path: root/sys/uvm/uvm_unix.c

/*	$OpenBSD: uvm_unix.c,v 1.49 2014/04/13 23:14:15 tedu Exp $	*/
/*	$NetBSD: uvm_unix.c,v 1.18 2000/09/13 15:00:25 thorpej Exp $	*/

/*
 * Copyright (c) 1997 Charles D. Cranor and Washington University.
 * Copyright (c) 1991, 1993 The Regents of the University of California.  
 * Copyright (c) 1988 University of Utah.
 *
 * 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 Charles D. Cranor,
 *	Washington University, 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 $Hdr: vm_unix.c 1.1 89/11/07$
 *      @(#)vm_unix.c   8.1 (Berkeley) 6/11/93
 * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
 */

/*
 * uvm_unix.c: traditional sbrk/grow interface to vm.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/vnode.h>
#include <sys/core.h>

#include <sys/mount.h>
#include <sys/syscallargs.h>

#include <uvm/uvm.h>

/*
 * sys_obreak: set break
 */

int
sys_obreak(struct proc *p, void *v, register_t *retval)
{
	struct sys_obreak_args /* {
		syscallarg(char *) nsize;
	} */ *uap = v;
	struct vmspace *vm = p->p_vmspace;
	vaddr_t new, old, base;
	int error;

	base = (vaddr_t)vm->vm_daddr;
	new = round_page((vaddr_t)SCARG(uap, nsize));
	if (new < base || (new - base) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
		return (ENOMEM);

	old = round_page(base + ptoa(vm->vm_dsize));

	if (new == old)
		return (0);

	/* grow or shrink? */
	if (new > old) {
		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
		    UVM_UNKNOWN_OFFSET, 0,
		    UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RWX, UVM_INH_COPY,
		    UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
		    UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
		if (error) {
			uprintf("sbrk: grow %ld failed, error = %d\n",
			    new - old, error);
			return (ENOMEM);
		}
		vm->vm_dsize += atop(new - old);
	} else {
		uvm_deallocate(&vm->vm_map, new, old - new);
		vm->vm_dsize -= atop(old - new);
	}

	return (0);
}

/*
 * uvm_grow: enlarge the "stack segment" to include sp.
 */
void
uvm_grow(struct proc *p, vaddr_t sp)
{
	struct vmspace *vm = p->p_vmspace;
	int si;

	/* For user defined stacks (from sendsig). */
	if (sp < (vaddr_t)vm->vm_maxsaddr)
		return;

	/* For common case of already allocated (from trap). */
#ifdef MACHINE_STACK_GROWS_UP
	if (sp < USRSTACK + ptoa(vm->vm_ssize))
#else
	if (sp >= USRSTACK - ptoa(vm->vm_ssize))
#endif
		return;

	/* Really need to check vs limit and increment stack size if ok. */
#ifdef MACHINE_STACK_GROWS_UP
	si = atop(sp - USRSTACK) - vm->vm_ssize + 1;
#else
	si = atop(USRSTACK - sp) - vm->vm_ssize;
#endif
	if (vm->vm_ssize + si <= atop(p->p_rlimit[RLIMIT_STACK].rlim_cur))
		vm->vm_ssize += si;
}

#ifndef SMALL_KERNEL

/*
 * uvm_coredump: dump core!
 */

int
uvm_coredump(struct proc *p, struct vnode *vp, struct ucred *cred,
    struct core *chdr)
{
	struct vmspace *vm = p->p_vmspace;
	vm_map_t map = &vm->vm_map;
	vm_map_entry_t entry, safe;
	vaddr_t start, end, top;
	struct coreseg cseg;
	off_t offset, coffset;
	int csize, chunk, flag, error = 0;

	offset = chdr->c_hdrsize + chdr->c_seghdrsize + chdr->c_cpusize;

	RB_FOREACH_SAFE(entry, uvm_map_addr, &map->addr, safe) {
		/* should never happen for a user process */
		if (UVM_ET_ISSUBMAP(entry)) {
			panic("uvm_coredump: user process with submap?");
		}

		if (!(entry->protection & VM_PROT_WRITE) &&
		    entry->start != p->p_p->ps_sigcode)
			continue;

