xref: /freebsd/sys/i386/linux/linux_sysvec.c (revision e8e8c939350bdf3c228a411caa9660c607c27a11)
1 /*-
2  * Copyright (c) 1994-1996 Søren Schmidt
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
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/exec.h>
35 #include <sys/fcntl.h>
36 #include <sys/imgact.h>
37 #include <sys/imgact_aout.h>
38 #include <sys/imgact_elf.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/signalvar.h>
46 #include <sys/syscallsubr.h>
47 #include <sys/sysctl.h>
48 #include <sys/sysent.h>
49 #include <sys/sysproto.h>
50 #include <sys/vnode.h>
51 #include <sys/eventhandler.h>
52 
53 #include <vm/vm.h>
54 #include <vm/pmap.h>
55 #include <vm/vm_extern.h>
56 #include <vm/vm_map.h>
57 #include <vm/vm_object.h>
58 #include <vm/vm_page.h>
59 #include <vm/vm_param.h>
60 
61 #include <machine/cpu.h>
62 #include <machine/cputypes.h>
63 #include <machine/md_var.h>
64 #include <machine/pcb.h>
65 
66 #include <i386/linux/linux.h>
67 #include <i386/linux/linux_proto.h>
68 #include <compat/linux/linux_emul.h>
69 #include <compat/linux/linux_futex.h>
70 #include <compat/linux/linux_ioctl.h>
71 #include <compat/linux/linux_mib.h>
72 #include <compat/linux/linux_misc.h>
73 #include <compat/linux/linux_signal.h>
74 #include <compat/linux/linux_util.h>
75 #include <compat/linux/linux_vdso.h>
76 
77 MODULE_VERSION(linux, 1);
78 
79 #if BYTE_ORDER == LITTLE_ENDIAN
80 #define SHELLMAGIC      0x2123 /* #! */
81 #else
82 #define SHELLMAGIC      0x2321
83 #endif
84 
85 #if defined(DEBUG)
86 SYSCTL_PROC(_compat_linux, OID_AUTO, debug,
87             CTLTYPE_STRING | CTLFLAG_RW,
88             0, 0, linux_sysctl_debug, "A",
89             "Linux debugging control");
90 #endif
91 
92 /*
93  * Allow the sendsig functions to use the ldebug() facility
94  * even though they are not syscalls themselves. Map them
95  * to syscall 0. This is slightly less bogus than using
96  * ldebug(sigreturn).
97  */
98 #define	LINUX_SYS_linux_rt_sendsig	0
99 #define	LINUX_SYS_linux_sendsig		0
100 
101 #define	LINUX_PS_STRINGS	(LINUX_USRSTACK - sizeof(struct ps_strings))
102 
103 static int linux_szsigcode;
104 static vm_object_t linux_shared_page_obj;
105 static char *linux_shared_page_mapping;
106 extern char _binary_linux_locore_o_start;
107 extern char _binary_linux_locore_o_end;
108 
109 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
110 
111 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
112 
113 static int	linux_fixup(register_t **stack_base,
114 		    struct image_params *iparams);
115 static int	elf_linux_fixup(register_t **stack_base,
116 		    struct image_params *iparams);
117 static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
118 static void	exec_linux_setregs(struct thread *td,
119 		    struct image_params *imgp, u_long stack);
120 static register_t *linux_copyout_strings(struct image_params *imgp);
121 static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
122 static void	linux_vdso_install(void *param);
123 static void	linux_vdso_deinstall(void *param);
124 
125 static int linux_szplatform;
126 const char *linux_kplatform;
127 
128 static eventhandler_tag linux_exit_tag;
129 static eventhandler_tag linux_exec_tag;
130 static eventhandler_tag linux_thread_dtor_tag;
131 
132 /*
133  * Linux syscalls return negative errno's, we do positive and map them
134  * Reference:
135  *   FreeBSD: src/sys/sys/errno.h
136  *   Linux:   linux-2.6.17.8/include/asm-generic/errno-base.h
137  *            linux-2.6.17.8/include/asm-generic/errno.h
138  */
139 static int bsd_to_linux_errno[ELAST + 1] = {
140 	-0,  -1,  -2,  -3,  -4,  -5,  -6,  -7,  -8,  -9,
141 	-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
142 	-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
143 	-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
144 	-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
145 	-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
146 	-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
147 	-116, -66,  -6,  -6,  -6,  -6,  -6, -37, -38,  -9,
148 	  -6,  -6, -43, -42, -75,-125, -84, -95, -16, -74,
149 	 -72, -67, -71
150 };
151 
152 #define LINUX_T_UNKNOWN  255
153 static int _bsd_to_linux_trapcode[] = {
154 	LINUX_T_UNKNOWN,	/* 0 */
155 	6,			/* 1  T_PRIVINFLT */
156 	LINUX_T_UNKNOWN,	/* 2 */
157 	3,			/* 3  T_BPTFLT */
158 	LINUX_T_UNKNOWN,	/* 4 */
159 	LINUX_T_UNKNOWN,	/* 5 */
160 	16,			/* 6  T_ARITHTRAP */
161 	254,			/* 7  T_ASTFLT */
162 	LINUX_T_UNKNOWN,	/* 8 */
163 	13,			/* 9  T_PROTFLT */
164 	1,			/* 10 T_TRCTRAP */
165 	LINUX_T_UNKNOWN,	/* 11 */
166 	14,			/* 12 T_PAGEFLT */
167 	LINUX_T_UNKNOWN,	/* 13 */
168 	17,			/* 14 T_ALIGNFLT */
169 	LINUX_T_UNKNOWN,	/* 15 */
170 	LINUX_T_UNKNOWN,	/* 16 */
171 	LINUX_T_UNKNOWN,	/* 17 */
172 	0,			/* 18 T_DIVIDE */
173 	2,			/* 19 T_NMI */
174 	4,			/* 20 T_OFLOW */
175 	5,			/* 21 T_BOUND */
176 	7,			/* 22 T_DNA */
177 	8,			/* 23 T_DOUBLEFLT */
178 	9,			/* 24 T_FPOPFLT */
179 	10,			/* 25 T_TSSFLT */
180 	11,			/* 26 T_SEGNPFLT */
181 	12,			/* 27 T_STKFLT */
182 	18,			/* 28 T_MCHK */
183 	19,			/* 29 T_XMMFLT */
184 	15			/* 30 T_RESERVED */
185 };
186 #define bsd_to_linux_trapcode(code) \
187     ((code)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \
188      _bsd_to_linux_trapcode[(code)]: \
189      LINUX_T_UNKNOWN)
190 
191 LINUX_VDSO_SYM_INTPTR(linux_sigcode);
192 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
193 LINUX_VDSO_SYM_INTPTR(linux_vsyscall);
194 
195 /*
196  * If FreeBSD & Linux have a difference of opinion about what a trap
197  * means, deal with it here.
