xref: /freebsd/sys/i386/linux/linux_sysvec.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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 	int issetugid;
242 
243 	KASSERT(curthread->td_proc == imgp->proc,
244 	    ("unsafe elf_linux_fixup(), should be curproc"));
245 
246 	p = imgp->proc;
247 	issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
248 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
249 	uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
250 	args = (Elf32_Auxargs *)imgp->auxargs;
251 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
252 
253 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
254 	    imgp->proc->p_sysent->sv_shared_page_base);
255 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall);
256 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
257 
258 	/*
259 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
260 	 * as it has appeared in the 2.4.0-rc7 first time.
261 	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
262 	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
263 	 * is not present.
264 	 * Also see linux_times() implementation.
265 	 */
266 	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
267 		AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
268 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
269 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
270 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
271 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
272 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
273 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
274 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
275 	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
276 	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
277 	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
278 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
279 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
280 	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
281 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
282 	if (imgp->execpathp != 0)
283 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
284 	if (args->execfd != -1)
285 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
286 	AUXARGS_ENTRY(pos, AT_NULL, 0);
287 
288 	free(imgp->auxargs, M_TEMP);
289 	imgp->auxargs = NULL;
290 
291 	(*stack_base)--;
292 	suword(*stack_base, (register_t)imgp->args->argc);
293 	return (0);
294 }
295 
296 /*
297  * Copied from kern/kern_exec.c
298  */
299 static register_t *
300 linux_copyout_strings(struct image_params *imgp)
301 {
302 	int argc, envc;
303 	char **vectp;
304 	char *stringp, *destp;
305 	register_t *stack_base;
306 	struct ps_strings *arginfo;
307 	char canary[LINUX_AT_RANDOM_LEN];
308 	size_t execpath_len;
309 	struct proc *p;
310 
311 	/*
312 	 * Calculate string base and vector table pointers.
313 	 */
314 	p = imgp->proc;
315 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
316 		execpath_len = strlen(imgp->execpath) + 1;
317 	else
318 		execpath_len = 0;
319 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
320 	destp = (caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform -
321 	    roundup(sizeof(canary), sizeof(char *)) -
322 	    roundup(execpath_len, sizeof(char *)) -
323 	    roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
324 
325 	/*
326 	 * install LINUX_PLATFORM
327 	 */
328 	copyout(linux_kplatform, ((caddr_t)arginfo - linux_szplatform),
329 	    linux_szplatform);
330 
331 	if (execpath_len != 0) {
332 		imgp->execpathp = (uintptr_t)arginfo -
333 		linux_szplatform - execpath_len;
334 		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
335 	}
336 
337 	/*
338 	 * Prepare the canary for SSP.
339 	 */
340 	arc4rand(canary, sizeof(canary), 0);
341 	imgp->canary = (uintptr_t)arginfo - linux_szplatform -
342 	    roundup(execpath_len, sizeof(char *)) -
343 	    roundup(sizeof(canary), sizeof(char *));
344 	copyout(canary, (void *)imgp->canary, sizeof(canary));
345 
346 	/*
347 	 * If we have a valid auxargs ptr, prepare some room
348 	 * on the stack.
349 	 */
350 	if (imgp->auxargs) {
351 		/*
352 		 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
353 		 * lower compatibility.
354 		 */
355 		imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
356 		    (LINUX_AT_COUNT * 2);
357 		/*
358 		 * The '+ 2' is for the null pointers at the end of each of
359 		 * the arg and env vector sets,and imgp->auxarg_size is room
360 		 * for argument of Runtime loader.
361 		 */
362 		vectp = (char **)(destp - (imgp->args->argc +
363 		    imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
364 	} else {
365 		/*
366 		 * The '+ 2' is for the null pointers at the end of each of
367 		 * the arg and env vector sets
368 		 */
369 		vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
370 		    sizeof(char *));
371 	}
372 
373 	/*
374 	 * vectp also becomes our initial stack base
375 	 */
376 	stack_base = (register_t *)vectp;
377 
378 	stringp = imgp->args->begin_argv;
379 	argc = imgp->args->argc;
380 	envc = imgp->args->envc;
381 
382 	/*
383 	 * Copy out strings - arguments and environment.
