freebsd-dev/sys/kern/imgact_aout.c
Jake Burkholder 05ba50f522 Use the fields in the sysentvec and in the vm map header in place of the
constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types.  Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.
2002-09-21 22:07:17 +00:00

315 lines
8.2 KiB
C

/*
* Copyright (c) 1993, David Greenman
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/imgact_aout.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/user.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_param.h>
static int exec_aout_imgact(struct image_params *imgp);
static int aout_fixup(register_t **stack_base, struct image_params *imgp);
struct sysentvec aout_sysvec = {
SYS_MAXSYSCALL,
sysent,
0,
0,
NULL,
0,
NULL,
NULL,
aout_fixup,
sendsig,
sigcode,
&szsigcode,
NULL,
"FreeBSD a.out",
aout_coredump,
NULL,
MINSIGSTKSZ,
PAGE_SIZE,
VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS,
USRSTACK,
PS_STRINGS,
VM_PROT_ALL,
exec_copyout_strings,
exec_setregs
};
static int
aout_fixup(stack_base, imgp)
register_t **stack_base;
struct image_params *imgp;
{
return (suword(--(*stack_base), imgp->argc));
}
static int
exec_aout_imgact(imgp)
struct image_params *imgp;
{
const struct exec *a_out = (const struct exec *) imgp->image_header;
struct vmspace *vmspace;
struct vnode *vp;
vm_map_t map;
vm_object_t object;
vm_offset_t text_end, data_end;
unsigned long virtual_offset;
unsigned long file_offset;
unsigned long bss_size;
int error;
GIANT_REQUIRED;
/*
* Linux and *BSD binaries look very much alike,
* only the machine id is different:
* 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
* NetBSD is in network byte order.. ugh.
*/
if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
((a_out->a_magic >> 16) & 0xff) != 0 &&
((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
return -1;
/*
* Set file/virtual offset based on a.out variant.
* We do two cases: host byte order and network byte order
* (for NetBSD compatibility)
*/
switch ((int)(a_out->a_magic & 0xffff)) {
case ZMAGIC:
virtual_offset = 0;
if (a_out->a_text) {
file_offset = PAGE_SIZE;
} else {
/* Bill's "screwball mode" */
file_offset = 0;
}
break;
case QMAGIC:
virtual_offset = PAGE_SIZE;
file_offset = 0;
/* Pass PS_STRINGS for BSD/OS binaries only. */
if (N_GETMID(*a_out) == MID_ZERO)
imgp->ps_strings = aout_sysvec.sv_psstrings;
break;
default:
/* NetBSD compatibility */
switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
case ZMAGIC:
case QMAGIC:
virtual_offset = PAGE_SIZE;
file_offset = 0;
break;
default:
return (-1);
}
}
bss_size = roundup(a_out->a_bss, PAGE_SIZE);
/*
* Check various fields in header for validity/bounds.
*/
if (/* entry point must lay with text region */
a_out->a_entry < virtual_offset ||
a_out->a_entry >= virtual_offset + a_out->a_text ||
/* text and data size must each be page rounded */
a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
return (-1);
/* text + data can't exceed file size */
if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
return (EFAULT);
/*
* text/data/bss must not exceed limits
*/
mtx_assert(&Giant, MA_OWNED);
if (/* text can't exceed maximum text size */
a_out->a_text > maxtsiz ||
/* data + bss can't exceed rlimit */
a_out->a_data + bss_size >
imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
return (ENOMEM);
/* copy in arguments and/or environment from old process */
error = exec_extract_strings(imgp);
if (error)
return (error);
/*
* Destroy old process VM and create a new one (with a new stack)
*/
exec_new_vmspace(imgp, &aout_sysvec);
/*
* The vm space can be changed by exec_new_vmspace
*/
vmspace = imgp->proc->p_vmspace;
vp = imgp->vp;
object = imgp->object;
map = &vmspace->vm_map;
vm_map_lock(map);
vm_object_reference(object);
text_end = virtual_offset + a_out->a_text;
error = vm_map_insert(map, object,
file_offset,
virtual_offset, text_end,
VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
MAP_COPY_ON_WRITE | MAP_PREFAULT);
if (error) {
vm_map_unlock(map);
return (error);
}
data_end = text_end + a_out->a_data;
if (a_out->a_data) {
vm_object_reference(object);
error = vm_map_insert(map, object,
file_offset + a_out->a_text,
text_end, data_end,
VM_PROT_ALL, VM_PROT_ALL,
MAP_COPY_ON_WRITE | MAP_PREFAULT);
if (error) {
vm_map_unlock(map);
return (error);
}
}
if (bss_size) {
error = vm_map_insert(map, NULL, 0,
data_end, data_end + bss_size,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (error) {
vm_map_unlock(map);
return (error);
}
}
vm_map_unlock(map);
/* Fill in process VM information */
vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
vmspace->vm_daddr = (caddr_t) (uintptr_t)
(virtual_offset + a_out->a_text);
/* Fill in image_params */
imgp->interpreted = 0;
imgp->entry_addr = a_out->a_entry;
imgp->proc->p_sysent = &aout_sysvec;
return (0);
}
/*
* Dump core, into a file named as described in the comments for
* expand_name(), unless the process was setuid/setgid.
*/
int
aout_coredump(td, vp, limit)
register struct thread *td;
register struct vnode *vp;
off_t limit;
{
struct proc *p = td->td_proc;
register struct ucred *cred = td->td_ucred;
register struct vmspace *vm = p->p_vmspace;
char *tempuser;
int error;
if (ctob((uarea_pages + kstack_pages)
+ vm->vm_dsize + vm->vm_ssize) >= limit)
return (EFAULT);
tempuser = malloc(ctob(uarea_pages + kstack_pages), M_TEMP,
M_WAITOK | M_ZERO);
if (tempuser == NULL)
return (ENOMEM);
PROC_LOCK(p);
fill_kinfo_proc(p, &p->p_uarea->u_kproc);
PROC_UNLOCK(p);
bcopy(p->p_uarea, tempuser, sizeof(struct user));
bcopy(td->td_frame,
tempuser + ctob(uarea_pages) +
((caddr_t)td->td_frame - (caddr_t)td->td_kstack),
sizeof(struct trapframe));
error = vn_rdwr(UIO_WRITE, vp, (caddr_t)tempuser,
ctob(uarea_pages + kstack_pages),
(off_t)0, UIO_SYSSPACE, IO_UNIT, cred, NOCRED,
(int *)NULL, td);
free(tempuser, M_TEMP);
if (error == 0)
error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
(int)ctob(vm->vm_dsize),
(off_t)ctob(uarea_pages + kstack_pages), UIO_USERSPACE,
IO_UNIT | IO_DIRECT, cred, NOCRED, (int *) NULL, td);
if (error == 0)
error = vn_rdwr_inchunks(UIO_WRITE, vp,
(caddr_t)trunc_page(p->p_sysent->sv_usrstack -
ctob(vm->vm_ssize)), round_page(ctob(vm->vm_ssize)),
(off_t)ctob(uarea_pages + kstack_pages) +
ctob(vm->vm_dsize), UIO_USERSPACE,
IO_UNIT | IO_DIRECT, cred, NOCRED, (int *) NULL, td);
return (error);
}
/*
* Tell kern_execve.c about it, with a little help from the linker.
*/
static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
EXEC_SET(aout, aout_execsw);