198  *
199  * MPSAFE
200  */
201 static int
202 translate_traps(int signal, int trap_code)
203 {
204 	if (signal != SIGBUS)
205 		return (signal);
206 	switch (trap_code) {
207 	case T_PROTFLT:
208 	case T_TSSFLT:
209 	case T_DOUBLEFLT:
210 	case T_PAGEFLT:
211 		return (SIGSEGV);
212 	default:
213 		return (signal);
214 	}
215 }
216 
217 static int
218 linux_fixup(register_t **stack_base, struct image_params *imgp)
219 {
220 	register_t *argv, *envp;
221 
222 	argv = *stack_base;
223 	envp = *stack_base + (imgp->args->argc + 1);
224 	(*stack_base)--;
225 	suword(*stack_base, (intptr_t)(void *)envp);
226 	(*stack_base)--;
227 	suword(*stack_base, (intptr_t)(void *)argv);
228 	(*stack_base)--;
229 	suword(*stack_base, imgp->args->argc);
230 	return (0);
231 }
232 
233 static int
234 elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
235 {
236 	struct proc *p;
237 	Elf32_Auxargs *args;
238 	Elf32_Addr *uplatform;
239 	struct ps_strings *arginfo;
240 	register_t *pos;
241 
242 	KASSERT(curthread->td_proc == imgp->proc,
243 	    ("unsafe elf_linux_fixup(), should be curproc"));
244 
245 	p = imgp->proc;
246 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
247 	uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
248 	args = (Elf32_Auxargs *)imgp->auxargs;
249 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
250 
251 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
252 	    imgp->proc->p_sysent->sv_shared_page_base);
253 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall);
254 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
255 
256 	/*
257 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
258 	 * as it has appeared in the 2.4.0-rc7 first time.
259 	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
260 	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
261 	 * is not present.
262 	 * Also see linux_times() implementation.
263 	 */
264 	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
265 		AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
266 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
267 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
268 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
269 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
270 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
271 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
272 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
273 	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, 0);
274 	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
275 	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
276 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
277 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
278 	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
279 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
280 	if (imgp->execpathp != 0)
281 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
282 	if (args->execfd != -1)
283 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
284 	AUXARGS_ENTRY(pos, AT_NULL, 0);
285 
286 	free(imgp->auxargs, M_TEMP);
287 	imgp->auxargs = NULL;
288 
289 	(*stack_base)--;
290 	suword(*stack_base, (register_t)imgp->args->argc);
291 	return (0);
292 }
293 
294 /*
295  * Copied from kern/kern_exec.c
296  */
297 static register_t *
298 linux_copyout_strings(struct image_params *imgp)
299 {
300 	int argc, envc;
301 	char **vectp;
302 	char *stringp, *destp;
303 	register_t *stack_base;
304 	struct ps_strings *arginfo;
305 	char canary[LINUX_AT_RANDOM_LEN];
306 	size_t execpath_len;
307 	struct proc *p;
308 
309 	/*
310 	 * Calculate string base and vector table pointers.
311 	 */
312 	p = imgp->proc;
313 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
314 		execpath_len = strlen(imgp->execpath) + 1;
315 	else
316 		execpath_len = 0;
317 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
318 	destp = (caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform -
319 	    roundup(sizeof(canary), sizeof(char *)) -
320 	    roundup(execpath_len, sizeof(char *)) -
321 	    roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
322 
323 	/*
324 	 * install LINUX_PLATFORM
325 	 */
326 	copyout(linux_kplatform, ((caddr_t)arginfo - linux_szplatform),
327 	    linux_szplatform);
328 
329 	if (execpath_len != 0) {
330 		imgp->execpathp = (uintptr_t)arginfo -
331 		linux_szplatform - execpath_len;
332 		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
333 	}
334 
335 	/*
336 	 * Prepare the canary for SSP.
