NetBSD-5.0.2/regress/sys/arch/i386/ldt/testldt.c
/* $NetBSD: testldt.c,v 1.14 2008/04/28 20:23:05 martin Exp $ */
/*-
* Copyright (c) 1993 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <err.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <machine/segments.h>
#include <machine/sysarch.h>
static void
set_fs(unsigned int val)
{
__asm volatile("mov %0,%%fs"::"r" ((unsigned short) val));
}
static unsigned char
get_fs_byte(const char *addr)
{
unsigned char _v;
__asm ("movb %%fs:%1,%0":"=q" (_v):"m" (*addr));
return _v;
}
static unsigned short
get_cs(void)
{
unsigned short _v;
__asm ("movw %%cs,%0": "=r" ((unsigned short) _v));
return _v;
}
static int
check_desc(int desc)
{
unsigned int sel = LSEL(desc, SEL_UPL);
set_fs(sel);
return(get_fs_byte((char *) 0));
}
static void
gated_call(void)
{
printf("Called from call gate...");
__asm volatile("movl %ebp,%esp");
__asm volatile("popl %ebp");
__asm volatile(".byte 0xcb");
}
static union descriptor *
make_sd(void *basep, unsigned limit, int type, int dpl, int seg32, int inpgs)
{
static union descriptor d;
unsigned long base = (unsigned long)basep;
d.sd.sd_lolimit = limit & 0x0000ffff;
d.sd.sd_lobase = base & 0x00ffffff;
d.sd.sd_type = type & 0x01f;
d.sd.sd_dpl = dpl & 0x3;
d.sd.sd_p = 1;
d.sd.sd_hilimit = (limit & 0x00ff0000) >> 16;
d.sd.sd_xx = 0;
d.sd.sd_def32 = seg32?1:0;
d.sd.sd_gran = inpgs?1:0;
d.sd.sd_hibase = (base & 0xff000000) >> 24;
return (&d);
}
static union descriptor *
make_gd(void *func, unsigned int sel, unsigned stkcpy, int type, int dpl)
{
static union descriptor d;
unsigned long offset = (unsigned long)func;
d.gd.gd_looffset = offset & 0x0000ffff;
d.gd.gd_selector = sel & 0xffff;
d.gd.gd_stkcpy = stkcpy & 0x1ff;
d.gd.gd_type = type & 0x1ff;
d.gd.gd_dpl = dpl & 0x3;
d.gd.gd_p = 1;
d.gd.gd_hioffset = (offset & 0xffff0000) >> 16;
return(&d);
}
static const char *
seg_type_name[] = {
"SYSNULL", "SYS286TSS", "SYSLDT", "SYS286BSY",
"SYS286CGT", "SYSTASKGT", "SYS286IGT", "SYS286TGT",
"SYSNULL2", "SYS386TSS", "SYSNULL3", "SYS386BSY",
"SYS386CGT", "SYSNULL4", "SYS386IGT", "SYS386TGT",
"MEMRO", "MEMROA", "MEMRW", "MEMRWA",
"MEMROD", "MEMRODA", "MEMRWD", "MEMRWDA",
"MEME", "MEMEA", "MEMER", "MEMERA",
"MEMEC", "MEMEAC", "MEMERC", "MEMERAC"
};
static const char *
segtype(unsigned int type)
{
if (type >= 32)
return "Out of range";
return seg_type_name[type];
}
static void
print_ldt(union descriptor *dp)
{
unsigned long base_addr, limit, offset, stack_copy;
unsigned int type, dpl;
unsigned long lp[2];
(void) memcpy(lp, dp, sizeof(lp));
base_addr = dp->sd.sd_lobase | (dp->sd.sd_hibase << 24);
limit = dp->sd.sd_lolimit | (dp->sd.sd_hilimit << 16);
offset = dp->gd.gd_looffset | (dp->gd.gd_hioffset << 16);
type = dp->sd.sd_type;
dpl = dp->sd.sd_dpl;
stack_copy = dp->gd.gd_stkcpy;
if (type == SDT_SYS386CGT || type == SDT_SYS286CGT)
printf("LDT: Gate Off %8.8lx, Sel %5.5x, Stkcpy %lu DPL %d,"
" Type %d/%s\n",
offset, dp->gd.gd_selector, stack_copy, dpl,
type, segtype(type));
else
printf("LDT: Seg Base %8.8lx, Limit %5.5lx, DPL %d, "
"Type %d/%s\n",
base_addr, limit, dpl,
type, segtype(type));
printf(" ");
if (type & 0x1)
printf("Accessed, ");
if (dp->sd.sd_p)
printf("Present, ");
if (type != SDT_SYS386CGT && type != SDT_SYS286CGT) {
if (type & 0x10)
printf("User, ");
if (type & 0x08)
printf("X, ");
if (dp->sd.sd_def32)
printf("32-bit, ");
else
printf("16-bit, ");
if (dp->sd.sd_gran)
printf("page limit, ");
else
printf("byte limit, ");
}
printf("\n");
printf(" Raw descriptor: %08lx %08lx\n", lp[0], lp[1]);
