/*- * Copyright (c) 1990 The Regents of the University of California. * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. * * from: @(#)sys_machdep.c 5.5 (Berkeley) 1/19/91 * $FreeBSD: src/sys/i386/i386/sys_machdep.c,v 1.47.2.3 2002/10/07 17:20:00 jhb Exp $ * $DragonFly: src/sys/platform/pc32/i386/sys_machdep.c,v 1.4 2003/06/23 17:55:38 dillon Exp $ * */ #include "opt_user_ldt.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* pcb.h included by sys/user.h */ #include #ifdef SMP #include #endif #include /* for kernel_map */ #define MAX_LD 8192 #define LD_PER_PAGE 512 #define NEW_MAX_LD(num) ((num + LD_PER_PAGE) & ~(LD_PER_PAGE-1)) #define SIZE_FROM_LARGEST_LD(num) (NEW_MAX_LD(num) << 3) #ifdef USER_LDT static int i386_get_ldt __P((struct proc *, char *)); static int i386_set_ldt __P((struct proc *, char *)); #endif static int i386_get_ioperm __P((struct proc *, char *)); static int i386_set_ioperm __P((struct proc *, char *)); int i386_extend_pcb __P((struct proc *)); /* * sysarch_args(int op, char *params) */ int sysarch(struct sysarch_args *uap) { struct proc *p = curproc; int error = 0; switch(uap->op) { #ifdef USER_LDT case I386_GET_LDT: error = i386_get_ldt(p, uap->parms); break; case I386_SET_LDT: error = i386_set_ldt(p, uap->parms); break; #endif case I386_GET_IOPERM: error = i386_get_ioperm(p, uap->parms); break; case I386_SET_IOPERM: error = i386_set_ioperm(p, uap->parms); break; case I386_VM86: error = vm86_sysarch(p, uap->parms); break; default: error = EOPNOTSUPP; break; } return (error); } int i386_extend_pcb(struct proc *p) { int i, offset; u_long *addr; struct pcb_ext *ext; struct soft_segment_descriptor ssd = { 0, /* segment base address (overwritten) */ ctob(IOPAGES + 1) - 1, /* length */ SDT_SYS386TSS, /* segment type */ 0, /* priority level */ 1, /* descriptor present */ 0, 0, 0, /* default 32 size */ 0 /* granularity */ }; ext = (struct pcb_ext *)kmem_alloc(kernel_map, ctob(IOPAGES+1)); if (ext == 0) return (ENOMEM); p->p_thread->td_pcb->pcb_ext = ext; bzero(ext, sizeof(struct pcb_ext)); ext->ext_tss.tss_esp0 = (unsigned)((char *)p->p_thread->td_pcb - 16); ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL); /* * The last byte of the i/o map must be followed by an 0xff byte. * We arbitrarily allocate 16 bytes here, to keep the starting * address on a doubleword boundary. */ offset = PAGE_SIZE - 16; ext->ext_tss.tss_ioopt = (offset - ((unsigned)&ext->ext_tss - (unsigned)ext)) << 16; ext->ext_iomap = (caddr_t)ext + offset; ext->ext_vm86.vm86_intmap = (caddr_t)ext + offset - 32; addr = (u_long *)ext->ext_vm86.vm86_intmap; for (i = 0; i < (ctob(IOPAGES) + 32 + 16) / sizeof(u_long); i++) *addr++ = ~0; ssd.ssd_base = (unsigned)&ext->ext_tss; ssd.ssd_limit -= ((unsigned)&ext->ext_tss - (unsigned)ext); ssdtosd(&ssd, &ext->ext_tssd); /* switch to the new TSS after syscall completes */ need_resched(); return 0; } static int i386_set_ioperm(p, args) struct proc *p; char *args; { int i, error; struct i386_ioperm_args ua; char *iomap; if ((error = copyin(args, &ua, sizeof(struct i386_ioperm_args))) != 0) return (error); if ((error = suser_xxx(p->p_ucred, 0)) != 0) return (error); if (securelevel > 0) return (EPERM); /* * XXX * While this is restricted to root, we should probably figure out * whether any other driver is using this i/o address, as so not to * cause confusion. This probably requires a global 'usage registry'. */ if (p->p_thread->td_pcb->pcb_ext == 0) if ((error = i386_extend_pcb(p)) != 0) return (error); iomap = (char *)p->p_thread->td_pcb->pcb_ext->ext_iomap; if (ua.start + ua.length > IOPAGES * PAGE_SIZE * NBBY) return (EINVAL); for (i = ua.start; i < ua.start + ua.length; i++) { if (ua.enable) iomap[i >> 3] &= ~(1 << (i & 7)); else iomap[i >> 3] |= (1 << (i & 7)); } return (error); } static int