Annotation of sys/kern/exec_aout.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: exec_aout.c,v 1.10 2005/11/12 04:31:24 jsg Exp $ */
! 2: /* $NetBSD: exec_aout.c,v 1.14 1996/02/04 02:15:01 christos Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1993, 1994 Christopher G. Demetriou
! 6: * All rights reserved.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. All advertising materials mentioning features or use of this software
! 17: * must display the following acknowledgement:
! 18: * This product includes software developed by Christopher G. Demetriou.
! 19: * 4. The name of the author may not be used to endorse or promote products
! 20: * derived from this software without specific prior written permission
! 21: *
! 22: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 23: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! 24: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! 25: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
! 26: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
! 27: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
! 28: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
! 29: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! 30: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
! 31: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! 32: */
! 33:
! 34: #include <sys/param.h>
! 35: #include <sys/systm.h>
! 36: #include <sys/proc.h>
! 37: #include <sys/malloc.h>
! 38: #include <sys/vnode.h>
! 39: #include <sys/exec.h>
! 40: #include <sys/resourcevar.h>
! 41: #include <uvm/uvm_extern.h>
! 42:
! 43: #if defined(_KERN_DO_AOUT)
! 44: #if defined(COMPAT_AOUT)
! 45: void aout_compat_setup(struct exec_package *epp);
! 46: #endif
! 47:
! 48: /*
! 49: * exec_aout_makecmds(): Check if it's an a.out-format executable.
! 50: *
! 51: * Given a proc pointer and an exec package pointer, see if the referent
! 52: * of the epp is in a.out format. First check 'standard' magic numbers for
! 53: * this architecture. If that fails, try a cpu-dependent hook.
! 54: *
! 55: * This function, in the former case, or the hook, in the latter, is
! 56: * responsible for creating a set of vmcmds which can be used to build
! 57: * the process's vm space and inserting them into the exec package.
! 58: */
! 59:
! 60: int
! 61: exec_aout_makecmds(struct proc *p, struct exec_package *epp)
! 62: {
! 63: u_long midmag, magic;
! 64: u_short mid;
! 65: int error;
! 66: struct exec *execp = epp->ep_hdr;
! 67:
! 68: if (epp->ep_hdrvalid < sizeof(struct exec))
! 69: return ENOEXEC;
! 70:
! 71: midmag = ntohl(execp->a_midmag);
! 72: mid = (midmag >> 16) & 0x3ff;
! 73: magic = midmag & 0xffff;
! 74:
! 75: midmag = mid << 16 | magic;
! 76:
! 77: switch (midmag) {
! 78: case (MID_MACHINE << 16) | ZMAGIC:
! 79: error = exec_aout_prep_zmagic(p, epp);
! 80: break;
! 81: case (MID_MACHINE << 16) | NMAGIC:
! 82: error = exec_aout_prep_nmagic(p, epp);
! 83: break;
! 84: case (MID_MACHINE << 16) | OMAGIC:
! 85: error = exec_aout_prep_omagic(p, epp);
! 86: break;
! 87: default:
! 88: error = cpu_exec_aout_makecmds(p, epp);
! 89: }
! 90:
! 91: if (error)
! 92: kill_vmcmds(&epp->ep_vmcmds);
! 93: #ifdef COMPAT_AOUT
! 94: aout_compat_setup(epp);
! 95: #endif
! 96:
! 97: return error;
! 98: }
! 99:
! 100: /*
! 101: * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package
! 102: *
! 103: * First, set of the various offsets/lengths in the exec package.
! 104: *
! 105: * Then, mark the text image busy (so it can be demand paged) or error
! 106: * out if this is not possible. Finally, set up vmcmds for the
! 107: * text, data, bss, and stack segments.
