{"id":390,"date":"2023-07-26T13:50:07","date_gmt":"2023-07-26T05:50:07","guid":{"rendered":"https:\/\/blog.taiyang.space\/?p=390"},"modified":"2023-07-26T13:50:08","modified_gmt":"2023-07-26T05:50:08","slug":"l3-%e7%b3%bb%e7%bb%9f%e8%b0%83%e7%94%a8","status":"publish","type":"post","link":"https:\/\/blog.taiyang.space\/?p=390","title":{"rendered":"L3-\u7cfb\u7edf\u8c03\u7528"},"content":{"rendered":"<h2 id=\"1\u64cd\u4f5c\u7cfb\u7edf\u63a5\u53e3\">1\u3001\u64cd\u4f5c\u7cfb\u7edf\u63a5\u53e3<\/h2>\n<p>\u63a5\u53e3\u662f\u7528\u6765\u5e72\u561b\u7684\u5462\uff1f\u63d2\u5ea7\u5c31\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u53ef\u4ee5\u60f3\u8c61\u4e00\u4e0b\uff1a\u6211\u4eec\u628a\u63d2\u5934\u63a5\u5728\u63d2\u5ea7\u4e0a\u5c31\u53ef\u4ee5\u4f7f\u7528\u7535\u4e86\u3002\u6211\u4eec\u4e0d\u7528\u5173\u5fc3\u600e\u4e48\u53d1\u7535\uff0c\u600e\u4e48\u628a\u7535\u9001\u5230\u5bb6\u91cc\u6765\uff0c\u800c\u4e14\u901a\u8fc7\u63d2\u5ea7\u4f7f\u7528\u7535\u4f1a\u6bd4\u76f4\u63a5\u7528\u7535\u7ebf\u5b89\u5168\u8bb8\u591a\u3002\u8fd9\u5c31\u662f\u63a5\u53e3\uff0c\u5b83\u5c4f\u853d\u4e86\u4e00\u4e9b\u7ec6\u8282\uff0c\u8ba9\u4f7f\u7528\u8d44\u6e90\u53d8\u5f97\u7b80\u5355\uff0c\u53ef\u9760\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u64cd\u4f5c\u7cfb\u7edf\u63a5\u53e3\u7528\u4e8e\u8fde\u63a5\u64cd\u4f5c\u7cfb\u7edf\u548c\u5e94\u7528\u8f6f\u4ef6\uff0c\u8fd9\u4e9b\u63a5\u53e3\u662f\u4e00\u4e9b\u7a0b\u5e8f\uff08\u50cfc\u8bed\u8a00\u7a0b\u5e8f\u8fd9\u4e9b\uff09\uff0c\u5e94\u7528\u8f6f\u4ef6\u901a\u8fc7\u8c03\u7528\u8fd9\u4e9b\u7a0b\u5e8f\u5c31\u53ef\u4ee5\u5c06\u64cd\u4f5c\u7cfb\u7edf\u548c\u81ea\u5df1\u8fde\u63a5\u8d77\u6765\u3002\u8fd9\u4e9b\u64cd\u4f5c\u7cfb\u7edf\u63a5\u53e3\u5c31\u662f\u7cfb\u7edf\u8c03\u7528\uff08\u901a\u5e38\u7cfb\u7edf\u8c03\u7528\u4f7f\u7528\u51fd\u6570\u7684\u5f62\u5f0f\u8fdb\u884c\u8c03\u7528\uff09\u3002\u5e73\u65f6\u4f7f\u7528\u7684 <code>open<\/code>\uff0c<code>write<\/code> \uff0c<code>close<\/code>\u7b49\u8fd9\u4e9b\u51fd\u6570\u90fd\u662f\u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u5c31\u50cf <a href=\"https:\/\/blog.taiyang.space\/?p=383\">L1-\u64cd\u4f5c\u7cfb\u7edf\u7684\u542f\u52a8<\/a> \u548c <a