title":{"rendered":"\u5728\u5185\u6838\u4e2d\u6dfb\u52a0\u7cfb\u7edf\u8c03\u7528"},"content":{"rendered":"

\u5982\u4f55\u5f80\u5185\u6838\u4e2d\u6dfb\u52a0\u81ea\u5df1\u5199\u7684\u7cfb\u7edf\u8c03\u7528\uff1f\u5176\u5b9e\u6b65\u9aa4\u975e\u5e38\u7b80\u5355\uff1a<\/p>\n

1.\u7f16\u5199\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\uff1b
\n2.\u5728\u7cfb\u7edf\u8c03\u7528\u8868\u672b\u5c3e\u52a0\u5165\u4e00\u4e2a\u65b0\u8868\u9879\uff1b
\n3.\u5728< asm\/unistd.h\u00a0>\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7684\u7cfb\u7edf\u8c03\u7528\u53f7\uff1b
\n4.\u91cd\u65b0\u7f16\u8bd1\u5185\u6838\uff1b<\/span><\/em><\/strong><\/p>\n

\u4e0a\u8ff0\u5de5\u4f5c\u5b8c\u6210\u540e\uff0c\u5c31\u53ef\u4ee5\u5728\u7528\u6237\u7a0b\u5e8f\u4e2d\u4f7f\u7528\u81ea\u5df1\u6240\u7f16\u5199\u7684\u7cfb\u7edf\u8c03\u7528\u4e86\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u9010\u6b65\u5206\u6790\u5982\u4f55\u4e0a\u8ff0\u6b65\u9aa4\u3002<\/p>\n

1.\u7f16\u5199\u7cfb\u7edf\u8c03\u7528<\/h4>\n

\u6211\u4eec\u5c06\u8981\u5b9e\u73b0\u4e00\u4e2a\u83b7\u5f97\u5f53\u524d\u8fdb\u7a0bpid\u7684\u7684\u7cfb\u7edf\u8c03\u7528\u3002\u5bf9\u4e8e\u4e00\u4e2a\u8fdb\u7a0b\uff0c\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7current->pid\u6765\u83b7\u5f97\u3002\u4e3a\u4e86\u4f7f\u5f97\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u540c\u6837\u9002\u7528\u4e8e\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u6211\u4eec\u4f7f\u7528current->tgid\u3002\u8fd9\u4e48\u505a\u7684\u539f\u56e0\u662f\u540c\u4e00\u4e2a\u7ebf\u7a0b\u7ec4\u5185\u7684\u6240\u6709\u7ebf\u7a0bTGID\u5747\u76f8\u540c\uff1b\u800c\u4e00\u4e2a\u8fdb\u7a0b\u7684PID\u548cTGID\u662f\u76f8\u540c\u7684\u3002<\/p>\n

asmlinkage long sys_mygetpid(void)\r\n{\r\n\treturn current->tgid;\r\n}<\/pre>\n
\u4e0e\u666e\u901a\u51fd\u6570\u4e0d\u540c\u7684\u662f\uff0c\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u7684\u51fd\u6570\u540d\u524d\u6709asmlinkage\u4fee\u9970\u7b26\u3002\u8fd9\u4e2a\u4fee\u9970\u7b26\u4f7f\u5f97GCC\u7f16\u8bd1\u5668\u4ece\u5806\u6808\u4e2d\u53d6\u8be5\u51fd\u6570\u7684\u53c2\u6570\u800c\u4e0d\u662f\u5bc4\u5b58\u5668\u4e2d\u3002\u53e6\u5916\uff0c\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\u7684\u547d\u540d\u89c4\u5219\u90fd\u662fsys_XXX\u7684\u5f62\u5f0f\u3002<\/p>\n
\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u7684\u8981\u505a\u7684\u662f\u5c06\u8fd9\u4e2a\u51fd\u6570\u653e\u4e8e\u4f55\u5904\u3002\u4e00\u79cd\u65b9\u6cd5\u662f\uff0c\u5c06\u4e0a\u8ff0\u51fd\u6570\u653e\u4e8e\/kernel\/\u4e0b\u7684\u67d0\u4e2a\u6587\u4ef6\u4e2d\uff1b\u53e6\u4e00\u79cd\u65b9\u5f0f\u662f\uff0c\u5c06\u8fd9\u4e2a\u51fd\u6570\u5355\u72ec\u5b58\u653e\u5728\/kernel\/\u4e0b\u7684\u4e00\u4e2a\u65b0\u5efa\u7684.c\u6587\u4ef6\u4e2d\u3002\u4e0d\u7ba1\u4f55\u79cd\u65b9\u6cd5\uff0c\u6240\u505a\u7684\u76ee\u7684\u90fd\u662f\u4e3a\u4e86\u5728\u91cd\u65b0\u7f16\u8bd1\u5185\u6838\u65f6\u5c06\u4e0a\u8ff0\u6211\u4eec\u6240\u7f16\u5199\u7684\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\u7f16\u8bd1\u8fdb\u5185\u6838\u3002<\/p>\n