		/* Don't dump mmaped devices. */
		if (entry->object.uvm_obj != NULL &&
		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
			continue;

		start = entry->start;
		end = entry->end;

		if (start >= VM_MAXUSER_ADDRESS)
			continue;

		if (end > VM_MAXUSER_ADDRESS)
			end = VM_MAXUSER_ADDRESS;

#ifdef MACHINE_STACK_GROWS_UP
		if (USRSTACK <= start && start < (USRSTACK + MAXSSIZ)) {
			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
			if (end > top)
				end = top;

			if (start >= end)
				continue;
#else
		if (start >= (vaddr_t)vm->vm_maxsaddr) {
			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
			if (start < top)
				start = top;

			if (start >= end)
				continue;
#endif
			flag = CORE_STACK;
		} else
			flag = CORE_DATA;

		/* Set up a new core file segment. */
		CORE_SETMAGIC(cseg, CORESEGMAGIC, CORE_GETMID(*chdr), flag);
		cseg.c_addr = start;
		cseg.c_size = end - start;

		error = vn_rdwr(UIO_WRITE, vp,
		    (caddr_t)&cseg, chdr->c_seghdrsize,
		    offset, UIO_SYSSPACE, IO_UNIT, cred, NULL, p);
		/*
		 * We might get an EFAULT on objects mapped beyond
		 * EOF. Ignore the error.
		 */
		if (error && error != EFAULT)
			break;

		offset += chdr->c_seghdrsize;

		coffset = 0;
		csize = (int)cseg.c_size;
		do {
			if (p->p_siglist & sigmask(SIGKILL))
				return (EINTR);

			/* Rest of the loop sleeps with lock held, so... */
			yield();

			chunk = MIN(csize, MAXPHYS);
			error = vn_rdwr(UIO_WRITE, vp,
			    (caddr_t)(u_long)cseg.c_addr + coffset,
			    chunk, offset + coffset, UIO_USERSPACE,
			    IO_UNIT, cred, NULL, p);
			if (error)
				return (error);

			coffset += chunk;
			csize -= chunk;
		} while (csize > 0);
		offset += cseg.c_size;

		/* Discard the memory */
		uvm_unmap(map, cseg.c_addr, cseg.c_addr + cseg.c_size);

		chdr->c_nseg++;
	}

	return (error);
}

int
uvm_coredump_walkmap(struct proc *p, void *iocookie,
    int (*func)(struct proc *, void *, struct uvm_coredump_state *),
    void *cookie)
{
	struct uvm_coredump_state state;
	struct vmspace *vm = p->p_vmspace;
	struct vm_map *map = &vm->vm_map;
	struct vm_map_entry *entry;
	vaddr_t top;
	int error;

	RB_FOREACH(entry, uvm_map_addr, &map->addr) {
		state.cookie = cookie;
		state.prot = entry->protection;
		state.flags = 0;

		/* should never happen for a user process */
		if (UVM_ET_ISSUBMAP(entry)) {
			panic("uvm_coredump: user process with submap?");
		}

		if (!(entry->protection & VM_PROT_WRITE) &&
		    entry->start != p->p_p->ps_sigcode)
			continue;

		/* Don't dump mmaped devices. */
		if (entry->object.uvm_obj != NULL &&
		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
			continue;

		state.start = entry->start;
		state.realend = entry->end;
		state.end = entry->end;

		if (state.start >= VM_MAXUSER_ADDRESS)
			continue;

		if (state.end > VM_MAXUSER_ADDRESS)
			state.end = VM_MAXUSER_ADDRESS;

#ifdef MACHINE_STACK_GROWS_UP
		if (USRSTACK <= state.start &&
		    state.start < (USRSTACK + MAXSSIZ)) {
			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
			if (state.end > top)
				state.end = top;

			if (state.start >= state.end)
				continue;
#else
		if (state.start >= (vaddr_t)vm->vm_maxsaddr) {
			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
			if (state.start < top)
				state.start = top;

			if (state.start >= state.end)
				continue;
#endif
			state.flags |= UVM_COREDUMP_STACK;
		}

		error = (*func)(p, iocookie, &state);
		if (error)
			return (error);
	}

	return (0);
}

#endif	/* !SMALL_KERNEL */