href=\"https:\/\/blog.taiyang.space\/?p=388\">L2-\u5bf9GDT\u4e0eLDT\u7684\u7406\u89e3<\/a> \u4e2d\u63d0\u5230\u7684\u4e00\u6837\uff0c\u64cd\u4f5c\u7cfb\u7edf\u5c06\u5185\u5b58\u8fdb\u884c\u4e86\u5206\u5272\uff0c\u6709\u5185\u6838\u533a\u548c\u7528\u6237\u533a\uff0c\u5e94\u7528\u7a0b\u5e8f\u53ea\u80fd\u8fd0\u884c\u5728\u7528\u6237\u533a\u4e2d\u3002\u5e94\u7528\u7a0b\u5e8f\u4e0d\u80fd\u968f\u610f\u7684\u8c03\u7528\u5185\u6838\u7684\u6570\u636e\uff0c\u5982\u679c\u4e00\u4e2a\u5e94\u7528\u8fdb\u7a0b\u80fd\u591f\u968f\u610f\u8bbf\u95ee\u5185\u6838\u6570\u636e\uff0c\u90a3\u8fd9\u4e2a\u64cd\u4f5c\u7cfb\u7edf\u5c31\u592a\u4e0d\u5b89\u5168\u4e86\u3002\u5904\u7406\u5668\u901a\u8fc7\u4e00\u4e9b\u786c\u4ef6\u8bbe\u8ba1\uff08\u7279\u6743\u7ea7\u68c0\u67e5\uff09\u4fdd\u8bc1\u5185\u6838\u533a\u4e0d\u88ab\u5e94\u7528\u7a0b\u5e8f\u8bbf\u95ee\u3002\u90a3\u6709\u65f6\u5019\u7528\u6237\u7a0b\u5e8f\u9700\u8981\u8bbf\u95ee\u5185\u6838\u533a\u600e\u4e48\u529e\u5462\uff1f\u5e94\u7528\u7a0b\u5e8f\u53ef\u4ee5\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528\u8bbf\u95ee\u5185\u6838\u8d44\u6e90\u3002\u7cfb\u7edf\u8c03\u7528\u662f\u4e00\u6bb5\u5305\u542b int \u6307\u4ee4\u7684\u4ee3\u7801\uff0c\u800c int \u6307\u4ee4\u4f1a\u5c06 CS \u5bc4\u5b58\u5668\u7684 CPL (\u5f53\u524d\u7279\u6743\u7ea7)\u4fee\u6539\u4e3a0\uff0c\u4ece\u800c\u8fdb\u5165\u5185\u6838\u3002\u5728 <a href=\"https:\/\/blog.taiyang.space\/?p=388\">L2-\u5bf9GDT\u4e0eLDT\u7684\u7406\u89e3 <\/a>\u4e2d\u4ecb\u7ecd\u4e86<strong>\u6bb5\u9009\u62e9\u5b50\u7684\u4f4e\u4e24\u4f4d\u4e3a\u7279\u6743\u7ea7<\/strong>\uff0c\u5173\u4e8e\u7279\u6743\u7ea7\u68c0\u67e5\u8bf7\u53c2\u8003\u8be5\u7ae0\u8282\u7684\u6bb5\u9009\u62e9\u5b50\u90e8\u5206\u3002<\/p>\n<h2 id=\"2\u7528\u6237\u6001\u548c\u5185\u6838\u6001\">2\u3001\u7528\u6237\u6001\u548c\u5185\u6838\u6001<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247693.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<h2 id=\"3\u7cfb\u7edf\u8c03\u7528\u7684\u5b9e\u73b0\">3\u3001\u7cfb\u7edf\u8c03\u7528\u7684\u5b9e\u73b0<\/h2>\n<p>\u672c\u8282\u4ee5 <code>lib\/close.c<\/code>\u4e2d\u7684 <code>close()<\/code> \u7cfb\u7edf\u8c03\u7528\u4e3a\u4f8b\uff0c\u4ecb\u7ecd\u7cfb\u7edf\u8c03\u7528\u7684\u5b9e\u73b0\u3002\u7cfb\u7edf\u8c03\u7528\u7684\u5b9e\u73b0\u539f\u7406\u5982\u4e0b\uff1a<\/p>\n<ol start=\"\">\n<li>\u9996\u5148\u5728\u6267\u884c\u5e94\u7528\u7a0b\u5e8f\u65f6\uff0c CS \u7b49\u6bb5\u5bc4\u5b58\u5668\u662f\u4e0d\u80fd\u88ab\u8f7b\u6613\u4fee\u6539\u7684\uff0c\u8fd9\u4e5f\u5c31\u610f\u5473\u7740 CPL \u4e0d\u80fd\u88ab\u8f7b\u6613\u4fee\u6539\uff0c\u5e94\u7528\u7a0b\u5e8f\u76f4\u63a5\u8bbf\u95ee\u5185\u6838\u65f6\u4e0d\u80fd\u901a\u8fc7\u7279\u6743\u7ea7\u68c0\u67e5\u3002\uff08\u4e0d\u8fc7\u5177\u4f53\u4e0d\u80fd\u4fee\u6539\u7684\u539f\u56e0\u6211\u8fd8\u6ca1\u6709\u5f04\u6e05\u695a\uff0c\u53ef\u80fd\u662f\u56e0\u4e3a\u4fdd\u62a4\u6a21\u5f0f\u4e0b\u63d0\u4f9b\u4e86\u67d0\u4e9b\u4fdd\u62a4\u673a\u5236\uff0c\u4e