337 	 */
338 	arc4rand(canary, sizeof(canary), 0);
339 	imgp->canary = (uintptr_t)arginfo - linux_szplatform -
340 	    roundup(execpath_len, sizeof(char *)) -
341 	    roundup(sizeof(canary), sizeof(char *));
342 	copyout(canary, (void *)imgp->canary, sizeof(canary));
343 
344 	/*
345 	 * If we have a valid auxargs ptr, prepare some room
346 	 * on the stack.
347 	 */
348 	if (imgp->auxargs) {
349 		/*
350 		 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
351 		 * lower compatibility.
352 		 */
353 		imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
354 		    (LINUX_AT_COUNT * 2);
355 		/*
356 		 * The '+ 2' is for the null pointers at the end of each of
357 		 * the arg and env vector sets,and imgp->auxarg_size is room
358 		 * for argument of Runtime loader.
359 		 */
360 		vectp = (char **)(destp - (imgp->args->argc +
361 		    imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
362 	} else {
363 		/*
364 		 * The '+ 2' is for the null pointers at the end of each of
365 		 * the arg and env vector sets
366 		 */
367 		vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
368 		    sizeof(char *));
369 	}
370 
371 	/*
372 	 * vectp also becomes our initial stack base
373 	 */
374 	stack_base = (register_t *)vectp;
375 
376 	stringp = imgp->args->begin_argv;
377 	argc = imgp->args->argc;
378 	envc = imgp->args->envc;
379 
380 	/*
381 	 * Copy out strings - arguments and environment.
382 	 */
383 	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
384 
385 	/*
386 	 * Fill in "ps_strings" struct for ps, w, etc.
387 	 */
388 	suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
389 	suword(&arginfo->ps_nargvstr, argc);
390 
391 	/*
392 	 * Fill in argument portion of vector table.
393 	 */
394 	for (; argc > 0; --argc) {
395 		suword(vectp++, (long)(intptr_t)destp);
396 		while (*stringp++ != 0)
397 			destp++;
398 		destp++;
399 	}
400 
401 	/* a null vector table pointer separates the argp's from the envp's */
402 	suword(vectp++, 0);
403 
404 	suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
405 	suword(&arginfo->ps_nenvstr, envc);
406 
407 	/*
408 	 * Fill in environment portion of vector table.
409 	 */
410 	for (; envc > 0; --envc) {
411 		suword(vectp++, (long)(intptr_t)destp);
412 		while (*stringp++ != 0)
413 			destp++;
414 		destp++;
415 	}
416 
417 	/* end of vector table is a null pointer */
418 	suword(vectp, 0);
419 
420 	return (stack_base);
421 }
422 
423 static void
424 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
425 {
426 	struct thread *td = curthread;
427 	struct proc *p = td->td_proc;
428 	struct sigacts *psp;
429 	struct trapframe *regs;
430 	struct l_rt_sigframe *fp, frame;
431 	int sig, code;
432 	int oonstack;
433 
434 	sig = ksi->ksi_signo;
435 	code = ksi->ksi_code;
436 	PROC_LOCK_ASSERT(p, MA_OWNED);
437 	psp = p->p_sigacts;
438 	mtx_assert(&psp->ps_mtx, MA_OWNED);
439 	regs = td->td_frame;
440 	oonstack = sigonstack(regs->tf_esp);
441 
442 #ifdef DEBUG
443 	if (ldebug(rt_sendsig))
444 		printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
445 		    catcher, sig, (void*)mask, code);
446 #endif
447 	/*
448 	 * Allocate space for the signal handler context.
449 	 */
450 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
451 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
452 		fp = (struct l_rt_sigframe *)(td->td_sigstk.ss_sp +
453 		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
454 	} else
455 		fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
456 	mtx_unlock(&psp->ps_mtx);
457 
458 	/*
459 	 * Build the argument list for the signal handler.
460 	 */
461 	sig = bsd_to_linux_signal(sig);
462 
463 	bzero(&frame, sizeof(frame));
464 
465 	frame.sf_handler = catcher;
466 	frame.sf_sig = sig;
467 	frame.sf_siginfo = &fp->sf_si;
468 	frame.sf_ucontext = &fp->sf_sc;
469 
470 	/* Fill in POSIX parts */
471 	ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
472 
473 	/*
474 	 * Build the signal context to be used by sigreturn.