384 	 */
385 	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
386 
387 	/*
388 	 * Fill in "ps_strings" struct for ps, w, etc.
389 	 */
390 	suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
391 	suword(&arginfo->ps_nargvstr, argc);
392 
393 	/*
394 	 * Fill in argument portion of vector table.
395 	 */
396 	for (; argc > 0; --argc) {
397 		suword(vectp++, (long)(intptr_t)destp);
398 		while (*stringp++ != 0)
399 			destp++;
400 		destp++;
401 	}
402 
403 	/* a null vector table pointer separates the argp's from the envp's */
404 	suword(vectp++, 0);
405 
406 	suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
407 	suword(&arginfo->ps_nenvstr, envc);
408 
409 	/*
410 	 * Fill in environment portion of vector table.
411 	 */
412 	for (; envc > 0; --envc) {
413 		suword(vectp++, (long)(intptr_t)destp);
414 		while (*stringp++ != 0)
415 			destp++;
416 		destp++;
417 	}
418 
419 	/* end of vector table is a null pointer */
420 	suword(vectp, 0);
421 
422 	return (stack_base);
423 }
424 
425 static void
426 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
427 {
428 	struct thread *td = curthread;
429 	struct proc *p = td->td_proc;
430 	struct sigacts *psp;
431 	struct trapframe *regs;
432 	struct l_rt_sigframe *fp, frame;
433 	int sig, code;
434 	int oonstack;
435 
436 	sig = ksi->ksi_signo;
437 	code = ksi->ksi_code;
438 	PROC_LOCK_ASSERT(p, MA_OWNED);
439 	psp = p->p_sigacts;
440 	mtx_assert(&psp->ps_mtx, MA_OWNED);
441 	regs = td->td_frame;
442 	oonstack = sigonstack(regs->tf_esp);
443 
444 #ifdef DEBUG
445 	if (ldebug(rt_sendsig))
446 		printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
447 		    catcher, sig, (void*)mask, code);
448 #endif
449 	/*
450 	 * Allocate space for the signal handler context.
451 	 */
452 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
453 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
454 		fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
455 		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
456 	} else
457 		fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
458 	mtx_unlock(&psp->ps_mtx);
459 
460 	/*
461 	 * Build the argument list for the signal handler.
462 	 */
463 	sig = bsd_to_linux_signal(sig);
464 
465 	bzero(&frame, sizeof(frame));
466 
467 	frame.sf_handler = catcher;
468 	frame.sf_sig = sig;
469 	frame.sf_siginfo = &fp->sf_si;
470 	frame.sf_ucontext = &fp->sf_sc;
471 
472 	/* Fill in POSIX parts */
473 	ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
474 
475 	/*
476 	 * Build the signal context to be used by sigreturn.
477 	 */
478 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
479 	frame.sf_sc.uc_link = NULL;		/* XXX ??? */
480 
481 	frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
482 	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
483 	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
484 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
485 	PROC_UNLOCK(p);
486 
487 	bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
488 
489 	frame.sf_sc.uc_mcontext.sc_mask   = frame.sf_sc.uc_sigmask.__mask;
490 	frame.sf_sc.uc_mcontext.sc_gs     = rgs();
491 	frame.sf_sc.uc_mcontext.sc_fs     = regs->tf_fs;
492 	frame.sf_sc.uc_mcontext.sc_es     = regs->tf_es;
493 	frame.sf_sc.uc_mcontext.sc_ds     = regs->tf_ds;
494 	frame.sf_sc.uc_mcontext.sc_edi    = regs->tf_edi;
495 	frame.sf_sc.uc_mcontext.sc_esi    = regs->tf_esi;
496 	frame.sf_sc.uc_mcontext.sc_ebp    = regs->tf_ebp;
497 	frame.sf_sc.uc_mcontext.sc_ebx    = regs->tf_ebx;
498 	frame.sf_sc.uc_mcontext.sc_esp    = regs->tf_esp;
499 	frame.sf_sc.uc_mcontext.sc_edx    = regs->tf_edx;
500 	frame.sf_sc.uc_mcontext.sc_ecx    = regs->tf_ecx;
501 	frame.sf_sc.uc_mcontext.sc_eax    = regs->tf_eax;
502 	frame.sf_sc.uc_mcontext.sc_eip    = regs->tf_eip;
503 	frame.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
504 	frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
505 	frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
506 	frame.sf_sc.uc_mcontext.sc_ss     = regs->tf_ss;
507 	frame.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
508 	frame.sf_sc.uc_mcontext.sc_cr2    = (register_t)ksi->ksi_addr;
509 	frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
510 
511 #ifdef DEBUG
512 	if (ldebug(rt_sendsig))
513 		printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
514 		    frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
515 		    td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
516 #endif
517 
518 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
519 		/*
520 		 * Process has trashed its stack; give it an illegal
521 		 * instruction to halt it in its tracks.
