Kernel VM Library Functions                        kvm_read(3KVM)

NAME
     kvm_read,  kvm_write,  kvm_uread,   kvm_uwrite,   kvm_kread,
     kvm_kwrite  - copy data to or from a kernel image or running
     system

SYNOPSIS
     #include <kvm.h>

     ssize_t  kvm_read(kvm_t  *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

     ssize_t kvm_write(kvm_t  *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

     ssize_t kvm_kread(kvm_t  *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

     ssize_t kvm_kwrite(kvm_t *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

     ssize_t kvm_uread(kvm_t  *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

     ssize_t kvm_uwrite(kvm_t *kd,  uintptr_t  addr,  void  *buf,
     size_t nbytes);

DESCRIPTION
  kvm_kread()
     The kvm_kread() function  transfers  data  from  the  kernel
     address  space  to  the address space of the process. nbytes
     bytes of data are copied from  the  kernel  virtual  address
     given by addr to the buffer pointed to by buf.

  kvm_kwrite()
     The kvm_kwrite() function is like kvm_kread(),  except  that
     the direction of the transfer is reversed. To use this func-
     tion, the kvm_open(3KVM) call that returned   kd  must  have
     specified write access.

  kvm_uread()
     The kvm_uread() function transfers  data  from  the  address
     space   of  the  processes  specified  in  the  most  recent
     kvm_getu(3KVM) call. nbytes bytes of data  are  copied  from
     the user virtual address given by addr to the buffer pointed
     to by buf.

  kvm_uwrite()
     The kvm_uwrite() function is like kvm_uread(),  except  that
     the direction of the transfer is reversed. To use this func-
     tion, the kvm_open(3KVM) call that returned   kd  must  have
     specified  write  access.  The  address  is  resolved in the
     address space of the process specified in  the  most  recent

SunOS 5.8           Last change: 22 Sep 1997                    1

Kernel VM Library Functions                        kvm_read(3KVM)

     kvm_getu(3KVM) call.

  kvm_read()
     The kvm_read() function transfers data from the kernel image
     specified by kd (see kvm_open(3KVM)) to the address space of
     the process. nbytes bytes of data are copied from the kernel
     virtual  address  given  by addr to the buffer pointed to by
     buf.

  kvm_write()
     The kvm_write() function is like kvm_read(), except that the
     direction  of  data  transfer is reversed. To use this func-
     tion, the kvm_open(3KVM) call that  returned  kd  must  have
     specified  write access. If a user virtual address is given,
     it is resolved in the address space of the process specified
     in the most recent kvm_getu(3KVM) call.

USAGE
     The  use  of  kvm_read()   and   kvm_write()   is   strongly
     discouraged.  On some platforms, there is considerable ambi-
     guity over which address space is to be  accessed  by  these
     functions,  possibly  leading  to  unexpected  results.  The
     kvm_kread(),  kvm_kwrite(),  kvm_uread(),  and  kvm_uwrite()
     functions are much more clearly defined in this respect.

RETURN VALUES
     On success, these functions return the number of bytes actu-
     ally transferred. On failure, they return -1.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Unsafe                      |
    |_____________________________|_____________________________|

SEE ALSO
     kvm_getu(3KVM),  kvm_nlist(3KVM),   kvm_open(3KVM),   attributes(5)
     

SunOS 5.8           Last change: 22 Sep 1997                    2