/* $NetBSD: vm_mmap.c,v 1.57 1998/05/10 12:35:58 mrg Exp $ */ /* * 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 8.10 (Berkeley) 2/19/95 */ /* * Mapped file (mmap) interface to VM */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG int mmapdebug = 0; #define MDB_FOLLOW 0x01 #define MDB_SYNC 0x02 #define MDB_MAPIT 0x04 #endif /* ARGSUSED */ int sys_sbrk(p, v, retval) struct proc *p; void *v; register_t *retval; { #if 0 struct sys_sbrk_args /* { syscallarg(int) incr; } */ *uap = v; #endif /* Not yet implemented */ return (EOPNOTSUPP); } /* ARGSUSED */ int sys_sstk(p, v, retval) struct proc *p; void *v; register_t *retval; { #if 0 struct sys_sstk_args /* { syscallarg(int) incr; } */ *uap = v; #endif /* Not yet implemented */ return (EOPNOTSUPP); } /* * 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. */ int sys_mmap(p, v, retval) struct proc *p; void *v; register_t *retval; { register struct sys_mmap_args /* { syscallarg(void *) addr; syscallarg(size_t) len; syscallarg(int) prot; syscallarg(int) flags; syscallarg(int) fd; syscallarg(long) pad; syscallarg(off_t) pos; } */ *uap = v; struct vattr va; register struct filedesc *fdp = p->p_fd; register struct file *fp; struct vnode *vp; vm_offset_t addr; off_t pos; vm_size_t size, pageoff; vm_prot_t prot, maxprot; caddr_t handle; int fd, flags, error; vm_offset_t vm_min_address = VM_MIN_ADDRESS; addr = (vm_offset_t) SCARG(uap, addr); size = (vm_size_t) SCARG(uap, len); prot = SCARG(uap, prot) & VM_PROT_ALL; flags = SCARG(uap, flags); fd = SCARG(uap, fd); pos = SCARG(uap, pos); #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("mmap(%d): addr %lx len %lx pro %x flg %x fd %d pos %qx\n", p->p_pid, addr, size, prot, flags, fd, pos); #endif /* make sure mapping fits into numeric range */ if (pos + size > (vm_offset_t)-PAGE_SIZE) { #ifdef DEBUG printf("mmap: pos=%qx, size=%lx too big\n", pos, size); #endif 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 */ /* Do not allow mappings that cause address wrap... */ if ((ssize_t)size < 0) return (EINVAL); /* * 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_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS) return (EINVAL); if (vm_min_address > 0 && addr < vm_min_address) return (EINVAL); if (addr > addr + size) 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. (To avoid VA cache alias problems, for example!) */ else if (addr < round_page(p->p_vmspace->vm_daddr + MAXDSIZ)) addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ); if ((flags & MAP_ANON) == 0) { /* * Mapping file, get fp for validation. * Obtain vnode and make sure it is of appropriate type. */ if (((unsigned)fd) >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) return (EBADF); if (fp->f_type != DTYPE_VNODE) return (ENODEV); vp = (struct vnode *)fp->f_data; if (vp->v_type != VREG && vp->v_type != VCHR) return (ENODEV); /* * XXX hack to handle use of /dev/zero to map anon * memory (ala SunOS). */ if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) { flags |= MAP_ANON; goto is_anon; } /* * Old programs may not select a specific sharing type, so * default to an appropriate one. */ if ((flags & (MAP_SHARED|MAP_PRIVATE|MAP_COPY)) == 0) { if (vp->v_type == VCHR) flags |= MAP_SHARED; /* for a device */ else flags |= MAP_PRIVATE; /* for a file */ } /* * MAP_PRIVATE device mappings don't make sense (and aren't * supported anyway). However, some programs rely on this, * so just change it to MAP_SHARED. */ if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) flags = (flags & ~MAP_PRIVATE) | MAP_SHARED; /* * 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) return (EACCES); if (flags & MAP_SHARED) { /* * if the file is writable, only add PROT_WRITE to * maxprot if the file is not immutable, append-only. * otherwise, if we have asked for PROT_WRITE, return * EPERM. */ if (fp->f_flag & FWRITE) { if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p))) return (error); if ((va.va_flags & (IMMUTABLE|APPEND)) == 0) maxprot |= VM_PROT_WRITE; else if (prot & PROT_WRITE) return (EPERM); } else if (prot & PROT_WRITE) return (EACCES); } else maxprot |= VM_PROT_WRITE; handle = (caddr_t)vp; } else { /* * (flags & MAP_ANON) == TRUE * Mapping blank space is trivial. */ if (fd != -1) return (EINVAL); is_anon: handle = NULL; maxprot = VM_PROT_ALL; pos = 0; } error = vm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot, flags, handle, pos); if (error == 0) *retval = (register_t)(addr + pageoff); return (error); } int sys___msync13(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys___msync13_args /* { syscallarg(void *) addr; syscallarg(size_t) len; syscallarg(int) flags; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; vm_map_t map; int rv, flags; boolean_t syncio, invalidate; addr = (vm_offset_t)SCARG(uap, addr); size = (vm_size_t)SCARG(uap, len); flags = SCARG(uap, flags); #ifdef DEBUG if (mmapdebug & (MDB_FOLLOW|MDB_SYNC)) printf("msync(%d): addr %lx len %lx flags %x\n", p->p_pid, addr, size, flags); #endif /* sanity check flags */ if ((flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE)) != 0 || (flags & (MS_ASYNC | MS_SYNC | MS_INVALIDATE)) == 0 || (flags & (MS_ASYNC | MS_SYNC)) == (MS_ASYNC | MS_SYNC)) return (EINVAL); if ((flags & (MS_ASYNC | MS_SYNC)) == 0) flags |= MS_SYNC; /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); /* Disallow wrap-around. */ if (addr + size < addr) return (ENOMEM); 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 (ENOMEM); addr = entry->start; size = entry->end - entry->start; } #ifdef DEBUG if (mmapdebug & MDB_SYNC) printf("msync: cleaning/flushing address range [%lx-%lx)\n", addr, addr+size); #endif #if 0 /* * XXX Asynchronous msync() causes: * . the process to hang on wchan "vospgw", and * . a "vm_object_page_clean: pager_put error" message to * be printed by the kernel. */ syncio = (flags & MS_SYNC) ? TRUE : FALSE; #else syncio = TRUE; #endif invalidate = (flags & MS_INVALIDATE) ? TRUE : FALSE; /* * Clean the pages and interpret the return value. */ rv = vm_map_clean(map, addr, addr+size, syncio, invalidate); switch (rv) { case KERN_SUCCESS: break; case KERN_INVALID_ADDRESS: return (ENOMEM); case KERN_FAILURE: return (EIO); case KERN_PAGES_LOCKED: return (EBUSY); default: return (EINVAL); } return (0); } int sys_munmap(p, v, retval) register struct proc *p; void *v; register_t *retval; { register struct sys_munmap_args /* { syscallarg(void *) addr; syscallarg(size_t) len; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; vm_map_t map; vm_offset_t vm_min_address = VM_MIN_ADDRESS; addr = (vm_offset_t) SCARG(uap, addr); size = (vm_size_t) SCARG(uap, len); #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("munmap(%d): addr %lx len %lx\n", p->p_pid, addr, size); #endif /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if ((int)size < 0) 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_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS) return (EINVAL); if (vm_min_address > 0 && addr < vm_min_address) return (EINVAL); if (addr > addr + size) return (EINVAL); map = &p->p_vmspace->vm_map; #if 0 /* * Make sure entire range is allocated. * XXX Too strict? */ if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) return(EINVAL); #endif /* returns nothing but KERN_SUCCESS anyway */ (void) vm_map_remove(map, addr, addr+size); return(0); } void munmapfd(p, fd) struct proc *p; int fd; { #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("munmapfd(%d): fd %d\n", p->p_pid, fd); #endif /* * XXX should vm_deallocate any regions mapped to this file */ p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED; } int sys_mprotect(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_mprotect_args /* { syscallarg(void *) addr; syscallarg(int) len; syscallarg(int) prot; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; register vm_prot_t prot; addr = (vm_offset_t)SCARG(uap, addr); size = (vm_size_t)SCARG(uap, len); prot = SCARG(uap, prot) & VM_PROT_ALL; #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("mprotect(%d): addr %lx len %lx prot %d\n", p->p_pid, addr, size, prot); #endif /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if ((int)size < 0) 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); } int sys_minherit(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_minherit_args /* { syscallarg(void *) addr; syscallarg(int) len; syscallarg(int) inherit; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; register vm_inherit_t inherit; addr = (vm_offset_t)SCARG(uap, addr); size = (vm_size_t)SCARG(uap, len); inherit = SCARG(uap, inherit); #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("minherit(%d): addr 0x%lx len %lx inherit %d\n", p->p_pid, addr, size, inherit); #endif /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if ((int)size < 0) 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); } /* ARGSUSED */ int sys_madvise(p, v, retval) struct proc *p; void *v; register_t *retval; { #if 0 struct sys_madvise_args /* { syscallarg(void *) addr; syscallarg(size_t) len; syscallarg(int) behav; } */ *uap = v; #endif /* Not yet implemented */ return (EOPNOTSUPP); } /* ARGSUSED */ int sys_mincore(p, v, retval) struct proc *p; void *v; register_t *retval; { #if 0 struct sys_mincore_args /* { syscallarg(void *) addr; syscallarg(size_t) len; syscallarg(char *) vec; } */ *uap = v; #endif /* Not yet implemented */ return (EOPNOTSUPP); } int sys_mlock(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_mlock_args /* { syscallarg(void *) addr; syscallarg(size_t) len; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; int error; extern int vm_page_max_wired; addr = (vm_offset_t)SCARG(uap, addr); size = (vm_size_t)SCARG(uap, len); #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("mlock(%d): addr %lx len %lx\n", p->p_pid, addr, size); #endif /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); /* Disallow wrap-around. */ if (addr + (int)size < addr) return (EINVAL); if (atop(size) + cnt.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 (EAGAIN); #else if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) return (error); #endif error = vm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, FALSE); return (error == KERN_SUCCESS ? 0 : ENOMEM); } int sys_munlock(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_munlock_args /* { syscallarg(void *) addr; syscallarg(size_t) len; } */ *uap = v; vm_offset_t addr; vm_size_t size, pageoff; int error; addr = (vm_offset_t)SCARG(uap, addr); size = (vm_size_t)SCARG(uap, len); #ifdef DEBUG if (mmapdebug & MDB_FOLLOW) printf("munlock(%d): addr %lx len %lx\n", p->p_pid, addr, size); #endif /* * Align the address to a page boundary, * and adjust the size accordingly. */ pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); /* Disallow wrap-around. */ if (addr + (int)size < addr) return (EINVAL); #ifndef pmap_wired_count if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) return (error); #endif