FreeBSD/Linux Kernel Cross Reference
sys/kern/exec_aout.c
1 /* $NetBSD: exec_aout.c,v 1.41 2019/11/20 19:37:53 pgoyette Exp $ */
2
3 /*
4 * Copyright (c) 1993, 1994 Christopher G. Demetriou
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Christopher G. Demetriou.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: exec_aout.c,v 1.41 2019/11/20 19:37:53 pgoyette Exp $");
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/proc.h>
39 #include <sys/vnode.h>
40 #include <sys/exec.h>
41 #include <sys/exec_aout.h>
42 #include <sys/resourcevar.h>
43 #include <sys/module.h>
44
45 #include <uvm/uvm_extern.h>
46
47 MODULE(MODULE_CLASS_EXEC, exec_aout, NULL);
48
49 static struct execsw exec_aout_execsw = {
50 .es_hdrsz = sizeof(struct exec),
51 .es_makecmds = exec_aout_makecmds,
52 .u = {
53 .elf_probe_func = NULL,
54 },
55 .es_emul = &emul_netbsd,
56 .es_prio = EXECSW_PRIO_ANY,
57 .es_arglen = 0,
58 .es_copyargs = copyargs,
59 .es_setregs = NULL,
60 .es_coredump = coredump_netbsd,
61 .es_setup_stack = exec_setup_stack,
62 };
63
64 static int
65 exec_aout_modcmd(modcmd_t cmd, void *arg)
66 {
67
68 switch (cmd) {
69 case MODULE_CMD_INIT:
70 return exec_add(&exec_aout_execsw, 1);
71
72 case MODULE_CMD_FINI:
73 return exec_remove(&exec_aout_execsw, 1);
74
75 default:
76 return ENOTTY;
77 }
78 }
79
80 /*
81 * exec_aout_makecmds(): Check if it's an a.out-format executable.
82 *
83 * Given a lwp pointer and an exec package pointer, see if the referent
84 * of the epp is in a.out format. First check 'standard' magic numbers for
85 * this architecture. If that fails, try a CPU-dependent hook.
86 *
87 * This function, in the former case, or the hook, in the latter, is
88 * responsible for creating a set of vmcmds which can be used to build
89 * the process's vm space and inserting them into the exec package.
90 */
91
92 int
93 exec_aout_makecmds(struct lwp *l, struct exec_package *epp)
94 {
95 u_long midmag, magic;
96 u_short mid;
97 int error;
98 struct exec *execp = epp->ep_hdr;
99
100 if (epp->ep_hdrvalid < sizeof(struct exec))
101 return ENOEXEC;
102
103 midmag = ntohl(execp->a_midmag);
104 mid = (midmag >> 16) & 0x3ff;
105 magic = midmag & 0xffff;
106
107 midmag = mid << 16 | magic;
108
109 switch (midmag) {
110 case (MID_MACHINE << 16) | ZMAGIC:
111 error = exec_aout_prep_zmagic(l, epp);
112 break;
113 case (MID_MACHINE << 16) | NMAGIC:
114 error = exec_aout_prep_nmagic(l, epp);
115 break;
116 case (MID_MACHINE << 16) | OMAGIC:
117 error = exec_aout_prep_omagic(l, epp);
118 break;
119 default:
120 error = cpu_exec_aout_makecmds(l, epp);
121 }
122
123 if (error)
124 kill_vmcmds(&epp->ep_vmcmds);
125 else
126 epp->ep_flags &= ~EXEC_TOPDOWN_VM;
127
128 return error;
129 }
130
131 /*
132 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package
133 *
134 * First, set of the various offsets/lengths in the exec package.
135 *
136 * Then, mark the text image busy (so it can be demand paged) or error
137 * out if this is not possible. Finally, set up vmcmds for the
138 * text, data, bss, and stack segments.
139 */
140
141 int
142 exec_aout_prep_zmagic(struct lwp *l, struct exec_package *epp)
143 {
144 struct exec *execp = epp->ep_hdr;
145 int error;
146
147 epp->ep_taddr = AOUT_LDPGSZ;
148 epp->ep_tsize = execp->a_text;
149 epp->ep_daddr = epp->ep_taddr + execp->a_text;
150 epp->ep_dsize = execp->a_data + execp->a_bss;
151 epp->ep_entry = execp->a_entry;
152
153 error = vn_marktext(epp->ep_vp);
154 if (error)
155 return (error);
156
157 /* set up command for text segment */
158 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text),
159 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
160
161 /* set up command for data segment */
162 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data),
163 epp->ep_daddr, epp->ep_vp, execp->a_text,
164 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
165
166 /* set up command for bss segment */
167 if (execp->a_bss > 0)
168 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
169 epp->ep_daddr + execp->a_data, NULLVP, 0,
170 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
171
172 return (*epp->ep_esch->es_setup_stack)(l, epp);
173 }
174
175 /*
176 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package
177 */
178
179 int
180 exec_aout_prep_nmagic(struct lwp *l, struct exec_package *epp)
181 {
182 struct exec *execp = epp->ep_hdr;
183 long bsize, baddr;
184
185 epp->ep_taddr = AOUT_LDPGSZ;
186 epp->ep_tsize = execp->a_text;
187 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ);
188 epp->ep_dsize = execp->a_data + execp->a_bss;
189 epp->ep_entry = execp->a_entry;
190
191 /* set up command for text segment */
192 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
193 epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
194 VM_PROT_READ|VM_PROT_EXECUTE);
195
196 /* set up command for data segment */
197 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
198 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
199 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
200
201 /* set up command for bss segment */
202 baddr = round_page(epp->ep_daddr + execp->a_data);
203 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
204 if (bsize > 0)
205 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
206 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
207
208 return (*epp->ep_esch->es_setup_stack)(l, epp);
209 }
210
211 /*
212 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package
213 */
214
215 int
216 exec_aout_prep_omagic(struct lwp *l, struct exec_package *epp)
217 {
218 struct exec *execp = epp->ep_hdr;
219 long dsize, bsize, baddr;
220
221 epp->ep_taddr = AOUT_LDPGSZ;
222 epp->ep_tsize = execp->a_text;
223 epp->ep_daddr = epp->ep_taddr + execp->a_text;
224 epp->ep_dsize = execp->a_data + execp->a_bss;
225 epp->ep_entry = execp->a_entry;
226
227 /* set up command for text and data segments */
228 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
229 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
230 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
231
232 /* set up command for bss segment */
233 baddr = round_page(epp->ep_daddr + execp->a_data);
234 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
235 if (bsize > 0)
236 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
237 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
238
239 /*
240 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
241 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
242 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
243 * respectively to page boundaries.
244 * Compensate `ep_dsize' for the amount of data covered by the last
245 * text page.
246 */
247 dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text);
248 epp->ep_dsize = (dsize > 0) ? dsize : 0;
249 return (*epp->ep_esch->es_setup_stack)(l, epp);
250 }
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