475 	 */
476 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
477 	frame.sf_sc.uc_link = NULL;		/* XXX ??? */
478 
479 	frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
480 	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
481 	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
482 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
483 	PROC_UNLOCK(p);
484 
485 	bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
486 
487 	frame.sf_sc.uc_mcontext.sc_mask   = frame.sf_sc.uc_sigmask.__mask;
488 	frame.sf_sc.uc_mcontext.sc_gs     = rgs();
489 	frame.sf_sc.uc_mcontext.sc_fs     = regs->tf_fs;
490 	frame.sf_sc.uc_mcontext.sc_es     = regs->tf_es;
491 	frame.sf_sc.uc_mcontext.sc_ds     = regs->tf_ds;
492 	frame.sf_sc.uc_mcontext.sc_edi    = regs->tf_edi;
493 	frame.sf_sc.uc_mcontext.sc_esi    = regs->tf_esi;
494 	frame.sf_sc.uc_mcontext.sc_ebp    = regs->tf_ebp;
495 	frame.sf_sc.uc_mcontext.sc_ebx    = regs->tf_ebx;
496 	frame.sf_sc.uc_mcontext.sc_esp    = regs->tf_esp;
497 	frame.sf_sc.uc_mcontext.sc_edx    = regs->tf_edx;
498 	frame.sf_sc.uc_mcontext.sc_ecx    = regs->tf_ecx;
499 	frame.sf_sc.uc_mcontext.sc_eax    = regs->tf_eax;
500 	frame.sf_sc.uc_mcontext.sc_eip    = regs->tf_eip;
501 	frame.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
502 	frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
503 	frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
504 	frame.sf_sc.uc_mcontext.sc_ss     = regs->tf_ss;
505 	frame.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
506 	frame.sf_sc.uc_mcontext.sc_cr2    = (register_t)ksi->ksi_addr;
507 	frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
508 
509 #ifdef DEBUG
510 	if (ldebug(rt_sendsig))
511 		printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
512 		    frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
513 		    td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
514 #endif
515 
516 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
517 		/*
518 		 * Process has trashed its stack; give it an illegal
519 		 * instruction to halt it in its tracks.
520 		 */
521 #ifdef DEBUG
522 		if (ldebug(rt_sendsig))
523 			printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
524 			    fp, oonstack);
525 #endif
526 		PROC_LOCK(p);
527 		sigexit(td, SIGILL);
528 	}
529 
530 	/*
531 	 * Build context to run handler in.
532 	 */
533 	regs->tf_esp = (int)fp;
534 	regs->tf_eip = linux_rt_sigcode;
535 	regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
536 	regs->tf_cs = _ucodesel;
537 	regs->tf_ds = _udatasel;
538 	regs->tf_es = _udatasel;
539 	regs->tf_fs = _udatasel;
540 	regs->tf_ss = _udatasel;
541 	PROC_LOCK(p);
542 	mtx_lock(&psp->ps_mtx);
543 }
544 
545 
546 /*
547  * Send an interrupt to process.
548  *
549  * Stack is set up to allow sigcode stored
550  * in u. to call routine, followed by kcall
551  * to sigreturn routine below.  After sigreturn
552  * resets the signal mask, the stack, and the
553  * frame pointer, it returns to the user
554  * specified pc, psl.
555  */
556 static void
557 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
558 {
559 	struct thread *td = curthread;
560 	struct proc *p = td->td_proc;
561 	struct sigacts *psp;
562 	struct trapframe *regs;
563 	struct l_sigframe *fp, frame;
564 	l_sigset_t lmask;
565 	int sig, code;
566 	int oonstack;
567 
568 	PROC_LOCK_ASSERT(p, MA_OWNED);
569 	psp = p->p_sigacts;
570 	sig = ksi->ksi_signo;
571 	code = ksi->ksi_code;
572 	mtx_assert(&psp->ps_mtx, MA_OWNED);
573 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
574 		/* Signal handler installed with SA_SIGINFO. */
575 		linux_rt_sendsig(catcher, ksi, mask);
576 		return;
577 	}
578 	regs = td->td_frame;
579 	oonstack = sigonstack(regs->tf_esp);
580 
581 #ifdef DEBUG
582 	if (ldebug(sendsig))
583 		printf(ARGS(sendsig, "%p, %d, %p, %u"),
584 		    catcher, sig, (void*)mask, code);
585 #endif
586 
587 	/*
588 	 * Allocate space for the signal handler context.
589 	 */
590 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
591 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
592 		fp = (struct l_sigframe *)(td->td_sigstk.ss_sp +
593 		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
594 	} else
595 		fp = (struct l_sigframe *)regs->tf_esp - 1;
596 	mtx_unlock(&psp->ps_mtx);
597 	PROC_UNLOCK(p);
598 
599 	/*
600 	 * Build the argument list for the signal handler.
601 	 */
602 	sig = bsd_to_linux_signal(sig);
603 
604 	bzero(&frame, sizeof(frame));
605 
606 	frame.sf_handler = catcher;
607 	frame.sf_sig = sig;
608 
609 	bsd_to_linux_sigset(mask, &lmask);
610 
611 	/*
612 	 * Build the signal context to be used by sigreturn.
613 	 */
614 	frame.sf_sc.sc_mask   = lmask.__mask;
615 	frame.sf_sc.sc_gs     = rgs();
616 	frame.sf_sc.sc_fs     = regs->tf_fs;
617 	frame.sf_sc.sc_es     = regs->tf_es;
618 	frame.sf_sc.sc_ds     = regs->tf_ds;
619 	frame.sf_sc.sc_edi    = regs->tf_edi;
620 	frame.sf_sc.sc_esi    = regs->tf_esi;
621 	frame.sf_sc.sc_ebp    = regs->tf_ebp;
622 	frame.sf_sc.sc_ebx    = regs->tf_ebx;
623 	frame.sf_sc.sc_esp    = regs->tf_esp;
624 	frame.sf_sc.sc_edx    = regs->tf_edx;
625 	frame.sf_sc.sc_ecx    = regs->tf_ecx;
626 	frame.sf_sc.sc_eax    = regs->tf_eax;
627 	frame.sf_sc.sc_eip    = regs->tf_eip;
628 	frame.sf_sc.sc_cs     = regs->tf_cs;
629 	frame.sf_sc.sc_eflags = regs->tf_eflags;
630 	frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
631 	frame.sf_sc.sc_ss     = regs->tf_ss;
632 	frame.sf_sc.sc_err    = regs->tf_err;
633 	frame.sf_sc.sc_cr2    = (register_t)ksi->ksi_addr;
634 	frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
635 
636 	frame.sf_extramask[0] = lmask.__mask;
637 
638 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
639 		/*
640 		 * Process has trashed its stack; give it an illegal
641 		 * instruction to halt it in its tracks.