00\u65e6\u7528\u6237\u4fee\u6539\u6bb5\u5bc4\u5b58\u5668\uff0c\u7a0b\u5e8f\u5c31\u4f1a\u8fd0\u884c\u9519\u8bef\u3002\u4e5f\u53ef\u80fd\u662f\u56e0\u4e3a\u67d0\u4e9b\u53ef\u4ee5\u4fee\u6539\u6bb5\u5bc4\u5b58\u5668\u7684\u6c47\u7f16\u6307\u4ee4\u53ea\u80fd\u5728\u7279\u6743\u7ea7\u4e3a0\u7684\u65f6\u5019\u6267\u884c\uff0c\u800c\u5e94\u7528\u7a0b\u5e8f\u7684\u7279\u6743\u7ea7\u4e3a3\uff0c\u4e0d\u80fd\u6267\u884c\u8fd9\u4e9b\u6307\u4ee4\uff09<\/li>\n<li>\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\u4f1a\u6267\u884c<code>int 0x80<\/code>; \u6307\u4ee4\u3002\u8be5\u6307\u4ee4\u4f1a\u901a\u8fc7 IDTR\uff08\u4e2d\u65ad\u63cf\u8ff0\u7b26\u8868\u5bc4\u5b58\u5668\uff09 \u4ece IDT \u4e2d\u627e\u5230\u7d22\u5f15\u4e3a0x80 \u7684 IDT\u63cf\u8ff0\u7b26\u3002IDT\u63cf\u8ff0\u7b26\u7ed3\u6784\u5982\u4e0b\uff1a<\/li>\n<\/ol>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247459.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p>\u5bf9\u4e8e\u7d22\u5f15\u4e3a0x80 \u7684 IDT\u63cf\u8ff0\u7b26\u6765\u8bf4\uff1a\u8fc7\u7a0b\u5165\u53e3\u70b9\u504f\u79fb\u503c\u4e3a system_call \u51fd\u6570\u7684\u504f\u79fb\u5730\u5740\uff0cDPL == 3 \u4e0e\u5e94\u7528\u7a0b\u5e8f\u7684 CPL \u76f8\u7b49\uff0c\u6bb5\u9009\u62e9\u7b26\u4e3a8\u3002\u7531\u4e8eDPL\u4e3a3\uff0c\u4e14\u8fd9\u91cc\u4e0d\u9700\u8981\u68c0\u67e5 RPL \uff0c\u56e0\u6b64\u5e94\u7528\u7a0b\u5e8f\u53ef\u4ee5\u8bbf\u95ee\u8be5\u63cf\u8ff0\u7b26\u3002\u5728\u5e94\u7528\u7a0b\u5e8f\u6267\u884c int 0x80; \u65f6\uff0c\u786c\u4ef6\u4f1a\u5c06\u6bb5\u9009\u62e9\u7b26\u8d4b\u503c\u7ed9CS\uff0c<strong>\u8ba9 CS = 8<\/strong>\u3002\u4e8e\u662f\u53ef\u4ee5\u8fdb\u5165\u5185\u6838\u4e86\u3002<\/p>\n<p>\u5f53CS=8\uff0cip=0\u65f6\uff0cCPL=0\uff08CS\u6700\u4f4e\u4e24\u4f4d\uff09<\/p>\n<ol start=\"\">\n<li>\u5f53\u7cfb\u7edf\u8c03\u7528\u6267\u884c\u5b8c\u6210\u540e\uff0c\u5c06 CS \u7684 CPL \u6539\u4e3a3\uff0c\u7136\u540e\u91cd\u65b0\u56de\u5230\u5e94\u7528\u7a0b\u5e8f\u6267\u884c\u3002<\/li>\n<\/ol>\n<p>Linux0.11 \u4e2d\u7cfb\u7edf\u8c03\u7528\u90fd\u662f\u91c7\u7528\u5b8f\u51fd\u6570\u7684\u5f62\u5f0f\uff0c\u4e0b\u9762\u7a0b\u5e8f\u662f <code>close()<\/code>\u7684API\uff1a<\/p>\n<pre><code class=\"language-c\" lang=\"c\">#define __LIBRARY__\n#include &lt;unistd.h&gt;\n\n_syscall1(int,close,int,fd)\n<\/code><\/pre>\n<p>_syscall1\u662f\u4e00\u4e2a\u5b8f\uff0c\u5728include\/unistd.h\u4e2d\u5b9a\u4e49\uff1a<\/p>\n<pre><code class=\"language-c\" lang=\"c\">#define _syscall1(type,name,atype,a) \\\ntype name(atype a) \\\n{ \\\nlong __res; \\\n__asm__ volatile (\"int $0x80\" \\\n: \"=a\" (__res) \\\n: \"0\" (__NR_##name),\"b\" ((long)(a))); \\\nif (__res &gt;= 0) \\\nreturn (type) __res; \\\nerrno = -__res; \\\nreturn -1; \\\n}\n<\/code><\/pre>\n<p>\u5728include\/unistd.h\u4e2d\u5b9a\u4e49<code>_syscalln<\/code>\uff08n\u53ef\u4ee5\u662f0~3\uff0c\u4ee3\u8868\u4f20\u5165\u53c2\u6570\u7684\u4e2a\u6570\uff09\uff0c<em>syscalln \u901a\u5e38\u7528 eax \u5b58\u653e\u7cfb\u7edf\u8c03\u7528\u53f7\uff0cebx\uff0cecx\uff0cedx\u5b58\u653e\u4f20\u5165\u53c2\u6570\uff0c\u540c\u65f6 eax \u4e5f\u4f5c\u4e3a\u8fd4\u56de\u503c\u3002<\/em>syscalln \u4e2d\u4f1a\u5305\u542b\u4e00\u4e2a\u4e2d\u6bb5\u8c03\u7528 <code>int $0x80<\/code> \u3002\u5728 <code>void sched_init(void)<\/code> \u4e2d\u8c03\u7528\u4e86\u4e00\u4e2a\u51fd\u6570 \uff1a<code>set_system_gate(0x80,&amp;system_call);<\/code> \uff0c\u8be5\u51fd\u6570\u4f1a\u8bbe\u7f6e IDT \u8868\uff0c\u5c06<code>int $0x80<\/code> \u7684\u4e2d\u65ad\u5904\u7406\u51fd\u6570\u8bbe\u7f6e\u4e3a system_call \u3002<\/p>\n<p>\u6211\u4eec\u5c06 <code>_syscall1(int,close,int,fd)<\/code> \u5c55\u5f00\uff1a<\/p>\n<pre><code class=\"language-c\" lang=\"c\">int close(int fd) { \n    long __res;      \/\/ \u8fd4\u56de\u503c\uff0c\u8fd4\u56de\u7cfb\u7edf\u8c03\u7528\u6267\u884c\u7ed3\u679c\uff0c0\u8868\u793a\u6210\u529f\uff0c\u8d1f\u503c\u8868\u793a\u5931\u8d25\n    \/\/ \u4e0b\u9762\u662f\u5d4c\u5165\u6c47\u7f16\u7a0b\u5e8f\n    __asm__ volatile (\"int $0x80\"            \/\/ \u6c47\u7f16\u8bed\u53e5\n        : \"=a\" (__res)                       \/\/ \u8f93\u51fa\u5bc4\u5b58\u5668\n        : \"0\" (__NR_close),\"b\" ((long)(fd)));\/\/ \u8f93\u5165\u5bc4\u5b58\u5668\uff0c__NR_close\u4e3a\u7cfb\u7edf\u8c03\u7528\u53f7\uff0c\u662f\u4e00\u4e2a\u5b8f\u5b9a\u4e49\uff0c\u5176\u503c\u4e3a6\u3002\n                                             \/\/ system_call \u4f1a\u6839\u636e __NR_close \u5bf9\u5e94\u7684\u9700\u8981\u6267\u884c\u51fd\u6570\n    \/\/ \u4e0b\u9762\u662f\u8fd4\u56de\u503c\u5904\u7406     \n    if (__res &gt;= 0)\n        return (int) __res; \n    errno = -__res; \/\/ __res\u4e3a\u9519\u8bef\u7c7b\u578b\u7801\uff0c\u5b83\u88ab\u5b58\u5728\u5168\u5c40\u53d8\u91cf errno \u4e2d\uff0c\n                    \/\/ \u53ef\u4ee5\u901a\u8fc7\u5e93\u51fd\u6570 perror() \u5c06\u9519\u8bef\u7c7b\u578b\u7801\u53ca\u5176\u5bf9\u5e94\u7684\u5b57\u7b26\u4e32\u6253\u5370\u51fa\u6765\n    return -1; \n}\n<\/code><\/pre>\n<p>\u5728\u5e94\u7528\u7a0b\u5e8f\u8c03\u7528 close() \u65f6\uff0cclose() \u4f1a\u53d1\u51fa\u4e00\u4e2a\u4e2d\u65ad\u8c03\u7528 <code>int $0x80<\/code>\uff0c\u5176\u4e2d\u65ad\u5904\u7406\u51fd\u6570\u4e3a