linux32_exec.c revision 1.18 
1/*	$NetBSD: linux32_exec.c,v 1.18 2009/03/14 21:04:18 dsl 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 1.18 2009/03/14 21:04:18 dsl 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(struct proc *p, struct proc *parent, int forkflags)
127{
128	struct linux_emuldata *e = p->p_emuldata;
129	struct linux_emuldata_shared *s;
130	struct linux_emuldata *ep = NULL;
131
132	if (!e) {
133		/* allocate new Linux emuldata */
134		e = malloc(sizeof(struct linux_emuldata),
135			M_EMULDATA, M_WAITOK);
136	} else  {
137		mutex_enter(proc_lock);
138		e->s->refs--;
139		if (e->s->refs == 0)
140			free(e->s, M_EMULDATA);
141		mutex_exit(proc_lock);
142	}
143
144	memset(e, '\0', sizeof(struct linux_emuldata));
145
146	e->proc = p;
147
148	if (parent)
149		ep = parent->p_emuldata;
150
151	if (forkflags & FORK_SHAREVM) {
152		mutex_enter(proc_lock);
153#ifdef DIAGNOSTIC
154		if (ep == NULL) {
155			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
156			mutex_exit(proc_lock);
157			return;
158		}
159#endif
160		s = ep->s;
161		s->refs++;
162	} else {
163		struct vmspace *vm;
164
165		s = malloc(sizeof(struct linux_emuldata_shared),
166			M_EMULDATA, M_WAITOK);
167		s->refs = 1;
168
169		/*
170		 * Set the process idea of the break to the real value.
171		 * For fork, we use parent's vmspace since our's
172		 * is not setup at the time of this call and is going
173		 * to be copy of parent's anyway. For exec, just
174		 * use our own vmspace.
175		 */
176		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
177		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
178
179		/*
180		 * Linux threads are emulated as NetBSD processes (not lwp)
181		 * We use native PID for Linux TID. The Linux TID is the
182		 * PID of the first process in the group. It is stored
183		 * here
184		 */
185		s->group_pid = p->p_pid;
186
187		/*
188		 * Initialize the list of threads in the group
189		 */
190		LIST_INIT(&s->threads);
191
192		s->xstat = 0;
193		s->flags = 0;
194		mutex_enter(proc_lock);
195	}
196
197	e->s = s;
198
199	/*
200	 * Add this thread in the group thread list
201	 */
202	LIST_INSERT_HEAD(&s->threads, e, threads);
203	mutex_exit(proc_lock);
204
205#ifdef LINUX32_NPTL
206	linux_nptl_proc_init(p, parent);
207#endif /* LINUX32_NPTL */
208
209	p->p_emuldata = e;
210}
211
212/*
213 * Allocate new per-process structures. Called when executing Linux
214 * process. We can reuse the old emuldata - if it's not null,
215 * the executed process is of same emulation as original forked one.
216 */
217static void
218linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
219{
220	/* exec, use our vmspace */
221	linux32_e_proc_init(p, NULL, 0);
222}
223
224/*
225 * Emulation per-process exit hook.
226 */
227static void
228linux32_e_proc_exit(struct proc *p)
229{
230	struct linux_emuldata *e = p->p_emuldata;
231
232#ifdef LINUX32_NPTL
233	linux_nptl_proc_exit(p);
234#endif /* LINUX32_NPTL */
235
236	/* Remove the thread for the group thread list */
237	mutex_enter(proc_lock);
238	LIST_REMOVE(e, threads);
239
240	/* free Linux emuldata and set the pointer to null */
241	e->s->refs--;
242	if (e->s->refs == 0)
243		free(e->s, M_EMULDATA);
244	p->p_emuldata = NULL;
245	mutex_exit(proc_lock);
246	free(e, M_EMULDATA);
247}
248
249/*
250 * Emulation fork hook.
251 */
252static void
253linux32_e_proc_fork(struct proc *p, struct proc *parent, 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