xref: /freebsd/sys/amd64/linux/linux_machdep.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2013 Dmitry Chagin
3  * Copyright (c) 2004 Tim J. Robbins
4  * Copyright (c) 2002 Doug Rabson
5  * Copyright (c) 2000 Marcel Moolenaar
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer
13  *    in this position and unchanged.
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.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/systm.h>
38 #include <sys/capability.h>
39 #include <sys/dirent.h>
40 #include <sys/file.h>
41 #include <sys/fcntl.h>
42 #include <sys/filedesc.h>
43 #include <sys/clock.h>
44 #include <sys/imgact.h>
45 #include <sys/ktr.h>
46 #include <sys/limits.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mman.h>
50 #include <sys/mutex.h>
51 #include <sys/priv.h>
52 #include <sys/proc.h>
53 #include <sys/resource.h>
54 #include <sys/resourcevar.h>
55 #include <sys/sched.h>
56 #include <sys/syscallsubr.h>
57 #include <sys/sysproto.h>
58 #include <sys/vnode.h>
59 #include <sys/unistd.h>
60 #include <sys/wait.h>
61 
62 #include <security/mac/mac_framework.h>
63 
64 #include <ufs/ufs/extattr.h>
65 #include <ufs/ufs/quota.h>
66 #include <ufs/ufs/ufsmount.h>
67 
68 #include <machine/frame.h>
69 #include <machine/md_var.h>
70 #include <machine/pcb.h>
71 #include <machine/psl.h>
72 #include <machine/segments.h>
73 #include <machine/specialreg.h>
74 
75 #include <vm/vm.h>
76 #include <vm/pmap.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_kern.h>
79 #include <vm/vm_map.h>
80 
81 #include <amd64/linux/linux.h>
82 #include <amd64/linux/linux_proto.h>
83 #include <compat/linux/linux_ipc.h>
84 #include <compat/linux/linux_file.h>
85 #include <compat/linux/linux_misc.h>
86 #include <compat/linux/linux_signal.h>
87 #include <compat/linux/linux_util.h>
88 #include <compat/linux/linux_emul.h>
89 
90 
91 int
92 linux_execve(struct thread *td, struct linux_execve_args *args)
93 {
94 	struct image_args eargs;
95 	char *path;
96 	int error;
97 
98 	LCONVPATHEXIST(td, args->path, &path);
99 
100 	LINUX_CTR(execve);
101 
102 	error = exec_copyin_args(&eargs, path, UIO_SYSSPACE, args->argp,
103 	    args->envp);
104 	free(path, M_TEMP);
105 	if (error == 0)
106 		error = linux_common_execve(td, &eargs);
107 	return (error);
108 }
109 
110 int
111 linux_set_upcall_kse(struct thread *td, register_t stack)
112 {
113 
114 	if (stack)
115 		td->td_frame->tf_rsp = stack;
116 
117 	/*
118 	 * The newly created Linux thread returns
119 	 * to the user space by the same path that a parent do.
120 	 */
121 	td->td_frame->tf_rax = 0;
122 	return (0);
123 }
124 
125 #define STACK_SIZE  (2 * 1024 * 1024)
126 #define GUARD_SIZE  (4 * PAGE_SIZE)
127 
128 int
129 linux_mmap2(struct thread *td, struct linux_mmap2_args *args)
130 {
131 	struct proc *p = td->td_proc;
132 	struct mmap_args /* {
133 		caddr_t addr;
134 		size_t len;
135 		int prot;
136 		int flags;
137 		int fd;
138 		long pad;
139 		off_t pos;
140 	} */ bsd_args;
141 	int error;
142 	struct file *fp;
143 	cap_rights_t rights;
144 
145 	LINUX_CTR6(mmap2, "0x%lx, %ld, %ld, 0x%08lx, %ld, 0x%lx",
146 	    args->addr, args->len, args->prot,
147 	    args->flags, args->fd, args->pgoff);
148 
149 	error = 0;
150 	bsd_args.flags = 0;
151 	fp = NULL;
152 
153 	/*
154 	 * Linux mmap(2):
155 	 * You must specify exactly one of MAP_SHARED and MAP_PRIVATE
156 	 */
157 	if (! ((args->flags & LINUX_MAP_SHARED) ^
158 	    (args->flags & LINUX_MAP_PRIVATE)))
159 		return (EINVAL);
160 
161 	if (args->flags & LINUX_MAP_SHARED)
162 		bsd_args.flags |= MAP_SHARED;
163 	if (args->flags & LINUX_MAP_PRIVATE)
164 		bsd_args.flags |= MAP_PRIVATE;
165 	if (args->flags & LINUX_MAP_FIXED)
166 		bsd_args.flags |= MAP_FIXED;
167 	if (args->flags & LINUX_MAP_ANON)
168 		bsd_args.flags |= MAP_ANON;
169 	else
170 		bsd_args.flags |= MAP_NOSYNC;
171 	if (args->flags & LINUX_MAP_GROWSDOWN)
172 		bsd_args.flags |= MAP_STACK;
173 
174 	/*
175 	 * PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC
176 	 * on Linux/i386. We do this to ensure maximum compatibility.
