xref: /freebsd/sys/amd64/linux32/linux32_sysvec.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2004 Tim J. Robbins
5  * Copyright (c) 2003 Peter Wemm
6  * Copyright (c) 2002 Doug Rabson
7  * Copyright (c) 1998-1999 Andrew Gallatin
8  * Copyright (c) 1994-1996 Søren Schmidt
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer
16  *    in this position and unchanged.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include "opt_compat.h"
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #ifndef COMPAT_FREEBSD32
41 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
42 #endif
43 
44 #define	__ELF_WORD_SIZE	32
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/exec.h>
49 #include <sys/fcntl.h>
50 #include <sys/imgact.h>
51 #include <sys/imgact_elf.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/module.h>
56 #include <sys/mutex.h>
57 #include <sys/proc.h>
58 #include <sys/resourcevar.h>
59 #include <sys/signalvar.h>
60 #include <sys/syscallsubr.h>
61 #include <sys/sysctl.h>
62 #include <sys/sysent.h>
63 #include <sys/sysproto.h>
64 #include <sys/vnode.h>
65 #include <sys/eventhandler.h>
66 
67 #include <vm/vm.h>
68 #include <vm/pmap.h>
69 #include <vm/vm_extern.h>
70 #include <vm/vm_map.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_page.h>
73 #include <vm/vm_param.h>
74 
75 #include <machine/cpu.h>
76 #include <machine/md_var.h>
77 #include <machine/pcb.h>
78 #include <machine/specialreg.h>
79 #include <machine/trap.h>
80 
81 #include <amd64/linux32/linux.h>
82 #include <amd64/linux32/linux32_proto.h>
83 #include <compat/linux/linux_emul.h>
84 #include <compat/linux/linux_futex.h>
85 #include <compat/linux/linux_ioctl.h>
86 #include <compat/linux/linux_mib.h>
87 #include <compat/linux/linux_misc.h>
88 #include <compat/linux/linux_signal.h>
89 #include <compat/linux/linux_util.h>
90 #include <compat/linux/linux_vdso.h>
91 
92 MODULE_VERSION(linux, 1);
93 
94 /*
95  * Allow the sendsig functions to use the ldebug() facility even though they
96  * are not syscalls themselves.  Map them to syscall 0.  This is slightly less
97  * bogus than using ldebug(sigreturn).
98  */
99 #define	LINUX32_SYS_linux_rt_sendsig	0
100 #define	LINUX32_SYS_linux_sendsig	0
101 
102 const char *linux_kplatform;
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_linux32_locore_o_start;
107 extern char _binary_linux32_locore_o_end;
108 
109 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL];
110 
111 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
112 
113 static int	linux_fixup_elf(register_t **stack_base,
114 		    struct image_params *iparams);
115 static register_t *linux_copyout_strings(struct image_params *imgp);
116 static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
117 static void	linux_exec_setregs(struct thread *td,
118 				   struct image_params *imgp, u_long stack);
119 static void	linux32_fixlimit(struct rlimit *rl, int which);
120 static bool	linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
121 static void	linux_vdso_install(void *param);
122 static void	linux_vdso_deinstall(void *param);
123 
124 #define LINUX_T_UNKNOWN  255
125 static int _bsd_to_linux_trapcode[] = {
126 	LINUX_T_UNKNOWN,	/* 0 */
127 	6,			/* 1  T_PRIVINFLT */
128 	LINUX_T_UNKNOWN,	/* 2 */
129 	3,			/* 3  T_BPTFLT */
130 	LINUX_T_UNKNOWN,	/* 4 */
131 	LINUX_T_UNKNOWN,	/* 5 */
132 	16,			/* 6  T_ARITHTRAP */
133 	254,			/* 7  T_ASTFLT */
134 	LINUX_T_UNKNOWN,	/* 8 */
135 	13,			/* 9  T_PROTFLT */
136 	1,			/* 10 T_TRCTRAP */
137 	LINUX_T_UNKNOWN,	/* 11 */
138 	14,			/* 12 T_PAGEFLT */
139 	LINUX_T_UNKNOWN,	/* 13 */
140 	17,			/* 14 T_ALIGNFLT */
141 	LINUX_T_UNKNOWN,	/* 15 */
142 	LINUX_T_UNKNOWN,	/* 16 */
143 	LINUX_T_UNKNOWN,	/* 17 */
144 	0,			/* 18 T_DIVIDE */
145 	2,			/* 19 T_NMI */
146 	4,			/* 20 T_OFLOW */
147 	5,			/* 21 T_BOUND */
148 	7,			/* 22 T_DNA */
149 	8,			/* 23 T_DOUBLEFLT */
150 	9,			/* 24 T_FPOPFLT */
151 	10,			/* 25 T_TSSFLT */
152 	11,			/* 26 T_SEGNPFLT */
153 	12,			/* 27 T_STKFLT */
154 	18,			/* 28 T_MCHK */
155 	19,			/* 29 T_XMMFLT */
156 	15			/* 30 T_RESERVED */
157 };
158 #define bsd_to_linux_trapcode(code) \
159     ((code)<nitems(_bsd_to_linux_trapcode)? \
160      _bsd_to_linux_trapcode[(code)]: \
161      LINUX_T_UNKNOWN)
162 
163 struct linux32_ps_strings {
164 	u_int32_t ps_argvstr;	/* first of 0 or more argument strings */
165 	u_int ps_nargvstr;	/* the number of argument strings */
166 	u_int32_t ps_envstr;	/* first of 0 or more environment strings */
167 	u_int ps_nenvstr;	/* the number of environment strings */
168 };
169 
170 LINUX_VDSO_SYM_INTPTR(linux32_sigcode);
171 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode);
172 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall);
173 LINUX_VDSO_SYM_CHAR(linux_platform);
174 
175 /*
176  * If FreeBSD & Linux have a difference of opinion about what a trap
177  * means, deal with it here.