system_call \u3002int \u6307\u4ee4\u4f1a\u5c06 cs \u5bc4\u5b58\u5668\u4e2d\u7684 CPL \u4fee\u6539\u4e3a 0 \uff0c\u4ee5\u4fbf\u8fdb\u5165\u5185\u6838\u533a\u3002\u4e0b\u9762\u770b\u4e00\u4e0bsystem_call \u5173\u4e8e\u7cfb\u7edf\u8c03\u7528\u7684\u4e3b\u8981\u90e8\u5206\uff1a<\/p>\n<pre><code class=\"language-shell\" lang=\"shell\">system_call:\n\u00b7\u00b7\u00b7\u00b7\u00b7\u00b7\n\tmovl $0x10,%edx\t\t# set up ds,es to kernel space\n\tmov %dx,%ds\n\tmov %dx,%es\n\tmovl $0x17,%edx\t\t# fs points to local data space\n\tmov %dx,%fs\n\tcall sys_call_table(,%eax,4)#eax\u662f\u7cfb\u7edf\u8c03\u7528\u53f7\n\u00b7\u00b7\u00b7\u00b7\u00b7\u00b7\nret_from_sys_call:\n\u00b7\u00b7\u00b7\u00b7\u00b7\u00b7\n3:\tpopl %eax\n\tpopl %ebx\n\tpopl %ecx\n\tpopl %edx\n\tpop %fs\n\tpop %es\n\tpop %ds\n\tiret\n<\/code><\/pre>\n<p>sys_call_table\u662f\u4e00\u5f20\u51fd\u6570\u6307\u9488\u8868\uff1a<\/p>\n<pre><code class=\"language-c\" lang=\"c\">fn_ptr sys_call_table[] = { sys_setup, sys_exit, sys_fork, sys_read,\nsys_write, sys_open, sys_close, sys_waitpid, sys_creat, sys_link,\nsys_unlink, sys_execve, sys_chdir, sys_time, sys_mknod, sys_chmod,\nsys_chown, sys_break, sys_stat, sys_lseek, sys_getpid, sys_mount,\nsys_umount, sys_setuid, sys_getuid, sys_stime, sys_ptrace, sys_alarm,\nsys_fstat, sys_pause, sys_utime, sys_stty, sys_gtty, sys_access,\nsys_nice, sys_ftime, sys_sync, sys_kill, sys_rename, sys_mkdir,\nsys_rmdir, sys_dup, sys_pipe, sys_times, sys_prof, sys_brk, sys_setgid,\nsys_getgid, sys_signal, sys_geteuid, sys_getegid, sys_acct, sys_phys,\nsys_lock, sys_ioctl, sys_fcntl, sys_mpx, sys_setpgid, sys_ulimit,\nsys_uname, sys_umask, sys_chroot, sys_ustat, sys_dup2, sys_getppid,\nsys_getpgrp, sys_setsid, sys_sigaction, sys_sgetmask, sys_ssetmask,\nsys_setreuid,sys_setregid };\n<\/code><\/pre>\n<p><code>sys_call_table(,%eax,4)<\/code>\u8868\u793a sys_call_table + %eax * 4\uff1b\u5f53 eax = __NR_close \u65f6 call \u8c03\u7528\u7684\u5c31\u662f sys_close() \u51fd\u6570\u3002\u4e5f\u5c31\u662f\u8bf4close() \u51fd\u6570\u7684\u771f\u6b63\u5b9e\u73b0\u5c31\u662f sys_close() \u3002\u6267\u884c\u5b8c sys_close()\u540e\uff0c\u4f1a\u63a5\u7740\u8fd4\u56de\u6267\u884c system_call \uff0csystem_call\u6700\u540e\u4f1a\u6267\u884c iret \u6307\u4ee4\uff0c\u5229\u7528\u8be5\u6307\u4ee4\u51fa\u6808\u7684\u539f\u7406\u5c06 CS \u7684 CPL \u91cd\u65b0\u8bbe\u7f6e\u4e3a3\uff0c\u8ba9\u7a0b\u5e8f\u56de\u5230\u7528\u6237\u6001\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u56fe\u89e3<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247657.