/* * Copyright (c) 1988 University of Utah. * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * 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: Utah $Hdr: vm_mmap.c 1.6 91/10/21$ * * @(#)vm_mmap.c 8.4 (Berkeley) 1/12/94 * $FreeBSD: src/sys/vm/vm_mmap.c,v 1.108.2.6 2002/07/02 20:06:19 dillon Exp $ * $DragonFly: src/sys/vm/vm_mmap.c,v 1.39 2007/04/30 07:18:57 dillon Exp $ */ /* * Mapped file (mmap) interface to VM */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int max_proc_mmap; SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, ""); int vkernel_enable; SYSCTL_INT(_vm, OID_AUTO, vkernel_enable, CTLFLAG_RW, &vkernel_enable, 0, ""); /* * Set the maximum number of vm_map_entry structures per process. Roughly * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100 * of our KVM malloc space still results in generous limits. We want a * default that is good enough to prevent the kernel running out of resources * if attacked from compromised user account but generous enough such that * multi-threaded processes are not unduly inconvenienced. */ static void vmmapentry_rsrc_init (void *); SYSINIT(vmmersrc, SI_BOOT1_POST, SI_ORDER_ANY, vmmapentry_rsrc_init, NULL) static void vmmapentry_rsrc_init(void *dummy) { max_proc_mmap = KvaSize / sizeof(struct vm_map_entry); max_proc_mmap /= 100; } /* ARGSUSED */ int sys_sbrk(struct sbrk_args *uap) { /* Not yet implemented */ return (EOPNOTSUPP); } /* * sstk_args(int incr) */ /* ARGSUSED */ int sys_sstk(struct sstk_args *uap) { /* Not yet implemented */ return (EOPNOTSUPP); } /* * mmap_args(void *addr, size_t len, int prot, int flags, int fd, * long pad, off_t pos) * * Memory Map (mmap) system call. Note that the file offset * and address are allowed to be NOT page aligned, though if * the MAP_FIXED flag it set, both must have the same remainder * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not * page-aligned, the actual mapping starts at trunc_page(addr) * and the return value is adjusted up by the page offset. * * Generally speaking, only character devices which are themselves * memory-based, such as a video framebuffer, can be mmap'd. Otherwise * there would be no cache coherency between a descriptor and a VM mapping * both to the same character device. * * Block devices can be mmap'd no matter what they represent. Cache coherency * is maintained as long as you do not write directly to the underlying * character device. */ int kern_mmap(struct vmspace *vms, caddr_t uaddr, size_t ulen, int uprot, int uflags, int fd, off_t upos, void **res) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp = NULL; struct vnode *vp; vm_offset_t addr; vm_size_t size, pageoff; vm_prot_t prot, maxprot; void *handle; int flags, error; int disablexworkaround; off_t pos; vm_object_t obj; KKASSERT(p); addr = (vm_offset_t) uaddr; size = ulen; prot = uprot & VM_PROT_ALL; flags = uflags; pos = upos; /* make sure mapping fits into numeric range etc */ if ((ssize_t) ulen < 0 || ((flags & MAP_ANON) && fd != -1)) return (EINVAL); if (flags & MAP_STACK) { if ((fd != -1) || ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE))) return (EINVAL); flags |= MAP_ANON; pos = 0; } /* * Virtual page tables cannot be used with MAP_STACK. Apart from * it not making any sense, the aux union is used by both * types. * * Because the virtual page table is stored in the backing object * and might be updated by the kernel, the mapping must be R+W. */ if (flags & MAP_VPAGETABLE) { if (vkernel_enable == 0) return (EOPNOTSUPP); if (flags & MAP_STACK) return (EINVAL); if ((prot & (PROT_READ|PROT_WRITE)) != (PROT_READ|PROT_WRITE)) return (EINVAL); } /* * Align the file position to a page boundary, * and save its page offset component. */ pageoff = (pos & PAGE_MASK); pos -= pageoff; /* Adjust size for rounding (on both ends). */ size += pageoff; /* low end... */ size = (vm_size_t) round_page(size); /* hi end */ /* * Check for illegal addresses. Watch out for address wrap... Note * that VM_*_ADDRESS are not constants due to casts (argh). */ if (flags & MAP_FIXED) { /* * The specified address must have the same remainder * as the file offset taken modulo PAGE_SIZE, so it * should be aligned after adjustment by pageoff. */ addr -= pageoff; if (addr & PAGE_MASK) return (EINVAL); /* Address range must be all in user VM space. */ if (VM_MAX_USER_ADDRESS > 0 && addr + size > VM_MAX_USER_ADDRESS) return (EINVAL); if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS) return (EINVAL); if (addr + size < addr) return (EINVAL); } /* * XXX for non-fixed mappings where no hint is provided or * the hint would fall in the potential heap space, * place it after the end of the largest possible heap. * * There should really be a pmap call to determine a reasonable * location. */ else if (addr == 0 || (addr >= round_page((vm_offset_t)vms->vm_taddr) && addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); if (flags & MAP_ANON) { /* * Mapping blank space is trivial. */ handle = NULL; maxprot = VM_PROT_ALL; pos = 0; } else { /* * Mapping file, get fp for validation. Obtain vnode and make * sure it is of appropriate type. */ fp = holdfp(p->p_fd, fd, -1); if (fp == NULL) return (EBADF); if (fp->f_type != DTYPE_VNODE) { error = EINVAL; goto done; } /* * POSIX shared-memory objects are defined to have * kernel persistence, and are not defined to support * read(2)/write(2) -- or even open(2). Thus, we can * use MAP_ASYNC to trade on-disk coherence for speed. * The shm_open(3) library routine turns on the FPOSIXSHM * flag to request this behavior. */ if (fp->f_flag & FPOSIXSHM) flags |= MAP_NOSYNC; vp = (struct vnode *) fp->f_data; /* * Validate the vnode for the operation. */ switch(vp->v_type) { case VREG: /* * Get the proper underlying object */ if ((obj = vp->v_object) == NULL) { error = EINVAL; goto done; } KKASSERT((struct vnode *)obj->handle == vp); break; case VCHR: /* * Make sure a device has not been revoked. * Mappability is handled by the device layer. */ if (vp->v_rdev == NULL) { error = EBADF; goto done; } break; default: /* * Nothing else is mappable. */ error = EINVAL; goto done; } /* * XXX hack to handle use of /dev/zero to map anon memory (ala * SunOS). */ if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) { handle = NULL; maxprot = VM_PROT_ALL; flags |= MAP_ANON; pos = 0; } else { /* * cdevs does not provide private mappings of any kind. */ /* * However, for XIG X server to continue to work, * we should allow the superuser to do it anyway. * We only allow it at securelevel < 1. * (Because the XIG X server writes directly to video * memory via /dev/mem, it should never work at any * other securelevel. * XXX this will have to go */ if (securelevel >= 1) disablexworkaround = 1; else disablexworkaround = suser(td); if (vp->v_type == VCHR && disablexworkaround && (flags & (MAP_PRIVATE|MAP_COPY))) { error = EINVAL; goto done; } /* * Ensure that file and memory protections are * compatible. Note that we only worry about * writability if mapping is shared; in this case, * current and max prot are dictated by the open file. * XXX use the vnode instead? Problem is: what * credentials do we use for determination? What if * proc does a setuid? */ maxprot = VM_PROT_EXECUTE; /* ??? */ if (fp->f_flag & FREAD) { maxprot |= VM_PROT_READ; } else if (prot & PROT_READ) { error = EACCES; goto done; } /* * If we are sharing potential changes (either via * MAP_SHARED or via the implicit sharing of character * device mappings), and we are trying to get write * permission although we opened it without asking * for it, bail out. Check for superuser, only if * we're at securelevel < 1, to allow the XIG X server * to continue to work. */ if ((flags & MAP_SHARED) != 0 || (vp->v_type == VCHR && disablexworkaround)) { if ((fp->f_flag & FWRITE) != 0) { struct vattr va; if ((error = VOP_GETATTR(vp, &va))) { goto done; } if ((va.va_flags & (IMMUTABLE|APPEND)) == 0) { maxprot |= VM_PROT_WRITE; } else if (prot & PROT_WRITE) { error = EPERM; goto done; } } else if ((prot & PROT_WRITE) != 0) { error = EACCES; goto done; } } else { maxprot |= VM_PROT_WRITE; } handle = (void *)vp; } } /* * Do not allow more then a certain number of vm_map_entry structures * per process. Scale with the number of rforks sharing the map * to make the limit reasonable for threads. */ if (max_proc_mmap && vms->vm_map.nentries >= max_proc_mmap * vms->vm_sysref.refcnt) { error = ENOMEM; goto done; } error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, flags, handle, pos); if (error == 0) *res = (void *)(addr + pageoff); done: if (fp) fdrop(fp); return (error); } int sys_mmap(struct mmap_args *uap) { int error; error = kern_mmap(curproc->p_vmspace, uap->addr, uap->len, uap->prot, uap->flags, uap->fd, uap->pos, &uap->sysmsg_resultp); return (error); } /* * msync_args(void *addr, int len, int flags) */ int sys_msync(struct msync_args *uap) { struct proc *p = curproc; vm_offset_t addr; vm_size_t size, pageoff; int flags; vm_map_t map; int rv; addr = (vm_offset_t) uap->addr; size = uap->len; flags = uap->flags; pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if (addr + size < addr) return(EINVAL); if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE)) return (EINVAL); map = &p->p_vmspace->vm_map; /* * XXX Gak! If size is zero we are supposed to sync "all modified * pages with the region containing addr". Unfortunately, we don't * really keep track of individual mmaps so we approximate by flushing * the range of the map entry containing addr. This can be incorrect * if the region splits or is coalesced with a neighbor. */ if (size == 0) { vm_map_entry_t entry; vm_map_lock_read(map); rv = vm_map_lookup_entry(map, addr, &entry); vm_map_unlock_read(map); if (rv == FALSE) return (EINVAL); addr = entry->start; size = entry->end - entry->start; } /* * Clean the pages and interpret the return value. */ rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0, (flags & MS_INVALIDATE) != 0); switch (rv) { case KERN_SUCCESS: break; case KERN_INVALID_ADDRESS: return (EINVAL); /* Sun returns ENOMEM? */ case KERN_FAILURE: return (EIO); default: return (EINVAL); } return (0); } /* * munmap_args(void *addr, size_t len) */ int sys_munmap(struct munmap_args *uap) { struct proc *p = curproc; vm_offset_t addr; vm_size_t size, pageoff; vm_map_t map; addr = (vm_offset_t) uap->addr; size = uap->len; pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if (addr + size < addr) return(EINVAL); if (size == 0) return (0); /* * Check for illegal addresses. Watch out for address wrap... Note * that VM_*_ADDRESS are not constants due to casts (argh). */ if (VM_MAX_USER_ADDRESS > 0 && addr + size > VM_MAX_USER_ADDRESS) return (EINVAL); if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS) return (EINVAL); map = &p->p_vmspace->vm_map; /* * Make sure entire range is allocated. */ if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) return (EINVAL); /* returns nothing but KERN_SUCCESS anyway */ vm_map_remove(map, addr, addr + size); return (0); } /* * mprotect_args(const void *addr, size_t len, int prot) */ int sys_mprotect(struct mprotect_args *uap) { struct proc *p = curproc; vm_offset_t addr; vm_size_t size, pageoff; vm_prot_t prot; addr = (vm_offset_t) uap->addr; size = uap->len; prot = uap->prot & VM_PROT_ALL; #if defined(VM_PROT_READ_IS_EXEC) if (prot & VM_PROT_READ) prot |= VM_PROT_EXECUTE; #endif pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if (addr + size < addr) return(EINVAL); switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot, FALSE)) { case KERN_SUCCESS: return (0); case KERN_PROTECTION_FAILURE: return (EACCES); } return (EINVAL); } /* * minherit_args(void *addr, size_t len, int inherit) */ int sys_minherit(struct minherit_args *uap) { struct proc *p = curproc; vm_offset_t addr; vm_size_t size, pageoff; vm_inherit_t inherit; addr = (vm_offset_t)uap->addr; size = uap->len; inherit = uap->inherit; pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if (addr + size < addr) return(EINVAL); switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size, inherit)) { case KERN_SUCCESS: return (0); case KERN_PROTECTION_FAILURE: return (EACCES); } return (EINVAL); } /* * madvise_args(void *addr, size_t len, int behav) */ /* ARGSUSED */ int sys_madvise(struct madvise_args *uap) { struct proc *p = curproc; vm_offset_t start, end; /* * Check for illegal behavior */ if (uap->behav < 0 || uap->behav >= MADV_CONTROL_END) return (EINVAL); /* * Check for illegal addresses. Watch out for address wrap... Note * that VM_*_ADDRESS are not constants due to casts (argh). */ if (VM_MAX_USER_ADDRESS > 0 && ((vm_offset_t) uap->addr + uap->len) > VM_MAX_USER_ADDRESS) return (EINVAL); if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS) return (EINVAL); if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) return (EINVAL); /* * Since this routine is only advisory, we default to conservative * behavior. */ start = trunc_page((vm_offset_t) uap->addr); end = round_page((vm_offset_t) uap->addr + uap->len); return (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav, 0)); } /* * mcontrol_args(void *addr, size_t len, int behav, off_t value) */ /* ARGSUSED */ int sys_mcontrol(struct mcontrol_args *uap) { struct proc *p = curproc; vm_offset_t start, end; /* * Check for illegal behavior */ if (uap->behav < 0 || uap->behav > MADV_CONTROL_END) return (EINVAL); /* * Check for illegal addresses. Watch out for address wrap... Note * that VM_*_ADDRESS are not constants due to casts (argh). */ if (VM_MAX_USER_ADDRESS > 0 && ((vm_offset_t) uap->addr + uap->len) > VM_MAX_USER_ADDRESS) return (EINVAL); if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS) return (EINVAL); if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) return (EINVAL); /* * Since this routine is only advisory, we default to conservative * behavior. */ start = trunc_page((vm_offset_t) uap->addr); end = round_page((vm_offset_t) uap->addr + uap->len); return (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav, uap->value)); } /* * mincore_args(const void *addr, size_t len, char *vec) */ /* ARGSUSED */ int sys_mincore(struct mincore_args *uap) { struct proc *p = curproc; vm_offset_t addr, first_addr; vm_offset_t end, cend; pmap_t pmap; vm_map_t map; char *vec; int error; int vecindex, lastvecindex; vm_map_entry_t current; vm_map_entry_t entry; int mincoreinfo; unsigned int timestamp; /* * Make sure that the addresses presented are valid for user * mode. */ first_addr = addr = trunc_page((vm_offset_t) uap->addr); end = addr + (vm_size_t)round_page(uap->len); if (VM_MAX_USER_ADDRESS > 0 && end > VM_MAX_USER_ADDRESS) return (EINVAL); if (end < addr) return (EINVAL); /* * Address of byte vector */ vec = uap->vec; map = &p->p_vmspace->vm_map; pmap = vmspace_pmap(p->p_vmspace); vm_map_lock_read(map); RestartScan: timestamp = map->timestamp; if (!vm_map_lookup_entry(map, addr, &entry)) entry = entry->next; /* * Do this on a map entry basis so that if the pages are not * in the current processes address space, we can easily look * up the pages elsewhere. */ lastvecindex = -1; for(current = entry; (current != &map->header) && (current->start < end); current = current->next) { /* * ignore submaps (for now) or null objects */ if (current->maptype != VM_MAPTYPE_NORMAL && current->maptype != VM_MAPTYPE_VPAGETABLE) { continue; } if (current->object.vm_object == NULL) continue; /* * limit this scan to the current map entry and the * limits for the mincore call */ if (addr < current->start) addr = current->start; cend = current->end; if (cend > end) cend = end; /* * scan this entry one page at a time */ while (addr < cend) { /* * Check pmap first, it is likely faster, also * it can provide info as to whether we are the * one referencing or modifying the page. * * If we have to check the VM object, only mess * around with normal maps. Do not mess around * with virtual page tables (XXX). */ mincoreinfo = pmap_mincore(pmap, addr); if (mincoreinfo == 0 && current->maptype == VM_MAPTYPE_NORMAL) { vm_pindex_t pindex; vm_ooffset_t offset; vm_page_t m; /* * calculate the page index into the object */ offset = current->offset + (addr - current->start); pindex = OFF_TO_IDX(offset); /* * if the page is resident, then gather * information about it. spl protection is * required to maintain the object * association. And XXX what if the page is * busy? What's the deal with that? */ crit_enter(); m = vm_page_lookup(current->object.vm_object, pindex); if (m && m->valid) { mincoreinfo = MINCORE_INCORE; if (m->dirty || pmap_is_modified(m)) mincoreinfo |= MINCORE_MODIFIED_OTHER; if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) { vm_page_flag_set(m, PG_REFERENCED); mincoreinfo |= MINCORE_REFERENCED_OTHER; } } crit_exit(); } /* * subyte may page fault. In case it needs to modify * the map, we release the lock. */ vm_map_unlock_read(map); /* * calculate index into user supplied byte vector */ vecindex = OFF_TO_IDX(addr - first_addr); /* * If we have skipped map entries, we need to make sure that * the byte vector is zeroed for those skipped entries. */ while((lastvecindex + 1) < vecindex) { error = subyte( vec + lastvecindex, 0); if (error) { return (EFAULT); } ++lastvecindex; } /* * Pass the page information to the user */ error = subyte( vec + vecindex, mincoreinfo); if (error) { return (EFAULT); } /* * If the map has changed, due to the subyte, the previous * output may be invalid. */ vm_map_lock_read(map); if (timestamp != map->timestamp) goto RestartScan; lastvecindex = vecindex; addr += PAGE_SIZE; } } /* * subyte may page fault. In case it needs to modify * the map, we release the lock. */ vm_map_unlock_read(map); /* * Zero the last entries in the byte vector. */ vecindex = OFF_TO_IDX(end - first_addr); while((lastvecindex + 1) < vecindex) { error = subyte( vec + lastvecindex, 0); if (error) { return (EFAULT); } ++lastvecindex; } /* * If the map has changed, due to the subyte, the previous * output may be invalid. */ vm_map_lock_read(map); if (timestamp != map->timestamp) goto RestartScan; vm_map_unlock_read(map); return (0); } /* * mlock_args(const void *addr, size_t len) */ int sys_mlock(struct mlock_args *uap) { vm_offset_t addr; vm_size_t size, pageoff; int error; struct proc *p = curproc; addr = (vm_offset_t) uap->addr; size = uap->len; pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); /* disable wrap around */ if (addr + size < addr) return (EINVAL); if (atop(size) + vmstats.v_wire_count > vm_page_max_wired) return (EAGAIN); #ifdef pmap_wired_count if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) > p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur) return (ENOMEM); #else error = suser_cred(p->p_ucred, 0); if (error) return (error); #endif error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE); return (error == KERN_SUCCESS ? 0 : ENOMEM); } /* * mlockall_args(int how) */ int sys_mlockall(struct mlockall_args *uap) { return 0; } /* * munlockall_args(void) */ int sys_munlockall(struct munlockall_args *uap) { return 0; } /* * munlock_args(const void *addr, size_t len) */ int sys_munlock(struct munlock_args *uap) { struct thread *td = curthread; struct proc *p = td->td_proc; vm_offset_t addr; vm_size_t size, pageoff; int error; addr = (vm_offset_t) uap->addr; size = uap->len; pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); /* disable wrap around */ if (addr + size < addr) return (EINVAL); #ifndef pmap_wired_count error = suser(td); if (error) return (error); #endif error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE); return (error == KERN_SUCCESS ? 