178  *
179  * MPSAFE
180  */
181 static int
182 linux_translate_traps(int signal, int trap_code)
183 {
184 	if (signal != SIGBUS)
185 		return (signal);
186 	switch (trap_code) {
187 	case T_PROTFLT:
188 	case T_TSSFLT:
189 	case T_DOUBLEFLT:
190 	case T_PAGEFLT:
191 		return (SIGSEGV);
192 	default:
193 		return (signal);
194 	}
195 }
196 
197 static int
198 linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
199 {
200 	Elf32_Auxargs *args;
201 	Elf32_Auxinfo *argarray, *pos;
202 	Elf32_Addr *auxbase, *base;
203 	struct linux32_ps_strings *arginfo;
204 	int error, issetugid;
205 
206 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
207 
208 	KASSERT(curthread->td_proc == imgp->proc,
209 	    ("unsafe linux_fixup_elf(), should be curproc"));
210 	base = (Elf32_Addr *)*stack_base;
211 	args = (Elf32_Auxargs *)imgp->auxargs;
212 	auxbase = base + (imgp->args->argc + 1 + imgp->args->envc + 1);
213 	argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
214 	    M_WAITOK | M_ZERO);
215 
216 	issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
217 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
218 	    imgp->proc->p_sysent->sv_shared_page_base);
219 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
220 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
221 
222 	/*
223 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
224 	 * as it has appeared in the 2.4.0-rc7 first time.
225 	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
226 	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
227 	 * is not present.
228 	 * Also see linux_times() implementation.
229 	 */
230 	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
231 		AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
232 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
233 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
234 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
235 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
236 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
237 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
238 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
239 	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
240 	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
241 	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
242 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
243 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
244 	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
245 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary));
246 	if (imgp->execpathp != 0)
247 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp));
248 	if (args->execfd != -1)
249 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
250 	AUXARGS_ENTRY(pos, AT_NULL, 0);
251 
252 	free(imgp->auxargs, M_TEMP);
253 	imgp->auxargs = NULL;
254 	KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
255 
256 	error = copyout(&argarray[0], auxbase,
257 	    sizeof(*argarray) * LINUX_AT_COUNT);
258 	free(argarray, M_TEMP);
259 	if (error != 0)
260 		return (error);
261 
262 	base--;
263 	if (suword32(base, (uint32_t)imgp->args->argc) == -1)
264 		return (EFAULT);
265 	*stack_base = (register_t *)base;
266 	return (0);
267 }
268 
269 static void
270 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
271 {
272 	struct thread *td = curthread;
273 	struct proc *p = td->td_proc;
274 	struct sigacts *psp;
275 	struct trapframe *regs;
276 	struct l_rt_sigframe *fp, frame;
277 	int oonstack;
278 	int sig;
279 	int code;
280 
281 	sig = ksi->ksi_signo;
282 	code = ksi->ksi_code;
283 	PROC_LOCK_ASSERT(p, MA_OWNED);
284 	psp = p->p_sigacts;
285 	mtx_assert(&psp->ps_mtx, MA_OWNED);
286 	regs = td->td_frame;
287 	oonstack = sigonstack(regs->tf_rsp);
288 
289 #ifdef DEBUG
290 	if (ldebug(rt_sendsig))
291 		printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
292 		    catcher, sig, (void*)mask, code);
293 #endif
294 	/* Allocate space for the signal handler context. */
295 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
296 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
297 		fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
298 		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
299 	} else
300 		fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
301 	mtx_unlock(&psp->ps_mtx);
302 
303 	/* Build the argument list for the signal handler. */
304 	sig = bsd_to_linux_signal(sig);
305 
306 	bzero(&frame, sizeof(frame));
307 
308 	frame.sf_handler = PTROUT(catcher);
309 	frame.sf_sig = sig;
310 	frame.sf_siginfo = PTROUT(&fp->sf_si);
311 	frame.sf_ucontext = PTROUT(&fp->sf_sc);
312 
313 	/* Fill in POSIX parts. */
314 	ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
315 
316 	/*
317 	 * Build the signal context to be used by sigreturn and libgcc unwind.
