linux_emul.c (e7153b2583ec32ced588706fe1996d909b23bc3c) linux_emul.c (ad2056f2c46cd6f28b2f7a4bd0e1a72198b19eee)
1/*-
2 * Copyright (c) 2006 Roman Divacky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright

--- 20 unchanged lines hidden (view full) ---

29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include "opt_compat.h"
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/imgact.h>
1/*-
2 * Copyright (c) 2006 Roman Divacky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright

--- 20 unchanged lines hidden (view full) ---

29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include "opt_compat.h"
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/imgact.h>
37#include <sys/kernel.h>
38#include <sys/lock.h>
39#include <sys/malloc.h>
40#include <sys/mutex.h>
41#include <sys/sx.h>
42#include <sys/proc.h>
43#include <sys/syscallsubr.h>
44#include <sys/sysproto.h>
45#include <sys/unistd.h>
46
37#include <sys/lock.h>
38#include <sys/malloc.h>
39#include <sys/mutex.h>
40#include <sys/sx.h>
41#include <sys/proc.h>
42#include <sys/syscallsubr.h>
43#include <sys/sysproto.h>
44#include <sys/unistd.h>
45
46#include <compat/linux/linux_emul.h>
47#include <compat/linux/linux_futex.h>
48
47#ifdef COMPAT_LINUX32
48#include <machine/../linux32/linux.h>
49#include <machine/../linux32/linux32_proto.h>
50#else
51#include <machine/../linux/linux.h>
52#include <machine/../linux/linux_proto.h>
53#endif
54
49#ifdef COMPAT_LINUX32
50#include <machine/../linux32/linux.h>
51#include <machine/../linux32/linux32_proto.h>
52#else
53#include <machine/../linux/linux.h>
54#include <machine/../linux/linux_proto.h>
55#endif
56
55#include <compat/linux/linux_emul.h>
56#include <compat/linux/linux_futex.h>
57struct sx emul_shared_lock;
58struct sx emul_lock;
57
59
58struct sx emul_shared_lock;
59struct mtx emul_lock;
60
61/* this returns locked reference to the emuldata entry (if found) */
62struct linux_emuldata *
63em_find(struct proc *p, int locked)
64{
65 struct linux_emuldata *em;
66
60/* this returns locked reference to the emuldata entry (if found) */
61struct linux_emuldata *
62em_find(struct proc *p, int locked)
63{
64 struct linux_emuldata *em;
65
67 if (locked == EMUL_DOLOCK)
68 EMUL_LOCK(&emul_lock);
66 if (locked == EMUL_UNLOCKED)
67 EMUL_LOCK(&emul_lock);
69
68
70 em = p->p_emuldata;
69 em = p->p_emuldata;
71
70
72 if (em == NULL && locked == EMUL_DOLOCK)
73 EMUL_UNLOCK(&emul_lock);
71 if (em == NULL && locked == EMUL_UNLOCKED)
72 EMUL_UNLOCK(&emul_lock);
74
75 return (em);
76}
77
78int
79linux_proc_init(struct thread *td, pid_t child, int flags)
80{
81 struct linux_emuldata *em, *p_em;
82 struct proc *p;
83
84 if (child != 0) {
73
74 return (em);
75}
76
77int
78linux_proc_init(struct thread *td, pid_t child, int flags)
79{
80 struct linux_emuldata *em, *p_em;
81 struct proc *p;
82
83 if (child != 0) {
85 /* non-exec call */
86 em = malloc(sizeof *em, M_LINUX, M_WAITOK | M_ZERO);
84 /* non-exec call */
85 MALLOC(em, struct linux_emuldata *, sizeof *em, M_LINUX, M_WAITOK | M_ZERO);
87 em->pid = child;
86 em->pid = child;
88 em->pdeath_signal = 0;
89 em->used_requeue = 0;
90 em->robust_futexes = NULL;
91 if (flags & LINUX_CLONE_THREAD) {
92 /* handled later in the code */
87 if (flags & CLONE_VM) {
88 /* handled later in the code */
93 } else {
89 } else {
94 struct linux_emuldata_shared *s;
90 struct linux_emuldata_shared *s;
95
91
96 s = malloc(sizeof *s, M_LINUX, M_WAITOK | M_ZERO);
92 MALLOC(s, struct linux_emuldata_shared *, sizeof *s, M_LINUX, M_WAITOK | M_ZERO);
93 em->shared = s;
97 s->refs = 1;
98 s->group_pid = child;
99
100 LIST_INIT(&s->threads);
94 s->refs = 1;
95 s->group_pid = child;
96
97 LIST_INIT(&s->threads);
101 em->shared = s;
102 }
98 }
99 p = pfind(child);
100 if (p == NULL)
101 panic("process not found in proc_init\n");
102 p->p_emuldata = em;
103 PROC_UNLOCK(p);
103 } else {
104 /* lookup the old one */
104 } else {
105 /* lookup the old one */
105 em = em_find(td->td_proc, EMUL_DOLOCK);