error = vm_map_pageable(&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. * This (internal) interface requires the file offset to be * page-aligned by the caller. (Also addr, if MAP_FIXED). */ int vm_mmap(map, addr, size, prot, maxprot, flags, handle, foff) register vm_map_t map; register vm_offset_t *addr; register vm_size_t size; vm_prot_t prot, maxprot; register int flags; caddr_t handle; /* XXX should be vp */ vm_offset_t foff; { register vm_pager_t pager; boolean_t fitit; vm_object_t object; struct vnode *vp = NULL; int type; int rv = KERN_SUCCESS; if (size == 0) return (0); /* The file offset must be page aligned. */ if (foff & PAGE_MASK) return (EINVAL); if ((flags & MAP_FIXED) == 0) { /* The address is just a hint */ fitit = TRUE; *addr = round_page(*addr); } else { /* * Use the specified address exactly * (but check alignment first). */ fitit = FALSE; if (*addr & PAGE_MASK) return (EINVAL); (void)vm_deallocate(map, *addr, size); } /* * Lookup/allocate pager. All except an unnamed anonymous lookup * gain a reference to ensure continued existance of the object. * (XXX the exception is to appease the pageout daemon) */ if (flags & MAP_ANON) { type = PG_DFLT; foff = 0; } else { vp = (struct vnode *)handle; if (vp->v_type == VCHR) { type = PG_DEVICE; handle = (caddr_t)(long)vp->v_rdev; } else type = PG_VNODE; } pager = vm_pager_allocate(type, handle, size, prot, foff); if (pager == NULL) return (type == PG_DEVICE ? EINVAL : ENOMEM); /* * Find object and release extra reference gained by lookup */ object = vm_object_lookup(pager); vm_object_deallocate(object); /* * Anonymous memory. */ if (flags & MAP_ANON) { rv = vm_allocate_with_pager(map, addr, size, fitit, pager, foff, TRUE); if (rv != KERN_SUCCESS) { if (handle == NULL) vm_pager_deallocate(pager); else vm_object_deallocate(object); goto out; } /* * Don't cache anonymous objects. * Loses the reference gained by vm_pager_allocate. * Note that object will be NULL when handle == NULL, * this is ok since vm_allocate_with_pager has made * sure that these objects are uncached. */ (void) pager_cache(object, FALSE); #ifdef DEBUG if (mmapdebug & MDB_MAPIT) printf("vm_mmap(%d): ANON *addr %lx size %lx pager %p\n", curproc->p_pid, *addr, size, pager); #endif } /* * Must be a mapped file. * Distinguish between character special and regular files. */ else if (vp->v_type == VCHR) { rv = vm_allocate_with_pager(map, addr, size, fitit, pager, foff, FALSE); /* * Uncache the object and lose the reference gained * by vm_pager_allocate(). If the call to * vm_allocate_with_pager() was sucessful, then we * gained an additional reference ensuring the object * will continue to exist. If the call failed then * the deallocate call below will terminate the * object which is fine. */ (void) pager_cache(object, FALSE); if (rv != KERN_SUCCESS) goto out; } /* * A regular file */ else { #ifdef DEBUG if (object == NULL) printf("vm_mmap: no object: vp %p, pager %p\n", vp, pager); #endif /* * Map it directly. * Allows modifications to go out to the vnode. */ if (flags & MAP_SHARED) { rv = vm_allocate_with_pager(map, addr, size, fitit, pager, foff, FALSE); if (rv != KERN_SUCCESS) { vm_object_deallocate(object); goto out; } /* * Don't cache the object. This is the easiest way * of ensuring that data gets back to the filesystem * because vnode_pager_deallocate() will fsync the * vnode. pager_cache() will lose the extra ref. */ if (prot & VM_PROT_WRITE) pager_cache(object, FALSE); else vm_object_deallocate(object); } /* * Copy-on-write of file. Two flavors. * MAP_COPY is true COW, you essentially get a snapshot of * the region at the time of mapping. MAP_PRIVATE