}
/* ARGSUSED */
static void
busfault(int signo)
{
errx(1, "%s\n - investigate.", sys_siglist[signo]);
}
static void
usage(int status)
{
errx(status, "Usage: testldt [-v]");
}
#define MAX_USER_LDT 1024
int
main(int argc, char *argv[])
{
union descriptor ldt[MAX_USER_LDT];
int n, ch;
int num;
unsigned int cs = get_cs();
unsigned char *data;
union descriptor *sd, *gd;
unsigned char one = 1, two = 2, val;
struct sigaction segv_act;
int verbose = 0;
segv_act.sa_handler = busfault;
if (sigaction(SIGBUS, &segv_act, NULL) < 0)
err(1, "sigaction");
while ((ch = getopt(argc, argv, "v")) != -1) {
switch (ch) {
case 'v':
verbose++;
break;
default:
usage(1);
break;
}
}
printf("Testing i386_get_ldt...\n");
if ((num = i386_get_ldt(0, ldt, MAX_USER_LDT)) < 0)
err(2, "get_ldt");
if (num == 0)
errx(1, "i386_get_ldt() returned empty initial LDT");
if (verbose) {
printf("Got %d (initial) LDT entries\n", num);
for (n=0; n < num; n++) {
printf("Entry %d: ", n);
print_ldt(&ldt[n]);
}
}
/*
* mmap a data area and assign an LDT to it
*/
printf("Testing i386_set_ldt...\n");
data = (void *) mmap( (char *)0x005f0000, 0x0fff,
PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, (off_t)0);
if (data == NULL)
err(1, "mmap");
if (verbose)
printf("data address: %p\n", data);
*data = 0x97;
/* Get the next free LDT and set it to the allocated data. */
sd = make_sd(data, 2048, SDT_MEMRW, SEL_UPL, 0, 0);
if ((num = i386_set_ldt(1024, sd, 1)) < 0)
err(1, "set_ldt");
if (verbose) printf("setldt returned: %d\n", num);
if ((n = i386_get_ldt(num, ldt, 1)) < 0)
err(1, "get_ldt");
if (verbose) {
printf("Entry %d: ", num);
print_ldt(&ldt[0]);
}
if (verbose)
printf("Checking desc (should be 0x97): 0x%x\n",
check_desc(num));
if (check_desc(num) != 0x97)
errx(1, "ERROR: descriptor check failed; "
"expected 0x97, got 0x%x", check_desc(num));
/*
* Test a Call Gate
*/
printf("Making Call Gate\n");
fflush(stdout);
gd = make_gd((void *)gated_call, cs, 0, SDT_SYS386CGT, SEL_UPL);
if ((num = i386_set_ldt(4095, gd, 1)) < 0)
err(1, "set_ldt: call gate");
if (verbose) {
printf("setldt returned: %d\n", num);
printf("Call gate sel = 0x%x\n", LSEL(num, SEL_UPL));
}
if ((n = i386_get_ldt(num, ldt, 1)) < 0)
err(1, "get_ldt");
if (verbose) {
printf("Entry %d: ", num);
print_ldt(&ldt[0]);
}
printf("Testing call gate...");
fflush(stdout);
/*
* Long call to call gate.
* Only the selector matters; offset is irrelevant.
*/
__asm volatile("lcall $0x7fff,$0x0");
printf("Gated call returned\n");
/*
* Test multiple sets.
*/
printf("Testing multiple descriptors at once.\n");
sd = (union descriptor *)malloc (sizeof(*sd) * 2);
if (sd == NULL)
err(1, "can't malloc");
sd[0] = *make_sd(&one, 1, SDT_MEMRO, SEL_UPL, 1, 0);
sd[1] = *make_sd(&two, 1, SDT_MEMRO, SEL_UPL, 1, 0);
if ((num = i386_set_ldt(8000, (union descriptor *)sd, 2)) < 0)
err(1, "set_ldt");
if (verbose) printf("setldt returned: %d\n", num);
if ((n = i386_get_ldt(num, ldt, 2)) < 0)
err(1, "get_ldt");
if (verbose) {
printf("Entry %d: ", num);
print_ldt(&ldt[0]);
printf("Entry %d: ", num+1);
print_ldt(&ldt[1]);
}
val = check_desc(num);
printf("contents of segment ONE: %x\n", val);
if (val != 1) {
errx(1, "ONE has unexpected value %x", val);
}
val = check_desc(num+1);
printf("contents of segment TWO: %x\n", val);
if (val != 2)
errx(1, "TWO has unexpected value %x", val);
if ((n = i386_get_ldt(num, ldt, 2)) < 0)
err(1, "get_ldt");
if (verbose) {
printf("Entry %d: ", num);
print_ldt(&ldt[0]);
printf("Entry %d: ", num+1);
print_ldt(&ldt[1]);
}
return 0;
}