2.\u5728\u7cfb\u7edf\u8c03\u7528\u8868\u4e2d\u6dfb\u52a0\u65b0\u7684\u8868\u9879<\/h4>\n
linux\u4e2d\u4e3a\u6bcf\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\u90fd\u5206\u914d\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\u53f7\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u6bcf\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\u53f7\u90fd\u552f\u4e00\u7684\u5bf9\u5e94\u7740\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\u3002\u5185\u6838\u4e2d\u4f7f\u7528\u7cfb\u7edf\u8c03\u7528\u8868\u6765\u8bb0\u5f55\u6240\u6709\u5df2\u7ecf\u6ce8\u518c\u8fc7\u7684\u7cfb\u7edf\u8c03\u7528\uff0c\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u8868\u5b58\u50a8\u5728sys_call_table\u4e2d\u3002\u5728yoursource\/arch\/x86\/kernel\/syscall_table_32.S\u4e2d\u53ef\u4ee5\u770b\u5230\u7cfb\u7edf\u7cfb\u7edf\u8c03\u7528\u8868\u3002<\/p>\n
\u6211\u4eec\u6240\u8981\u505a\u7684\u5c31\u662f\u5728\u8be5\u8868\u7684\u672b\u5c3e\u6dfb\u52a0\u6211\u4eec\u521a\u7f16\u5199\u7684\u7cfb\u7edf\u8c03\u7528\uff1a.long sys_getpid\u3002\u6211\u4eec\u5e76\u4e0d\u9700\u8981\u663e\u5f0f\u7684\u6307\u5b9a\u7cfb\u7edf\u8c03\u7528\u53f7\uff0c\u4ece0\u5f00\u59cb\u7b97\u8d77\uff0c\u6211\u4eec\u6240\u7f16\u5199\u7684\u51fd\u6570\u7684\u7cfb\u7edf\u8c03\u7528\u53f7\u4e3a341\u3002<\/p>\n
   ENTRY(sys_call_table)\r\n          .long sys_restart_syscall       \/* 0 - old \"setup()\" system call, used for restarting *\/\r\n          .long sys_exit\r\n          .long ptregs_fork\r\n          .long sys_read\r\n          .long sys_write\r\n          .long sys_open          \/* 5 *\/\r\n             \u2026\u2026 \u2026\u2026\r\n         .long sys_perf_event_open\r\n         .long sys_recvmmsg\r\n         .long sys_fanotify_init\r\n         .long sys_fanotify_mark\r\n         .long sys_prlimit64             \/* 340 *\/\r\n         .long sys_mygetpid<\/pre>\n
3.\u5728< asm\/unistd.h\u00a0>\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7684\u7cfb\u7edf\u8c03\u7528\u53f7<\/h4>\n
\u4e0a\u4e00\u6b65\uff0c\u5728\u7cfb\u7edf\u8c03\u7528\u8868\u4e2d\u6dfb\u52a0\u65b0\u7684\u8868\u9879\u662f\u4e3a\u4e86\u5c06\u7cfb\u7edf\u8c03\u7528\u53f7\u548c\u7cfb\u7edf\u8c03\u7528\u5173\u8054\u8d77\u6765\u3002\u73b0\u5728\uff0c\u6211\u4eec\u9700\u8981\u5728unistd.h\u6587\u4ef6\u4e2d\u6dfb\u52a0\u5177\u4f53\u7684\u7cfb\u7edf\u8c03\u7528\u53f7\uff0c\u8fd9\u6837\u4f7f\u5f97\u7cfb\u7edf\u53ef\u4ee5\u6839\u636e\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u53f7\u5728\u7cfb\u7edf\u8c03\u7528\u8868\u4e2d\u67e5\u627e\u5177\u4f53\u7684\u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n