106 em = em_find(td->td_proc, EMUL_UNLOCKED);
106 KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
107 }
108
109 em->child_clear_tid = NULL;
110 em->child_set_tid = NULL;
111
107 KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
108 }
109
110 em->child_clear_tid = NULL;
111 em->child_set_tid = NULL;
112
112 /*
113 * allocate the shared struct only in clone()/fork cases in the case
114 * of clone() td = calling proc and child = pid of the newly created
115 * proc
113 /* allocate the shared struct only in clone()/fork cases
114 * in the case of clone() td = calling proc and child = pid of
115 * the newly created proc
116 */
117 if (child != 0) {
116 */
117 if (child != 0) {
118 if (flags & LINUX_CLONE_THREAD) {
119 /* lookup the parent */
120 /*
121 * we dont have to lock the p_em because
122 * its waiting for us in linux_clone so
123 * there is no chance of it changing the
124 * p_em->shared address
125 */
126 p_em = em_find(td->td_proc, EMUL_DONTLOCK);
127 KASSERT(p_em != NULL, ("proc_init: parent emuldata not found for CLONE_THREAD\n"));
118 if (flags & CLONE_VM) {
119 /* lookup the parent */
120 p_em = em_find(td->td_proc, EMUL_LOCKED);
121 KASSERT(p_em != NULL, ("proc_init: parent emuldata not found for CLONE_VM\n"));
128 em->shared = p_em->shared;
122 em->shared = p_em->shared;
129 EMUL_SHARED_WLOCK(&emul_shared_lock);
130 em->shared->refs++;
123 em->shared->refs++;
131 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
132 } else {
124 } else {
133 /*
134 * handled earlier to avoid malloc(M_WAITOK) with
135 * rwlock held
136 */
125 /* handled earlier to avoid malloc(M_WAITOK) with rwlock held */
137 }
138 }
126 }
127 }
128
129
139 if (child != 0) {
130 if (child != 0) {
140 EMUL_SHARED_WLOCK(&emul_shared_lock);
141 LIST_INSERT_HEAD(&em->shared->threads, em, threads);
142 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
131 EMUL_SHARED_WLOCK(&emul_shared_lock);
132 LIST_INSERT_HEAD(&em->shared->threads, em, threads);
133 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
143
144 p = pfind(child);
134
135 p = pfind(child);
145 KASSERT(p != NULL, ("process not found in proc_init\n"));
146 p->p_emuldata = em;
147 PROC_UNLOCK(p);
136 PROC_UNLOCK(p);
137 /* we might have a sleeping linux_schedtail */
138 wakeup(&p->p_emuldata);
148 } else
139 } else
149 EMUL_UNLOCK(&emul_lock);
140 EMUL_UNLOCK(&emul_lock);
150
141
151 return (0);
142 return (0);
152}
153
154void
155linux_proc_exit(void *arg __unused, struct proc *p)
156{
143}
144
145void
146linux_proc_exit(void *arg __unused, struct proc *p)
147{
157 struct linux_emuldata *em;
148 struct linux_emuldata *em;
158 int error;
159 struct thread *td = FIRST_THREAD_IN_PROC(p);
160 int *child_clear_tid;
149 int error;
150 struct thread *td = FIRST_THREAD_IN_PROC(p);
151 int *child_clear_tid;
161 struct proc *q, *nq;
162
163 if (__predict_true(p->p_sysent != &elf_linux_sysvec))
152
153 if (__predict_true(p->p_sysent != &elf_linux_sysvec))
164 return;
154 return;
165
155
166 release_futexes(p);
167
168 /* find the emuldata */
156 /* find the emuldata */
169 em = em_find(p, EMUL_DOLOCK);
157 em = em_find(p, EMUL_UNLOCKED);
170
171 KASSERT(em != NULL, ("proc_exit: emuldata not found.\n"));
172
158
159 KASSERT(em != NULL, ("proc_exit: emuldata not found.\n"));
160
173 /* reparent all procs that are not a thread leader to initproc */
174 if (em->shared->group_pid != p->p_pid) {
175 child_clear_tid = em->child_clear_tid;
176 EMUL_UNLOCK(&emul_lock);
177 sx_xlock(&proctree_lock);
178 wakeup(initproc);
179 PROC_LOCK(p);
180 proc_reparent(p, initproc);
181 p->p_sigparent = SIGCHLD;
182 PROC_UNLOCK(p);
183 sx_xunlock(&proctree_lock);
184 } else {
185 child_clear_tid = em->child_clear_tid;
186 EMUL_UNLOCK(&emul_lock);
187 }
161 child_clear_tid = em->child_clear_tid;
162
163 EMUL_UNLOCK(&emul_lock);
188
189 EMUL_SHARED_WLOCK(&emul_shared_lock);
190 LIST_REMOVE(em, threads);
191
164
165 EMUL_SHARED_WLOCK(&emul_shared_lock);
