/* $OpenBSD: sys_machdep.c,v 1.26 2006/09/19 11:06:33 jsg Exp $ */ /* $NetBSD: sys_machdep.c,v 1.28 1996/05/03 19:42:29 christos Exp $ */ /*- * Copyright (c) 1995 Charles M. Hannum. All rights reserved. * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * 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. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)sys_machdep.c 5.5 (Berkeley) 1/19/91 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef VM86 #include #endif extern struct vm_map *kernel_map; int i386_iopl(struct proc *, void *, register_t *); int i386_get_ioperm(struct proc *, void *, register_t *); int i386_set_ioperm(struct proc *, void *, register_t *); #ifdef USER_LDT #ifdef LDT_DEBUG static void i386_print_ldt(int, const struct segment_descriptor *); static void i386_print_ldt(int i, const struct segment_descriptor *d) { printf("[%d] lolimit=0x%x, lobase=0x%x, type=%u, dpl=%u, p=%u, " "hilimit=0x%x, xx=%x, def32=%u, gran=%u, hibase=0x%x\n", i, d->sd_lolimit, d->sd_lobase, d->sd_type, d->sd_dpl, d->sd_p, d->sd_hilimit, d->sd_xx, d->sd_def32, d->sd_gran, d->sd_hibase); } #endif int i386_get_ldt(struct proc *p, void *args, register_t *retval) { int error; pmap_t pmap = p->p_vmspace->vm_map.pmap; int nldt, num; union descriptor *lp, *cp; struct i386_get_ldt_args ua; if (user_ldt_enable == 0) return (ENOSYS); if ((error = copyin(args, &ua, sizeof(ua))) != 0) return (error); #ifdef LDT_DEBUG printf("i386_get_ldt: start=%d num=%d descs=%p\n", ua.start, ua.num, ua.desc); #endif if (ua.start < 0 || ua.num < 0 || ua.start > 8192 || ua.num > 8192 || ua.start + ua.num > 8192) return (EINVAL); cp = malloc(ua.num * sizeof(union descriptor), M_TEMP, M_WAITOK); if (cp == NULL) return ENOMEM; simple_lock(&pmap->pm_lock); if (pmap->pm_flags & PMF_USER_LDT) { nldt = pmap->pm_ldt_len; lp = pmap->pm_ldt; } else { nldt = NLDT; lp = ldt; } if (ua.start > nldt) { simple_unlock(&pmap->pm_lock); free(cp, M_TEMP); return (EINVAL); } lp += ua.start; num = min(ua.num, nldt - ua.start); #ifdef LDT_DEBUG { int i; for (i = 0; i < num; i++) i386_print_ldt(i, &lp[i].sd); } #endif memcpy(cp, lp, num * sizeof(union descriptor)); simple_unlock(&pmap->pm_lock); error = copyout(cp, ua.desc, num * sizeof(union descriptor)); if (error == 0) *retval = num; free(cp, M_TEMP); return (error); } int i386_set_ldt(struct proc *p, void *args, register_t *retval) { int error, i, n; struct pcb *pcb = &p->p_addr->u_pcb; pmap_t pmap = p->p_vmspace->vm_map.pmap; struct i386_set_ldt_args ua; union descriptor *descv; size_t old_len, new_len, ldt_len; union descriptor *old_ldt, *new_ldt; if (user_ldt_enable == 0) return (ENOSYS); if ((error = copyin(args, &ua, sizeof(ua))) != 0) return (error); if (ua.start < 0 || ua.num < 0 || ua.start > 8192 || ua.num > 8192 || ua.start + ua.num > 8192) return (EINVAL); descv = malloc(sizeof (*descv) * ua.num, M_TEMP, M_NOWAIT); if (descv == NULL) return (ENOMEM); if ((error = copyin(ua.desc, descv, sizeof (*descv) * ua.num)) != 0) goto out; /* Check descriptors for access violations. */ for (i = 0; i < ua.num; i++) { union descriptor *desc = &descv[i]; switch (desc->sd.sd_type) { case SDT_SYSNULL: desc->sd.sd_p = 0; break; case SDT_SYS286CGT: case SDT_SYS386CGT: /* * Only allow call gates targeting a segment * in the LDT or a user segment in the fixed * part of the gdt. Segments in the LDT are * constrained (below) to be user segments. */ if (desc->gd.gd_p != 0 && !ISLDT(desc->gd.gd_selector) && ((IDXSEL(desc->gd.gd_selector) >= NGDT) || (gdt[IDXSEL(desc->gd.gd_selector)].sd.sd_dpl != SEL_UPL))) { error = EACCES; goto out; } break; case SDT_MEMEC: case