2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1994-1996 Søren Schmidt
5 * Copyright (c) 2006 Roman Divacky
6 * Copyright (c) 2013 Dmitry Chagin
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/fcntl.h>
37 #include <sys/imgact.h>
38 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/mutex.h>
45 #include <sys/resourcevar.h>
46 #include <sys/syscallsubr.h>
47 #include <sys/sysent.h>
49 #include <compat/linux/linux_emul.h>
50 #include <compat/linux/linux_mib.h>
51 #include <compat/linux/linux_misc.h>
52 #include <compat/linux/linux_persona.h>
53 #include <compat/linux/linux_util.h>
55 #if BYTE_ORDER == LITTLE_ENDIAN
56 #define SHELLMAGIC 0x2123 /* #! */
58 #define SHELLMAGIC 0x2321
62 * This returns reference to the thread emuldata entry (if found)
64 * Hold PROC_LOCK when referencing emuldata from other threads.
66 struct linux_emuldata *
67 em_find(struct thread *td)
69 struct linux_emuldata *em;
77 * This returns reference to the proc pemuldata entry (if found)
79 * Hold PROC_LOCK when referencing proc pemuldata from other threads.
80 * Hold LINUX_PEM_LOCK wher referencing pemuldata members.
82 struct linux_pemuldata *
83 pem_find(struct proc *p)
85 struct linux_pemuldata *pem;
93 * Linux apps generally expect the soft open file limit to be set
94 * to 1024, often iterating over all the file descriptors up to that
95 * limit instead of using closefrom(2). Give them what they want,
96 * unless there already is a resource limit in place.
99 linux_set_default_openfiles(struct thread *td, struct proc *p)
104 if (linux_default_openfiles < 0)
108 lim_rlimit_proc(p, RLIMIT_NOFILE, &rlim);
110 if (rlim.rlim_cur != rlim.rlim_max ||
111 rlim.rlim_cur <= linux_default_openfiles)
113 rlim.rlim_cur = linux_default_openfiles;
114 error = kern_proc_setrlimit(td, p, RLIMIT_NOFILE, &rlim);
115 KASSERT(error == 0, ("kern_proc_setrlimit failed"));
119 * The default stack size limit in Linux is 8MB.
122 linux_set_default_stacksize(struct thread *td, struct proc *p)
127 if (linux_default_stacksize < 0)
131 lim_rlimit_proc(p, RLIMIT_STACK, &rlim);
133 if (rlim.rlim_cur != rlim.rlim_max ||
134 rlim.rlim_cur <= linux_default_stacksize)
136 rlim.rlim_cur = linux_default_stacksize;
137 error = kern_proc_setrlimit(td, p, RLIMIT_STACK, &rlim);
138 KASSERT(error == 0, ("kern_proc_setrlimit failed"));
142 linux_proc_init(struct thread *td, struct thread *newtd, int flags)
144 struct linux_emuldata *em;
145 struct linux_pemuldata *pem;
152 em = malloc(sizeof(*em), M_TEMP, M_WAITOK | M_ZERO);
153 if (flags & LINUX_CLONE_THREAD) {
154 LINUX_CTR1(proc_init, "thread newtd(%d)",
157 em->em_tid = newtd->td_tid;
159 LINUX_CTR1(proc_init, "fork newtd(%d)", p->p_pid);
161 em->em_tid = p->p_pid;
163 pem = malloc(sizeof(*pem), M_LINUX, M_WAITOK | M_ZERO);
164 sx_init(&pem->pem_sx, "lpemlk");
167 newtd->td_emuldata = em;
169 linux_set_default_openfiles(td, p);
170 linux_set_default_stacksize(td, p);
175 LINUX_CTR1(proc_init, "exec newtd(%d)", p->p_pid);
177 /* lookup the old one */
179 KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
181 em->em_tid = p->p_pid;
183 em->robust_futexes = NULL;
184 em->child_clear_tid = NULL;
185 em->child_set_tid = NULL;
188 KASSERT(pem != NULL, ("proc_exit: proc emuldata not found.\n"));
195 linux_on_exit(struct proc *p)
197 struct linux_pemuldata *pem;
198 struct thread *td = curthread;
200 MPASS(SV_CURPROC_ABI() == SV_ABI_LINUX);
202 LINUX_CTR3(proc_exit, "thread(%d) proc(%d) p %p",
203 td->td_tid, p->p_pid, p);
208 (p->p_sysent->sv_thread_detach)(td);
210 p->p_emuldata = NULL;
212 sx_destroy(&pem->pem_sx);
217 * If a Linux binary is exec'ing something, try this image activator
218 * first. We override standard shell script execution in order to
219 * be able to modify the interpreter path. We only do this if a Linux
220 * binary is doing the exec, so we do not create an EXEC module for it.
