int
main(void)
{
union ldt_entry descs;
char *buf;
u_long pgsz = sysconf(_SC_PAGESIZE);
if ((buf = (char *)malloc(pgsz * 4)) == -1) {
perror("malloc");
exit(EXIT_FAILURE);
}
memset(buf, 0x41, pgsz * 4);
buf = (char *)(((u_long)buf & ~pgsz) + pgsz);
if (mprotect((char *)((u_long)buf + (pgsz * 2)), (size_t)pgsz,
PROT_WRITE) == -1) {
perror("mprotect");
exit(EXIT_FAILURE);
}
/*
* This will result in kalloc() size argument being 0x00000000 and
copyin()
* size argument being 0xfffffff8.
*/
if (i386_set_ldt(1024, (union ldt_entry *)&buf, -1) == -1) {
perror("i386_set_ldt");
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}
int main(int argc,char **argv){
if(i386_set_ldt(LUDATA_SEL+1,NULL,-1)==-1){
perror("i386_set_ldt");
exit(EXIT_FAILURE);
}
exit(EXIT_FAILURE);
}
int
linux_write_ldt(struct proc *p, struct linux_sys_modify_ldt_args *uap,
register_t *retval)
{
struct linux_ldt_info ldt_info;
struct segment_descriptor sd;
struct i386_set_ldt_args sl;
int error;
caddr_t sg;
char *parms;
if (user_ldt_enable == 0)
return (ENOSYS);
if (SCARG(uap, bytecount) != sizeof(ldt_info))
return (EINVAL);
if ((error = copyin(SCARG(uap, ptr), &ldt_info, sizeof(ldt_info))) != 0)
return error;
if (ldt_info.contents == 3)
return (EINVAL);
sg = stackgap_init(p->p_emul);
sd.sd_lobase = ldt_info.base_addr & 0xffffff;
sd.sd_hibase = (ldt_info.base_addr >> 24) & 0xff;
sd.sd_lolimit = ldt_info.limit & 0xffff;
sd.sd_hilimit = (ldt_info.limit >> 16) & 0xf;
sd.sd_type =
16 | (ldt_info.contents << 2) | (!ldt_info.read_exec_only << 1);
sd.sd_dpl = SEL_UPL;
sd.sd_p = !ldt_info.seg_not_present;
sd.sd_def32 = ldt_info.seg_32bit;
sd.sd_gran = ldt_info.limit_in_pages;
sl.start = ldt_info.entry_number;
sl.desc = stackgap_alloc(&sg, sizeof(sd));
sl.num = 1;
#if 0
printf("linux_write_ldt: idx=%d, base=%x, limit=%x\n",
ldt_info.entry_number, ldt_info.base_addr, ldt_info.limit);
#endif
parms = stackgap_alloc(&sg, sizeof(sl));
if ((error = copyout(&sd, sl.desc, sizeof(sd))) != 0)
return (error);
if ((error = copyout(&sl, parms, sizeof(sl))) != 0)
return (error);
if ((error = i386_set_ldt(p, parms, retval)) != 0)
return (error);
*retval = 0;
return (0);
}
int
sys_sysarch(struct proc *p, void *v, register_t *retval)
{
struct sys_sysarch_args /* {
syscallarg(int) op;
syscallarg(void *) parms;
} */ *uap = v;
int error = 0;
switch(SCARG(uap, op)) {
#ifdef USER_LDT
case I386_GET_LDT:
error = i386_get_ldt(p, SCARG(uap, parms), retval);
break;
case I386_SET_LDT:
error = i386_set_ldt(p, SCARG(uap, parms), retval);
break;
#endif
case I386_IOPL:
error = i386_iopl(p, SCARG(uap, parms), retval);
break;
case I386_GET_IOPERM:
error = i386_get_ioperm(p, SCARG(uap, parms), retval);
break;
case I386_SET_IOPERM:
error = i386_set_ioperm(p, SCARG(uap, parms), retval);
break;
#ifdef VM86
case I386_VM86:
error = i386_vm86(p, SCARG(uap, parms), retval);
break;
#endif
case I386_GET_FSBASE:
{
uint32_t base = i386_get_threadbase(p, TSEG_FS);
error = copyout(&base, SCARG(uap, parms), sizeof(base));
break;
}
case I386_SET_FSBASE:
{
uint32_t base;
if ((error = copyin(SCARG(uap, parms), &base, sizeof(base))))
break;
error = i386_set_threadbase(p, base, TSEG_FS);
break;
}
case I386_GET_GSBASE:
{
uint32_t base = i386_get_threadbase(p, TSEG_GS);
error = copyout(&base, SCARG(uap, parms), sizeof(base));
break;
}
case I386_SET_GSBASE:
{
uint32_t base;
if ((error = copyin(SCARG(uap, parms), &base, sizeof(base))))
break;
error = i386_set_threadbase(p, base, TSEG_GS);
break;
}
default:
error = EINVAL;
break;
}
return (error);
}
