Annotation of sys/kern/exec_aout.c, Revision 1.1.1.1
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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