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247443.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p>jmpi 0\uff0c8<\/p>\n<p>\u5f53CS=8\uff0cIP=0\u65f6\uff0cCPL=0\uff08CS\u6700\u4f4e\u4e24\u4f4d\uff09<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247626.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p>sys_call_table \u4e00\u5b9a\u662f\u4e00\u4e2a\u51fd\u6570\u6307\u9488\u6570\u7ec4\u7684\u8d77\u59cb\u5730\u5740<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247649.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/picture.chentaiyang.space\/202307261247057.png\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<h2 id=\"4\u603b\u7ed3\">4\u3001\u603b\u7ed3<\/h2>\n<p>\u6700\u540e\u603b\u7ed3\u4e00\u4e0b\u7cfb\u7edf\u8c03\u7528\u7684\u6838\u5fc3\uff1a<\/p>\n<ol start=\"\">\n<li>\u7528\u6237\u7a0b\u5e8f\u4e2d\u5305\u542b\u4e00\u6bb5\u5305\u542bint\u6307\u4ee4\u7684\u4ee3\u7801\uff08\u8fd9\u4e2a\u7528\u6237\u7a0b\u5e8f\u5c31\u662f\u5e93\u51fd\u6570\uff09<\/li>\n<li>\u64cd\u4f5c\u7cfb\u7edf\u5199\u4e2d\u65ad\u5904\u7406\uff0c\u83b7\u53d6\u60f3\u8c03\u7a0b\u5e8f\u7684\u7f16\u53f7\uff08\u5982 __NR_close\uff09<\/li>\n<li>\u64cd\u4f5c\u7cfb\u7edf\u6839\u636e\u7f16\u53f7\u6267\u884c\u76f8\u5e94\u4ee3\u7801\uff08\u5982 <code>sys_close()<\/code> \uff09<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>API \u5e76\u4e0d\u80fd\u5b8c\u6210\u7cfb\u7edf\u8c03\u7528\u7684\u771f\u6b63\u529f\u80fd\uff0c\u5b83\u8981\u505a\u7684\u662f\u53bb\u8c03\u7528\u771f\u6b63\u7684\u7cfb\u7edf\u8c03\u7528\uff0c\u8fc7\u7a0b\u662f\uff1a<\/p>\n<ul>\n<li>\u628a<strong>\u7cfb\u7edf\u8c03\u7528\u7684\u7f16\u53f7<\/strong>\u5b58\u5165 EAX\uff1b<\/li>\n<li>\u628a\u51fd\u6570\u53c2\u6570\u5b58\u5165\u5176\u5b83\u901a\u7528\u5bc4\u5b58\u5668\uff1b<\/li>\n<li>\u89e6\u53d1 <strong>0x80<\/strong> \u53f7\u4e2d\u65ad\uff08int 0x80\uff09<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u5e93\u51fd\u6570\u6700\u540e\u8c03\u7528\u7684\u662f\u7cfb\u7edf\u63a5\u53e3<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[122,123,124,125],"class_list":["post-390","post","type-post","status-publish","format-standard","hentry","category-10","tag-cpl","tag-dpl","tag-124","tag-125"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.0 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>L3-\u7cfb\u7edf\u8c03\u7528 - #\u762b\u7537\u65e5\u8bb0<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/blog.taiyang.space\/?p=390\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" 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