/* $OpenBSD: exec_aout.c,v 1.2 1996/03/03 17:19:36 niklas Exp $ */ /* $NetBSD: exec_aout.c,v 1.14 1996/02/04 02:15:01 christos Exp $ */ /* * Copyright (c) 1993, 1994 Christopher G. Demetriou * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Christopher G. Demetriou. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. */ #include #include #include #include #include #include #include #include /* * exec_aout_makecmds(): Check if it's an a.out-format executable. * * Given a proc pointer and an exec package pointer, see if the referent * of the epp is in a.out format. First check 'standard' magic numbers for * this architecture. If that fails, try a cpu-dependent hook. * * This function, in the former case, or the hook, in the latter, is * responsible for creating a set of vmcmds which can be used to build * the process's vm space and inserting them into the exec package. */ int exec_aout_makecmds(p, epp) struct proc *p; struct exec_package *epp; { u_long midmag, magic; u_short mid; int error; struct exec *execp = epp->ep_hdr; if (epp->ep_hdrvalid < sizeof(struct exec)) return ENOEXEC; midmag = ntohl(execp->a_midmag); mid = (midmag >> 16) & 0x3ff; magic = midmag & 0xffff; midmag = mid << 16 | magic; switch (midmag) { case (MID_MACHINE << 16) | ZMAGIC: error = exec_aout_prep_zmagic(p, epp); break; case (MID_MACHINE << 16) | NMAGIC: error = exec_aout_prep_nmagic(p, epp); break; case (MID_MACHINE << 16) | OMAGIC: error = exec_aout_prep_omagic(p, epp); break; default: error = cpu_exec_aout_makecmds(p, epp); } if (error) kill_vmcmds(&epp->ep_vmcmds); return error; } /* * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package * * First, set of the various offsets/lengths in the exec package. * * Then, mark the text image busy (so it can be demand paged) or error * out if this is not possible. Finally, set up vmcmds for the * text, data, bss, and stack segments. */ int exec_aout_prep_zmagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; epp->ep_taddr = USRTEXT; epp->ep_tsize = execp->a_text; epp->ep_daddr = epp->ep_taddr + execp->a_text; epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* * check if vnode is in open for writing, because we want to * demand-page out of it. if it is, don't do it, for various * reasons */ if ((execp->a_text != 0 || execp->a_data != 0) && epp->ep_vp->v_writecount != 0) { #ifdef DIAGNOSTIC if (epp->ep_vp->v_flag & VTEXT) panic("exec: a VTEXT vnode has writecount != 0\n"); #endif return ETXTBSY; } epp->ep_vp->v_flag |= VTEXT; /* set up command for text segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); /* set up command for data segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, epp->ep_daddr, epp->ep_vp, execp->a_text, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, epp->ep_daddr + execp->a_data, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return exec_aout_setup_stack(p, epp); } /* * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package */ int exec_aout_prep_nmagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; long bsize, baddr; epp->ep_taddr = USRTEXT; epp->ep_tsize = execp->a_text; epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* set up command for text segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, epp->ep_taddr, epp->ep_vp, sizeof(struct exec), VM_PROT_READ|VM_PROT_EXECUTE); /* set up command for data segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); bsize = epp->ep_daddr + epp->ep_dsize - baddr; if (bsize > 0) NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return exec_aout_setup_stack(p, epp); } /* * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package */ int exec_aout_prep_omagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; long dsize, bsize, baddr; epp->ep_taddr = USRTEXT; epp->ep_tsize = execp->a_text; epp->ep_daddr = epp->ep_taddr + execp->a_text; epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* set up command for text and data segments */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); bsize = epp->ep_daddr + epp->ep_dsize - baddr; if (bsize > 0) NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' * respectively to page boundaries. * Compensate `ep_dsize' for the amount of data covered by the last * text page. */ dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); epp->ep_dsize = (dsize > 0) ? dsize : 0; return exec_aout_setup_stack(p, epp); } /* * exec_aout_setup_stack(): Set up the stack segment for an a.out * executable. * * Note that the ep_ssize parameter must be set to be the current stack * limit; this is adjusted in the body of execve() to yield the * appropriate stack segment usage once the argument length is * calculated. * * This function returns an int for uniformity with other (future) formats' * stack setup functions. They might have errors to return. */ int exec_aout_setup_stack(p, epp) struct proc *p; struct exec_package *epp; { epp->ep_maxsaddr = USRSTACK - MAXSSIZ; epp->ep_minsaddr = USRSTACK; epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; /* * set up commands for stack. note that this takes *two*, one to * map the part of the stack which we can access, and one to map * the part which we can't. * * arguably, it could be made into one, but that would require the * addition of another mapping proc, which is unnecessary * * note that in memory, things assumed to be: 0 ....... ep_maxsaddr * ep_minsaddr */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return 0; }