/* * 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. * 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 */ /* * Mapped file (mmap) interface to VM */ #include __FBSDID("$FreeBSD$"); #include "opt_compat.h" #include "opt_mac.h" #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 #ifndef _SYS_SYSPROTO_H_ struct sbrk_args { int incr; }; #endif static int max_proc_mmap; SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 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_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL) static void vmmapentry_rsrc_init(dummy) void *dummy; { max_proc_mmap = vm_kmem_size / sizeof(struct vm_map_entry); max_proc_mmap /= 100; } static int vm_mmap_vnode(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *, int *, struct vnode *, vm_ooffset_t, vm_object_t *); /* * MPSAFE */ /* ARGSUSED */ int sbrk(td, uap) struct thread *td; struct sbrk_args *uap; { /* Not yet implemented */ /* mtx_lock(&Giant); */ /* mtx_unlock(&Giant); */ return (EOPNOTSUPP); } #ifndef _SYS_SYSPROTO_H_ struct sstk_args { int incr; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sstk(td, uap) struct thread *td; struct sstk_args *uap; { /* Not yet implemented */ /* mtx_lock(&Giant); */ /* mtx_unlock(&Giant); */ return (EOPNOTSUPP); } #if defined(COMPAT_43) || defined(COMPAT_SUNOS) #ifndef _SYS_SYSPROTO_H_ struct getpagesize_args { int dummy; }; #endif /* ARGSUSED */ int ogetpagesize(td, uap) struct thread *td; struct getpagesize_args *uap; { /* MP SAFE */ td->td_retval[0] = PAGE_SIZE; return (0); } #endif /* COMPAT_43 || COMPAT_SUNOS */ /* * 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. */ #ifndef _SYS_SYSPROTO_H_ struct mmap_args { void *addr; size_t len; int prot; int flags; int fd; long pad; off_t pos; }; #endif /* * MPSAFE */ int mmap(td, uap) struct thread *td; struct mmap_args *uap; { struct file *fp; struct vnode *vp; vm_offset_t addr; vm_size_t size, pageoff; vm_prot_t prot, maxprot; void *handle; int flags, error; off_t pos; struct vmspace *vms = td->td_proc->p_vmspace; addr = (vm_offset_t) uap->addr; size = uap->len; prot = uap->prot & VM_PROT_ALL; flags = uap->flags; pos = uap->pos; fp = NULL; /* make sure mapping fits into numeric range etc */ if ((ssize_t) uap->len < 0 || ((flags & MAP_ANON) && uap->fd != -1)) return (EINVAL); if (flags & MAP_STACK) { if ((uap->fd != -1) || ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE))) return (EINVAL); flags |= MAP_ANON; pos = 0; } /* * 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 (addr < vm_map_min(&vms->vm_map) || addr + size > vm_map_max(&vms->vm_map)) return (EINVAL); if (addr + size < addr) return (EINVAL); } else { /* * 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. */ PROC_LOCK(td->td_proc); if (addr == 0 || (addr >= round_page((vm_offset_t)vms->vm_taddr) && addr < round_page((vm_offset_t)vms->vm_daddr + lim_max(td->td_proc, RLIMIT_DATA)))) addr = round_page((vm_offset_t)vms->vm_daddr + lim_max(td->td_proc, RLIMIT_DATA)); PROC_UNLOCK(td->td_proc); } 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. * don't let the descriptor disappear on us if we block */ if ((error = fget(td, uap->fd, &fp)) != 0) goto done; 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 = fp->f_vnode; /* * 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? */ if (vp->v_mount->mnt_flag & MNT_NOEXEC) maxprot = VM_PROT_NONE; else 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. */ if ((flags & MAP_SHARED) != 0) { if ((fp->f_flag & FWRITE) != 0) { maxprot |= VM_PROT_WRITE; } else if ((prot & PROT_WRITE) != 0) { error = EACCES; goto done; } } else if (vp->v_type != VCHR || (fp->f_flag & FWRITE) != 0) { 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_refcnt) { error = ENOMEM; goto done; } error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, flags, handle, pos); if (error == 0) td->td_retval[0] = (register_t) (addr + pageoff); done: if (fp) fdrop(fp, td); return (error); } #ifdef COMPAT_43 #ifndef _SYS_SYSPROTO_H_ struct ommap_args { caddr_t addr; int len; int prot; int flags; int fd; long pos; }; #endif int ommap(td, uap) struct thread *td; struct ommap_args *uap; { struct mmap_args nargs; static const char cvtbsdprot[8] = { 0, PROT_EXEC, PROT_WRITE, PROT_EXEC | PROT_WRITE, PROT_READ, PROT_EXEC | PROT_READ, PROT_WRITE | PROT_READ, PROT_EXEC | PROT_WRITE | PROT_READ, }; #define OMAP_ANON 0x0002 #define OMAP_COPY 0x0020 #define OMAP_SHARED 0x0010 #define OMAP_FIXED 0x0100 nargs.addr = uap->addr; nargs.len = uap->len; nargs.prot = cvtbsdprot[uap->prot & 0x7]; nargs.flags = 0; if (uap->flags & OMAP_ANON) nargs.flags |= MAP_ANON; if (uap->flags & OMAP_COPY) nargs.flags |= MAP_COPY; if (uap->flags & OMAP_SHARED) nargs.flags |= MAP_SHARED; else nargs.flags |= MAP_PRIVATE; if (uap->flags & OMAP_FIXED) nargs.flags |= MAP_FIXED; nargs.fd = uap->fd; nargs.pos = uap->pos; return (mmap(td, &nargs)); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct msync_args { void *addr; int len; int flags; }; #endif /* * MPSAFE */ int msync(td, uap) struct thread *td; struct msync_args *uap; { 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 = &td->td_proc->p_vmspace->vm_map; /* * Clean the pages and interpret the return value. */ rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0, (flags & MS_INVALIDATE) != 0); switch (rv) { case KERN_SUCCESS: return (0); case KERN_INVALID_ADDRESS: return (EINVAL); /* Sun returns ENOMEM? */ case KERN_INVALID_ARGUMENT: return (EBUSY); default: return (EINVAL); } } #ifndef _SYS_SYSPROTO_H_ struct munmap_args { void *addr; size_t len; }; #endif /* * MPSAFE */ int munmap(td, uap) struct thread *td; struct munmap_args *uap; { vm_offset_t addr; vm_size_t size, pageoff; vm_map_t map; addr = (vm_offset_t) uap->addr; size = uap->len; if (size == 0) return (EINVAL); pageoff = (addr & PAGE_MASK); addr -= pageoff; size += pageoff; size = (vm_size_t) round_page(size); if (addr + size < addr) return (EINVAL); /* * Check for illegal addresses. Watch out for address wrap... */ map = &td->td_proc->p_vmspace->vm_map; if (addr < vm_map_min(map) || addr + size > vm_map_max(map)) return (EINVAL); vm_map_lock(map); /* * Make sure entire range is allocated. */ if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) { vm_map_unlock(map); return (EINVAL); } /* returns nothing but KERN_SUCCESS anyway */ vm_map_delete(map, addr, addr + size); vm_map_unlock(map); return (0); } #ifndef _SYS_SYSPROTO_H_ struct mprotect_args { const void *addr; size_t len; int prot; }; #endif /* * MPSAFE */ int mprotect(td, uap) struct thread *td; struct mprotect_args *uap; { 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(&td->td_proc->p_vmspace->vm_map, addr, addr + size, prot, FALSE)) { case KERN_SUCCESS: return (0); case KERN_PROTECTION_FAILURE: return (EACCES); } return (EINVAL); } #ifndef _SYS_SYSPROTO_H_ struct minherit_args { void *addr; size_t len; int inherit; }; #endif /* * MPSAFE */ int minherit(td, uap) struct thread *td; struct minherit_args *uap; { 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(&td->td_proc->p_vmspace->vm_map, addr, addr + size, inherit)) { case KERN_SUCCESS: return (0); case KERN_PROTECTION_FAILURE: return (EACCES); } return (EINVAL); } #ifndef _SYS_SYSPROTO_H_ struct madvise_args { void *addr; size_t len; int behav; }; #endif /* * MPSAFE */ /* ARGSUSED */ int madvise(td, uap) struct thread *td; struct madvise_args *uap; { vm_offset_t start, end; vm_map_t map; struct proc *p; int error; /* * Check for our special case, advising the swap pager we are * "immortal." */ if (uap->behav == MADV_PROTECT) { error = suser(td); if (error == 0) { p = td->td_proc; PROC_LOCK(p); p->p_flag |= P_PROTECTED; PROC_UNLOCK(p); } return (error); } /* * Check for illegal behavior */ if (uap->behav < 0 || uap->behav > MADV_CORE) return (EINVAL); /* * Check for illegal addresses. Watch out for address wrap... Note * that VM_*_ADDRESS are not constants due to casts (argh). */ map = &td->td_proc->p_vmspace->vm_map; if ((vm_offset_t)uap->addr < vm_map_min(map) || (vm_offset_t)uap->addr + uap->len > vm_map_max(map)) 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); if (vm_map_madvise(map, start, end, uap->behav)) return (EINVAL); return (0); } #ifndef _SYS_SYSPROTO_H_ struct mincore_args { const void *addr; size_t len; char *vec; }; #endif /* * MPSAFE */ /* ARGSUSED */ int mincore(td, uap) struct thread *td; struct mincore_args *uap; { vm_offset_t addr, first_addr; vm_offset_t end, cend; pmap_t pmap; vm_map_t map; char *vec; int error = 0; 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); map = &td->td_proc->p_vmspace->vm_map; if (end > vm_map_max(map) || end < addr) return (EINVAL); /* * Address of byte vector */ vec = uap->vec; pmap = vmspace_pmap(td->td_proc->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->eflags & MAP_ENTRY_IS_SUB_MAP) || 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. */ mtx_lock(&Giant); mincoreinfo = pmap_mincore(pmap, addr); mtx_unlock(&Giant); if (!mincoreinfo) { 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); VM_OBJECT_LOCK(current->object.vm_object); m = vm_page_lookup(current->object.vm_object, pindex); /* * if the page is resident, then gather information about * it. */ if (m != NULL && m->valid != 0) { mincoreinfo = MINCORE_INCORE; vm_page_lock_queues(); 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; } vm_page_unlock_queues(); } VM_OBJECT_UNLOCK(current->object.vm_object); } /* * 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) { error = EFAULT; goto done2; } ++lastvecindex; } /* * Pass the page information to the user */ error = subyte(vec + vecindex, mincoreinfo); if (error) { error = EFAULT; goto done2; } /* * 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) { error = EFAULT; goto done2; } ++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); done2: return (error); } #ifndef _SYS_SYSPROTO_H_ struct mlock_args { const void *addr; size_t len; }; #endif /* * MPSAFE */ int mlock(td, uap) struct thread *td; struct mlock_args *uap; { struct proc *proc; vm_offset_t addr, end, last, start; vm_size_t npages, size; int error; error = suser(td); if (error) return (error); addr = (vm_offset_t)uap->addr; size = uap->len; last = addr + size; start = trunc_page(addr); end = round_page(last); if (last < addr || end < addr) return (EINVAL); npages = atop(end - start); if (npages > vm_page_max_wired) return (ENOMEM); proc = td->td_proc; PROC_LOCK(proc); if (ptoa(npages + pmap_wired_count(vm_map_pmap(&proc->p_vmspace->vm_map))) > lim_cur(proc, RLIMIT_MEMLOCK)) { PROC_UNLOCK(proc); return (ENOMEM); } PROC_UNLOCK(proc); if (npages + cnt.v_wire_count > vm_page_max_wired) return (EAGAIN); error = vm_map_wire(&proc->p_vmspace->vm_map, start, end, VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); return (error == KERN_SUCCESS ? 0 : ENOMEM); } #ifndef _SYS_SYSPROTO_H_ struct mlockall_args { int how; }; #endif /* * MPSAFE */ int mlockall(td, uap) struct thread *td; struct mlockall_args *uap; { vm_map_t map; int error; map = &td->td_proc->p_vmspace->vm_map; error = 0; if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0)) return (EINVAL); #if 0 /* * If wiring all pages in the process would cause it to exceed * a hard resource limit, return ENOMEM. */ PROC_LOCK(td->td_proc); if (map->size - ptoa(pmap_wired_count(vm_map_pmap(map)) > lim_cur(td->td_proc, RLIMIT_MEMLOCK))) { PROC_UNLOCK(td->td_proc); return (ENOMEM); } PROC_UNLOCK(td->td_proc); #else error = suser(td); if (error) return (error); #endif if (uap->how & MCL_FUTURE) { vm_map_lock(map); vm_map_modflags(map, MAP_WIREFUTURE, 0); vm_map_unlock(map); error = 0; } if (uap->how & MCL_CURRENT) { /* * P1003.1-2001 mandates that all currently mapped pages * will be memory resident and locked (wired) upon return * from mlockall(). vm_map_wire() will wire pages, by * calling vm_fault_wire() for each page in the region. */ error = vm_map_wire(map, vm_map_min(map), vm_map_max(map), VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK); error = (error == KERN_SUCCESS ? 0 : EAGAIN); } return (error); } #ifndef _SYS_SYSPROTO_H_ struct munlockall_args { register_t dummy; }; #endif /* * MPSAFE */ int munlockall(td, uap) struct thread *td; struct munlockall_args *uap; { vm_map_t map; int error; map = &td->td_proc->p_vmspace->vm_map; error = suser(td); if (error) return (error); /* Clear the MAP_WIREFUTURE flag from this vm_map. */ vm_map_lock(map); vm_map_modflags(map, 0, MAP_WIREFUTURE); vm_map_unlock(map); /* Forcibly unwire all pages. */ error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map), VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK); return (error); } #ifndef _SYS_SYSPROTO_H_ struct munlock_args { const void *addr; size_t len; }; #endif /* * MPSAFE */ int munlock(td, uap) struct thread *td; struct munlock_args *uap; { vm_offset_t addr, end, last, start; vm_size_t size; int error; error = suser(td); if (error) return (error); addr = (vm_offset_t)uap->addr; size = uap->len; last = addr + size; start = trunc_page(addr); end = round_page(last); if (last < addr || end < addr) return (EINVAL); error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end, VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); return (error == KERN_SUCCESS ? 