File:sysent.c - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

2900 #

2901 /*

2902  */

2903

2904 /*

2905  * This table is the switch used to transfer

2906  * to the appropriate routine for processing a system call.

2907  * Each row contains the number of arguments expected

2908  * and a pointer to the routine.

2909  */

2910 int sysent[]

• 系统调用函数入口
• 每项包括 函数参数个数 和 函数地址

2911 {

2912     0, &nullsys, /* 0 = indir */

2913     0, &rexit, /* 1 = exit */

2914     0, &fork, /* 2 = fork */

2915     2, &read, /* 3 = read */

2916     2, &write, /* 4 = write */

2917     2, &open, /* 5 = open */

2918     0, &close, /* 6 = close */

2919     0, &wait, /* 7 = wait */

2920     2, &creat, /* 8 = creat */

2921     2, &link, /* 9 = link */

2922     1, &unlink, /* 10 = ulink */

2923     2, &exec, /* 11 = exec */

2924     1, &chdir, /* 12 = chdir */

2925     0, &gtime, /* 13 = time */

2926     3, &mknod, /* 14 = mknod */

2927     2, &chmod, /* 15 = chmod */

2928     2, &chown, /* 16 = chown */

2929     1, &sbreak, /* 17 = break */

2930     2, &stat, /* 18 = stat */

2931     2, &seek, /* 19 = seek */

2932     0, &getpid, /* 20 = getpid */

2933     3, &smount, /* 21 = mount */

2934     1, &sumount, /* 22 = unmount */

2935     0, &setuid, /* 23 = setuid */

2936     0, &getuid, /* 24 = getuid */

2937     0, &stime, /* 25 = stime */

2938     3, &ptrace, /* 26 = ptrace */

2939     0, &nosys, /* 27 = x */

2940     1, &fstat, /* 28 = fstat */

2941     0, &nosys, /* 29 = x */

2942     1, &nullsys, /* inoperative /* 30 = smdate */

2943     1, &stty, /* 31 = stty */

2944     1, &gtty, /* 32 = gtty */

2945     0, &nosys, /* 33 = x */

2946     0, &nice, /* 34 = nice */

2947     0, &sslep, /* 35 = sleep */

2948     0, &sync, /* 36 = sync */

2949     1, &kill, /* 37 = kill */

2950     0, &getswit, /* 38 = switch */

2951     0, &nosys, /* 39 = x */

2952     0, &nosys, /* 40 = x */

2953     0, &dup, /* 41 = dup */

2954     0, &pipe, /* 42 = pipe */

2955     1, &times, /* 43 = times */

2956     4, &profil, /* 44 = prof */

2957     0, &nosys, /* 45 = tui */

2958     0, &setgid, /* 46 = setgid */

2959     0, &getgid, /* 47 = getgid */

2960     2, &ssig, /* 48 = sig */

2961     0, &nosys, /* 49 = x */

2962     0, &nosys, /* 50 = x */

2963     0, &nosys, /* 51 = x */

2964     0, &nosys, /* 52 = x */

2965     0, &nosys, /* 53 = x */

2966     0, &nosys, /* 54 = x */

2967     0, &nosys, /* 55 = x */

2968     0, &nosys, /* 56 = x */

2969     0, &nosys, /* 57 = x */

2970     0, &nosys, /* 58 = x */

2971     0, &nosys, /* 59 = x */

2972     0, &nosys, /* 60 = x */

2973     0, &nosys, /* 61 = x */

2974     0, &nosys, /* 62 = x */

2975     0, &nosys, /* 63 = x */

2976 };

2977 /* ------------------------- */

2978

2979

2980

2981

2982

2983

2984

2985

2986

2987

2988

2989

2990

2991

2992

2993

2994

2995

2996

2997

2998

2999

• 系统调用