linux_exec_aout.c revision 1.37 1 /* $NetBSD: linux_exec_aout.c,v 1.37 1999/02/09 20:37:19 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas, Frank van der Linden and Eric Haszlakiewicz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 /*
40 * based on exec_aout.c, sunos_exec.c and svr4_exec.c
41 */
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/proc.h>
47 #include <sys/malloc.h>
48 #include <sys/namei.h>
49 #include <sys/vnode.h>
50 #include <sys/mount.h>
51 #include <sys/exec.h>
52 #include <sys/exec_elf.h>
53
54 #include <sys/mman.h>
55 #include <sys/syscallargs.h>
56
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #include <vm/vm_map.h>
60
61 #include <machine/cpu.h>
62 #include <machine/reg.h>
63
64 #include <compat/linux/common/linux_types.h>
65 #include <compat/linux/common/linux_signal.h>
66 #include <compat/linux/common/linux_util.h>
67 #include <compat/linux/common/linux_exec.h>
68 #include <compat/linux/common/linux_machdep.h>
69 #include <compat/linux/common/linux_errno.h>
70
71 #include <compat/linux/linux_syscallargs.h>
72 #include <compat/linux/linux_syscall.h>
73
74
75 static void *linux_aout_copyargs __P((struct exec_package *,
76 struct ps_strings *, void *, void *));
77
78 #define LINUX_AOUT_AUX_ARGSIZ 2
79
80 extern char linux_sigcode[], linux_esigcode[];
81 extern struct sysent linux_sysent[];
82 extern char *linux_syscallnames[];
83
84 int exec_linux_aout_prep_zmagic __P((struct proc *, struct exec_package *));
85 int exec_linux_aout_prep_nmagic __P((struct proc *, struct exec_package *));
86 int exec_linux_aout_prep_omagic __P((struct proc *, struct exec_package *));
87 int exec_linux_aout_prep_qmagic __P((struct proc *, struct exec_package *));
88
89 struct emul emul_linux_aout = {
90 "linux",
91 native_to_linux_errno,
92 linux_sendsig,
93 LINUX_SYS_syscall,
94 LINUX_SYS_MAXSYSCALL,
95 linux_sysent,
96 linux_syscallnames,
97 LINUX_AOUT_AUX_ARGSIZ,
98 linux_aout_copyargs,
99 linux_setregs,
100 linux_sigcode,
101 linux_esigcode,
102 };
103
104 static void *
105 linux_aout_copyargs(pack, arginfo, stack, argp)
106 struct exec_package *pack;
107 struct ps_strings *arginfo;
108 void *stack;
109 void *argp;
110 {
111 char **cpp = stack;
112 char **stk = stack;
113 char *dp, *sp;
114 size_t len;
115 void *nullp = NULL;
116 int argc = arginfo->ps_nargvstr;
117 int envc = arginfo->ps_nenvstr;
118
119 if (copyout(&argc, cpp++, sizeof(argc)))
120 return NULL;
121
122 /* leave room for envp and argv */
123 cpp += 2;
124 if (copyout(&cpp, &stk[1], sizeof (cpp)))
125 return NULL;
126
127 dp = (char *) (cpp + argc + envc + 2);
128 sp = argp;
129
130 /* XXX don't copy them out, remap them! */
131 arginfo->ps_argvstr = cpp; /* remember location of argv for later */
132
133 for (; --argc >= 0; sp += len, dp += len)
134 if (copyout(&dp, cpp++, sizeof(dp)) ||
135 copyoutstr(sp, dp, ARG_MAX, &len))
136 return NULL;
137
138 if (copyout(&nullp, cpp++, sizeof(nullp)))
139 return NULL;
140
141 if (copyout(&cpp, &stk[2], sizeof (cpp)))
142 return NULL;
143
144 arginfo->ps_envstr = cpp; /* remember location of envp for later */
145
146 for (; --envc >= 0; sp += len, dp += len)
147 if (copyout(&dp, cpp++, sizeof(dp)) ||
148 copyoutstr(sp, dp, ARG_MAX, &len))
149 return NULL;
150
151 if (copyout(&nullp, cpp++, sizeof(nullp)))
152 return NULL;
153
154 return cpp;
155 }
156
157 int
158 exec_linux_aout_makecmds(p, epp)
159 struct proc *p;
160 struct exec_package *epp;
161 {
162 struct exec *linux_ep = epp->ep_hdr;
163 int machtype, magic;
164 int error = ENOEXEC;
165
166 magic = LINUX_N_MAGIC(linux_ep);
167 machtype = LINUX_N_MACHTYPE(linux_ep);
168
169
170 if (machtype != LINUX_MID_MACHINE)
171 return (ENOEXEC);
172
173 switch (magic) {
174 case QMAGIC:
175 error = exec_linux_aout_prep_qmagic(p, epp);
176 break;
177 case ZMAGIC:
178 error = exec_linux_aout_prep_zmagic(p, epp);
179 break;
180 case NMAGIC:
181 error = exec_linux_aout_prep_nmagic(p, epp);
182 break;
183 case OMAGIC:
184 error = exec_linux_aout_prep_omagic(p, epp);
185 break;