177 	 * Linux/ia64 does the same in i386 emulation mode.
178 	 */
179 	bsd_args.prot = args->prot;
180 	if (bsd_args.prot & (PROT_READ | PROT_WRITE | PROT_EXEC))
181 		bsd_args.prot |= PROT_READ | PROT_EXEC;
182 
183 	/* Linux does not check file descriptor when MAP_ANONYMOUS is set. */
184 	bsd_args.fd = (bsd_args.flags & MAP_ANON) ? -1 : args->fd;
185 	if (bsd_args.fd != -1) {
186 		/*
187 		 * Linux follows Solaris mmap(2) description:
188 		 * The file descriptor fildes is opened with
189 		 * read permission, regardless of the
190 		 * protection options specified.
191 		 */
192 
193 		error = fget(td, bsd_args.fd,
194 		    cap_rights_init(&rights, CAP_MMAP), &fp);
195 		if (error != 0 )
196 			return (error);
197 		if (fp->f_type != DTYPE_VNODE) {
198 			fdrop(fp, td);
199 			return (EINVAL);
200 		}
201 
202 		/* Linux mmap() just fails for O_WRONLY files */
203 		if (!(fp->f_flag & FREAD)) {
204 			fdrop(fp, td);
205 			return (EACCES);
206 		}
207 
208 		fdrop(fp, td);
209 	}
210 
211 	if (args->flags & LINUX_MAP_GROWSDOWN) {
212 		/*
213 		 * The Linux MAP_GROWSDOWN option does not limit auto
214 		 * growth of the region.  Linux mmap with this option
215 		 * takes as addr the inital BOS, and as len, the initial
216 		 * region size.  It can then grow down from addr without
217 		 * limit.  However, Linux threads has an implicit internal
218 		 * limit to stack size of STACK_SIZE.  Its just not
219 		 * enforced explicitly in Linux.  But, here we impose
220 		 * a limit of (STACK_SIZE - GUARD_SIZE) on the stack
221 		 * region, since we can do this with our mmap.
222 		 *
223 		 * Our mmap with MAP_STACK takes addr as the maximum
224 		 * downsize limit on BOS, and as len the max size of
225 		 * the region.  It then maps the top SGROWSIZ bytes,
226 		 * and auto grows the region down, up to the limit
227 		 * in addr.
228 		 *
229 		 * If we don't use the MAP_STACK option, the effect
230 		 * of this code is to allocate a stack region of a
231 		 * fixed size of (STACK_SIZE - GUARD_SIZE).
232 		 */
233 
234 		if ((caddr_t)PTRIN(args->addr) + args->len >
235 		    p->p_vmspace->vm_maxsaddr) {
236 			/*
237 			 * Some Linux apps will attempt to mmap
238 			 * thread stacks near the top of their
239 			 * address space.  If their TOS is greater
240 			 * than vm_maxsaddr, vm_map_growstack()
241 			 * will confuse the thread stack with the
242 			 * process stack and deliver a SEGV if they
243 			 * attempt to grow the thread stack past their
244 			 * current stacksize rlimit.  To avoid this,
245 			 * adjust vm_maxsaddr upwards to reflect
246 			 * the current stacksize rlimit rather
247 			 * than the maximum possible stacksize.
248 			 * It would be better to adjust the
249 			 * mmap'ed region, but some apps do not check
250 			 * mmap's return value.
251 			 */
252 			PROC_LOCK(p);
253 			p->p_vmspace->vm_maxsaddr = (char *)USRSTACK -
254 			    lim_cur_proc(p, RLIMIT_STACK);
255 			PROC_UNLOCK(p);
256 		}
257 
258 		/*
259 		 * This gives us our maximum stack size and a new BOS.
260 		 * If we're using VM_STACK, then mmap will just map
261 		 * the top SGROWSIZ bytes, and let the stack grow down
262 		 * to the limit at BOS.  If we're not using VM_STACK
263 		 * we map the full stack, since we don't have a way
264 		 * to autogrow it.
