linux32_exec.c revision 1.16 
1/*	$NetBSD: linux32_exec.c,v 1.16 2008/11/19 18:36:04 ad Exp $ */
2
3/*-
4 * Copyright (c) 1994-2007 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, Eric Haszlakiewicz,
9 * Thor Lancelot Simon, and Emmanuel Dreyfus.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: linux32_exec.c,v 1.16 2008/11/19 18:36:04 ad Exp $");
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/kernel.h>
39#include <sys/proc.h>
40#include <sys/malloc.h>
41#include <sys/namei.h>
42#include <sys/vnode.h>
43#include <sys/mount.h>
44#include <sys/exec.h>
45#include <sys/exec_elf.h>
46
47#include <sys/mman.h>
48#include <sys/syscallargs.h>
49#include <sys/ptrace.h>		/* For proc_reparent() */
50
51#include <uvm/uvm_extern.h>
52
53#include <sys/cpu.h>
54#include <machine/reg.h>
55
56#include <compat/linux/common/linux_types.h>
57#include <compat/linux/common/linux_emuldata.h>
58
59#include <compat/linux32/common/linux32_exec.h>
60#include <compat/linux32/common/linux32_types.h>
61#include <compat/linux32/common/linux32_signal.h>
62#include <compat/linux32/common/linux32_machdep.h>
63
64#include <compat/linux32/linux32_syscallargs.h>
65#include <compat/linux32/linux32_syscall.h>
66
67extern char linux32_sigcode[1];
68extern char linux32_rt_sigcode[1];
69extern char linux32_esigcode[1];
70
71extern struct sysent linux32_sysent[];
72extern const char * const linux32_syscallnames[];
73
74static void linux32_e_proc_exec(struct proc *, struct exec_package *);
75static void linux32_e_proc_fork(struct proc *, struct proc *, int);
76static void linux32_e_proc_exit(struct proc *);
77static void linux32_e_proc_init(struct proc *, struct proc *, int);
78
79#ifdef LINUX32_NPTL
80void linux32_userret(void);
81void linux_nptl_proc_fork(struct proc *, struct proc *, void (*luserret)(void));
82void linux_nptl_proc_exit(struct proc *);
83void linux_nptl_proc_init(struct proc *, struct proc *);
84#endif
85
86/*
87 * Emulation switch.
88 */
89
90struct uvm_object *emul_linux32_object;
91
92struct emul emul_linux32 = {
93	"linux32",
94	"/emul/linux32",
95#ifndef __HAVE_MINIMAL_EMUL
96	0,
97	NULL,
98	LINUX32_SYS_syscall,
99	LINUX32_SYS_NSYSENT,
100#endif
101	linux32_sysent,
102	linux32_syscallnames,
103	linux32_sendsig,
104	trapsignal,
105	NULL,
106	linux32_sigcode,
107	linux32_esigcode,
108	&emul_linux32_object,
109	linux32_setregs,
110	linux32_e_proc_exec,
111	linux32_e_proc_fork,
112	linux32_e_proc_exit,
113	NULL,
114	NULL,
115	linux32_syscall_intern,
116	NULL,
117	NULL,
118	netbsd32_vm_default_addr,
119	NULL,
120	NULL,
121	0,
122	NULL
123};
124
125static void
126linux32_e_proc_init(p, parent, forkflags)
127	struct proc *p, *parent;
128	int forkflags;
129{
130	struct linux_emuldata *e = p->p_emuldata;
131	struct linux_emuldata_shared *s;
132	struct linux_emuldata *ep = NULL;
133
134	if (!e) {
135		/* allocate new Linux emuldata */
136		MALLOC(e, void *, sizeof(struct linux_emuldata),
137			M_EMULDATA, M_WAITOK);
138	} else  {
139		mutex_enter(proc_lock);
140		e->s->refs--;
141		if (e->s->refs == 0)
142			FREE(e->s, M_EMULDATA);
143		mutex_exit(proc_lock);
144	}
145
146	memset(e, '\0', sizeof(struct linux_emuldata));
147
148	e->proc = p;
149
150	if (parent)
151		ep = parent->p_emuldata;
152
153	if (forkflags & FORK_SHAREVM) {
154		mutex_enter(proc_lock);
155#ifdef DIAGNOSTIC
156		if (ep == NULL) {
157			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
158			mutex_exit(proc_lock);
159			return;
160		}
161#endif
162		s = ep->s;
163		s->refs++;
164	} else {
165		struct vmspace *vm;
166
167		MALLOC(s, void *, sizeof(struct linux_emuldata_shared),
168			M_EMULDATA, M_WAITOK);
169		s->refs = 1;
170
171		/*
172		 * Set the process idea of the break to the real value.