318 	 */
319 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
320 	frame.sf_sc.uc_link = 0;		/* XXX ??? */
321 
322 	frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
323 	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
324 	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
325 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
326 	PROC_UNLOCK(p);
327 
328 	bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
329 
330 	frame.sf_sc.uc_mcontext.sc_mask   = frame.sf_sc.uc_sigmask.__mask;
331 	frame.sf_sc.uc_mcontext.sc_edi    = regs->tf_rdi;
332 	frame.sf_sc.uc_mcontext.sc_esi    = regs->tf_rsi;
333 	frame.sf_sc.uc_mcontext.sc_ebp    = regs->tf_rbp;
334 	frame.sf_sc.uc_mcontext.sc_ebx    = regs->tf_rbx;
335 	frame.sf_sc.uc_mcontext.sc_esp    = regs->tf_rsp;
336 	frame.sf_sc.uc_mcontext.sc_edx    = regs->tf_rdx;
337 	frame.sf_sc.uc_mcontext.sc_ecx    = regs->tf_rcx;
338 	frame.sf_sc.uc_mcontext.sc_eax    = regs->tf_rax;
339 	frame.sf_sc.uc_mcontext.sc_eip    = regs->tf_rip;
340 	frame.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
341 	frame.sf_sc.uc_mcontext.sc_gs     = regs->tf_gs;
342 	frame.sf_sc.uc_mcontext.sc_fs     = regs->tf_fs;
343 	frame.sf_sc.uc_mcontext.sc_es     = regs->tf_es;
344 	frame.sf_sc.uc_mcontext.sc_ds     = regs->tf_ds;
345 	frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags;
346 	frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
347 	frame.sf_sc.uc_mcontext.sc_ss     = regs->tf_ss;
348 	frame.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
349 	frame.sf_sc.uc_mcontext.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
350 	frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
351 
352 #ifdef DEBUG
353 	if (ldebug(rt_sendsig))
354 		printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
355 		    frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
356 		    td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
357 #endif
358 
359 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
360 		/*
361 		 * Process has trashed its stack; give it an illegal
362 		 * instruction to halt it in its tracks.
363 		 */
364 #ifdef DEBUG
365 		if (ldebug(rt_sendsig))
366 			printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
367 			    fp, oonstack);
368 #endif
369 		PROC_LOCK(p);
370 		sigexit(td, SIGILL);
371 	}
372 
373 	/* Build context to run handler in. */
374 	regs->tf_rsp = PTROUT(fp);
375 	regs->tf_rip = linux32_rt_sigcode;
376 	regs->tf_rflags &= ~(PSL_T | PSL_D);
377 	regs->tf_cs = _ucode32sel;
378 	regs->tf_ss = _udatasel;
379 	regs->tf_ds = _udatasel;
380 	regs->tf_es = _udatasel;
381 	regs->tf_fs = _ufssel;
382 	regs->tf_gs = _ugssel;
383 	regs->tf_flags = TF_HASSEGS;
384 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
385 	PROC_LOCK(p);
386 	mtx_lock(&psp->ps_mtx);
387 }
388 
389 
390 /*
391  * Send an interrupt to process.
392  *
393  * Stack is set up to allow sigcode stored
394  * in u. to call routine, followed by kcall
395  * to sigreturn routine below.  After sigreturn
396  * resets the signal mask, the stack, and the
397  * frame pointer, it returns to the user
398  * specified pc, psl.
399  */
400 static void
401 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
402 {
403 	struct thread *td = curthread;
404 	struct proc *p = td->td_proc;
405 	struct sigacts *psp;
406 	struct trapframe *regs;
407 	struct l_sigframe *fp, frame;
408 	l_sigset_t lmask;
409 	int oonstack;
410 	int sig, code;
411 
412 	sig = ksi->ksi_signo;
413 	code = ksi->ksi_code;
414 	PROC_LOCK_ASSERT(p, MA_OWNED);
415 	psp = p->p_sigacts;
416 	mtx_assert(&psp->ps_mtx, MA_OWNED);
417 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
418 		/* Signal handler installed with SA_SIGINFO. */
419 		linux_rt_sendsig(catcher, ksi, mask);
420 		return;
421 	}
422 
423 	regs = td->td_frame;
424 	oonstack = sigonstack(regs->tf_rsp);
425 
426 #ifdef DEBUG
427 	if (ldebug(sendsig))
428 		printf(ARGS(sendsig, "%p, %d, %p, %u"),
429 		    catcher, sig, (void*)mask, code);
430 #endif
431 
432 	/* Allocate space for the signal handler context. */
433 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
434 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
435 		fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
436 		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
437 	} else
438 		fp = (struct l_sigframe *)regs->tf_rsp - 1;
439 	mtx_unlock(&psp->ps_mtx);
440 	PROC_UNLOCK(p);
441 
442 	/* Build the argument list for the signal handler. */
443 	sig = bsd_to_linux_signal(sig);
444 
445 	bzero(&frame, sizeof(frame));
446 
447 	frame.sf_handler = PTROUT(catcher);
448 	frame.sf_sig = sig;
449 
450 	bsd_to_linux_sigset(mask, &lmask);
451 
452 	/* Build the signal context to be used by sigreturn. */
