NAME    [Toc]    [Back]

     i386_get_ldt, i386_set_ldt - manage i386 per-process Local Descriptor
     Table entries

LIBRARY    [Toc]    [Back]

     i386 Architecture Library (libi386, -li386)

SYNOPSIS    [Toc]    [Back]

     #include <sys/types.h>
     #include <machine/segments.h>
     #include <machine/sysarch.h>

     int
     i386_get_ldt(int start_sel, union descriptor *descs, int num_sels);

     int
     i386_set_ldt(int start_sel, union descriptor *descs, int num_sels);

DESCRIPTION    [Toc]    [Back]

     i386_get_ldt() will return the list of i386 descriptors that the process
     has in its LDT.  i386_set_ldt() will set a list of i386 descriptors for
     the current process in its LDT.  Both routines accept a starting selector
     number start_sel , an array of memory that will contain the descriptors
     to be set or returned descs , and the number of entries to set or return
     num_sels.

     The argument descs can be either segment_descriptor or gate_descriptor
     and are defined in <i386/segments.h> .
     These structures are defined by the architecure as disjoint bit-fields,
     so care must be taken in constructing them.

RETURN VALUES    [Toc]    [Back]

     Upon successful completion, i386_get_ldt() returns the number of descriptors
 currently in the LDT.  i386_set_ldt() returns the first selector
     set.  Otherwise, a value of -1 is returned and the global variable errno
     is set to indicate the error.

ERRORS    [Toc]    [Back]

     i386_get_ldt() and i386_set_ldt() will fail if:

     [EINVAL]  An inappropriate parameter was used for start_sel or num_sels.

     [EACESS]  The caller attempted to use a descriptor that would circumvent
               protection or cause a failure.

REFERENCES    [Toc]    [Back]

     i386 Microprocessor Programmer's Reference Manual, Intel

WARNING    [Toc]    [Back]

     You can really hose your process using this.

BSD                           September 20, 1993                           BSD