means only * that your changes are not reflected back to the object. * Changes made by others will be seen. */ else { vm_map_t tmap; vm_offset_t off; /* locate and allocate the target address space */ vm_map_lock(map); if (fitit) { /* * Find space in the map at a location * that is compatible with the object/offset * we're going to attach there. */ again: if (vm_map_findspace(map, *addr, size, addr) == 1) { rv = KERN_NO_SPACE; } else { #ifdef PMAP_PREFER PMAP_PREFER(foff, addr); #endif rv = vm_map_insert(map, NULL, (vm_offset_t)0, *addr, *addr+size); /* * vm_map_insert() may fail if * PMAP_PREFER() has altered * the initial address. * If so, we start again. */ if (rv == KERN_NO_SPACE) goto again; } } else { rv = vm_map_insert(map, NULL, (vm_offset_t)0, *addr, *addr + size); #ifdef DEBUG /* * Check against PMAP preferred address. If * there's a mismatch, these pages should not * be shared with others. */ if (rv == KERN_SUCCESS && (mmapdebug & MDB_MAPIT)) { vm_offset_t paddr = *addr; #ifdef PMAP_PREFER PMAP_PREFER(foff, &paddr); #endif if (paddr != *addr) printf( "vm_mmap: pmap botch! " "[foff %lx, addr %lx, paddr %lx]\n", foff, *addr, paddr); } #endif } vm_map_unlock(map); if (rv != KERN_SUCCESS) { vm_object_deallocate(object); goto out; } tmap = vm_map_create(pmap_create(size), VM_MIN_ADDRESS, VM_MIN_ADDRESS+size, TRUE); off = VM_MIN_ADDRESS; rv = vm_allocate_with_pager(tmap, &off, size, FALSE, pager, foff, FALSE); if (rv != KERN_SUCCESS) { vm_object_deallocate(object); vm_map_deallocate(tmap); goto out; } /* * (XXX) * MAP_PRIVATE implies that we see changes made by * others. To ensure that we need to guarentee that * no copy object is created (otherwise original * pages would be pushed to the copy object and we * would never see changes made by others). We * totally sleeze it right now by marking the object * internal temporarily. */ if ((flags & MAP_COPY) == 0) object->flags |= OBJ_INTERNAL; rv = vm_map_copy(map, tmap, *addr, size, off, FALSE, FALSE); object->flags &= ~OBJ_INTERNAL; /* * (XXX) * My oh my, this only gets worse... * Force creation of a shadow object so that * vm_map_fork will do the right thing. */ if ((flags & MAP_COPY) == 0) { vm_map_t tmap; vm_map_entry_t tentry; vm_object_t tobject; vm_offset_t toffset; vm_prot_t tprot; boolean_t twired, tsu; tmap = map; vm_map_lookup(&tmap, *addr, VM_PROT_WRITE, &tentry, &tobject, &toffset, &tprot, &twired, &tsu); vm_map_lookup_done(tmap, tentry); } /* * (XXX) * Map copy code cannot detect sharing unless a * sharing map is involved. So we cheat and write * protect everything ourselves. */ vm_object_pmap_copy(object, foff, foff + size); vm_object_deallocate(object); vm_map_deallocate(tmap); if (rv != KERN_SUCCESS) goto out; } #ifdef DEBUG if (mmapdebug & MDB_MAPIT) printf("vm_mmap(%d): FILE *addr %lx size %lx pager %p\n", curproc->p_pid, *addr, size, pager); #endif } /* * Correct protection (default is VM_PROT_ALL). * If maxprot is different than prot, we must set both explicitly. */ rv = KERN_SUCCESS; if (maxprot != VM_PROT_ALL) rv = vm_map_protect(map, *addr, *addr+size, maxprot, TRUE); if (rv == KERN_SUCCESS && prot != maxprot) rv = vm_map_protect(map, *addr, *addr+size, prot, FALSE); if (rv != KERN_SUCCESS) { (void) vm_deallocate(map, *addr, size); goto out; } /* * Shared memory is also shared with children. */ if (flags & MAP_SHARED) { rv = vm_map_inherit(map, *addr, *addr+size, VM_INHERIT_SHARE); if (rv != KERN_SUCCESS) { (void) vm_deallocate(map, *addr, size); goto out; } } out: #ifdef DEBUG if (mmapdebug & MDB_MAPIT) printf("vm_mmap: rv %d\n", rv); #endif 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); } }