\u5f53\u7528\u6237\u8fdb\u7a0b\u8c03\u7528\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\u65f6\uff0c\u5176\u5b9e\u662f\u901a\u8fc7\u4e00\u4e2a\u4e2d\u65ad\u53f7\u4e3a128\u7684\u8f6f\u4e2d\u65ad\u6765\u901a\u77e5\u5185\u6838\u7684\u3002\u6b64\u65f6\uff0c\u5185\u6838\u4f1a\u7531\u7528\u6237\u6001\u5207\u6362\u5230\u5185\u6838\u6001\u8f6c\u800c\u53bb\u6267\u884c\u8fd9\u4e2a\u8f6f\u4e2d\u65ad\u5bf9\u5e94\u7684\u4e2d\u65ad\u5904\u7406\u7a0b\u5e8f\u3002\u800c\u8fd9\u4e2a\u4e2d\u65ad\u5904\u7406\u7a0b\u5e8f\u6070\u597d\u5c31\u662f\u7cfb\u7edf\u8c03\u7528\u5904\u7406\u7a0b\u5e8f\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u4efb\u4f55\u7cfb\u7edf\u8c03\u7528\u90fd\u4f1a\u5f15\u53d1CPU\u53bb\u6267\u884c\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u5904\u7406\u7a0b\u5e8f\u3002\u56e0\u6b64\uff0c\u5fc5\u987b\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528\u53f7\u6765\u8bc6\u522b\u4e0d\u540c\u7684\u7cfb\u7edf\u8c03\u7528\u3002\u7cfb\u7edf\u8c03\u7528\u53f7\u901a\u5e38\u4f1a\u5b58\u50a8\u5728eax\u5bc4\u5b58\u5668\u4e2d\u3002<\/p>\n
\u73b0\u5728\u6211\u4eec\u5c31\u5728yoursource\/arch\/x86\/include\/asm\/unistd_32.h\u6587\u4ef6\u4e2d\u6dfb\u52a0\u65b0\u7684\u7cfb\u7edf\u8c03\u7528\u53f7\u3002\u5728\u4e0a\u4e00\u6b65\u6211\u4eec\u6240\u6dfb\u52a0\u7684sys_mygetpid\u7cfb\u7edf\u8c03\u7528\u5bf9\u5e94\u7684\u7f16\u53f7\u4e3a341\uff0c\u56e0\u6b64\u6211\u4eec\u5728\u8be5\u6587\u4ef6\u7684\u672b\u5c3e\u6dfb\u52a0\u4e0b\u9762\u7684\u8bed\u53e5\uff1a#define __NR_mygetpid 341\u3002\u6ce8\u610f\u8fd9\u91cc\u7684\u5b8f\u547d\u540d\u89c4\u5219\uff0c\u4ee5__NR_\u5f00\u5934\u3002<\/p>\n
 #define __NR_restart_syscall      0\r\n #define __NR_exit                 1\r\n #define __NR_fork                 2\r\n #define __NR_read                 3\r\n #define __NR_write                4\r\n        \u2026\u2026\u2026\u2026\r\n #define __NR_fanotify_mark      339\r\n #define __NR_prlimit64          340\r\n #define __NR_mygetpid         341<\/pre>\n
4.\u7f16\u8bd1\u5185\u6838<\/h4>\n
\u5982\u679c\u4e0a\u8ff0\u4e09\u4e2a\u6b65\u9aa4\u90fd\u5b8c\u6210\u540e\uff0c\u90a3\u4e48\u63a5\u4e0b\u6765\u91cd\u65b0\u7f16\u8bd1\u5185\u6838\u5373\u53ef\u3002\u5177\u4f53\u53ef\u53c2\u89c1\u8fd9\u91cc<\/a>\u3002<\/p>\n
5.\u7f16\u5199\u7528\u6237\u6001\u7684\u7a0b\u5e8f<\/h4>\n
#include < linux\/unistd.h >\r\n\r\n_syscall0(int,mygetpid)\r\n\r\nint main()\r\n{\r\n\tprintf(\"The current process's pid is %d\\n\",mygetpid());\r\n\treturn 0;\r\n}<\/pre>\n
