Re: Re: Question about "fd" token

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Date: Mon May 18 2009 - 04:17:53 PDT

  • Next message: Paul H. Hargrove: "Re: Question about "fd" token"
    Hello, Professor:
    Thank you very much for your help, I have understand what you have told me.
    I am not the person who asks questions as soon as they meet with a problem, It's only when I can not work it out and can not find answer through other ways will I resort to you . please excuse me..
    I know we can pass some arguments when we are calling ioctl syscall.For example:
    #define CR_OP_HAND_CHKPT_INFO	_IOR  (CR_IOCTL_BASE, 0x0a, struct cr_chkpt_info *)
    #define CR_OP_CHKPT_REQ	_IOW (CR_IOCTL_BASE, 0x10, struct cr_chkpt_args *)
    #define CR_OP_CHKPT_FWD _IOW (CR_IOCTL_BASE, 0x13, struct cr_fwd_args *)
    when issue a ioctl syscall, struct"cr_chkpt_info" "cr_chkpt_args" "cr_fwd_args" are passed. 
    "struct cr_chkpt_args req;"
    "rc = cri_syscall_token(token, CR_OP_CHKPT_REQ, (uintptr_t)&req)"
    However, I can not find the definition of these structure... 
    Are they allocated dynamically? I have never seen such a usage... 
    Is that because the arguments are from user space??? or some other reasons???

  • Next message: Paul H. Hargrove: "Re: Question about "fd" token"