522 		 */
523 #ifdef DEBUG
524 		if (ldebug(rt_sendsig))
525 			printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
526 			    fp, oonstack);
527 #endif
528 		PROC_LOCK(p);
529 		sigexit(td, SIGILL);
530 	}
531 
532 	/*
533 	 * Build context to run handler in.
534 	 */
535 	regs->tf_esp = (int)fp;
536 	regs->tf_eip = linux_rt_sigcode;
537 	regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
538 	regs->tf_cs = _ucodesel;
539 	regs->tf_ds = _udatasel;
540 	regs->tf_es = _udatasel;
541 	regs->tf_fs = _udatasel;
542 	regs->tf_ss = _udatasel;
543 	PROC_LOCK(p);
544 	mtx_lock(&psp->ps_mtx);
545 }
546 
547 
548 /*
549  * Send an interrupt to process.
550  *
551  * Stack is set up to allow sigcode stored
552  * in u. to call routine, followed by kcall
553  * to sigreturn routine below.  After sigreturn
554  * resets the signal mask, the stack, and the
555  * frame pointer, it returns to the user
556  * specified pc, psl.
557  */
558 static void
559 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
560 {
561 	struct thread *td = curthread;
562 	struct proc *p = td->td_proc;
563 	struct sigacts *psp;
564 	struct trapframe *regs;
565 	struct l_sigframe *fp, frame;
566 	l_sigset_t lmask;
567 	int sig, code;
568 	int oonstack;
569 
570 	PROC_LOCK_ASSERT(p, MA_OWNED);
571 	psp = p->p_sigacts;
572 	sig = ksi->ksi_signo;
573 	code = ksi->ksi_code;
574 	mtx_assert(&psp->ps_mtx, MA_OWNED);
575 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
576 		/* Signal handler installed with SA_SIGINFO. */
577 		linux_rt_sendsig(catcher, ksi, mask);
578 		return;
579 	}
580 	regs = td->td_frame;
581 	oonstack = sigonstack(regs->tf_esp);
582 
583 #ifdef DEBUG
584 	if (ldebug(sendsig))
585 		printf(ARGS(sendsig, "%p, %d, %p, %u"),
586 		    catcher, sig, (void*)mask, code);
587 #endif
588 
589 	/*
590 	 * Allocate space for the signal handler context.
591 	 */
592 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
593 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
594 		fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
595 		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
596 	} else
597 		fp = (struct l_sigframe *)regs->tf_esp - 1;
598 	mtx_unlock(&psp->ps_mtx);
599 	PROC_UNLOCK(p);
600 
601 	/*
602 	 * Build the argument list for the signal handler.
603 	 */
604 	sig = bsd_to_linux_signal(sig);
605 
606 	bzero(&frame, sizeof(frame));
607 
608 	frame.sf_handler = catcher;
609 	frame.sf_sig = sig;
610 
611 	bsd_to_linux_sigset(mask, &lmask);
612 
613 	/*
614 	 * Build the signal context to be used by sigreturn.