\u4e0a\u8ff0\u7528\u6237\u7a0b\u5e8f\u53ef\u80fd\u4e0e\u6211\u4eec\u5e73\u65e5\u91cc\u6240\u5199\u7684\u7a0d\u6709\u4e0d\u540c\u3002\u4e3b\u8981\u533a\u522b\u662f\u589e\u52a0\u4e86_syscall0(int,mygetpid)\u8fd9\u4e2a\u5b8f\u3002\u56e0\u4e3a\u6211\u4eec\u73b0\u5728\u76f4\u63a5\u5728\u7a0b\u5e8f\u4e2d\u8c03\u7528\u7cfb\u7edf\u8c03\u7528\uff0c\u800c\u6211\u4eec\u5e73\u65f6\u5219\u662f\u901a\u8fc7\u8c03\u7528C\u5e93\u4e2d\u7684API\u6765\u95f4\u63a5\u8c03\u7528\u7cfb\u7edf\u8c03\u7528\u3002\u5728unistd.h\u6587\u4ef6\u4e2d\u6709_syscallN()\u5b8f\u7684\u5b9a\u4e49\uff0c\u8fd9\u91cc\u7684N\u53ef\u53d60\uff5e6\u3002N\u4ee3\u8868\u7684\u662f\u9700\u8981\u4f20\u9012\u7ed9\u7cfb\u7edf\u8c03\u7528\u7684\u53c2\u6570\u4e2a\u6570\u3002\u7531\u4e8emygetpid\u7cfb\u7edf\u8c03\u7528\u9700\u4f20\u9012\u7684\u53c2\u6570\u4e2a\u6570\u4e3a0\uff0c\u56e0\u6b64\u9009\u53d6_syscall0\u3002\u53e6\u5916\uff0c\u8fd9\u7ec4\u5b8f\u7684\u5185\u90e8\u53c2\u6570\u5206\u5e03\u6709\u5982\u4e0b\u7279\u70b9\uff1a\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u7cfb\u7edf\u8c03\u7528\u8fd4\u56de\u503c\u7684\u7c7b\u578b\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\u7684\u540d\u79f0\uff0c\u63a5\u4e0b\u6765\u7684\u53c2\u6570\u6309\u7167\u7cfb\u7edf\u8c03\u7528\u53c2\u6570\u7684\u6b21\u5e8f\u4f9d\u6b21\u662f\u53c2\u6570\u7c7b\u578b\u548c\u53c2\u6570\u540d\u79f0\u3002\u5bf9\u4e8e\u6bcf\u4e2a\u5b8f\u6765\u8bf4\uff0c\u90fd\u67092+2*N\u4e2a\u53c2\u6570\u3002<\/p>\n
OK\uff0c\u4e0a\u8ff0\u65b9\u6cd5\u5373\u53ef\u4ee5\u5c06\u6211\u4eec\u81ea\u5df1\u7f16\u5199\u7684\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\u52a0\u5165\u5230\u5185\u6838\u3002try\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5982\u4f55\u5f80\u5185\u6838\u4e2d\u6dfb\u52a0\u81ea\u5df1\u5199\u7684\u7cfb\u7edf\u8c03\u7528\uff1f\u5176\u5b9e\u6b65\u9aa4\u975e\u5e38\u7b80\u5355\uff1a 1.\u7f16\u5199\u4e00\u4e2a\u7cfb\u7edf\u8c03\u7528\uff1b 2.\u5728\u7cfb\u7edf\u8c03\u7528\u8868\u672b\u5c3e\u52a0\u5165\u4e00\u4e2a\u65b0\u8868 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[110],"tags":[179],"class_list":["post-2086","post","type-post","status-publish","format-standard","hentry","category-linux","tag-179"],"views":9622,"_links":{"self":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts\/2086","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/comments?post=2086"}],"version-history":[{"count":0,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts\/2086\/revisions"}],"wp:attachment":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/media?parent=2086"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/categories?post=2086"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/tags?post=2086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}