0 : ENOMEM); } /* * vm_mmap_vnode() * * MPSAFE * * Helper function for vm_mmap. Perform sanity check specific for mmap * operations on vnodes. */ int vm_mmap_vnode(struct thread *td, vm_size_t objsize, vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp, struct vnode *vp, vm_ooffset_t foff, vm_object_t *objp) { struct vattr va; void *handle; vm_object_t obj; int disablexworkaround, error, flags, type; mtx_lock(&Giant); if ((error = vget(vp, LK_EXCLUSIVE, td)) != 0) { mtx_unlock(&Giant); return (error); } flags = *flagsp; if (vp->v_type == VREG) { /* * Get the proper underlying object */ if (VOP_GETVOBJECT(vp, &obj) != 0) { error = EINVAL; goto done; } if (obj->handle != vp) { vput(vp); vp = (struct vnode*)obj->handle; vget(vp, LK_EXCLUSIVE, td); } type = OBJT_VNODE; handle = vp; } else if (vp->v_type == VCHR) { type = OBJT_DEVICE; handle = vp->v_rdev; if(vp->v_rdev->si_devsw->d_flags & D_MMAP_ANON) { *maxprotp = VM_PROT_ALL; *flagsp |= MAP_ANON; error = 0; goto done; } /* * cdevs does not provide private mappings of any kind. */ if ((*maxprotp & VM_PROT_WRITE) == 0 && (prot & PROT_WRITE) != 0) { error = EACCES; goto done; } /* * 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_ge(td->td_ucred, 1)) disablexworkaround = 1; else disablexworkaround = suser(td); if (disablexworkaround && (flags & (MAP_PRIVATE|MAP_COPY))) { error = EINVAL; goto done; } /* * Force device mappings to be shared. */ flags &= ~(MAP_PRIVATE|MAP_COPY); flags |= MAP_SHARED; } else { error = EINVAL; goto done; } if ((error = VOP_GETATTR(vp, &va, td->td_ucred, td))) { goto done; } if ((flags & MAP_SHARED) != 0) { if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) { if (prot & PROT_WRITE) { error = EPERM; goto done; } *maxprotp &= ~VM_PROT_WRITE; } #ifdef MAC error = mac_check_vnode_mmap(td->td_ucred, vp, prot); if (error != 0) goto done; #endif } /* * If it is a regular file without any references * we do not need to sync it. * Adjust object size to be the size of actual file. */ if (vp->v_type == VREG) { objsize = round_page(va.va_size); if (va.va_nlink == 0) flags |= MAP_NOSYNC; } obj = vm_pager_allocate(type, handle, objsize, prot, foff); if (obj == NULL) { error = (type == OBJT_DEVICE ? EINVAL : ENOMEM); goto done; } *objp = obj; *flagsp = flags; done: vput(vp); mtx_unlock(&Giant); return (error); } /* * vm_mmap() * * MPSAFE * * 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; int rv = KERN_SUCCESS; vm_ooffset_t objsize; int docow, error; struct thread *td = curthread; if (size == 0) return (0); objsize = size = round_page(size); PROC_LOCK(td->td_proc); if (td->td_proc->p_vmspace->vm_map.size + size > lim_cur(td->td_proc, RLIMIT_VMEM)) { PROC_UNLOCK(td->td_proc); return(ENOMEM); } PROC_UNLOCK(td->td_proc); /* * 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; (void) vm_map_remove(map, *addr, *addr + size); } /* * Lookup/allocate object. */ if (handle != NULL) { error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, handle, foff, &object); if (error) { return (error); } } if (flags & MAP_ANON) { object = NULL; docow = 0; /* * Unnamed anonymous regions always start at 0. */ if (handle == 0) foff = 0; } else { docow = MAP_PREFAULT_PARTIAL; } 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); if (flags & MAP_STACK) rv = vm_map_stack(map, *addr, size, prot, maxprot, docow | MAP_STACK_GROWS_DOWN); else rv = vm_map_find(map, object, foff, addr, size, fitit, 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); } else if (flags & MAP_SHARED) { /* * Shared memory is also shared with children. */ rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE); if (rv != KERN_SUCCESS) (void) vm_map_remove(map, *addr, *addr + size); } /* * If the process has requested that all future mappings * be wired, then heed this. */ if ((rv == KERN_SUCCESS) && (map->flags & MAP_WIREFUTURE)) vm_map_wire(map, *addr, *addr + size, VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 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); } }