/*- * SPDX-License-Identifier: BSD-3-Clause * * 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. 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 $Hdr: vm_unix.c 1.1 89/11/07$ * * @(#)vm_unix.c 8.1 (Berkeley) 6/11/93 */ /* * Traditional sbrk/grow interface to VM */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #if defined(__amd64__) || defined(__i386__) /* for i386_read_exec */ #include #endif #include #include #include #include #ifndef _SYS_SYSPROTO_H_ struct break_args { char *nsize; }; #endif int sys_break(struct thread *td, struct break_args *uap) { #if !defined(__aarch64__) && !defined(__riscv) uintptr_t addr; int error; addr = (uintptr_t)uap->nsize; error = kern_break(td, &addr); if (error == 0) td->td_retval[0] = addr; return (error); #else /* defined(__aarch64__) || defined(__riscv) */ return (ENOSYS); #endif /* defined(__aarch64__) || defined(__riscv) */ } int kern_break(struct thread *td, uintptr_t *addr) { struct vmspace *vm = td->td_proc->p_vmspace; vm_map_t map = &vm->vm_map; vm_offset_t new, old, base; rlim_t datalim, lmemlim, vmemlim; int prot, rv; int error = 0; datalim = lim_cur(td, RLIMIT_DATA); lmemlim = lim_cur(td, RLIMIT_MEMLOCK); vmemlim = lim_cur(td, RLIMIT_VMEM); new = round_page(*addr); vm_map_lock(map); base = round_page((vm_offset_t) vm->vm_daddr); old = base + ctob(vm->vm_dsize); if (new > base) { /* * Check the resource limit, but allow a process to reduce * its usage, even if it remains over the limit. */ if (new - base > datalim && new > old) { error = ENOMEM; goto done; } if (new > vm_map_max(map)) { error = ENOMEM; goto done; } } else if (new < base) { /* * Simply return the current break address without * modifying any state. This is an ad-hoc interface * used by libc to determine the initial break address, * avoiding a dependency on magic features in the system * linker. */ new = old; goto done; } if (new > old) { if (!old_mlock && map->flags & MAP_WIREFUTURE) { if (ptoa(pmap_wired_count(map->pmap)) + (new - old) > lmemlim) { error = ENOMEM; goto done; } } if (map->size + (new - old) > vmemlim) { error = ENOMEM; goto done; } #ifdef RACCT if (racct_enable) { PROC_LOCK(td->td_proc); error = racct_set(td->td_proc, RACCT_DATA, new - base); if (error != 0) { PROC_UNLOCK(td->td_proc); error = ENOMEM; goto done; } error = racct_set(td->td_proc, RACCT_VMEM, map->size + (new - old)); if (error != 0) { racct_set_force(td->td_proc, RACCT_DATA, old - base); PROC_UNLOCK(td->td_proc); error = ENOMEM; goto done; } if (!old_mlock && map->flags & MAP_WIREFUTURE) { error = racct_set(td->td_proc, RACCT_MEMLOCK, ptoa(pmap_wired_count(map->pmap)) + (new - old)); if (error != 0) { racct_set_force(td->td_proc, RACCT_DATA, old - base); racct_set_force(td->td_proc, RACCT_VMEM, map->size); PROC_UNLOCK(td->td_proc); error = ENOMEM; goto done; } } PROC_UNLOCK(td->td_proc); } #endif prot = VM_PROT_RW; #if (defined(COMPAT_FREEBSD32) && defined(__amd64__)) || defined(__i386__) if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32)) prot |= VM_PROT_EXECUTE; #endif rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0); if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) { rv = vm_map_wire_locked(map, old, new, VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); if (rv != KERN_SUCCESS) (void)vm_map_delete(map, old, new); } if (rv != KERN_SUCCESS) { #ifdef RACCT if (racct_enable) { PROC_LOCK(td->td_proc); racct_set_force(td->td_proc, RACCT_DATA, old - base); racct_set_force(td->td_proc, RACCT_VMEM, map->size); if (!old_mlock && map->flags & MAP_WIREFUTURE) { racct_set_force(td->td_proc, RACCT_MEMLOCK, ptoa(pmap_wired_count(map->pmap))); } PROC_UNLOCK(td->td_proc); } #endif error = ENOMEM; goto done; } vm->vm_dsize += btoc(new - old); } else if (new < old) { rv = vm_map_delete(map, new, old); if (rv != KERN_SUCCESS) { error = ENOMEM; goto done; } vm->vm_dsize -= btoc(old - new); #ifdef RACCT if (racct_enable) { PROC_LOCK(td->td_proc); racct_set_force(td->td_proc, RACCT_DATA, new - base); racct_set_force(td->td_proc, RACCT_VMEM, map->size); if (!old_mlock && map->flags & MAP_WIREFUTURE) { racct_set_force(td->td_proc, RACCT_MEMLOCK, ptoa(pmap_wired_count(map->pmap))); } PROC_UNLOCK(td->td_proc); } #endif } done: vm_map_unlock(map); if (error == 0) *addr = new; return (error); } #ifdef COMPAT_FREEBSD11 int freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap) { return (EINVAL); } #endif