615 	 */
616 	frame.sf_sc.sc_mask   = lmask.__mask;
617 	frame.sf_sc.sc_gs     = rgs();
618 	frame.sf_sc.sc_fs     = regs->tf_fs;
619 	frame.sf_sc.sc_es     = regs->tf_es;
620 	frame.sf_sc.sc_ds     = regs->tf_ds;
621 	frame.sf_sc.sc_edi    = regs->tf_edi;
622 	frame.sf_sc.sc_esi    = regs->tf_esi;
623 	frame.sf_sc.sc_ebp    = regs->tf_ebp;
624 	frame.sf_sc.sc_ebx    = regs->tf_ebx;
625 	frame.sf_sc.sc_esp    = regs->tf_esp;
626 	frame.sf_sc.sc_edx    = regs->tf_edx;
627 	frame.sf_sc.sc_ecx    = regs->tf_ecx;
628 	frame.sf_sc.sc_eax    = regs->tf_eax;
629 	frame.sf_sc.sc_eip    = regs->tf_eip;
630 	frame.sf_sc.sc_cs     = regs->tf_cs;
631 	frame.sf_sc.sc_eflags = regs->tf_eflags;
632 	frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
633 	frame.sf_sc.sc_ss     = regs->tf_ss;
634 	frame.sf_sc.sc_err    = regs->tf_err;
635 	frame.sf_sc.sc_cr2    = (register_t)ksi->ksi_addr;
636 	frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
637 
638 	frame.sf_extramask[0] = lmask.__mask;
639 
640 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
641 		/*
642 		 * Process has trashed its stack; give it an illegal
643 		 * instruction to halt it in its tracks.
644 		 */
645 		PROC_LOCK(p);
646 		sigexit(td, SIGILL);
647 	}
648 
649 	/*
650 	 * Build context to run handler in.
651 	 */
652 	regs->tf_esp = (int)fp;
653 	regs->tf_eip = linux_sigcode;
654 	regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
655 	regs->tf_cs = _ucodesel;
656 	regs->tf_ds = _udatasel;
657 	regs->tf_es = _udatasel;
658 	regs->tf_fs = _udatasel;
659 	regs->tf_ss = _udatasel;
660 	PROC_LOCK(p);
661 	mtx_lock(&psp->ps_mtx);
662 }
663 
664 /*
665  * System call to cleanup state after a signal
666  * has been taken.  Reset signal mask and
667  * stack state from context left by sendsig (above).
668  * Return to previous pc and psl as specified by
669  * context left by sendsig. Check carefully to
670  * make sure that the user has not modified the
671  * psl to gain improper privileges or to cause
672  * a machine fault.
673  */
674 int
675 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
676 {
677 	struct l_sigframe frame;
678 	struct trapframe *regs;
679 	l_sigset_t lmask;
680 	sigset_t bmask;
681 	int eflags;
682 	ksiginfo_t ksi;
683 
684 	regs = td->td_frame;
685 
686 #ifdef DEBUG
687 	if (ldebug(sigreturn))
688 		printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
689 #endif
690 	/*
691 	 * The trampoline code hands us the sigframe.
692 	 * It is unsafe to keep track of it ourselves, in the event that a
693 	 * program jumps out of a signal handler.
694 	 */
695 	if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
696 		return (EFAULT);
697 
698 	/*
699 	 * Check for security violations.
700 	 */
701 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
702 	eflags = frame.sf_sc.sc_eflags;
703 	if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
704 		return (EINVAL);
705 
706 	/*
707 	 * Don't allow users to load a valid privileged %cs.  Let the
708 	 * hardware check for invalid selectors, excess privilege in
709 	 * other selectors, invalid %eip's and invalid %esp's.
710 	 */
711 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
712 	if (!CS_SECURE(frame.sf_sc.sc_cs)) {
713 		ksiginfo_init_trap(&ksi);
714 		ksi.ksi_signo = SIGBUS;
715 		ksi.ksi_code = BUS_OBJERR;
716 		ksi.ksi_trapno = T_PROTFLT;
717 		ksi.ksi_addr = (void *)regs->tf_eip;
718 		trapsignal(td, &ksi);
719 		return (EINVAL);
720 	}
721 
722 	lmask.__mask = frame.sf_sc.sc_mask;
723 	linux_to_bsd_sigset(&lmask, &bmask);
724 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
725 
726 	/*
727 	 * Restore signal context.