i386_get_ioperm(p, args) struct proc *p; char *args; { int i, state, error; struct i386_ioperm_args ua; char *iomap; if ((error = copyin(args, &ua, sizeof(struct i386_ioperm_args))) != 0) return (error); if (ua.start >= IOPAGES * PAGE_SIZE * NBBY) return (EINVAL); if (p->p_thread->td_pcb->pcb_ext == 0) { ua.length = 0; goto done; } iomap = (char *)p->p_thread->td_pcb->pcb_ext->ext_iomap; i = ua.start; state = (iomap[i >> 3] >> (i & 7)) & 1; ua.enable = !state; ua.length = 1; for (i = ua.start + 1; i < IOPAGES * PAGE_SIZE * NBBY; i++) { if (state != ((iomap[i >> 3] >> (i & 7)) & 1)) break; ua.length++; } done: error = copyout(&ua, args, sizeof(struct i386_ioperm_args)); return (error); } #ifdef USER_LDT /* * Update the GDT entry pointing to the LDT to point to the LDT of the * current process. Do not staticize. */ void set_user_ldt(struct pcb *pcb) { struct pcb_ldt *pcb_ldt; if (pcb != curthread->td_pcb) return; pcb_ldt = pcb->pcb_ldt; #ifdef SMP gdt[cpuid * NGDT + GUSERLDT_SEL].sd = pcb_ldt->ldt_sd; #else gdt[GUSERLDT_SEL].sd = pcb_ldt->ldt_sd; #endif lldt(GSEL(GUSERLDT_SEL, SEL_KPL)); currentldt = GSEL(GUSERLDT_SEL, SEL_KPL); } struct pcb_ldt * user_ldt_alloc(struct pcb *pcb, int len) { struct pcb_ldt *pcb_ldt, *new_ldt; MALLOC(new_ldt, struct pcb_ldt *, sizeof(struct pcb_ldt), M_SUBPROC, M_WAITOK); if (new_ldt == NULL) return NULL; new_ldt->ldt_len = len = NEW_MAX_LD(len); new_ldt->ldt_base = (caddr_t)kmem_alloc(kernel_map, len * sizeof(union descriptor)); if (new_ldt->ldt_base == NULL) { FREE(new_ldt, M_SUBPROC); return NULL; } new_ldt->ldt_refcnt = 1; new_ldt->ldt_active = 0; gdt_segs[GUSERLDT_SEL].ssd_base = (unsigned)new_ldt->ldt_base; gdt_segs[GUSERLDT_SEL].ssd_limit = len * sizeof(union descriptor) - 1; ssdtosd(&gdt_segs[GUSERLDT_SEL], &new_ldt->ldt_sd); if ((pcb_ldt = pcb->pcb_ldt)) { if (len > pcb_ldt->ldt_len) len = pcb_ldt->ldt_len; bcopy(pcb_ldt->ldt_base, new_ldt->ldt_base, len * sizeof(union descriptor)); } else { bcopy(ldt, new_ldt->ldt_base, sizeof(ldt)); } return new_ldt; } void user_ldt_free(struct pcb *pcb) { struct pcb_ldt *pcb_ldt = pcb->pcb_ldt; if (pcb_ldt == NULL) return; if (pcb == curthread->td_pcb) { lldt(_default_ldt); currentldt = _default_ldt; } if (--pcb_ldt->ldt_refcnt == 0) { kmem_free(kernel_map, (vm_offset_t)pcb_ldt->ldt_base, pcb_ldt->ldt_len * sizeof(union descriptor)); FREE(pcb_ldt, M_SUBPROC); } pcb->pcb_ldt = NULL; } static int i386_get_ldt(p, args) struct proc *p; char *args; { int error = 0; struct pcb *pcb = p->p_thread->td_pcb; struct pcb_ldt *pcb_ldt = pcb->pcb_ldt; int nldt, num; union descriptor *lp; int s; struct i386_ldt_args ua, *uap = &ua; if ((error = copyin(args, uap, sizeof(struct i386_ldt_args))) < 0) return(error); #ifdef DEBUG printf("i386_get_ldt: start=%d num=%d descs=%p\n", uap->start, uap->num, (void *)uap->descs); #endif /* verify range of LDTs exist */ if ((uap->start < 0) || (uap->num <= 0)) return(EINVAL); s = splhigh(); if (pcb_ldt) { nldt = pcb_ldt->ldt_len; num = min(uap->num, nldt); lp = &((union descriptor *)(pcb_ldt->ldt_base))[uap->start]; } else { nldt = sizeof(ldt)/sizeof(ldt[0]); num = min(uap->num, nldt); lp = &ldt[uap->start]; } if (uap->start + num > nldt) { splx(s); return(EINVAL); } error = copyout(lp, uap->descs, num * sizeof(union descriptor)); if (!error) p->p_retval[0] = num; splx(s); return(error); } static int i386_set_ldt(p, args) struct proc *p; char *args; { int error = 0, i, n; int largest_ld; struct pcb *pcb = p->p_thread->td_pcb; struct pcb_ldt *pcb_ldt = pcb->pcb_ldt; union descriptor *descs; int descs_size, s; struct i386_ldt_args ua, *uap = &ua; if ((error = copyin(args, uap, sizeof(struct i386_ldt_args))) < 0) return(error); #ifdef DEBUG printf("i386_set_ldt: start=%d num=%d descs=%p\n", uap->start, uap->num, (void *)uap->descs); #endif /* verify range of descriptors