转自：

 

通过property_set("ctl.start", service_xx);

来启动init.rc中的service是一个很方便方法来调用某个可执行程序或某个脚本程序

service service_xx  /system/bin/xx

disabled

    oneshot

但在非AID_ROOT、AID_SYSTEM 用户的进程中调用ctl.start ctl.stop会碰到权限问题:

system/core/init/property_service.c

/*  

 * White list of UID that are allowed to start/stop services.    * Currently there are no user apps that require.    */   struct {        const char *service;        unsigned int uid;        unsigned int gid;    } control_perms[] = {        { "dumpstate",AID_SHELL, AID_LOG },         {NULL, 0, 0 }    };       /*    * Checks permissions for starting/stoping system services.    * AID_SYSTEM and AID_ROOT are always allowed.    *    * Returns 1 if uid allowed, 0 otherwise.    */   static int check_control_perms(const char *name, int uid, int gid) {        int i;        if (uid == AID_SYSTEM || uid == AID_ROOT)            return 1;           /* Search the ACL */       for (i = 0; control_perms[i].service; i++) {            if (strcmp(control_perms[i].service, name) == 0) {                if ((uid && control_perms[i].uid == uid) ||                    (gid && control_perms[i].gid == gid)) {                    return 1;                }            }        }        return 0;    } 

本文来自CSDN博客，转载请标明出处：

只有uid == AID_SYSTEM || uid == AID_ROOT

或符合 control_perms[] = {

    { "dumpstate",AID_SHELL, AID_LOG },      {NULL, 0, 0 } }; 的uid进程才有权限star/stop services

因此，如果我们碰到了权限问题，根据log提示，在/system/core/include/private/_filesystem_config.h

中查到进程定义，添加到control_perms[]列表

比如，uid ==AID_WIFI的某个程序需要权限启动service_xx

control_perms[] = {

    { "dumpstate",AID_SHELL, AID_LOG },

+  { "service_xx ",AID_WIFI, AID_WIFI},

     {NULL, 0, 0 } };

本文转自张昺华-sky博客园博客，原文链接：http://www.cnblogs.com/sky-heaven/p/5261606.html，如需转载请自行联系原作者