2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1994-1996 Søren Schmidt
5 * Copyright (c) 2006 Roman Divacky
7 * Copyright (c) 2013 Dmitry Chagin <dchagin@FreeBSD.org>
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/fcntl.h>
36 #include <sys/imgact.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
42 #include <sys/resourcevar.h>
44 #include <sys/syscallsubr.h>
45 #include <sys/sysent.h>
47 #include <compat/linux/linux_emul.h>
48 #include <compat/linux/linux_mib.h>
49 #include <compat/linux/linux_misc.h>
50 #include <compat/linux/linux_persona.h>
51 #include <compat/linux/linux_util.h>
53 #if BYTE_ORDER == LITTLE_ENDIAN
54 #define SHELLMAGIC 0x2123 /* #! */
56 #define SHELLMAGIC 0x2321
60 * This returns reference to the thread emuldata entry (if found)
62 * Hold PROC_LOCK when referencing emuldata from other threads.
64 struct linux_emuldata *
65 em_find(struct thread *td)
67 struct linux_emuldata *em;
75 * This returns reference to the proc pemuldata entry (if found)
77 * Hold PROC_LOCK when referencing proc pemuldata from other threads.
78 * Hold LINUX_PEM_LOCK wher referencing pemuldata members.
80 struct linux_pemuldata *
81 pem_find(struct proc *p)
83 struct linux_pemuldata *pem;
91 * Linux apps generally expect the soft open file limit to be set
92 * to 1024, often iterating over all the file descriptors up to that
93 * limit instead of using closefrom(2). Give them what they want,
94 * unless there already is a resource limit in place.
97 linux_set_default_openfiles(struct thread *td, struct proc *p)
100 int error __diagused;
102 if (linux_default_openfiles < 0)
106 lim_rlimit_proc(p, RLIMIT_NOFILE, &rlim);
108 if (rlim.rlim_cur != rlim.rlim_max ||
109 rlim.rlim_cur <= linux_default_openfiles)
111 rlim.rlim_cur = linux_default_openfiles;
112 error = kern_proc_setrlimit(td, p, RLIMIT_NOFILE, &rlim);
113 KASSERT(error == 0, ("kern_proc_setrlimit failed"));
117 * The default stack size limit in Linux is 8MB.
120 linux_set_default_stacksize(struct thread *td, struct proc *p)
123 int error __diagused;
125 if (linux_default_stacksize < 0)
129 lim_rlimit_proc(p, RLIMIT_STACK, &rlim);
131 if (rlim.rlim_cur != rlim.rlim_max ||
132 rlim.rlim_cur <= linux_default_stacksize)
134 rlim.rlim_cur = linux_default_stacksize;
135 error = kern_proc_setrlimit(td, p, RLIMIT_STACK, &rlim);
136 KASSERT(error == 0, ("kern_proc_setrlimit failed"));
140 linux_proc_init(struct thread *td, struct thread *newtd, bool init_thread)
142 struct linux_emuldata *em;
143 struct linux_pemuldata *pem;
150 em = malloc(sizeof(*em), M_TEMP, M_WAITOK | M_ZERO);
152 LINUX_CTR1(proc_init, "thread newtd(%d)",
155 em->em_tid = newtd->td_tid;
157 LINUX_CTR1(proc_init, "fork newtd(%d)", p->p_pid);
159 em->em_tid = p->p_pid;
161 pem = malloc(sizeof(*pem), M_LINUX, M_WAITOK | M_ZERO);
162 sx_init(&pem->pem_sx, "lpemlk");
165 newtd->td_emuldata = em;
167 linux_set_default_openfiles(td, p);
168 linux_set_default_stacksize(td, p);
173 LINUX_CTR1(proc_init, "exec newtd(%d)", p->p_pid);
175 /* lookup the old one */
177 KASSERT(em != NULL, ("proc_init: thread emuldata not found.\n"));
179 em->em_tid = p->p_pid;
181 em->robust_futexes = NULL;
182 em->child_clear_tid = NULL;
183 em->child_set_tid = NULL;
186 KASSERT(pem != NULL, ("proc_init: proc emuldata not found.\n"));
188 pem->oom_score_adj = 0;
193 linux_on_exit(struct proc *p)
195 struct linux_pemuldata *pem;
196 struct thread *td = curthread;
198 MPASS(SV_CURPROC_ABI() == SV_ABI_LINUX);
200 LINUX_CTR3(proc_exit, "thread(%d) proc(%d) p %p",
201 td->td_tid, p->p_pid, p);
206 (p->p_sysent->sv_thread_detach)(td);
208 p->p_emuldata = NULL;
210 sx_destroy(&pem->pem_sx);
215 * If a Linux binary is exec'ing something, try this image activator
216 * first. We override standard shell script execution in order to
217 * be able to modify the interpreter path. We only do this if a Linux
218 * binary is doing the exec, so we do not create an EXEC module for it.