186 }
187 if (error == 0)
188 epp->ep_emul = &emul_linux_aout;
189 return error;
190 }
191
192 /*
193 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400
194 * is very likely not page aligned on most architectures, it is treated
195 * as an NMAGIC here. XXX
196 */
197
198 int
199 exec_linux_aout_prep_zmagic(p, epp)
200 struct proc *p;
201 struct exec_package *epp;
202 {
203 struct exec *execp = epp->ep_hdr;
204
205 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC);
206 epp->ep_tsize = execp->a_text;
207 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC);
208 epp->ep_dsize = execp->a_data + execp->a_bss;
209 epp->ep_entry = execp->a_entry;
210
211 /* set up command for text segment */
212 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
213 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC),
214 VM_PROT_READ|VM_PROT_EXECUTE);
215
216 /* set up command for data segment */
217 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
218 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC),
219 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
220
221 /* set up command for bss segment */
222 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
223 epp->ep_daddr + execp->a_data, NULLVP, 0,
224 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
225
226 return exec_aout_setup_stack(p, epp);
227 }
228
229 /*
230 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package.
231 * Not different from the normal stuff.
232 */
233
234 int
235 exec_linux_aout_prep_nmagic(p, epp)
236 struct proc *p;
237 struct exec_package *epp;
238 {
239 struct exec *execp = epp->ep_hdr;
240 long bsize, baddr;
241
242 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC);
243 epp->ep_tsize = execp->a_text;
244 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC);
245 epp->ep_dsize = execp->a_data + execp->a_bss;
246 epp->ep_entry = execp->a_entry;
247
248 /* set up command for text segment */
249 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
250 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC),
251 VM_PROT_READ|VM_PROT_EXECUTE);
252
253 /* set up command for data segment */
254 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
255 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC),
256 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
257
258 /* set up command for bss segment */
259 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
260 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
261 if (bsize > 0)
262 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
263 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
264
265 return exec_aout_setup_stack(p, epp);
266 }
267
268 /*
269 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package.
270 * Business as usual.
271 */
272
273 int
274 exec_linux_aout_prep_omagic(p, epp)
275 struct proc *p;
276 struct exec_package *epp;
277 {
278 struct exec *execp = epp->ep_hdr;
279 long dsize, bsize, baddr;
280
281 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC);
282 epp->ep_tsize = execp->a_text;
283 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC);
284 epp->ep_dsize = execp->a_data + execp->a_bss;
285 epp->ep_entry = execp->a_entry;
286
287 /* set up command for text and data segments */
288 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
289 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
290 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
291
292 /* set up command for bss segment */
293 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
294 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
295 if (bsize > 0)
296 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
297 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
298
299 /*
300 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
301 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
302 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
303 * respectively to page boundaries.
304 * Compensate `ep_dsize' for the amount of data covered by the last
305 * text page.
