linux32_exec.c revision 1.13 
1/*	$NetBSD: linux32_exec.c,v 1.13 2008/04/28 20:23:44 martin 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 1.13 2008/04/28 20:23:44 martin 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
92const struct 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};
120
121static void
122linux32_e_proc_init(p, parent, forkflags)
123	struct proc *p, *parent;
124	int forkflags;
125{
126	struct linux_emuldata *e = p->p_emuldata;
127	struct linux_emuldata_shared *s;
128	struct linux_emuldata *ep = NULL;
129
130	if (!e) {
131		/* allocate new Linux emuldata */
132		MALLOC(e, void *, sizeof(struct linux_emuldata),
133			M_EMULDATA, M_WAITOK);
134	} else  {
135		mutex_enter(proc_lock);
136		e->s->refs--;
137		if (e->s->refs == 0)
138			FREE(e->s, M_EMULDATA);
139		mutex_exit(proc_lock);
140	}
141
142	memset(e, '\0', sizeof(struct linux_emuldata));
143
144	e->proc = p;
145
146	if (parent)
147		ep = parent->p_emuldata;
148
149	if (forkflags & FORK_SHAREVM) {
150		mutex_enter(proc_lock);
151#ifdef DIAGNOSTIC
152		if (ep == NULL) {
153			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
154			mutex_exit(proc_lock);
155			return;
156		}
157#endif
158		s = ep->s;
159		s->refs++;
160	} else {
161		struct vmspace *vm;
162
163		MALLOC(s, void *, sizeof(struct linux_emuldata_shared),
164			M_EMULDATA, M_WAITOK);
165		s->refs = 1;
166
167		/*
168		 * Set the process idea of the break to the real value.
169		 * For fork, we use parent's vmspace since our's
170		 * is not setup at the time of this call and is going
171		 * to be copy of parent's anyway. For exec, just
172		 * use our own vmspace.
173		 */
174		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
175		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
176
177		/*
178		 * Linux threads are emulated as NetBSD processes (not lwp)
179		 * We use native PID for Linux TID. The Linux TID is the
180		 * PID of the first process in the group. It is stored
181		 * here
182		 */
183		s->group_pid = p->p_pid;
184
185		/*
186		 * Initialize the list of threads in the group
187		 */
188		LIST_INIT(&s->threads);
189
190		s->xstat = 0;
191		s->flags = 0;
192		mutex_enter(proc_lock);
193	}
194
195	e->s = s;
196
197	/*
198	 * Add this thread in the group thread list
199	 */
200	LIST_INSERT_HEAD(&s->threads, e, threads);
201	mutex_exit(proc_lock);
202
203#ifdef LINUX32_NPTL
204	linux_nptl_proc_init(p, parent);
205#endif /* LINUX32_NPTL */
206
207	p->p_emuldata = e;
208}
209
210/*
211 * Allocate new per-process structures. Called when executing Linux
212 * process. We can reuse the old emuldata - if it's not null,
213 * the executed process is of same emulation as original forked one.
214 */
215static void
216linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
217{
218	/* exec, use our vmspace */
219	linux32_e_proc_init(p, NULL, 0);
220}
221
222/*
223 * Emulation per-process exit hook.
224 */
225static void
226linux32_e_proc_exit(struct proc *p)
227{
228	struct linux_emuldata *e = p->p_emuldata;
229
230#ifdef LINUX32_NPTL
231	linux_nptl_proc_exit(p);
232#endif /* LINUX32_NPTL */
233
234	/* Remove the thread for the group thread list */
235	mutex_enter(proc_lock);
236	LIST_REMOVE(e, threads);
237
238	/* free Linux emuldata and set the pointer to null */
239	e->s->refs--;
240	if (e->s->refs == 0)
241		FREE(e->s, M_EMULDATA);
242	p->p_emuldata = NULL;
243	mutex_exit(proc_lock);
244	FREE(e, M_EMULDATA);
245}
246
247/*
248 * Emulation fork hook.
249 */
250static void
251linux32_e_proc_fork(p, parent, forkflags)
252	struct proc *p, *parent;
253	int forkflags;
254{
255	/*
256	 * The new process might share some vmspace-related stuff
257	 * with parent, depending on fork flags (CLONE_VM et.al).
258	 * Force allocation of new base emuldata, and share the
259	 * VM-related parts only if necessary.
260	 */
261	p->p_emuldata = NULL;
262	linux32_e_proc_init(p, parent, forkflags);
263
264#ifdef LINUX32_NPTL
265	linux_nptl_proc_fork(p, parent, linux32_userret);
266#endif
267
268	return;
269}
270
271#ifdef LINUX32_NPTL
272void
273linux32_userret(void)
274{
275	struct lwp *l = curlwp;
276	struct proc *p = l->l_proc;
277	struct linux_emuldata *led = p->p_emuldata;
278	int error;
279
280	/* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory  */
281	if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) {
282		if ((error = copyout(&l->l_proc->p_pid,
283		    led->child_tidptr,  sizeof(l->l_proc->p_pid))) != 0)
284			printf("linux32_userret: LINUX_CLONE_CHILD_SETTID "
285			    "failed (led->child_tidptr = %p, p->p_pid = %d)\n",
286			    led->child_tidptr, p->p_pid);
287	}
288
289	/* LINUX_CLONE_SETTLS: allocate a new TLS */
290	if (led->clone_flags & LINUX_CLONE_SETTLS) {
291		if (linux32_set_newtls(l, linux32_get_newtls(l)) != 0)
292			printf("linux32_userret: linux32_set_tls failed");
293	}
294
295	return;
296}
297#endif /* LINUX32_NPTL */
298