! 108: */
! 109:
! 110: int
! 111: exec_aout_prep_zmagic(struct proc *p, struct exec_package *epp)
! 112: {
! 113: struct exec *execp = epp->ep_hdr;
! 114:
! 115: epp->ep_taddr = USRTEXT;
! 116: epp->ep_tsize = execp->a_text;
! 117: epp->ep_daddr = epp->ep_taddr + execp->a_text;
! 118: epp->ep_dsize = execp->a_data + execp->a_bss;
! 119: epp->ep_entry = execp->a_entry;
! 120:
! 121: /*
! 122: * check if vnode is in open for writing, because we want to
! 123: * demand-page out of it. if it is, don't do it, for various
! 124: * reasons
! 125: */
! 126: if ((execp->a_text != 0 || execp->a_data != 0) &&
! 127: epp->ep_vp->v_writecount != 0) {
! 128: #ifdef DIAGNOSTIC
! 129: if (epp->ep_vp->v_flag & VTEXT)
! 130: panic("exec: a VTEXT vnode has writecount != 0");
! 131: #endif
! 132: return ETXTBSY;
! 133: }
! 134: vn_marktext(epp->ep_vp);
! 135:
! 136: /* set up command for text segment */
! 137: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
! 138: epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
! 139:
! 140: /* set up command for data segment */
! 141: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
! 142: epp->ep_daddr, epp->ep_vp, execp->a_text,
! 143: VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
! 144:
! 145: /* set up command for bss segment */
! 146: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
! 147: epp->ep_daddr + execp->a_data, NULLVP, 0,
! 148: VM_PROT_READ|VM_PROT_WRITE);
! 149:
! 150: return exec_setup_stack(p, epp);
! 151: }
! 152:
! 153: /*
! 154: * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package
! 155: */
! 156:
! 157: int
! 158: exec_aout_prep_nmagic(struct proc *p, struct exec_package *epp)
! 159: {
! 160: struct exec *execp = epp->ep_hdr;
! 161: long bsize, baddr;
! 162:
! 163: epp->ep_taddr = USRTEXT;
! 164: epp->ep_tsize = execp->a_text;
! 165: epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ);
! 166: epp->ep_dsize = execp->a_data + execp->a_bss;
! 167: epp->ep_entry = execp->a_entry;
! 168:
! 169: /* set up command for text segment */
! 170: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
! 171: epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
! 172: VM_PROT_READ|VM_PROT_EXECUTE);
! 173:
! 174: /* set up command for data segment */
! 175: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
! 176: epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
! 177: VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
! 178:
! 179: /* set up command for bss segment */
! 180: baddr = round_page(epp->ep_daddr + execp->a_data);
! 181: bsize = epp->ep_daddr + epp->ep_dsize - baddr;
! 182: if (bsize > 0)
! 183: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
! 184: NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE);
! 185:
! 186: return exec_setup_stack(p, epp);
! 187: }
! 188:
! 189: /*
! 190: * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package
! 191: */
! 192:
! 193: int
! 194: exec_aout_prep_omagic(struct proc *p, struct exec_package *epp)
! 195: {
! 196: struct exec *execp = epp->ep_hdr;
! 197: long dsize, bsize, baddr;
! 198:
! 199: epp->ep_taddr = USRTEXT;
! 200: epp->ep_tsize = execp->a_text;
! 201: epp->ep_daddr = epp->ep_taddr + execp->a_text;
! 202: epp->ep_dsize = execp->a_data + execp->a_bss;
! 203: epp->ep_entry = execp->a_entry;
! 204:
! 205: /* set up command for text and data segments */
! 206: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
! 207: execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
! 208: sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
! 209:
! 210: /* set up command for bss segment */
! 211: baddr = round_page(epp->ep_daddr + execp->a_data);
! 212: bsize = epp->ep_daddr + epp->ep_dsize - baddr;
! 213: if (bsize > 0)
! 214: NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
! 215: NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE);
! 216:
! 217: /*
! 218: * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
! 219: * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
! 220: * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
! 221: * respectively to page boundaries.
! 222: * Compensate `ep_dsize' for the amount of data covered by the last
! 223: * text page.
! 224: */
! 225: dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text);
! 226: epp->ep_dsize = (dsize > 0) ? dsize : 0;
! 227: return exec_setup_stack(p, epp);
! 228: }
! 229:
! 230: #endif /* _KERN_DO_AOUT */
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