306 */
307 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG);
308 epp->ep_dsize = (dsize > 0) ? dsize : 0;
309 return exec_aout_setup_stack(p, epp);
310 }
311
312 int
313 exec_linux_aout_prep_qmagic(p, epp)
314 struct proc *p;
315 struct exec_package *epp;
316 {
317 struct exec *execp = epp->ep_hdr;
318
319 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC);
320 epp->ep_tsize = execp->a_text;
321 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC);
322 epp->ep_dsize = execp->a_data + execp->a_bss;
323 epp->ep_entry = execp->a_entry;
324
325 /*
326 * check if vnode is in open for writing, because we want to
327 * demand-page out of it. if it is, don't do it, for various
328 * reasons
329 */
330 if ((execp->a_text != 0 || execp->a_data != 0) &&
331 epp->ep_vp->v_writecount != 0) {
332 #ifdef DIAGNOSTIC
333 if (epp->ep_vp->v_flag & VTEXT)
334 panic("exec: a VTEXT vnode has writecount != 0\n");
335 #endif
336 return ETXTBSY;
337 }
338 epp->ep_vp->v_flag |= VTEXT;
339
340 /* set up command for text segment */
341 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
342 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC),
343 VM_PROT_READ|VM_PROT_EXECUTE);
344
345 /* set up command for data segment */
346 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
347 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC),
348 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
349
350 /* set up command for bss segment */
351 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
352 epp->ep_daddr + execp->a_data, NULLVP, 0,
353 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
354
355 return exec_aout_setup_stack(p, epp);
356 }
357
358 /*
359 * The Linux system call to load shared libraries, a.out version. The
360 * a.out shared libs are just files that are mapped onto a fixed
361 * address in the process' address space. The address is given in
362 * a_entry. Read in the header, set up some VM commands and run them.
363 *
364 * Yes, both text and data are mapped at once, so we're left with
365 * writeable text for the shared libs. The Linux crt0 seemed to break
366 * sometimes when data was mapped seperately. It munmapped a uselib()
367 * of ld.so by hand, which failed with shared text and data for ld.so
368 * Yuck.
369 *
370 * Because of the problem with ZMAGIC executables (text starts
371 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC
372 * shared libs are not handled very efficiently :-(
373 */
374
375 int
376 linux_sys_uselib(p, v, retval)
377 struct proc *p;
378 void *v;
379 register_t *retval;
380 {
381 struct linux_sys_uselib_args /* {
382 syscallarg(const char *) path;
383 } */ *uap = v;
384 caddr_t sg;
385 long bsize, dsize, tsize, taddr, baddr, daddr;
386 struct nameidata ni;
387 struct vnode *vp;
388 struct exec hdr;
389 struct exec_vmcmd_set vcset;
390 int i, magic, error;
391 size_t rem;
392
393 sg = stackgap_init(p->p_emul);
394 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
395
396 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
397
398 if ((error = namei(&ni)))
399 return error;
400
401 vp = ni.ni_vp;
402
403 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE,
404 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
405 &rem, p))) {
406 vrele(vp);
407 return error;
408 }
409
410 if (rem != 0) {
411 vrele(vp);
412 return ENOEXEC;
413 }
414
415 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE)
416 return ENOEXEC;
417
418 magic = LINUX_N_MAGIC(&hdr);
419 taddr = hdr.a_entry & (~(NBPG - 1));
420 tsize = hdr.a_text;
421 daddr = taddr + tsize;
422 dsize = hdr.a_data + hdr.a_bss;
423
424 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) {
425 vrele(vp);
426 return ETXTBSY;
427 }
428 vp->v_flag |= VTEXT;
429
430 vcset.evs_cnt = 0;
431 vcset.evs_used = 0;
432
433 NEW_VMCMD(&vcset,
434 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn,
435 hdr.a_text + hdr.a_data, taddr,
436 vp, LINUX_N_TXTOFF(hdr, magic),
437 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE);
438
439 baddr = roundup(daddr + hdr.a_data, NBPG);
440 bsize = daddr + dsize - baddr;
441 if (bsize > 0) {
442 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr,
443 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
444 }
445
446 for (i = 0; i < vcset.evs_used && !error; i++) {
447 struct exec_vmcmd *vcp;
448
449 vcp = &vcset.evs_cmds[i];
450 error = (*vcp->ev_proc)(p, vcp);
451 }
452
453 kill_vmcmds(&vcset);
454
455 vrele(vp);
456
457 return error;
458 }
459