642 		 */
643 		PROC_LOCK(p);
644 		sigexit(td, SIGILL);
645 	}
646 
647 	/*
648 	 * Build context to run handler in.
649 	 */
650 	regs->tf_esp = (int)fp;
651 	regs->tf_eip = linux_sigcode;
652 	regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
653 	regs->tf_cs = _ucodesel;
654 	regs->tf_ds = _udatasel;
655 	regs->tf_es = _udatasel;
656 	regs->tf_fs = _udatasel;
657 	regs->tf_ss = _udatasel;
658 	PROC_LOCK(p);
659 	mtx_lock(&psp->ps_mtx);
660 }
661 
662 /*
663  * System call to cleanup state after a signal
664  * has been taken.  Reset signal mask and
665  * stack state from context left by sendsig (above).
666  * Return to previous pc and psl as specified by
667  * context left by sendsig. Check carefully to
668  * make sure that the user has not modified the
669  * psl to gain improper privileges or to cause
670  * a machine fault.
671  */
672 int
673 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
674 {
675 	struct l_sigframe frame;
676 	struct trapframe *regs;
677 	l_sigset_t lmask;
678 	sigset_t bmask;
679 	int eflags;
680 	ksiginfo_t ksi;
681 
682 	regs = td->td_frame;
683 
684 #ifdef DEBUG
685 	if (ldebug(sigreturn))
686 		printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
687 #endif
688 	/*
689 	 * The trampoline code hands us the sigframe.
690 	 * It is unsafe to keep track of it ourselves, in the event that a
691 	 * program jumps out of a signal handler.
692 	 */
693 	if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
694 		return (EFAULT);
695 
696 	/*
697 	 * Check for security violations.
698 	 */
699 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
700 	eflags = frame.sf_sc.sc_eflags;
701 	if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
702 		return (EINVAL);
703 
704 	/*
705 	 * Don't allow users to load a valid privileged %cs.  Let the
706 	 * hardware check for invalid selectors, excess privilege in
707 	 * other selectors, invalid %eip's and invalid %esp's.
708 	 */
709 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
710 	if (!CS_SECURE(frame.sf_sc.sc_cs)) {
711 		ksiginfo_init_trap(&ksi);
712 		ksi.ksi_signo = SIGBUS;
713 		ksi.ksi_code = BUS_OBJERR;
714 		ksi.ksi_trapno = T_PROTFLT;
715 		ksi.ksi_addr = (void *)regs->tf_eip;
716 		trapsignal(td, &ksi);
717 		return (EINVAL);
718 	}
719 
720 	lmask.__mask = frame.sf_sc.sc_mask;
721 	linux_to_bsd_sigset(&lmask, &bmask);
722 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
723 
724 	/*
725 	 * Restore signal context.
726 	 */
727 	/* %gs was restored by the trampoline. */
728 	regs->tf_fs     = frame.sf_sc.sc_fs;
729 	regs->tf_es     = frame.sf_sc.sc_es;
730 	regs->tf_ds     = frame.sf_sc.sc_ds;
731 	regs->tf_edi    = frame.sf_sc.sc_edi;
732 	regs->tf_esi    = frame.sf_sc.sc_esi;
733 	regs->tf_ebp    = frame.sf_sc.sc_ebp;
734 	regs->tf_ebx    = frame.sf_sc.sc_ebx;
735 	regs->tf_edx    = frame.sf_sc.sc_edx;
736 	regs->tf_ecx    = frame.sf_sc.sc_ecx;
737 	regs->tf_eax    = frame.sf_sc.sc_eax;
738 	regs->tf_eip    = frame.sf_sc.sc_eip;
739 	regs->tf_cs     = frame.sf_sc.sc_cs;
740 	regs->tf_eflags = eflags;
741 	regs->tf_esp    = frame.sf_sc.sc_esp_at_signal;
742 	regs->tf_ss     = frame.sf_sc.sc_ss;
743 
744 	return (EJUSTRETURN);
745 }
746 
747 /*
748  * System call to cleanup state after a signal
749  * has been taken.  Reset signal mask and
750  * stack state from context left by rt_sendsig (above).
751  * Return to previous pc and psl as specified by
752  * context left by sendsig. Check carefully to
753  * make sure that the user has not modified the
754  * psl to gain improper privileges or to cause
755  * a machine fault.
756  */
757 int
758 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
759 {
760 	struct l_ucontext uc;
761 	struct l_sigcontext *context;
762 	sigset_t bmask;
763 	l_stack_t *lss;
764 	stack_t ss;
765 	struct trapframe *regs;
766 	int eflags;
767 	ksiginfo_t ksi;
768 
769 	regs = td->td_frame;
770 
771 #ifdef DEBUG
772 	if (ldebug(rt_sigreturn))
773 		printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
774 #endif
775 	/*
776 	 * The trampoline code hands us the ucontext.