453 	frame.sf_sc.sc_mask   = lmask.__mask;
454 	frame.sf_sc.sc_gs     = regs->tf_gs;
455 	frame.sf_sc.sc_fs     = regs->tf_fs;
456 	frame.sf_sc.sc_es     = regs->tf_es;
457 	frame.sf_sc.sc_ds     = regs->tf_ds;
458 	frame.sf_sc.sc_edi    = regs->tf_rdi;
459 	frame.sf_sc.sc_esi    = regs->tf_rsi;
460 	frame.sf_sc.sc_ebp    = regs->tf_rbp;
461 	frame.sf_sc.sc_ebx    = regs->tf_rbx;
462 	frame.sf_sc.sc_esp    = regs->tf_rsp;
463 	frame.sf_sc.sc_edx    = regs->tf_rdx;
464 	frame.sf_sc.sc_ecx    = regs->tf_rcx;
465 	frame.sf_sc.sc_eax    = regs->tf_rax;
466 	frame.sf_sc.sc_eip    = regs->tf_rip;
467 	frame.sf_sc.sc_cs     = regs->tf_cs;
468 	frame.sf_sc.sc_eflags = regs->tf_rflags;
469 	frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
470 	frame.sf_sc.sc_ss     = regs->tf_ss;
471 	frame.sf_sc.sc_err    = regs->tf_err;
472 	frame.sf_sc.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
473 	frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
474 
475 	frame.sf_extramask[0] = lmask.__mask;
476 
477 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
478 		/*
479 		 * Process has trashed its stack; give it an illegal
480 		 * instruction to halt it in its tracks.
481 		 */
482 		PROC_LOCK(p);
483 		sigexit(td, SIGILL);
484 	}
485 
486 	/* Build context to run handler in. */
487 	regs->tf_rsp = PTROUT(fp);
488 	regs->tf_rip = linux32_sigcode;
489 	regs->tf_rflags &= ~(PSL_T | PSL_D);
490 	regs->tf_cs = _ucode32sel;
491 	regs->tf_ss = _udatasel;
492 	regs->tf_ds = _udatasel;
493 	regs->tf_es = _udatasel;
494 	regs->tf_fs = _ufssel;
495 	regs->tf_gs = _ugssel;
496 	regs->tf_flags = TF_HASSEGS;
497 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
498 	PROC_LOCK(p);
499 	mtx_lock(&psp->ps_mtx);
500 }
501 
502 /*
503  * System call to cleanup state after a signal
504  * has been taken.  Reset signal mask and
505  * stack state from context left by sendsig (above).
506  * Return to previous pc and psl as specified by
507  * context left by sendsig. Check carefully to
508  * make sure that the user has not modified the
509  * psl to gain improper privileges or to cause
510  * a machine fault.
511  */
512 int
513 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
514 {
515 	struct l_sigframe frame;
516 	struct trapframe *regs;
517 	sigset_t bmask;
518 	l_sigset_t lmask;
519 	int eflags;
520 	ksiginfo_t ksi;
521 
522 	regs = td->td_frame;
523 
524 #ifdef DEBUG
525 	if (ldebug(sigreturn))
526 		printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
527 #endif
528 	/*
529 	 * The trampoline code hands us the sigframe.
530 	 * It is unsafe to keep track of it ourselves, in the event that a
531 	 * program jumps out of a signal handler.
532 	 */
533 	if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
534 		return (EFAULT);
535 
536 	/* Check for security violations. */
537 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
538 	eflags = frame.sf_sc.sc_eflags;
539 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
540 		return(EINVAL);
541 
542 	/*
543 	 * Don't allow users to load a valid privileged %cs.  Let the
544 	 * hardware check for invalid selectors, excess privilege in
545 	 * other selectors, invalid %eip's and invalid %esp's.
546 	 */
547 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
548 	if (!CS_SECURE(frame.sf_sc.sc_cs)) {
549 		ksiginfo_init_trap(&ksi);
550 		ksi.ksi_signo = SIGBUS;
551 		ksi.ksi_code = BUS_OBJERR;
552 		ksi.ksi_trapno = T_PROTFLT;
553 		ksi.ksi_addr = (void *)regs->tf_rip;
554 		trapsignal(td, &ksi);
555 		return(EINVAL);
556 	}
557 
558 	lmask.__mask = frame.sf_sc.sc_mask;
559 	lmask.__mask = frame.sf_extramask[0];
560 	linux_to_bsd_sigset(&lmask, &bmask);
561 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
562 
563 	/* Restore signal context. */
564 	regs->tf_rdi    = frame.sf_sc.sc_edi;
565 	regs->tf_rsi    = frame.sf_sc.sc_esi;
566 	regs->tf_rbp    = frame.sf_sc.sc_ebp;
567 	regs->tf_rbx    = frame.sf_sc.sc_ebx;
568 	regs->tf_rdx    = frame.sf_sc.sc_edx;
569 	regs->tf_rcx    = frame.sf_sc.sc_ecx;
570 	regs->tf_rax    = frame.sf_sc.sc_eax;
571 	regs->tf_rip    = frame.sf_sc.sc_eip;
572 	regs->tf_cs     = frame.sf_sc.sc_cs;
573 	regs->tf_ds     = frame.sf_sc.sc_ds;
574 	regs->tf_es     = frame.sf_sc.sc_es;
575 	regs->tf_fs     = frame.sf_sc.sc_fs;
576 	regs->tf_gs     = frame.sf_sc.sc_gs;
577 	regs->tf_rflags = eflags;
578 	regs->tf_rsp    = frame.sf_sc.sc_esp_at_signal;
579 	regs->tf_ss     = frame.sf_sc.sc_ss;
580 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
581 
582 	return (EJUSTRETURN);
583 }
584 
585 /*
586  * System call to cleanup state after a signal
587  * has been taken.  Reset signal mask and
588  * stack state from context left by rt_sendsig (above).