728 	 */
729 	/* %gs was restored by the trampoline. */
730 	regs->tf_fs     = frame.sf_sc.sc_fs;
731 	regs->tf_es     = frame.sf_sc.sc_es;
732 	regs->tf_ds     = frame.sf_sc.sc_ds;
733 	regs->tf_edi    = frame.sf_sc.sc_edi;
734 	regs->tf_esi    = frame.sf_sc.sc_esi;
735 	regs->tf_ebp    = frame.sf_sc.sc_ebp;
736 	regs->tf_ebx    = frame.sf_sc.sc_ebx;
737 	regs->tf_edx    = frame.sf_sc.sc_edx;
738 	regs->tf_ecx    = frame.sf_sc.sc_ecx;
739 	regs->tf_eax    = frame.sf_sc.sc_eax;
740 	regs->tf_eip    = frame.sf_sc.sc_eip;
741 	regs->tf_cs     = frame.sf_sc.sc_cs;
742 	regs->tf_eflags = eflags;
743 	regs->tf_esp    = frame.sf_sc.sc_esp_at_signal;
744 	regs->tf_ss     = frame.sf_sc.sc_ss;
745 
746 	return (EJUSTRETURN);
747 }
748 
749 /*
750  * System call to cleanup state after a signal
751  * has been taken.  Reset signal mask and
752  * stack state from context left by rt_sendsig (above).
753  * Return to previous pc and psl as specified by
754  * context left by sendsig. Check carefully to
755  * make sure that the user has not modified the
756  * psl to gain improper privileges or to cause
757  * a machine fault.
758  */
759 int
760 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
761 {
762 	struct l_ucontext uc;
763 	struct l_sigcontext *context;
764 	sigset_t bmask;
765 	l_stack_t *lss;
766 	stack_t ss;
767 	struct trapframe *regs;
768 	int eflags;
769 	ksiginfo_t ksi;
770 
771 	regs = td->td_frame;
772 
773 #ifdef DEBUG
774 	if (ldebug(rt_sigreturn))
775 		printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
776 #endif
777 	/*
778 	 * The trampoline code hands us the ucontext.
779 	 * It is unsafe to keep track of it ourselves, in the event that a
780 	 * program jumps out of a signal handler.
781 	 */
782 	if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
783 		return (EFAULT);
784 
785 	context = &uc.uc_mcontext;
786 
787 	/*
788 	 * Check for security violations.
789 	 */
790 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
791 	eflags = context->sc_eflags;
792 	if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
793 		return (EINVAL);
794 
795 	/*
796 	 * Don't allow users to load a valid privileged %cs.  Let the
797 	 * hardware check for invalid selectors, excess privilege in
798 	 * other selectors, invalid %eip's and invalid %esp's.
799 	 */
800 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
801 	if (!CS_SECURE(context->sc_cs)) {
802 		ksiginfo_init_trap(&ksi);
803 		ksi.ksi_signo = SIGBUS;
804 		ksi.ksi_code = BUS_OBJERR;
805 		ksi.ksi_trapno = T_PROTFLT;
806 		ksi.ksi_addr = (void *)regs->tf_eip;
807 		trapsignal(td, &ksi);
808 		return (EINVAL);
809 	}
810 
811 	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
812 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
813 
814 	/*
815 	 * Restore signal context
816 	 */
817 	/* %gs was restored by the trampoline. */
818 	regs->tf_fs     = context->sc_fs;
819 	regs->tf_es     = context->sc_es;
820 	regs->tf_ds     = context->sc_ds;
821 	regs->tf_edi    = context->sc_edi;
822 	regs->tf_esi    = context->sc_esi;
823 	regs->tf_ebp    = context->sc_ebp;
824 	regs->tf_ebx    = context->sc_ebx;
825 	regs->tf_edx    = context->sc_edx;
826 	regs->tf_ecx    = context->sc_ecx;
827 	regs->tf_eax    = context->sc_eax;
828 	regs->tf_eip    = context->sc_eip;
829 	regs->tf_cs     = context->sc_cs;
830 	regs->tf_eflags = eflags;
831 	regs->tf_esp    = context->sc_esp_at_signal;
832 	regs->tf_ss     = context->sc_ss;
833 
834 	/*
835 	 * call sigaltstack & ignore results..