166 LIST_REMOVE(em, threads);
167
168 PROC_LOCK(p);
169 p->p_emuldata = NULL;
170 PROC_UNLOCK(p);
171
192 em->shared->refs--;
172 em->shared->refs--;
193 if (em->shared->refs == 0) {
194 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
195 free(em->shared, M_LINUX);
196 } else
197 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
173 if (em->shared->refs == 0)
174 FREE(em->shared, M_LINUX);
175 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
198
199 if (child_clear_tid != NULL) {
176
177 if (child_clear_tid != NULL) {
200 struct linux_sys_futex_args cup;
178 struct linux_sys_futex_args cup;
201 int null = 0;
202
203 error = copyout(&null, child_clear_tid, sizeof(null));
179 int null = 0;
180
181 error = copyout(&null, child_clear_tid, sizeof(null));
204 if (error) {
205 free(em, M_LINUX);
206 return;
207 }
182 if (error)
183 return;
208
209 /* futexes stuff */
210 cup.uaddr = child_clear_tid;
211 cup.op = LINUX_FUTEX_WAKE;
184
185 /* futexes stuff */
186 cup.uaddr = child_clear_tid;
187 cup.op = LINUX_FUTEX_WAKE;
212 cup.val = 0x7fffffff; /* Awake everyone */
188 cup.val = 0x7fffffff; /* Awake everyone */
213 cup.timeout = NULL;
214 cup.uaddr2 = NULL;
215 cup.val3 = 0;
216 error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup);
189 cup.timeout = NULL;
190 cup.uaddr2 = NULL;
191 cup.val3 = 0;
192 error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup);
217 /*
218 * this cannot happen at the moment and if this happens it
219 * probably means there is a user space bug
220 */
193 /* this cannot happen at the moment and if this happens
194 * it probably mean there is a userspace bug
195 */
221 if (error)
196 if (error)
222 printf(LMSG("futex stuff in proc_exit failed.\n"));
197 printf(LMSG("futex stuff in proc_exit failed.\n"));
223 }
224
225 /* clean the stuff up */
198 }
199
200 /* clean the stuff up */
226 free(em, M_LINUX);
227
228 /* this is a little weird but rewritten from exit1() */
229 sx_xlock(&proctree_lock);
230 q = LIST_FIRST(&p->p_children);
231 for (; q != NULL; q = nq) {
232 nq = LIST_NEXT(q, p_sibling);
233 if (q->p_flag & P_WEXIT)
234 continue;
235 if (__predict_false(q->p_sysent != &elf_linux_sysvec))
236 continue;
237 em = em_find(q, EMUL_DOLOCK);
238 KASSERT(em != NULL, ("linux_reparent: emuldata not found: %i\n", q->p_pid));
239 PROC_LOCK(q);
240 if ((q->p_flag & P_WEXIT) == 0 && em->pdeath_signal != 0) {
241 psignal(q, em->pdeath_signal);
242 }
243 PROC_UNLOCK(q);
244 EMUL_UNLOCK(&emul_lock);
245 }
246 sx_xunlock(&proctree_lock);
201 FREE(em, M_LINUX);
247}
248
202}
203
249/*
250 * This is used in a case of transition from FreeBSD binary execing to linux binary
204/* This is used in a case of transition from FreeBSD binary execing to linux binary
251 * in this case we create linux emuldata proc entry with the pid of the currently running
252 * process.
253 */
205 * in this case we create linux emuldata proc entry with the pid of the currently running
206 * process.
207 */
254void
255linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
208void linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
256{
209{
257 if (__predict_false(imgp->sysent == &elf_linux_sysvec
258 && p->p_sysent != &elf_linux_sysvec))
259 linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0);
210 if (__predict_false(imgp->sysent == &elf_linux_sysvec
211 && p->p_sysent != &elf_linux_sysvec))
212 linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0);
260 if (__predict_false(imgp->sysent != &elf_linux_sysvec
213 if (__predict_false(imgp->sysent != &elf_linux_sysvec
261 && p->p_sysent == &elf_linux_sysvec)) {
262 struct linux_emuldata *em;
214 && p->p_sysent == &elf_linux_sysvec)) {
215 struct linux_emuldata *em;
263
216
264 /*
265 * XXX:There's a race because here we assign p->p_emuldata NULL
266 * but the process is still counted as linux one for a short
267 * time so some other process might reference it and try to
268 * access its p->p_emuldata and panicing on a NULL reference.