589  * Return to previous pc and psl as specified by
590  * context left by sendsig. Check carefully to
591  * make sure that the user has not modified the
592  * psl to gain improper privileges or to cause
593  * a machine fault.
594  */
595 int
596 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
597 {
598 	struct l_ucontext uc;
599 	struct l_sigcontext *context;
600 	sigset_t bmask;
601 	l_stack_t *lss;
602 	stack_t ss;
603 	struct trapframe *regs;
604 	int eflags;
605 	ksiginfo_t ksi;
606 
607 	regs = td->td_frame;
608 
609 #ifdef DEBUG
610 	if (ldebug(rt_sigreturn))
611 		printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
612 #endif
613 	/*
614 	 * The trampoline code hands us the ucontext.
615 	 * It is unsafe to keep track of it ourselves, in the event that a
616 	 * program jumps out of a signal handler.
617 	 */
618 	if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
619 		return (EFAULT);
620 
621 	context = &uc.uc_mcontext;
622 
623 	/* Check for security violations. */
624 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
625 	eflags = context->sc_eflags;
626 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
627 		return(EINVAL);
628 
629 	/*
630 	 * Don't allow users to load a valid privileged %cs.  Let the
631 	 * hardware check for invalid selectors, excess privilege in
632 	 * other selectors, invalid %eip's and invalid %esp's.
633 	 */
634 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
635 	if (!CS_SECURE(context->sc_cs)) {
636 		ksiginfo_init_trap(&ksi);
637 		ksi.ksi_signo = SIGBUS;
638 		ksi.ksi_code = BUS_OBJERR;
639 		ksi.ksi_trapno = T_PROTFLT;
640 		ksi.ksi_addr = (void *)regs->tf_rip;
641 		trapsignal(td, &ksi);
642 		return(EINVAL);
643 	}
644 
645 	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
646 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
647 
648 	/*
649 	 * Restore signal context
650 	 */
651 	regs->tf_gs	= context->sc_gs;
652 	regs->tf_fs	= context->sc_fs;
653 	regs->tf_es	= context->sc_es;
654 	regs->tf_ds	= context->sc_ds;
655 	regs->tf_rdi    = context->sc_edi;
656 	regs->tf_rsi    = context->sc_esi;
657 	regs->tf_rbp    = context->sc_ebp;
658 	regs->tf_rbx    = context->sc_ebx;
659 	regs->tf_rdx    = context->sc_edx;
660 	regs->tf_rcx    = context->sc_ecx;
661 	regs->tf_rax    = context->sc_eax;
662 	regs->tf_rip    = context->sc_eip;
663 	regs->tf_cs     = context->sc_cs;
664 	regs->tf_rflags = eflags;
665 	regs->tf_rsp    = context->sc_esp_at_signal;
666 	regs->tf_ss     = context->sc_ss;
667 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
668 
669 	/*
670 	 * call sigaltstack & ignore results..
671 	 */
672 	lss = &uc.uc_stack;
673 	ss.ss_sp = PTRIN(lss->ss_sp);
674 	ss.ss_size = lss->ss_size;
675 	ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
676 
677 #ifdef DEBUG
678 	if (ldebug(rt_sigreturn))
679 		printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
680 		    ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
681 #endif
682 	(void)kern_sigaltstack(td, &ss, NULL);
683 
684 	return (EJUSTRETURN);
685 }
686 
687 static int
688 linux32_fetch_syscall_args(struct thread *td)
689 {
690 	struct proc *p;
691 	struct trapframe *frame;
692 	struct syscall_args *sa;
693 
694 	p = td->td_proc;
695 	frame = td->td_frame;
696 	sa = &td->td_sa;
697 
698 	sa->args[0] = frame->tf_rbx;
699 	sa->args[1] = frame->tf_rcx;
700 	sa->args[2] = frame->tf_rdx;
701 	sa->args[3] = frame->tf_rsi;
702 	sa->args[4] = frame->tf_rdi;
703 	sa->args[5] = frame->tf_rbp;	/* Unconfirmed */
704 	sa->code = frame->tf_rax;
705 
706 	if (sa->code >= p->p_sysent->sv_size)
707 		/* nosys */
708 		sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
709 	else
710 		sa->callp = &p->p_sysent->sv_table[sa->code];
711 	sa->narg = sa->callp->sy_narg;
712 
713 	td->td_retval[0] = 0;
714 	td->td_retval[1] = frame->tf_rdx;
715 
716 	return (0);
717 }
718 
719 /*
720  * Clear registers on exec
721  * XXX copied from ia32_signal.c.