223 linux_exec_imgact_try(struct image_params *imgp)
225 const char *head = (const char *)imgp->image_header;
230 * The interpreter for shell scripts run from a Linux binary needs
231 * to be located in /compat/linux if possible in order to recursively
232 * maintain Linux path emulation.
234 if (((const short *)head)[0] == SHELLMAGIC) {
236 * Run our normal shell image activator. If it succeeds attempt
237 * to use the alternate path for the interpreter. If an
238 * alternate path is found, use our stringspace to store it.
240 if ((error = exec_shell_imgact(imgp)) == 0) {
241 linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
242 imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0,
245 imgp->args->fname_buf =
246 imgp->interpreter_name = rpath;
253 linux_common_execve(struct thread *td, struct image_args *eargs)
255 struct linux_pemuldata *pem;
256 struct vmspace *oldvmspace;
257 struct linux_emuldata *em;
263 error = pre_execve(td, &oldvmspace);
267 error = kern_execve(td, eargs, NULL, oldvmspace);
268 post_execve(td, error, oldvmspace);
269 if (error != EJUSTRETURN)
273 * In a case of transition from Linux binary execing to
274 * FreeBSD binary we destroy Linux emuldata thread & proc entries.
276 if (SV_CURPROC_ABI() != SV_ABI_LINUX) {
279 KASSERT(em != NULL, ("proc_exec: thread emuldata not found.\n"));
280 td->td_emuldata = NULL;
283 KASSERT(pem != NULL, ("proc_exec: proc pemuldata not found.\n"));
284 p->p_emuldata = NULL;
290 return (EJUSTRETURN);
294 linux_on_exec(struct proc *p, struct image_params *imgp)
297 struct thread *othertd;
298 #if defined(__amd64__)
299 struct linux_pemuldata *pem;
303 MPASS((imgp->sysent->sv_flags & SV_ABI_MASK) == SV_ABI_LINUX);
306 * When execing to Linux binary, we create Linux emuldata
309 if (SV_PROC_ABI(p) == SV_ABI_LINUX) {
311 * Process already was under Linuxolator
312 * before exec. Update emuldata to reflect
313 * single-threaded cleaned state after exec.
315 linux_proc_init(td, NULL, 0);
318 * We are switching the process to Linux emulator.
320 linux_proc_init(td, td, 0);
323 * Create a transient td_emuldata for all suspended
324 * threads, so that p->p_sysent->sv_thread_detach() ==
325 * linux_thread_detach() can find expected but unused
328 FOREACH_THREAD_IN_PROC(td->td_proc, othertd) {
331 linux_proc_init(td, othertd, LINUX_CLONE_THREAD);
334 #if defined(__amd64__)
336 * An IA32 executable which has executable stack will have the
337 * READ_IMPLIES_EXEC personality flag set automatically.
339 if (SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
340 imgp->stack_prot & VM_PROT_EXECUTE) {
342 pem->persona |= LINUX_READ_IMPLIES_EXEC;
348 linux_thread_dtor(struct thread *td)
350 struct linux_emuldata *em;
355 td->td_emuldata = NULL;
357 LINUX_CTR1(thread_dtor, "thread(%d)", em->em_tid);
363 linux_schedtail(struct thread *td)
365 struct linux_emuldata *em;
373 KASSERT(em != NULL, ("linux_schedtail: thread emuldata not found.\n"));
374 child_set_tid = em->child_set_tid;
376 if (child_set_tid != NULL) {
377 error = copyout(&em->em_tid, child_set_tid,
379 LINUX_CTR4(schedtail, "thread(%d) %p stored %d error %d",
380 td->td_tid, child_set_tid, em->em_tid, error);
382 LINUX_CTR1(schedtail, "thread(%d)", em->em_tid);