0 : ENOMEM); } /* * Internal version of mmap. * Currently used by mmap, exec, and sys5 shared memory. * Handle is either a vnode pointer or NULL for MAP_ANON. */ int vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, vm_prot_t maxprot, int flags, void *handle, vm_ooffset_t foff) { boolean_t fitit; vm_object_t object; struct vnode *vp = NULL; struct proc *p; objtype_t type; int rv = KERN_SUCCESS; off_t objsize; int docow; if (size == 0) return (0); objsize = size = round_page(size); /* * XXX messy code, fixme */ if ((p = curproc) != NULL && map == &p->p_vmspace->vm_map) { if (map->size + size > p->p_rlimit[RLIMIT_VMEM].rlim_cur) return(ENOMEM); } /* * We currently can only deal with page aligned file offsets. * The check is here rather than in the syscall because the * kernel calls this function internally for other mmaping * operations (such as in exec) and non-aligned offsets will * cause pmap inconsistencies...so we want to be sure to * disallow this in all cases. */ if (foff & PAGE_MASK) return (EINVAL); if ((flags & MAP_FIXED) == 0) { fitit = TRUE; *addr = round_page(*addr); } else { if (*addr != trunc_page(*addr)) return (EINVAL); fitit = FALSE; vm_map_remove(map, *addr, *addr + size); } /* * Lookup/allocate object. */ if (flags & MAP_ANON) { type = OBJT_DEFAULT; /* * Unnamed anonymous regions always start at 0. */ if (handle == 0) foff = 0; } else { vp = (struct vnode *) handle; if (vp->v_type == VCHR) { type = OBJT_DEVICE; handle = (void *)(intptr_t)vp->v_rdev; } else { struct vattr vat; int error; error = VOP_GETATTR(vp, &vat); if (error) return (error); objsize = vat.va_size; type = OBJT_VNODE; /* * if it is a regular file without any references * we do not need to sync it. */ if (vp->v_type == VREG && vat.va_nlink == 0) { flags |= MAP_NOSYNC; } } } if (handle == NULL) { object = NULL; docow = 0; } else { object = vm_pager_allocate(type, handle, objsize, prot, foff); if (object == NULL) return (type == OBJT_DEVICE ? EINVAL : ENOMEM); docow = MAP_PREFAULT_PARTIAL; } /* * Force device mappings to be shared. */ if (type == OBJT_DEVICE || type == OBJT_PHYS) { flags &= ~(MAP_PRIVATE|MAP_COPY); flags |= MAP_SHARED; } if ((flags & (MAP_ANON|MAP_SHARED)) == 0) docow |= MAP_COPY_ON_WRITE; if (flags & MAP_NOSYNC) docow |= MAP_DISABLE_SYNCER; if (flags & MAP_NOCORE) docow |= MAP_DISABLE_COREDUMP; #if defined(VM_PROT_READ_IS_EXEC) if (prot & VM_PROT_READ) prot |= VM_PROT_EXECUTE; if (maxprot & VM_PROT_READ) maxprot |= VM_PROT_EXECUTE; #endif if (fitit) { *addr = pmap_addr_hint(object, *addr, size); } /* * Stack mappings need special attention. Mappings that use virtual * page tables will default to storing the page table at offset 0. */ if (flags & MAP_STACK) { rv = vm_map_stack (map, *addr, size, prot, maxprot, docow); } else if (flags & MAP_VPAGETABLE) { rv = vm_map_find(map, object, foff, addr, size, fitit, VM_MAPTYPE_VPAGETABLE, prot, maxprot, docow); } else { rv = vm_map_find(map, object, foff, addr, size, fitit, VM_MAPTYPE_NORMAL, prot, maxprot, docow); } if (rv != KERN_SUCCESS) { /* * Lose the object reference. Will destroy the * object if it's an unnamed anonymous mapping * or named anonymous without other references. */ vm_object_deallocate(object); goto out; } /* * Shared memory is also shared with children. */ if (flags & (MAP_SHARED|MAP_INHERIT)) { rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE); if (rv != KERN_SUCCESS) { vm_map_remove(map, *addr, *addr + size); goto out; } } out: switch (rv) { case KERN_SUCCESS: return (0); case KERN_INVALID_ADDRESS: case KERN_NO_SPACE: return (ENOMEM); case KERN_PROTECTION_FAILURE: return (EACCES); default: return (EINVAL); } }