722  */
723 static void
724 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
725 {
726 	struct trapframe *regs = td->td_frame;
727 	struct pcb *pcb = td->td_pcb;
728 	register_t saved_rflags;
729 
730 	regs = td->td_frame;
731 	pcb = td->td_pcb;
732 
733 	if (td->td_proc->p_md.md_ldt != NULL)
734 		user_ldt_free(td);
735 
736 	critical_enter();
737 	wrmsr(MSR_FSBASE, 0);
738 	wrmsr(MSR_KGSBASE, 0);	/* User value while we're in the kernel */
739 	pcb->pcb_fsbase = 0;
740 	pcb->pcb_gsbase = 0;
741 	critical_exit();
742 	pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
743 
744 	saved_rflags = regs->tf_rflags & PSL_T;
745 	bzero((char *)regs, sizeof(struct trapframe));
746 	regs->tf_rip = imgp->entry_addr;
747 	regs->tf_rsp = stack;
748 	regs->tf_rflags = PSL_USER | saved_rflags;
749 	regs->tf_gs = _ugssel;
750 	regs->tf_fs = _ufssel;
751 	regs->tf_es = _udatasel;
752 	regs->tf_ds = _udatasel;
753 	regs->tf_ss = _udatasel;
754 	regs->tf_flags = TF_HASSEGS;
755 	regs->tf_cs = _ucode32sel;
756 	regs->tf_rbx = imgp->ps_strings;
757 
758 	fpstate_drop(td);
759 
760 	/* Do full restore on return so that we can change to a different %cs */
761 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
762 }
763 
764 /*
765  * XXX copied from ia32_sysvec.c.
766  */
767 static register_t *
768 linux_copyout_strings(struct image_params *imgp)
769 {
770 	int argc, envc;
771 	u_int32_t *vectp;
772 	char *stringp, *destp;
773 	u_int32_t *stack_base;
774 	struct linux32_ps_strings *arginfo;
775 	char canary[LINUX_AT_RANDOM_LEN];
776 	size_t execpath_len;
777 
778 	/* Calculate string base and vector table pointers. */
779 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
780 		execpath_len = strlen(imgp->execpath) + 1;
781 	else
782 		execpath_len = 0;
783 
784 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
785 	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
786 	    roundup(sizeof(canary), sizeof(char *)) -
787 	    roundup(execpath_len, sizeof(char *)) -
788 	    roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
789 
790 	if (execpath_len != 0) {
791 		imgp->execpathp = (uintptr_t)arginfo - execpath_len;
792 		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
793 	}
794 
795 	/* Prepare the canary for SSP. */
796 	arc4rand(canary, sizeof(canary), 0);
797 	imgp->canary = (uintptr_t)arginfo -
798 	    roundup(execpath_len, sizeof(char *)) -
799 	    roundup(sizeof(canary), sizeof(char *));
800 	copyout(canary, (void *)imgp->canary, sizeof(canary));
801 
802 	vectp = (uint32_t *)destp;
803 	if (imgp->auxargs) {
804 		/*
805 		 * Allocate room on the stack for the ELF auxargs
806 		 * array.  It has LINUX_AT_COUNT entries.
807 		 */
808 		vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo),
809 		    sizeof(*vectp));
810 	}
811 
812 	/*
813 	 * Allocate room for the argv[] and env vectors including the
814 	 * terminating NULL pointers.
