linux_exec_aout.c revision 1.1 1 /* $NetBSD: linux_exec_aout.c,v 1.1 1995/02/28 23:24:46 fvdl Exp $ */
2
3 /*
4 * Copyright (c) 1995 Frank van der Linden
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 for the NetBSD Project
18 * by Frank van der Linden
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 * based on kern/exec_aout.c and compat/sunos/sunos_exec.c
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/filedesc.h>
39 #include <sys/kernel.h>
40 #include <sys/proc.h>
41 #include <sys/mount.h>
42 #include <sys/malloc.h>
43 #include <sys/namei.h>
44 #include <sys/vnode.h>
45 #include <sys/file.h>
46 #include <sys/resourcevar.h>
47 #include <sys/wait.h>
48
49 #include <sys/mman.h>
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <vm/vm_map.h>
53 #include <vm/vm_kern.h>
54 #include <vm/vm_pager.h>
55
56 #include <machine/cpu.h>
57 #include <machine/reg.h>
58 #include <machine/exec.h>
59
60 #include <compat/linux/linux_types.h>
61 #include <compat/linux/linux_syscallargs.h>
62 #include <compat/linux/linux_util.h>
63 #include <compat/linux/linux_exec.h>
64
65 int
66 exec_linux_aout_makecmds(p, epp)
67 struct proc *p;
68 struct exec_package *epp;
69 {
70 struct exec *linux_ep = epp->ep_hdr;
71 int machtype, magic;
72 int error = ENOEXEC;
73
74 magic = LINUX_N_MAGIC(linux_ep);
75 machtype = LINUX_N_MACHTYPE(linux_ep);
76
77
78 if (machtype != LINUX_MID_MACHINE)
79 return (ENOEXEC);
80
81 switch (magic) {
82 case QMAGIC:
83 error = exec_linux_aout_prep_qmagic(p, epp);
84 break;
85 case ZMAGIC:
86 error = exec_linux_aout_prep_zmagic(p, epp);
87 break;
88 case NMAGIC:
89 error = exec_linux_aout_prep_nmagic(p, epp);
90 break;
91 case OMAGIC:
92 error = exec_linux_aout_prep_omagic(p, epp);
93 break;
94 }
95 if (error == 0)
96 epp->ep_emul = EMUL_LINUX;
97 return error;
98 }
99
100 /*
101 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400
102 * is very likely not page aligned on most architectures, it is treated
103 * as an NMAGIC here. XXX
104 */
105
106 int
107 exec_linux_aout_prep_zmagic(p, epp)
108 struct proc *p;
109 struct exec_package *epp;
110 {
111 struct exec *execp = epp->ep_hdr;
112
113 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC);
114 epp->ep_tsize = execp->a_text;
115 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC);
116 epp->ep_dsize = execp->a_data + execp->a_bss;
117 epp->ep_entry = execp->a_entry;
118
119 /* set up command for text segment */
120 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
121 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC),
122 VM_PROT_READ|VM_PROT_EXECUTE);
123
124 /* set up command for data segment */
125 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
126 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC),
127 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
128
129 /* set up command for bss segment */
130 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
131 epp->ep_daddr + execp->a_data, NULLVP, 0,
132 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
133
134 return exec_aout_setup_stack(p, epp);
135 }
136
137 /*
138 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package.
139 * Not different from the normal stuff.
140 */
141
142 int
143 exec_linux_aout_prep_nmagic(p, epp)
144 struct proc *p;
145 struct exec_package *epp;
146 {
147 struct exec *execp = epp->ep_hdr;
148 long bsize, baddr;
149
150 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC);
151 epp->ep_tsize = execp->a_text;
152 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC);
153 epp->ep_dsize = execp->a_data + execp->a_bss;
154 epp->ep_entry = execp->a_entry;
155
156 /* set up command for text segment */
157 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
158 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC),
159 VM_PROT_READ|VM_PROT_EXECUTE);
160
161 /* set up command for data segment */
162 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
163 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC),
164 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
165
166 /* set up command for bss segment */
167 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
168 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
169 if (bsize > 0)
170 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
171 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
172
173 return exec_aout_setup_stack(p, epp);
174 }
175
176 /*
177 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package.
178 * Business as usual.
179 */
180
181 int
182 exec_linux_aout_prep_omagic(p, epp)
183 struct proc *p;
184 struct exec_package *epp;
185 {
186 struct exec *execp = epp->ep_hdr;
187 long dsize, bsize, baddr;
188
189 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC);
190 epp->ep_tsize = execp->a_text;
191 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC);
192 epp->ep_dsize = execp->a_data + execp->a_bss;
193 epp->ep_entry = execp->a_entry;
194
195 /* set up command for text and data segments */
196 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
197 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
198 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
199
200 /* set up command for bss segment */
201 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
202 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
203 if (bsize > 0)
204 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
205 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
206
207 /*
208 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
209 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
210 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
211 * respectively to page boundaries.
212 * Compensate `ep_dsize' for the amount of data covered by the last
213 * text page.
