Originální popis anglicky:
modify_ldt - get or set ldt
Návod, kniha: Linux Programmer's Manual
#include <linux/ldt.h>
#include <linux/unistd.h>
_syscall3(int, modify_ldt, int, func, void *,
ptr, unsigned long, bytecount)
int modify_ldt(int func, void *ptr, unsigned long
bytecount);
modify_ldt reads or writes the local descriptor table (ldt) for a
process. The ldt is a per-process memory management table used by the i386
processor. For more information on this table, see an Intel 386 processor
handbook.
When
func is 0,
modify_ldt reads the ldt into the memory pointed
to by
ptr. The number of bytes read is the smaller of
bytecount
and the actual size of the ldt.
When
func is 1,
modify_ldt modifies one ldt entry.
ptr
points to a
modify_ldt_ldt_s structure and
bytecount must equal
the size of this structure.
On success,
modify_ldt returns either the actual number of bytes read
(for reading) or 0 (for writing). On failure,
modify_ldt returns -1 and
sets
errno.
- EFAULT
- ptr points outside the address space.
- EINVAL
- ptr is 0, or func is 1 and bytecount
is not equal to the size of the structure modify_ldt_ldt_s, or
func is 1 and the new ldt entry has invalid values.
- ENOSYS
- func is neither 0 nor 1.
This call in Linux-specific and should not be used in programs intended to be
portable.
vm86(2)