815 	 */
816 	vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
817 
818 	/* vectp also becomes our initial stack base. */
819 	stack_base = vectp;
820 
821 	stringp = imgp->args->begin_argv;
822 	argc = imgp->args->argc;
823 	envc = imgp->args->envc;
824 	/* Copy out strings - arguments and environment. */
825 	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
826 
827 	/* Fill in "ps_strings" struct for ps, w, etc. */
828 	suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp);
829 	suword32(&arginfo->ps_nargvstr, argc);
830 
831 	/* Fill in argument portion of vector table. */
832 	for (; argc > 0; --argc) {
833 		suword32(vectp++, (uint32_t)(intptr_t)destp);
834 		while (*stringp++ != 0)
835 			destp++;
836 		destp++;
837 	}
838 
839 	/* A null vector table pointer separates the argp's from the envp's. */
840 	suword32(vectp++, 0);
841 
842 	suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp);
843 	suword32(&arginfo->ps_nenvstr, envc);
844 
845 	/* Fill in environment portion of vector table. */
846 	for (; envc > 0; --envc) {
847 		suword32(vectp++, (uint32_t)(intptr_t)destp);
848 		while (*stringp++ != 0)
849 			destp++;
850 		destp++;
851 	}
852 
853 	/* The end of the vector table is a null pointer. */
854 	suword32(vectp, 0);
855 
856 	return ((register_t *)stack_base);
857 }
858 
859 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0,
860     "32-bit Linux emulation");
861 
862 static u_long	linux32_maxdsiz = LINUX32_MAXDSIZ;
863 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
864     &linux32_maxdsiz, 0, "");
865 static u_long	linux32_maxssiz = LINUX32_MAXSSIZ;
866 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
867     &linux32_maxssiz, 0, "");
868 static u_long	linux32_maxvmem = LINUX32_MAXVMEM;
869 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
870     &linux32_maxvmem, 0, "");
871 
872 #if defined(DEBUG)
873 SYSCTL_PROC(_compat_linux32, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
874     linux_sysctl_debug, "A", "Linux debugging control");
875 #endif
876 
877 static void
878 linux32_fixlimit(struct rlimit *rl, int which)
879 {
880 
881 	switch (which) {
882 	case RLIMIT_DATA:
883 		if (linux32_maxdsiz != 0) {
884 			if (rl->rlim_cur > linux32_maxdsiz)
885 				rl->rlim_cur = linux32_maxdsiz;
886 			if (rl->rlim_max > linux32_maxdsiz)
887 				rl->rlim_max = linux32_maxdsiz;
888 		}
889 		break;
890 	case RLIMIT_STACK:
891 		if (linux32_maxssiz != 0) {
892 			if (rl->rlim_cur > linux32_maxssiz)
893 				rl->rlim_cur = linux32_maxssiz;
894 			if (rl->rlim_max > linux32_maxssiz)
895 				rl->rlim_max = linux32_maxssiz;
896 		}
897 		break;
898 	case RLIMIT_VMEM:
899 		if (linux32_maxvmem != 0) {
900 			if (rl->rlim_cur > linux32_maxvmem)
901 				rl->rlim_cur = linux32_maxvmem;
902 			if (rl->rlim_max > linux32_maxvmem)
903 				rl->rlim_max = linux32_maxvmem;
904 		}
905 		break;
906 	}
907 }
908 
909 struct sysentvec elf_linux_sysvec = {
910 	.sv_size	= LINUX32_SYS_MAXSYSCALL,
911 	.sv_table	= linux32_sysent,
912 	.sv_errsize	= ELAST + 1,
913 	.sv_errtbl	= linux_errtbl,
914 	.sv_transtrap	= linux_translate_traps,
915 	.sv_fixup	= linux_fixup_elf,
916 	.sv_sendsig	= linux_sendsig,
917 	.sv_sigcode	= &_binary_linux32_locore_o_start,
918 	.sv_szsigcode	= &linux_szsigcode,
919 	.sv_name	= "Linux ELF32",
920 	.sv_coredump	= elf32_coredump,
921 	.sv_imgact_try	= linux_exec_imgact_try,
922 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
923 	.sv_pagesize	= PAGE_SIZE,
924 	.sv_minuser	= VM_MIN_ADDRESS,
925 	.sv_maxuser	= LINUX32_MAXUSER,
926 	.sv_usrstack	= LINUX32_USRSTACK,
927 	.sv_psstrings	= LINUX32_PS_STRINGS,
928 	.sv_stackprot	= VM_PROT_ALL,
929 	.sv_copyout_strings = linux_copyout_strings,
930 	.sv_setregs	= linux_exec_setregs,
931 	.sv_fixlimit	= linux32_fixlimit,
932 	.sv_maxssiz	= &linux32_maxssiz,
933 	.sv_flags	= SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP,
934 	.sv_set_syscall_retval = cpu_set_syscall_retval,
935 	.sv_fetch_syscall_args = linux32_fetch_syscall_args,
936 	.sv_syscallnames = NULL,
937 	.sv_shared_page_base = LINUX32_SHAREDPAGE,
938 	.sv_shared_page_len = PAGE_SIZE,
939 	.sv_schedtail	= linux_schedtail,
940 	.sv_thread_detach = linux_thread_detach,
941 	.sv_trap	= NULL,
942 };
943 
944 static void
945 linux_vdso_install(void *param)
946 {
947 
948 	linux_szsigcode = (&_binary_linux32_locore_o_end -
949 	    &_binary_linux32_locore_o_start);
950 
951 	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
952 		panic("Linux invalid vdso size\n");
953 
954 	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
955 
956 	linux_shared_page_obj = __elfN(linux_shared_page_init)
957 	    (&linux_shared_page_mapping);
958 
959 	__elfN(linux_vdso_reloc)(&elf_linux_sysvec);
960 
961 	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