777 	 * It is unsafe to keep track of it ourselves, in the event that a
778 	 * program jumps out of a signal handler.
779 	 */
780 	if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
781 		return (EFAULT);
782 
783 	context = &uc.uc_mcontext;
784 
785 	/*
786 	 * Check for security violations.
787 	 */
788 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
789 	eflags = context->sc_eflags;
790 	if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
791 		return (EINVAL);
792 
793 	/*
794 	 * Don't allow users to load a valid privileged %cs.  Let the
795 	 * hardware check for invalid selectors, excess privilege in
796 	 * other selectors, invalid %eip's and invalid %esp's.
797 	 */
798 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
799 	if (!CS_SECURE(context->sc_cs)) {
800 		ksiginfo_init_trap(&ksi);
801 		ksi.ksi_signo = SIGBUS;
802 		ksi.ksi_code = BUS_OBJERR;
803 		ksi.ksi_trapno = T_PROTFLT;
804 		ksi.ksi_addr = (void *)regs->tf_eip;
805 		trapsignal(td, &ksi);
806 		return (EINVAL);
807 	}
808 
809 	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
810 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
811 
812 	/*
813 	 * Restore signal context
814 	 */
815 	/* %gs was restored by the trampoline. */
816 	regs->tf_fs     = context->sc_fs;
817 	regs->tf_es     = context->sc_es;
818 	regs->tf_ds     = context->sc_ds;
819 	regs->tf_edi    = context->sc_edi;
820 	regs->tf_esi    = context->sc_esi;
821 	regs->tf_ebp    = context->sc_ebp;
822 	regs->tf_ebx    = context->sc_ebx;
823 	regs->tf_edx    = context->sc_edx;
824 	regs->tf_ecx    = context->sc_ecx;
825 	regs->tf_eax    = context->sc_eax;
826 	regs->tf_eip    = context->sc_eip;
827 	regs->tf_cs     = context->sc_cs;
828 	regs->tf_eflags = eflags;
829 	regs->tf_esp    = context->sc_esp_at_signal;
830 	regs->tf_ss     = context->sc_ss;
831 
832 	/*
833 	 * call sigaltstack & ignore results..
834 	 */
835 	lss = &uc.uc_stack;
836 	ss.ss_sp = lss->ss_sp;
837 	ss.ss_size = lss->ss_size;
838 	ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
839 
840 #ifdef DEBUG
841 	if (ldebug(rt_sigreturn))
842 		printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
843 		    ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
844 #endif
845 	(void)kern_sigaltstack(td, &ss, NULL);
846 
847 	return (EJUSTRETURN);
848 }
849 
850 static int
851 linux_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
852 {
853 	struct proc *p;
854 	struct trapframe *frame;
855 
856 	p = td->td_proc;
857 	frame = td->td_frame;
858 
859 	sa->code = frame->tf_eax;
860 	sa->args[0] = frame->tf_ebx;
861 	sa->args[1] = frame->tf_ecx;
862 	sa->args[2] = frame->tf_edx;
863 	sa->args[3] = frame->tf_esi;
864 	sa->args[4] = frame->tf_edi;
865 	sa->args[5] = frame->tf_ebp;	/* Unconfirmed */
866 
867 	if (sa->code >= p->p_sysent->sv_size)
868 		/* nosys */
869 		sa->callp = &p->p_sysent->sv_table[LINUX_SYS_MAXSYSCALL];
870  	else
871  		sa->callp = &p->p_sysent->sv_table[sa->code];
872 	sa->narg = sa->callp->sy_narg;
873 
874 	td->td_retval[0] = 0;
875 	td->td_retval[1] = frame->tf_edx;
876 
877 	return (0);
878 }
879 
880 /*
881  * If a linux binary is exec'ing something, try this image activator
882  * first.  We override standard shell script execution in order to
883  * be able to modify the interpreter path.  We only do this if a linux
884  * binary is doing the exec, so we do not create an EXEC module for it.
885  */
886 static int	exec_linux_imgact_try(struct image_params *iparams);
887 
888 static int
889 exec_linux_imgact_try(struct image_params *imgp)
890 {
891     const char *head = (const char *)imgp->image_header;
892     char *rpath;
893     int error = -1;
894 
895     /*
896      * The interpreter for shell scripts run from a linux binary needs
897      * to be located in /compat/linux if possible in order to recursively
898      * maintain linux path emulation.
899      */
900     if (((const short *)head)[0] == SHELLMAGIC) {
901 	    /*
902 	     * Run our normal shell image activator.  If it succeeds attempt
903 	     * to use the alternate path for the interpreter.  If an alternate
904 	     * path is found, use our stringspace to store it.
905 	     */
906 	    if ((error = exec_shell_imgact(imgp)) == 0) {
907 		    linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
908 			imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0, AT_FDCWD);
909 		    if (rpath != NULL)
910 			    imgp->args->fname_buf =
911 				imgp->interpreter_name = rpath;
912 	    }
913     }
914     return (error);
915 }
916 
917 /*
918  * exec_setregs may initialize some registers differently than Linux
919  * does, thus potentially confusing Linux binaries. If necessary, we
920  * override the exec_setregs default(s) here.
