设置ctl.start 属性启动init.rc 中service以及权限问题

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

[cpp] view plain copy
/*

• 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;