836 	 */
837 	lss = &uc.uc_stack;
838 	ss.ss_sp = lss->ss_sp;
839 	ss.ss_size = lss->ss_size;
840 	ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
841 
842 #ifdef DEBUG
843 	if (ldebug(rt_sigreturn))
844 		printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
845 		    ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
846 #endif
847 	(void)kern_sigaltstack(td, &ss, NULL);
848 
849 	return (EJUSTRETURN);
850 }
851 
852 static int
853 linux_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
854 {
855 	struct proc *p;
856 	struct trapframe *frame;
857 
858 	p = td->td_proc;
859 	frame = td->td_frame;
860 
861 	sa->code = frame->tf_eax;
862 	sa->args[0] = frame->tf_ebx;
863 	sa->args[1] = frame->tf_ecx;
864 	sa->args[2] = frame->tf_edx;
865 	sa->args[3] = frame->tf_esi;
866 	sa->args[4] = frame->tf_edi;
867 	sa->args[5] = frame->tf_ebp;	/* Unconfirmed */
868 
869 	if (sa->code >= p->p_sysent->sv_size)
870 		/* nosys */
871 		sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
872  	else
873  		sa->callp = &p->p_sysent->sv_table[sa->code];
874 	sa->narg = sa->callp->sy_narg;
875 
876 	td->td_retval[0] = 0;
877 	td->td_retval[1] = frame->tf_edx;
878 
879 	return (0);
880 }
881 
882 /*
883  * If a linux binary is exec'ing something, try this image activator
884  * first.  We override standard shell script execution in order to
885  * be able to modify the interpreter path.  We only do this if a linux
886  * binary is doing the exec, so we do not create an EXEC module for it.
887  */
888 static int	exec_linux_imgact_try(struct image_params *iparams);
889 
890 static int
891 exec_linux_imgact_try(struct image_params *imgp)
892 {
893     const char *head = (const char *)imgp->image_header;
894     char *rpath;
895     int error = -1;
896 
897     /*
898      * The interpreter for shell scripts run from a linux binary needs
899      * to be located in /compat/linux if possible in order to recursively
900      * maintain linux path emulation.
901      */
902     if (((const short *)head)[0] == SHELLMAGIC) {
903 	    /*
904 	     * Run our normal shell image activator.  If it succeeds attempt
905 	     * to use the alternate path for the interpreter.  If an alternate
906 	     * path is found, use our stringspace to store it.
907 	     */
908 	    if ((error = exec_shell_imgact(imgp)) == 0) {
909 		    linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
910 			imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0, AT_FDCWD);
911 		    if (rpath != NULL)
912 			    imgp->args->fname_buf =
913 				imgp->interpreter_name = rpath;
914 	    }
915     }
916     return (error);
917 }
918 
919 /*
920  * exec_setregs may initialize some registers differently than Linux
921  * does, thus potentially confusing Linux binaries. If necessary, we
922  * override the exec_setregs default(s) here.
923  */
924 static void
925 exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
926 {
927 	struct pcb *pcb = td->td_pcb;
928 
929 	exec_setregs(td, imgp, stack);
930 
931 	/* Linux sets %gs to 0, we default to _udatasel */
932 	pcb->pcb_gs = 0;
933 	load_gs(0);
934 
935 	pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
936 }
937 
938 static void
939 linux_get_machine(const char **dst)
940 {
941 
942 	switch (cpu_class) {
943 	case CPUCLASS_686:
944 		*dst = "i686";
945 		break;
946 	case CPUCLASS_586:
947 		*dst = "i586";
948 		break;
949 	case CPUCLASS_486:
950 		*dst = "i486";
951 		break;
952 	default:
953 		*dst = "i386";
954 	}
955 }
956 
957 struct sysentvec linux_sysvec = {
958 	.sv_size	= LINUX_SYS_MAXSYSCALL,
959 	.sv_table	= linux_sysent,
960 	.sv_mask	= 0,
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_name	= "Linux a.out",
969 	.sv_coredump	= NULL,
970 	.sv_imgact_try	= exec_linux_imgact_try,