962 	    linux_szsigcode);
963 	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
964 
965 	linux_kplatform = linux_shared_page_mapping +
966 	    (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
967 }
968 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
969     linux_vdso_install, NULL);
970 
971 static void
972 linux_vdso_deinstall(void *param)
973 {
974 
975 	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
976 }
977 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
978     linux_vdso_deinstall, NULL);
979 
980 static char GNU_ABI_VENDOR[] = "GNU";
981 static int GNULINUX_ABI_DESC = 0;
982 
983 static bool
984 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
985 {
986 	const Elf32_Word *desc;
987 	uintptr_t p;
988 
989 	p = (uintptr_t)(note + 1);
990 	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
991 
992 	desc = (const Elf32_Word *)p;
993 	if (desc[0] != GNULINUX_ABI_DESC)
994 		return (false);
995 
996 	/*
997 	 * For Linux we encode osrel using the Linux convention of
998 	 * 	(version << 16) | (major << 8) | (minor)
999 	 * See macro in linux_mib.h
1000 	 */
1001 	*osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
1002 
1003 	return (true);
1004 }
1005 
1006 static Elf_Brandnote linux32_brandnote = {
1007 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
1008 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
1009 	.hdr.n_type	= 1,
1010 	.vendor		= GNU_ABI_VENDOR,
1011 	.flags		= BN_TRANSLATE_OSREL,
1012 	.trans_osrel	= linux32_trans_osrel
1013 };
1014 
1015 static Elf32_Brandinfo linux_brand = {
1016 	.brand		= ELFOSABI_LINUX,
1017 	.machine	= EM_386,
1018 	.compat_3_brand	= "Linux",
1019 	.emul_path	= "/compat/linux",
1020 	.interp_path	= "/lib/ld-linux.so.1",
1021 	.sysvec		= &elf_linux_sysvec,
1022 	.interp_newpath	= NULL,
1023 	.brand_note	= &linux32_brandnote,
1024 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1025 };
1026 
1027 static Elf32_Brandinfo linux_glibc2brand = {
1028 	.brand		= ELFOSABI_LINUX,
1029 	.machine	= EM_386,
1030 	.compat_3_brand	= "Linux",
1031 	.emul_path	= "/compat/linux",
1032 	.interp_path	= "/lib/ld-linux.so.2",
1033 	.sysvec		= &elf_linux_sysvec,
1034 	.interp_newpath	= NULL,
1035 	.brand_note	= &linux32_brandnote,
1036 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1037 };
1038 
1039 static Elf32_Brandinfo linux_muslbrand = {
1040 	.brand		= ELFOSABI_LINUX,
1041 	.machine	= EM_386,
1042 	.compat_3_brand	= "Linux",
1043 	.emul_path	= "/compat/linux",
1044 	.interp_path	= "/lib/ld-musl-i386.so.1",
1045 	.sysvec		= &elf_linux_sysvec,
1046 	.interp_newpath	= NULL,
1047 	.brand_note	= &linux32_brandnote,
1048 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1049 };
1050 
1051 Elf32_Brandinfo *linux_brandlist[] = {
1052 	&linux_brand,
1053 	&linux_glibc2brand,
1054 	&linux_muslbrand,
1055 	NULL
1056 };
1057 
1058 static int
1059 linux_elf_modevent(module_t mod, int type, void *data)
1060 {
1061 	Elf32_Brandinfo **brandinfo;
1062 	int error;
1063 	struct linux_ioctl_handler **lihp;
1064 
1065 	error = 0;
1066 
1067 	switch(type) {
1068 	case MOD_LOAD:
1069 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1070 		     ++brandinfo)
1071 			if (elf32_insert_brand_entry(*brandinfo) < 0)
1072 				error = EINVAL;
1073 		if (error == 0) {
1074 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1075 				linux32_ioctl_register_handler(*lihp);
1076 			LIST_INIT(&futex_list);
1077 			mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1078 			stclohz = (stathz ? stathz : hz);
1079 			if (bootverbose)
1080 				printf("Linux ELF exec handler installed\n");
1081 		} else
1082 			printf("cannot insert Linux ELF brand handler\n");
1083 		break;
1084 	case MOD_UNLOAD:
1085 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1086 		     ++brandinfo)
1087 			if (elf32_brand_inuse(*brandinfo))
1088 				error = EBUSY;
1089 		if (error == 0) {
1090 			for (brandinfo = &linux_brandlist[0];
1091 			     *brandinfo != NULL; ++brandinfo)
1092 				if (elf32_remove_brand_entry(*brandinfo) < 0)
1093 					error = EINVAL;
1094 		}
1095 		if (error == 0) {
1096 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1097 				linux32_ioctl_unregister_handler(*lihp);
1098 			mtx_destroy(&futex_mtx);
1099 			if (bootverbose)
1100 				printf("Linux ELF exec handler removed\n");
1101 		} else
1102 			printf("Could not deinstall ELF interpreter entry\n");
1103 		break;
1104 	default:
1105 		return (EOPNOTSUPP);
1106 	}
1107 	return (error);
1108 }
1109 
1110 static moduledata_t linux_elf_mod = {
1111 	"linuxelf",
1112 	linux_elf_modevent,
1113 	0
1114 };
1115 
1116 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1117 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1);
1118 FEATURE(linux, "Linux 32bit support");
1119