265 		 */
266 		if (args->len > STACK_SIZE - GUARD_SIZE) {
267 			bsd_args.addr = (caddr_t)PTRIN(args->addr);
268 			bsd_args.len = args->len;
269 		} else {
270 			bsd_args.addr = (caddr_t)PTRIN(args->addr) -
271 			    (STACK_SIZE - GUARD_SIZE - args->len);
272 			bsd_args.len = STACK_SIZE - GUARD_SIZE;
273 		}
274 	} else {
275 		bsd_args.addr = (caddr_t)PTRIN(args->addr);
276 		bsd_args.len  = args->len;
277 	}
278 	bsd_args.pos = (off_t)args->pgoff;
279 
280 	error = sys_mmap(td, &bsd_args);
281 
282 	LINUX_CTR2(mmap2, "return: %d (%p)",
283 	    error, td->td_retval[0]);
284 	return (error);
285 }
286 
287 int
288 linux_mprotect(struct thread *td, struct linux_mprotect_args *uap)
289 {
290 	struct mprotect_args bsd_args;
291 
292 	LINUX_CTR(mprotect);
293 
294 	bsd_args.addr = uap->addr;
295 	bsd_args.len = uap->len;
296 	bsd_args.prot = uap->prot;
297 	if (bsd_args.prot & (PROT_READ | PROT_WRITE | PROT_EXEC))
298 		bsd_args.prot |= PROT_READ | PROT_EXEC;
299 	return (sys_mprotect(td, &bsd_args));
300 }
301 
302 int
303 linux_iopl(struct thread *td, struct linux_iopl_args *args)
304 {
305 	int error;
306 
307 	LINUX_CTR(iopl);
308 
309 	if (args->level > 3)
310 		return (EINVAL);
311 	if ((error = priv_check(td, PRIV_IO)) != 0)
312 		return (error);
313 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
314 		return (error);
315 	td->td_frame->tf_rflags = (td->td_frame->tf_rflags & ~PSL_IOPL) |
316 	    (args->level * (PSL_IOPL / 3));
317 
318 	return (0);
319 }
320 
321 int
322 linux_rt_sigsuspend(struct thread *td, struct linux_rt_sigsuspend_args *uap)
323 {
324 	l_sigset_t lmask;
325 	sigset_t sigmask;
326 	int error;
327 
328 	LINUX_CTR2(rt_sigsuspend, "%p, %ld",
329 	    uap->newset, uap->sigsetsize);
330 
331 	if (uap->sigsetsize != sizeof(l_sigset_t))
332 		return (EINVAL);
333 
334 	error = copyin(uap->newset, &lmask, sizeof(l_sigset_t));
335 	if (error)
336 		return (error);
337 
338 	linux_to_bsd_sigset(&lmask, &sigmask);
339 	return (kern_sigsuspend(td, sigmask));
340 }
341 
342 int
343 linux_pause(struct thread *td, struct linux_pause_args *args)
344 {
345 	struct proc *p = td->td_proc;
346 	sigset_t sigmask;
347 
348 	LINUX_CTR(pause);
349 
350 	PROC_LOCK(p);
351 	sigmask = td->td_sigmask;
352 	PROC_UNLOCK(p);
353 	return (kern_sigsuspend(td, sigmask));
354 }
355 
356 int
357 linux_sigaltstack(struct thread *td, struct linux_sigaltstack_args *uap)
358 {
359 	stack_t ss, oss;
360 	l_stack_t lss;
361 	int error;
362 
363 	LINUX_CTR2(sigaltstack, "%p, %p", uap->uss, uap->uoss);
364 
365 	if (uap->uss != NULL) {
366 		error = copyin(uap->uss, &lss, sizeof(l_stack_t));
367 		if (error)
368 			return (error);
369 
370 		ss.ss_sp = PTRIN(lss.ss_sp);
371 		ss.ss_size = lss.ss_size;
372 		ss.ss_flags = linux_to_bsd_sigaltstack(lss.ss_flags);
373 	}
374 	error = kern_sigaltstack(td, (uap->uss != NULL) ? &ss : NULL,
375 	    (uap->uoss != NULL) ? &oss : NULL);
376 	if (!error && uap->uoss != NULL) {
377 		lss.ss_sp = PTROUT(oss.ss_sp);
378 		lss.ss_size = oss.ss_size;
379 		lss.ss_flags = bsd_to_linux_sigaltstack(oss.ss_flags);
380 		error = copyout(&lss, uap->uoss, sizeof(l_stack_t));
381 	}
382 
383 	return (error);
384 }
385 
386 int
387 linux_arch_prctl(struct thread *td, struct linux_arch_prctl_args *args)
388 {
389 	int error;
390 	struct pcb *pcb;
391 
392 	LINUX_CTR2(arch_prctl, "0x%x, %p", args->code, args->addr);
393 
394 	error = ENOTSUP;
395 	pcb = td->td_pcb;
396 
397 	switch (args->code) {
398 	case LINUX_ARCH_GET_GS:
399 		error = copyout(&pcb->pcb_gsbase, (unsigned long *)args->addr,
400 		    sizeof(args->addr));
401 		break;
402 	case LINUX_ARCH_SET_GS:
403 		if (args->addr >= VM_MAXUSER_ADDRESS)
404 			return(EPERM);
405 		break;
406 	case LINUX_ARCH_GET_FS:
407 		error = copyout(&pcb->pcb_fsbase, (unsigned long *)args->addr,
408 		    sizeof(args->addr));
409 		break;
410 	case LINUX_ARCH_SET_FS:
411 		error = linux_set_cloned_tls(td, (void *)args->addr);
412 		break;
413 	default:
414 		error = EINVAL;
415 	}
416 	return (error);
417 }
418 
419 int
420 linux_set_cloned_tls(struct thread *td, void *desc)
421 {
422 	struct pcb *pcb;
423 
424 	if ((uint64_t)desc >= VM_MAXUSER_ADDRESS)
425 		return (EPERM);
426 
427 	pcb = td->td_pcb;
428 	pcb->pcb_fsbase = (register_t)desc;
429 	td->td_frame->tf_fs = _ufssel;
430 
431 	return (0);
432 }
433