971 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
972 	.sv_pagesize	= PAGE_SIZE,
973 	.sv_minuser	= VM_MIN_ADDRESS,
974 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
975 	.sv_usrstack	= LINUX_USRSTACK,
976 	.sv_psstrings	= PS_STRINGS,
977 	.sv_stackprot	= VM_PROT_ALL,
978 	.sv_copyout_strings = exec_copyout_strings,
979 	.sv_setregs	= exec_linux_setregs,
980 	.sv_fixlimit	= NULL,
981 	.sv_maxssiz	= NULL,
982 	.sv_flags	= SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
983 	.sv_set_syscall_retval = cpu_set_syscall_retval,
984 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
985 	.sv_syscallnames = NULL,
986 	.sv_shared_page_base = LINUX_SHAREDPAGE,
987 	.sv_shared_page_len = PAGE_SIZE,
988 	.sv_schedtail	= linux_schedtail,
989 	.sv_thread_detach = linux_thread_detach,
990 	.sv_trap	= NULL,
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_errsize	= ELAST + 1,
999 	.sv_errtbl	= bsd_to_linux_errno,
1000 	.sv_transtrap	= translate_traps,
1001 	.sv_fixup	= elf_linux_fixup,
1002 	.sv_sendsig	= linux_sendsig,
1003 	.sv_sigcode	= &_binary_linux_locore_o_start,
1004 	.sv_szsigcode	= &linux_szsigcode,
1005 	.sv_name	= "Linux ELF",
1006 	.sv_coredump	= elf32_coredump,
1007 	.sv_imgact_try	= exec_linux_imgact_try,
1008 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
1009 	.sv_pagesize	= PAGE_SIZE,
1010 	.sv_minuser	= VM_MIN_ADDRESS,
1011 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
1012 	.sv_usrstack	= LINUX_USRSTACK,
1013 	.sv_psstrings	= LINUX_PS_STRINGS,
1014 	.sv_stackprot	= VM_PROT_ALL,
1015 	.sv_copyout_strings = linux_copyout_strings,
1016 	.sv_setregs	= exec_linux_setregs,
1017 	.sv_fixlimit	= NULL,
1018 	.sv_maxssiz	= NULL,
1019 	.sv_flags	= SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
1020 	.sv_set_syscall_retval = cpu_set_syscall_retval,
1021 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
1022 	.sv_syscallnames = NULL,
1023 	.sv_shared_page_base = LINUX_SHAREDPAGE,
1024 	.sv_shared_page_len = PAGE_SIZE,
1025 	.sv_schedtail	= linux_schedtail,
1026 	.sv_thread_detach = linux_thread_detach,
1027 	.sv_trap	= NULL,
1028 };
1029 
1030 static void
1031 linux_vdso_install(void *param)
1032 {
1033 
1034 	linux_szsigcode = (&_binary_linux_locore_o_end -
1035 	    &_binary_linux_locore_o_start);
1036 
1037 	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
1038 		panic("Linux invalid vdso size\n");
1039 
1040 	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
1041 
1042 	linux_shared_page_obj = __elfN(linux_shared_page_init)
1043 	    (&linux_shared_page_mapping);
1044 
1045 	__elfN(linux_vdso_reloc)(&elf_linux_sysvec, LINUX_SHAREDPAGE);
1046 
1047 	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
1048 	    linux_szsigcode);
1049 	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
1050 }
1051 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
1052     (sysinit_cfunc_t)linux_vdso_install, NULL);
1053 
1054 static void
1055 linux_vdso_deinstall(void *param)
1056 {
1057 
1058 	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
1059 };
1060 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
1061     (sysinit_cfunc_t)linux_vdso_deinstall, NULL);
1062 
1063 static char GNU_ABI_VENDOR[] = "GNU";
1064 static int GNULINUX_ABI_DESC = 0;
1065 
1066 static boolean_t
1067 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
1068 {
1069 	const Elf32_Word *desc;
1070 	uintptr_t p;
1071 
1072 	p = (uintptr_t)(note + 1);
1073 	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1074 
1075 	desc = (const Elf32_Word *)p;
1076 	if (desc[0] != GNULINUX_ABI_DESC)
1077 		return (FALSE);
1078 
1079 	/*
1080 	 * For linux we encode osrel as follows (see linux_mib.c):
1081 	 * VVVMMMIII (version, major, minor), see linux_mib.c.