921  */
922 static void
923 exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
924 {
925 	struct pcb *pcb = td->td_pcb;
926 
927 	exec_setregs(td, imgp, stack);
928 
929 	/* Linux sets %gs to 0, we default to _udatasel */
930 	pcb->pcb_gs = 0;
931 	load_gs(0);
932 
933 	pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
934 }
935 
936 static void
937 linux_get_machine(const char **dst)
938 {
939 
940 	switch (cpu_class) {
941 	case CPUCLASS_686:
942 		*dst = "i686";
943 		break;
944 	case CPUCLASS_586:
945 		*dst = "i586";
946 		break;
947 	case CPUCLASS_486:
948 		*dst = "i486";
949 		break;
950 	default:
951 		*dst = "i386";
952 	}
953 }
954 
955 struct sysentvec linux_sysvec = {
956 	.sv_size	= LINUX_SYS_MAXSYSCALL,
957 	.sv_table	= linux_sysent,
958 	.sv_mask	= 0,
959 	.sv_sigsize	= 0,
960 	.sv_sigtbl	= NULL,
961 	.sv_errsize	= ELAST + 1,
962 	.sv_errtbl	= bsd_to_linux_errno,
963 	.sv_transtrap	= translate_traps,
964 	.sv_fixup	= linux_fixup,
965 	.sv_sendsig	= linux_sendsig,
966 	.sv_sigcode	= &_binary_linux_locore_o_start,
967 	.sv_szsigcode	= &linux_szsigcode,
968 	.sv_prepsyscall	= NULL,
969 	.sv_name	= "Linux a.out",
970 	.sv_coredump	= NULL,
971 	.sv_imgact_try	= exec_linux_imgact_try,
972 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
973 	.sv_pagesize	= PAGE_SIZE,
974 	.sv_minuser	= VM_MIN_ADDRESS,
975 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
976 	.sv_usrstack	= LINUX_USRSTACK,
977 	.sv_psstrings	= PS_STRINGS,
978 	.sv_stackprot	= VM_PROT_ALL,
979 	.sv_copyout_strings = exec_copyout_strings,
980 	.sv_setregs	= exec_linux_setregs,
981 	.sv_fixlimit	= NULL,
982 	.sv_maxssiz	= NULL,
983 	.sv_flags	= SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
984 	.sv_set_syscall_retval = cpu_set_syscall_retval,
985 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
986 	.sv_syscallnames = NULL,
987 	.sv_shared_page_base = LINUX_SHAREDPAGE,
988 	.sv_shared_page_len = PAGE_SIZE,
989 	.sv_schedtail	= linux_schedtail,
990 	.sv_thread_detach = linux_thread_detach,
991 };
992 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
993 
994 struct sysentvec elf_linux_sysvec = {
995 	.sv_size	= LINUX_SYS_MAXSYSCALL,
996 	.sv_table	= linux_sysent,
997 	.sv_mask	= 0,
998 	.sv_sigsize	= 0,
999 	.sv_sigtbl	= NULL,
1000 	.sv_errsize	= ELAST + 1,
1001 	.sv_errtbl	= bsd_to_linux_errno,
1002 	.sv_transtrap	= translate_traps,
1003 	.sv_fixup	= elf_linux_fixup,
1004 	.sv_sendsig	= linux_sendsig,
1005 	.sv_sigcode	= &_binary_linux_locore_o_start,
1006 	.sv_szsigcode	= &linux_szsigcode,
1007 	.sv_prepsyscall	= NULL,
1008 	.sv_name	= "Linux ELF",
1009 	.sv_coredump	= elf32_coredump,
1010 	.sv_imgact_try	= exec_linux_imgact_try,
1011 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
1012 	.sv_pagesize	= PAGE_SIZE,
1013 	.sv_minuser	= VM_MIN_ADDRESS,
1014 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
1015 	.sv_usrstack	= LINUX_USRSTACK,
1016 	.sv_psstrings	= LINUX_PS_STRINGS,
1017 	.sv_stackprot	= VM_PROT_ALL,
1018 	.sv_copyout_strings = linux_copyout_strings,
1019 	.sv_setregs	= exec_linux_setregs,
1020 	.sv_fixlimit	= NULL,
1021 	.sv_maxssiz	= NULL,
1022 	.sv_flags	= SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
1023 	.sv_set_syscall_retval = cpu_set_syscall_retval,
1024 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
1025 	.sv_syscallnames = NULL,
1026 	.sv_shared_page_base = LINUX_SHAREDPAGE,
1027 	.sv_shared_page_len = PAGE_SIZE,
1028 	.sv_schedtail	= linux_schedtail,
1029 	.sv_thread_detach = linux_thread_detach,
1030 };
1031 
1032 static void
1033 linux_vdso_install(void *param)
1034 {
1035 
1036 	linux_szsigcode = (&_binary_linux_locore_o_end -
1037 	    &_binary_linux_locore_o_start);
1038 
1039 	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
1040 		panic("Linux invalid vdso size\n");
1041 
1042 	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
1043 
1044 	linux_shared_page_obj = __elfN(linux_shared_page_init)
1045 	    (&linux_shared_page_mapping);
1046 
1047 	__elfN(linux_vdso_reloc)(&elf_linux_sysvec, LINUX_SHAREDPAGE);
1048 
1049 	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
1050 	    linux_szsigcode);
1051 	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
1052 }
1053 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
1054     (sysinit_cfunc_t)linux_vdso_install, NULL);
1055 
1056 static void
1057 linux_vdso_deinstall(void *param)
1058 {
1059 
1060 	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
1061 };
1062 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
1063     (sysinit_cfunc_t)linux_vdso_deinstall, NULL);
1064 
1065 static char GNU_ABI_VENDOR[] = "GNU";
1066 static int GNULINUX_ABI_DESC = 0;
1067 
1068 static boolean_t
1069 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
1070 {
1071 	const Elf32_Word *desc;
1072 	uintptr_t p;
1073 
1074 	p = (uintptr_t)(note + 1);
1075 	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1076 
1077 	desc = (const Elf32_Word *)p;
1078 	if (desc[0] != GNULINUX_ABI_DESC)
1079 		return (FALSE);
1080 
1081 	/*
1082 	 * For linux we encode osrel as follows (see linux_mib.c):
1083 	 * VVVMMMIII (version, major, minor), see linux_mib.c.