269 */
270 em = em_find(p, EMUL_DONTLOCK);
217 em = em_find(p, EMUL_UNLOCKED);
271
272 KASSERT(em != NULL, ("proc_exec: emuldata not found.\n"));
218
219 KASSERT(em != NULL, ("proc_exec: emuldata not found.\n"));
220
221 EMUL_UNLOCK(&emul_lock);
273
274 EMUL_SHARED_WLOCK(&emul_shared_lock);
275 LIST_REMOVE(em, threads);
276
277 PROC_LOCK(p);
278 p->p_emuldata = NULL;
279 PROC_UNLOCK(p);
280
281 em->shared->refs--;
222
223 EMUL_SHARED_WLOCK(&emul_shared_lock);
224 LIST_REMOVE(em, threads);
225
226 PROC_LOCK(p);
227 p->p_emuldata = NULL;
228 PROC_UNLOCK(p);
229
230 em->shared->refs--;
282 if (em->shared->refs == 0) {
283 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
284 free(em->shared, M_LINUX);
285 } else
286 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
231 if (em->shared->refs == 0)
232 FREE(em->shared, M_LINUX);
233 EMUL_SHARED_WUNLOCK(&emul_shared_lock);
287
234
288 free(em, M_LINUX);
235 FREE(em, M_LINUX);
289 }
290}
291
236 }
237}
238
239extern int hz; /* in subr_param.c */
240
292void
293linux_schedtail(void *arg __unused, struct proc *p)
294{
295 struct linux_emuldata *em;
296 int error = 0;
241void
242linux_schedtail(void *arg __unused, struct proc *p)
243{
244 struct linux_emuldata *em;
245 int error = 0;
246#ifdef DEBUG
247 struct thread *td = FIRST_THREAD_IN_PROC(p);
248#endif
297 int *child_set_tid;
298
249 int *child_set_tid;
250
299 if (__predict_true(p->p_sysent != &elf_linux_sysvec))
300 return;
251 if (p->p_sysent != &elf_linux_sysvec)
252 return;
301
253
254retry:
302 /* find the emuldata */
255 /* find the emuldata */
303 em = em_find(p, EMUL_DOLOCK);
256 em = em_find(p, EMUL_UNLOCKED);
304
257
305 KASSERT(em != NULL, ("linux_schedtail: emuldata not found.\n"));
258 if (em == NULL) {
259 /* We might have been called before proc_init for this process so
260 * tsleep and be woken up by it. We use p->p_emuldata for this
261 */
262
263 error = tsleep(&p->p_emuldata, PLOCK, "linux_schedtail", hz);
264 if (error == 0)
265 goto retry;
266 panic("no emuldata found for userreting process.\n");
267 }
306 child_set_tid = em->child_set_tid;
307 EMUL_UNLOCK(&emul_lock);
308
309 if (child_set_tid != NULL)
268 child_set_tid = em->child_set_tid;
269 EMUL_UNLOCK(&emul_lock);
270
271 if (child_set_tid != NULL)
310 error = copyout(&p->p_pid, (int *)child_set_tid,
311 sizeof(p->p_pid));
272 error = copyout(&p->p_pid, (int *) child_set_tid, sizeof(p->p_pid));
312
313 return;
314}
315
316int
317linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args)
318{
273
274 return;
275}
276
277int
278linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args)
279{
319 struct linux_emuldata *em;
280 struct linux_emuldata *em;
320
321#ifdef DEBUG
322 if (ldebug(set_tid_address))
323 printf(ARGS(set_tid_address, "%p"), args->tidptr);
324#endif
325
281
282#ifdef DEBUG
283 if (ldebug(set_tid_address))
284 printf(ARGS(set_tid_address, "%p"), args->tidptr);
285#endif
286
326 /* find the emuldata */
327 em = em_find(td->td_proc, EMUL_DOLOCK);
287 /* find the emuldata */
288 em = em_find(td->td_proc, EMUL_UNLOCKED);
328
329 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n"));
330
331 em->child_clear_tid = args->tidptr;
332 td->td_retval[0] = td->td_proc->p_pid;
333
334 EMUL_UNLOCK(&emul_lock);
335 return 0;
336}
289
290 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n"));
291
292 em->child_clear_tid = args->tidptr;
293 td->td_retval[0] = td->td_proc->p_pid;
294
295 EMUL_UNLOCK(&emul_lock);
296 return 0;
297}