1082 	 */
1083 	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
1084 
1085 	return (TRUE);
1086 }
1087 
1088 static Elf_Brandnote linux_brandnote = {
1089 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
1090 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
1091 	.hdr.n_type	= 1,
1092 	.vendor		= GNU_ABI_VENDOR,
1093 	.flags		= BN_TRANSLATE_OSREL,
1094 	.trans_osrel	= linux_trans_osrel
1095 };
1096 
1097 static Elf32_Brandinfo linux_brand = {
1098 	.brand		= ELFOSABI_LINUX,
1099 	.machine	= EM_386,
1100 	.compat_3_brand	= "Linux",
1101 	.emul_path	= "/compat/linux",
1102 	.interp_path	= "/lib/ld-linux.so.1",
1103 	.sysvec		= &elf_linux_sysvec,
1104 	.interp_newpath	= NULL,
1105 	.brand_note	= &linux_brandnote,
1106 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1107 };
1108 
1109 static Elf32_Brandinfo linux_glibc2brand = {
1110 	.brand		= ELFOSABI_LINUX,
1111 	.machine	= EM_386,
1112 	.compat_3_brand	= "Linux",
1113 	.emul_path	= "/compat/linux",
1114 	.interp_path	= "/lib/ld-linux.so.2",
1115 	.sysvec		= &elf_linux_sysvec,
1116 	.interp_newpath	= NULL,
1117 	.brand_note	= &linux_brandnote,
1118 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1119 };
1120 
1121 Elf32_Brandinfo *linux_brandlist[] = {
1122 	&linux_brand,
1123 	&linux_glibc2brand,
1124 	NULL
1125 };
1126 
1127 static int
1128 linux_elf_modevent(module_t mod, int type, void *data)
1129 {
1130 	Elf32_Brandinfo **brandinfo;
1131 	int error;
1132 	struct linux_ioctl_handler **lihp;
1133 
1134 	error = 0;
1135 
1136 	switch(type) {
1137 	case MOD_LOAD:
1138 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1139 		     ++brandinfo)
1140 			if (elf32_insert_brand_entry(*brandinfo) < 0)
1141 				error = EINVAL;
1142 		if (error == 0) {
1143 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1144 				linux_ioctl_register_handler(*lihp);
1145 			LIST_INIT(&futex_list);
1146 			mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1147 			linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, linux_proc_exit,
1148 			      NULL, 1000);
1149 			linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_exec,
1150 			      NULL, 1000);
1151 			linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
1152 			    linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
1153 			linux_get_machine(&linux_kplatform);
1154 			linux_szplatform = roundup(strlen(linux_kplatform) + 1,
1155 			    sizeof(char *));
1156 			linux_osd_jail_register();
1157 			stclohz = (stathz ? stathz : hz);
1158 			if (bootverbose)
1159 				printf("Linux ELF exec handler installed\n");
1160 		} else
1161 			printf("cannot insert Linux ELF brand handler\n");
1162 		break;
1163 	case MOD_UNLOAD:
1164 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1165 		     ++brandinfo)
1166 			if (elf32_brand_inuse(*brandinfo))
1167 				error = EBUSY;
1168 		if (error == 0) {
1169 			for (brandinfo = &linux_brandlist[0];
1170 			     *brandinfo != NULL; ++brandinfo)
1171 				if (elf32_remove_brand_entry(*brandinfo) < 0)
1172 					error = EINVAL;
1173 		}
1174 		if (error == 0) {
1175 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1176 				linux_ioctl_unregister_handler(*lihp);
1177 			mtx_destroy(&futex_mtx);
1178 			EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
1179 			EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
1180 			EVENTHANDLER_DEREGISTER(thread_dtor, linux_thread_dtor_tag);
1181 			linux_osd_jail_deregister();
1182 			if (bootverbose)
1183 				printf("Linux ELF exec handler removed\n");
1184 		} else
1185 			printf("Could not deinstall ELF interpreter entry\n");
1186 		break;
1187 	default:
1188 		return (EOPNOTSUPP);
1189 	}
1190 	return (error);
1191 }
1192 
1193 static moduledata_t linux_elf_mod = {
1194 	"linuxelf",
1195 	linux_elf_modevent,
1196 	0
1197 };
1198 
1199 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1200