to modify */ if ((uap->start < 0) || (uap->start >= MAX_LD) || (uap->num < 0) || (uap->num > MAX_LD)) { return(EINVAL); } largest_ld = uap->start + uap->num - 1; if (largest_ld >= MAX_LD) return(EINVAL); /* allocate user ldt */ if (!pcb_ldt || largest_ld >= pcb_ldt->ldt_len) { struct pcb_ldt *new_ldt = user_ldt_alloc(pcb, largest_ld); if (new_ldt == NULL) return ENOMEM; if (pcb_ldt) { pcb_ldt->ldt_sd = new_ldt->ldt_sd; kmem_free(kernel_map, (vm_offset_t)pcb_ldt->ldt_base, pcb_ldt->ldt_len * sizeof(union descriptor)); pcb_ldt->ldt_base = new_ldt->ldt_base; pcb_ldt->ldt_len = new_ldt->ldt_len; FREE(new_ldt, M_SUBPROC); } else pcb->pcb_ldt = pcb_ldt = new_ldt; #ifdef SMP /* signal other cpus to reload ldt */ smp_rendezvous(NULL, (void (*)(void *))set_user_ldt, NULL, pcb); #else set_user_ldt(pcb); #endif } descs_size = uap->num * sizeof(union descriptor); descs = (union descriptor *)kmem_alloc(kernel_map, descs_size); if (descs == NULL) return (ENOMEM); error = copyin(&uap->descs[0], descs, descs_size); if (error) { kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return (error); } /* Check descriptors for access violations */ for (i = 0, n = uap->start; i < uap->num; i++, n++) { union descriptor *dp; dp = &descs[i]; switch (dp->sd.sd_type) { case SDT_SYSNULL: /* system null */ dp->sd.sd_p = 0; break; case SDT_SYS286TSS: /* system 286 TSS available */ case SDT_SYSLDT: /* system local descriptor table */ case SDT_SYS286BSY: /* system 286 TSS busy */ case SDT_SYSTASKGT: /* system task gate */ case SDT_SYS286IGT: /* system 286 interrupt gate */ case SDT_SYS286TGT: /* system 286 trap gate */ case SDT_SYSNULL2: /* undefined by Intel */ case SDT_SYS386TSS: /* system 386 TSS available */ case SDT_SYSNULL3: /* undefined by Intel */ case SDT_SYS386BSY: /* system 386 TSS busy */ case SDT_SYSNULL4: /* undefined by Intel */ case SDT_SYS386IGT: /* system 386 interrupt gate */ case SDT_SYS386TGT: /* system 386 trap gate */ case SDT_SYS286CGT: /* system 286 call gate */ case SDT_SYS386CGT: /* system 386 call gate */ /* I can't think of any reason to allow a user proc * to create a segment of these types. They are * for OS use only. */ kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return EACCES; /* memory segment types */ case SDT_MEMEC: /* memory execute only conforming */ case SDT_MEMEAC: /* memory execute only accessed conforming */ case SDT_MEMERC: /* memory execute read conforming */ case SDT_MEMERAC: /* memory execute read accessed conforming */ /* Must be "present" if executable and conforming. */ if (dp->sd.sd_p == 0) { kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return (EACCES); } break; case SDT_MEMRO: /* memory read only */ case SDT_MEMROA: /* memory read only accessed */ case SDT_MEMRW: /* memory read write */ case SDT_MEMRWA: /* memory read write accessed */ case SDT_MEMROD: /* memory read only expand dwn limit */ case SDT_MEMRODA: /* memory read only expand dwn lim accessed */ case SDT_MEMRWD: /* memory read write expand dwn limit */ case SDT_MEMRWDA: /* memory read write expand dwn lim acessed */ case SDT_MEME: /* memory execute only */ case SDT_MEMEA: /* memory execute only accessed */ case SDT_MEMER: /* memory execute read */ case SDT_MEMERA: /* memory execute read accessed */ break; default: kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return(EINVAL); /*NOTREACHED*/ } /* Only user (ring-3) descriptors may be present. */ if ((dp->sd.sd_p != 0) && (dp->sd.sd_dpl != SEL_UPL)) { kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return (EACCES); } } s = splhigh(); /* Fill in range */ bcopy(descs, &((union descriptor *)(pcb_ldt->ldt_base))[uap->start], uap->num * sizeof(union descriptor)); p->p_retval[0] = uap->start; splx(s); kmem_free(kernel_map, (vm_offset_t)descs, descs_size); return (0); } #endif /* USER_LDT */