1084 	 */
1085 	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
1086 
1087 	return (TRUE);
1088 }
1089 
1090 static Elf_Brandnote linux_brandnote = {
1091 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
1092 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
1093 	.hdr.n_type	= 1,
1094 	.vendor		= GNU_ABI_VENDOR,
1095 	.flags		= BN_TRANSLATE_OSREL,
1096 	.trans_osrel	= linux_trans_osrel
1097 };
1098 
1099 static Elf32_Brandinfo linux_brand = {
1100 	.brand		= ELFOSABI_LINUX,
1101 	.machine	= EM_386,
1102 	.compat_3_brand	= "Linux",
1103 	.emul_path	= "/compat/linux",
1104 	.interp_path	= "/lib/ld-linux.so.1",
1105 	.sysvec		= &elf_linux_sysvec,
1106 	.interp_newpath	= NULL,
1107 	.brand_note	= &linux_brandnote,
1108 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1109 };
1110 
1111 static Elf32_Brandinfo linux_glibc2brand = {
1112 	.brand		= ELFOSABI_LINUX,
1113 	.machine	= EM_386,
1114 	.compat_3_brand	= "Linux",
1115 	.emul_path	= "/compat/linux",
1116 	.interp_path	= "/lib/ld-linux.so.2",
1117 	.sysvec		= &elf_linux_sysvec,
1118 	.interp_newpath	= NULL,
1119 	.brand_note	= &linux_brandnote,
1120 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1121 };
1122 
1123 Elf32_Brandinfo *linux_brandlist[] = {
1124 	&linux_brand,
1125 	&linux_glibc2brand,
1126 	NULL
1127 };
1128 
1129 static int
1130 linux_elf_modevent(module_t mod, int type, void *data)
1131 {
1132 	Elf32_Brandinfo **brandinfo;
1133 	int error;
1134 	struct linux_ioctl_handler **lihp;
1135 
1136 	error = 0;
1137 
1138 	switch(type) {
1139 	case MOD_LOAD:
1140 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1141 		     ++brandinfo)
1142 			if (elf32_insert_brand_entry(*brandinfo) < 0)
1143 				error = EINVAL;
1144 		if (error == 0) {
1145 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1146 				linux_ioctl_register_handler(*lihp);
1147 			LIST_INIT(&futex_list);
1148 			mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1149 			linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, linux_proc_exit,
1150 			      NULL, 1000);
1151 			linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_exec,
1152 			      NULL, 1000);
1153 			linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
1154 			    linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
1155 			linux_get_machine(&linux_kplatform);
1156 			linux_szplatform = roundup(strlen(linux_kplatform) + 1,
1157 			    sizeof(char *));
1158 			linux_osd_jail_register();
1159 			stclohz = (stathz ? stathz : hz);
1160 			if (bootverbose)
1161 				printf("Linux ELF exec handler installed\n");
1162 		} else
1163 			printf("cannot insert Linux ELF brand handler\n");
1164 		break;
1165 	case MOD_UNLOAD:
1166 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1167 		     ++brandinfo)
1168 			if (elf32_brand_inuse(*brandinfo))
1169 				error = EBUSY;
1170 		if (error == 0) {
1171 			for (brandinfo = &linux_brandlist[0];
1172 			     *brandinfo != NULL; ++brandinfo)
1173 				if (elf32_remove_brand_entry(*brandinfo) < 0)
1174 					error = EINVAL;
1175 		}
1176 		if (error == 0) {
1177 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1178 				linux_ioctl_unregister_handler(*lihp);
1179 			mtx_destroy(&futex_mtx);
1180 			EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
1181 			EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
1182 			EVENTHANDLER_DEREGISTER(thread_dtor, linux_thread_dtor_tag);
1183 			linux_osd_jail_deregister();
1184 			if (bootverbose)
1185 				printf("Linux ELF exec handler removed\n");
1186 		} else
1187 			printf("Could not deinstall ELF interpreter entry\n");
1188 		break;
1189 	default:
1190 		return (EOPNOTSUPP);
1191 	}
1192 	return (error);
1193 }
1194 
1195 static moduledata_t linux_elf_mod = {
1196 	"linuxelf",
1197 	linux_elf_modevent,
1198 	0
1199 };
1200 
1201 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1202