SDT_MEMEAC: case SDT_MEMERC: case SDT_MEMERAC: /* Must be "present" if executable and conforming. */ if (desc->sd.sd_p == 0) { error = EACCES; goto out; } break; case SDT_MEMRO: case SDT_MEMROA: case SDT_MEMRW: case SDT_MEMRWA: case SDT_MEMROD: case SDT_MEMRODA: case SDT_MEMRWD: case SDT_MEMRWDA: case SDT_MEME: case SDT_MEMEA: case SDT_MEMER: case SDT_MEMERA: break; default: /* * Make sure that unknown descriptor types are * not marked present. */ if (desc->sd.sd_p != 0) { error = EACCES; goto out; } break; } if (desc->sd.sd_p != 0) { /* Only user (ring-3) descriptors may be present. */ if (desc->sd.sd_dpl != SEL_UPL) { error = EACCES; goto out; } } } /* allocate user ldt */ simple_lock(&pmap->pm_lock); if (pmap->pm_ldt == 0 || (ua.start + ua.num) > pmap->pm_ldt_len) { if (pmap->pm_flags & PMF_USER_LDT) ldt_len = pmap->pm_ldt_len; else ldt_len = 512; while ((ua.start + ua.num) > ldt_len) ldt_len *= 2; new_len = ldt_len * sizeof(union descriptor); simple_unlock(&pmap->pm_lock); new_ldt = (union descriptor *)uvm_km_alloc(kernel_map, new_len); simple_lock(&pmap->pm_lock); if (pmap->pm_ldt != NULL && ldt_len <= pmap->pm_ldt_len) { /* * Another thread (re)allocated the LDT to * sufficient size while we were blocked in * uvm_km_alloc. Oh well. The new entries * will quite probably not be right, but * hey.. not our problem if user applications * have race conditions like that. */ uvm_km_free(kernel_map, (vaddr_t)new_ldt, new_len); goto copy; } old_ldt = pmap->pm_ldt; if (old_ldt != NULL) { old_len = pmap->pm_ldt_len * sizeof(union descriptor); } else { old_len = NLDT * sizeof(union descriptor); old_ldt = ldt; } memcpy(new_ldt, old_ldt, old_len); memset((caddr_t)new_ldt + old_len, 0, new_len - old_len); if (old_ldt != ldt) uvm_km_free(kernel_map, (vaddr_t)old_ldt, old_len); pmap->pm_ldt = new_ldt; pmap->pm_ldt_len = ldt_len; if (pmap->pm_flags & PMF_USER_LDT) ldt_free(pmap); else pmap->pm_flags |= PMF_USER_LDT; ldt_alloc(pmap, new_ldt, new_len); pcb->pcb_ldt_sel = pmap->pm_ldt_sel; if (pcb == curpcb) lldt(pcb->pcb_ldt_sel); } copy: /* Now actually replace the descriptors. */ for (i = 0, n = ua.start; i < ua.num; i++, n++) pmap->pm_ldt[n] = descv[i]; simple_unlock(&pmap->pm_lock); *retval = ua.start; out: free(descv, M_TEMP); return (error); } #endif /* USER_LDT */ #ifdef APERTURE extern int allowaperture; #endif int i386_iopl(struct proc *p, void *args, register_t *retval) { int error; struct trapframe *tf = p->p_md.md_regs; struct i386_iopl_args ua; if ((error = suser(p, 0)) != 0) return error; #ifdef APERTURE if (!allowaperture && securelevel > 0) return EPERM; #else if (securelevel > 0) return EPERM; #endif if ((error = copyin(args, &ua, sizeof(ua))) != 0) return error; if (ua.iopl) tf->tf_eflags |= PSL_IOPL; else tf->tf_eflags &= ~PSL_IOPL; return 0; } int i386_get_ioperm(struct proc *p, void *args, register_t *retval) { int error; struct pcb *pcb = &p->p_addr->u_pcb; struct i386_get_ioperm_args ua; if ((error = copyin(args, &ua, sizeof(ua))) != 0) return (error); return copyout(pcb->pcb_iomap, ua.iomap, sizeof(pcb->pcb_iomap)); } int i386_set_ioperm(struct proc *p, void *args, register_t *retval) { int error; struct pcb *pcb = &p->p_addr->u_pcb; struct i386_set_ioperm_args ua; if ((error = suser(p, 0)) != 0) return error; #ifdef APERTURE if (!allowaperture && securelevel > 0) return EPERM; #else if (securelevel > 0) return EPERM; #endif if ((error = copyin(args, &ua, sizeof(ua))) != 0) return (error); return copyin(ua.iomap, pcb->pcb_iomap, sizeof(pcb->pcb_iomap)); } 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 default: error = EINVAL; break; } return (error); }