214 */
215 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG);
216 epp->ep_dsize = (dsize > 0) ? dsize : 0;
217 return exec_aout_setup_stack(p, epp);
218 }
219
220 int
221 exec_linux_aout_prep_qmagic(p, epp)
222 struct proc *p;
223 struct exec_package *epp;
224 {
225 struct exec *execp = epp->ep_hdr;
226
227 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC);
228 epp->ep_tsize = execp->a_text;
229 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC);
230 epp->ep_dsize = execp->a_data + execp->a_bss;
231 epp->ep_entry = execp->a_entry;
232
233 /*
234 * check if vnode is in open for writing, because we want to
235 * demand-page out of it. if it is, don't do it, for various
236 * reasons
237 */
238 if ((execp->a_text != 0 || execp->a_data != 0) &&
239 epp->ep_vp->v_writecount != 0) {
240 #ifdef DIAGNOSTIC
241 if (epp->ep_vp->v_flag & VTEXT)
242 panic("exec: a VTEXT vnode has writecount != 0\n");
243 #endif
244 return ETXTBSY;
245 }
246 epp->ep_vp->v_flag |= VTEXT;
247
248 /* set up command for text segment */
249 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
250 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC),
251 VM_PROT_READ|VM_PROT_EXECUTE);
252
253 /* set up command for data segment */
254 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
255 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC),
256 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
257
258 /* set up command for bss segment */
259 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
260 epp->ep_daddr + execp->a_data, NULLVP, 0,
261 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
262
263 return exec_aout_setup_stack(p, epp);
264 }
265
266 /*
267 * The Linux system call to load shared libraries. The current shared
268 * libraries are just (QMAGIC) a.out files that are mapped onto a fixed
269 * address * in the process' address space. The address is given in
270 * a_entry. Read in the header, set up some VM commands and run them.
271 *
272 * Yes, both text and data are mapped at once, so we're left with
273 * writeable text for the shared libs. The Linux crt0 seemed to break
274 * sometimes when data was mapped seperately. It munmapped a uselib()
275 * of ld.so by hand, which failed with shared text and data for ld.so
276 * Yuck.
277 *
278 * Because of the problem with ZMAGIC executables (text starts
279 * at 0x400 in the file, but needs t be mapped at 0), ZMAGIC
280 * shared libs are not handled very efficiently :-(
281 */
282
283 int
284 linux_uselib(p, uap, retval)
285 struct proc *p;
286 struct linux_uselib_args /* {
287 syscallarg(char *) path;
288 } */ *uap;
289 register_t *retval;
290 {
291 caddr_t sg;
292 long bsize, dsize, tsize, taddr, baddr, daddr;
293 struct nameidata ni;
294 struct vnode *vp;
295 struct exec hdr;
296 struct exec_vmcmd_set vcset;
297 int rem, i, magic, error;
298
299 sg = stackgap_init();
300 CHECK_ALT(p, &sg, SCARG(uap, path));
301
302 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
303
304 if ((error = namei(&ni)))
305 return error;
306
307 vp = ni.ni_vp;
308
309 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE,
310 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
311 &rem, p))) {
312 vrele(vp);
313 return error;
314 }
315
316 if (rem != 0) {
317 vrele(vp);
318 return ENOEXEC;
319 }
320
321 magic = LINUX_N_MAGIC(&hdr);
322 taddr = hdr.a_entry & (~(NBPG - 1));
323 tsize = hdr.a_text;
324 daddr = taddr + tsize;
325 dsize = hdr.a_data + hdr.a_bss;
326
327 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) {
328 vrele(vp);
329 return ETXTBSY;
330 }
331 vp->v_flag |= VTEXT;
332
333 vcset.evs_cnt = 0;
334 vcset.evs_used = 0;
335
336 NEW_VMCMD(&vcset,
337 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn,
338 hdr.a_text + hdr.a_data, taddr,
339 vp, LINUX_N_TXTOFF(hdr, magic),
340 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE);
341
342 baddr = roundup(daddr + hdr.a_data, NBPG);
343 bsize = daddr + dsize - baddr;
344 if (bsize > 0) {
345 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr,
346 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
347 }
348
349 for (i = 0; i < vcset.evs_used && !error; i++) {
350 struct exec_vmcmd *vcp;
351
352 vcp = &vcset.evs_cmds[i];
353 error = (*vcp->ev_proc)(p, vcp);
354 }
355
356 kill_vmcmds(&vcset);
357
358 vrele(vp);
359
360 return error;
361 }
362
363 /*
364 * Execve(2). Just check the alternate emulation path, and pass it on
365 * to the NetBSD execve().
366 */
367 int
368 linux_execve(p, uap, retval)
369 struct proc *p;
370 struct linux_execve_args /* {
371 syscallarg(char *) path;
372 syscallarg(char **) argv;
373 syscallarg(char **) envp;
374 } */ *uap;
375 register_t *retval;
376 {
377 caddr_t sg;
378
379 sg = stackgap_init();
380 CHECK_ALT(p, &sg, SCARG(uap, path));
381
382 return execve(p, uap, retval);
383 }
384