173		 * For fork, we use parent's vmspace since our's
174		 * is not setup at the time of this call and is going
175		 * to be copy of parent's anyway. For exec, just
176		 * use our own vmspace.
177		 */
178		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
179		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
180
181		/*
182		 * Linux threads are emulated as NetBSD processes (not lwp)
183		 * We use native PID for Linux TID. The Linux TID is the
184		 * PID of the first process in the group. It is stored
185		 * here
186		 */
187		s->group_pid = p->p_pid;
188
189		/*
190		 * Initialize the list of threads in the group
191		 */
192		LIST_INIT(&s->threads);
193
194		s->xstat = 0;
195		s->flags = 0;
196		mutex_enter(proc_lock);
197	}
198
199	e->s = s;
200
201	/*
202	 * Add this thread in the group thread list
203	 */
204	LIST_INSERT_HEAD(&s->threads, e, threads);
205	mutex_exit(proc_lock);
206
207#ifdef LINUX32_NPTL
208	linux_nptl_proc_init(p, parent);
209#endif /* LINUX32_NPTL */
210
211	p->p_emuldata = e;
212}
213
214/*
215 * Allocate new per-process structures. Called when executing Linux
216 * process. We can reuse the old emuldata - if it's not null,
217 * the executed process is of same emulation as original forked one.
218 */
219static void
220linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
221{
222	/* exec, use our vmspace */
223	linux32_e_proc_init(p, NULL, 0);
224}
225
226/*
227 * Emulation per-process exit hook.
228 */
229static void
230linux32_e_proc_exit(struct proc *p)
231{
232	struct linux_emuldata *e = p->p_emuldata;
233
234#ifdef LINUX32_NPTL
235	linux_nptl_proc_exit(p);
236#endif /* LINUX32_NPTL */
237
238	/* Remove the thread for the group thread list */
239	mutex_enter(proc_lock);
240	LIST_REMOVE(e, threads);
241
242	/* free Linux emuldata and set the pointer to null */
243	e->s->refs--;
244	if (e->s->refs == 0)
245		FREE(e->s, M_EMULDATA);
246	p->p_emuldata = NULL;
247	mutex_exit(proc_lock);
248	FREE(e, M_EMULDATA);
249}
250
251/*
252 * Emulation fork hook.
253 */
254static void
255linux32_e_proc_fork(p, parent, forkflags)
256	struct proc *p, *parent;
257	int forkflags;
258{
259	/*
260	 * The new process might share some vmspace-related stuff
261	 * with parent, depending on fork flags (CLONE_VM et.al).
262	 * Force allocation of new base emuldata, and share the
263	 * VM-related parts only if necessary.
264	 */
265	p->p_emuldata = NULL;
266	linux32_e_proc_init(p, parent, forkflags);
267
268#ifdef LINUX32_NPTL
269	linux_nptl_proc_fork(p, parent, linux32_userret);
270#endif
271
272	return;
273}
274
275#ifdef LINUX32_NPTL
276void
277linux32_userret(void)
278{
279	struct lwp *l = curlwp;
280	struct proc *p = l->l_proc;
281	struct linux_emuldata *led = p->p_emuldata;
282	int error;
283
284	/* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory  */
285	if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) {
286		if ((error = copyout(&l->l_proc->p_pid,
287		    led->child_tidptr,  sizeof(l->l_proc->p_pid))) != 0)
288			printf("linux32_userret: LINUX_CLONE_CHILD_SETTID "
289			    "failed (led->child_tidptr = %p, p->p_pid = %d)\n",
290			    led->child_tidptr, p->p_pid);
291	}
292
293	/* LINUX_CLONE_SETTLS: allocate a new TLS */
294	if (led->clone_flags & LINUX_CLONE_SETTLS) {
295		if (linux32_set_newtls(l, linux32_get_newtls(l)) != 0)
296			printf("linux32_userret: linux32_set_tls failed");
297	}
298
299	return;
300}
301#endif /* LINUX32_NPTL */
302