221 linux_exec_imgact_try(struct image_params *imgp)
223 const char *head = (const char *)imgp->image_header;
228 * The interpreter for shell scripts run from a Linux binary needs
229 * to be located in /compat/linux if possible in order to recursively
230 * maintain Linux path emulation.
232 if (((const short *)head)[0] == SHELLMAGIC) {
234 * Run our normal shell image activator. If it succeeds attempt
235 * to use the alternate path for the interpreter. If an
236 * alternate path is found, use our stringspace to store it.
238 if ((error = exec_shell_imgact(imgp)) == 0) {
239 linux_emul_convpath(imgp->interpreter_name, UIO_SYSSPACE,
240 &rpath, 0, AT_FDCWD);
242 imgp->args->fname_buf =
243 imgp->interpreter_name = rpath;
250 linux_common_execve(struct thread *td, struct image_args *eargs)
252 struct linux_pemuldata *pem;
253 struct vmspace *oldvmspace;
254 struct linux_emuldata *em;
260 error = pre_execve(td, &oldvmspace);
264 error = kern_execve(td, eargs, NULL, oldvmspace);
265 post_execve(td, error, oldvmspace);
266 if (error != EJUSTRETURN)
270 * In a case of transition from Linux binary execing to
271 * FreeBSD binary we destroy Linux emuldata thread & proc entries.
273 if (SV_CURPROC_ABI() != SV_ABI_LINUX) {
276 KASSERT(em != NULL, ("proc_exec: thread emuldata not found.\n"));
277 td->td_emuldata = NULL;
280 KASSERT(pem != NULL, ("proc_exec: proc pemuldata not found.\n"));
281 p->p_emuldata = NULL;
287 return (EJUSTRETURN);
291 linux_on_exec(struct proc *p, struct image_params *imgp)
294 struct thread *othertd;
295 #if defined(__amd64__)
296 struct linux_pemuldata *pem;
300 MPASS((imgp->sysent->sv_flags & SV_ABI_MASK) == SV_ABI_LINUX);
303 * When execing to Linux binary, we create Linux emuldata
306 if (SV_PROC_ABI(p) == SV_ABI_LINUX) {
308 * Process already was under Linuxolator
309 * before exec. Update emuldata to reflect
310 * single-threaded cleaned state after exec.
312 linux_proc_init(td, NULL, false);
315 * We are switching the process to Linux emulator.
317 linux_proc_init(td, td, false);
320 * Create a transient td_emuldata for all suspended
321 * threads, so that p->p_sysent->sv_thread_detach() ==
322 * linux_thread_detach() can find expected but unused
325 FOREACH_THREAD_IN_PROC(td->td_proc, othertd) {
328 linux_proc_init(td, othertd, true);
331 #if defined(__amd64__)
333 * An IA32 executable which has executable stack will have the
334 * READ_IMPLIES_EXEC personality flag set automatically.
336 if (SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
337 imgp->stack_prot & VM_PROT_EXECUTE) {
339 pem->persona |= LINUX_READ_IMPLIES_EXEC;
345 linux_thread_dtor(struct thread *td)
347 struct linux_emuldata *em;
352 td->td_emuldata = NULL;
354 LINUX_CTR1(thread_dtor, "thread(%d)", em->em_tid);
360 linux_schedtail(struct thread *td)
362 struct linux_emuldata *em;
371 KASSERT(em != NULL, ("linux_schedtail: thread emuldata not found.\n"));
372 child_set_tid = em->child_set_tid;
374 if (child_set_tid != NULL) {
375 error = copyout(&em->em_tid, child_set_tid,
377 LINUX_CTR4(schedtail, "thread(%d) %p stored %d error %d",
378 td->td_tid, child_set_tid, em->em_tid, error);
380 LINUX_CTR1(schedtail, "thread(%d)", em->em_tid);