xref: /freebsd/sys/amd64/linux32/linux32_sysvec.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 2004 Tim J. Robbins
3  * Copyright (c) 2003 Peter Wemm
4  * Copyright (c) 2002 Doug Rabson
5  * Copyright (c) 1998-1999 Andrew Gallatin
6  * Copyright (c) 1994-1996 Søren Schmidt
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer
14  *    in this position and unchanged.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 #include "opt_compat.h"
36 
37 #ifndef COMPAT_FREEBSD32
38 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
39 #endif
40 
41 #define	__ELF_WORD_SIZE	32
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/exec.h>
46 #include <sys/fcntl.h>
47 #include <sys/imgact.h>
48 #include <sys/imgact_elf.h>
49 #include <sys/kernel.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/module.h>
53 #include <sys/mutex.h>
54 #include <sys/proc.h>
55 #include <sys/resourcevar.h>
56 #include <sys/signalvar.h>
57 #include <sys/sysctl.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/sysent.h>
60 #include <sys/sysproto.h>
61 #include <sys/vnode.h>
62 #include <sys/eventhandler.h>
63 
64 #include <vm/vm.h>
65 #include <vm/pmap.h>
66 #include <vm/vm_extern.h>
67 #include <vm/vm_map.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_page.h>
70 #include <vm/vm_param.h>
71 
72 #include <machine/cpu.h>
73 #include <machine/md_var.h>
74 #include <machine/pcb.h>
75 #include <machine/specialreg.h>
76 
77 #include <amd64/linux32/linux.h>
78 #include <amd64/linux32/linux32_proto.h>
79 #include <compat/linux/linux_emul.h>
80 #include <compat/linux/linux_futex.h>
81 #include <compat/linux/linux_ioctl.h>
82 #include <compat/linux/linux_mib.h>
83 #include <compat/linux/linux_misc.h>
84 #include <compat/linux/linux_signal.h>
85 #include <compat/linux/linux_util.h>
86 #include <compat/linux/linux_vdso.h>
87 
88 MODULE_VERSION(linux, 1);
89 
90 #define	AUXARGS_ENTRY_32(pos, id, val)	\
91 	do {				\
92 		suword32(pos++, id);	\
93 		suword32(pos++, val);	\
94 	} while (0)
95 
96 #if BYTE_ORDER == LITTLE_ENDIAN
97 #define SHELLMAGIC      0x2123 /* #! */
98 #else
99 #define SHELLMAGIC      0x2321
100 #endif
101 
102 /*
103  * Allow the sendsig functions to use the ldebug() facility
104  * even though they are not syscalls themselves. Map them
105  * to syscall 0. This is slightly less bogus than using
106  * ldebug(sigreturn).
107  */
108 #define	LINUX32_SYS_linux_rt_sendsig	0
109 #define	LINUX32_SYS_linux_sendsig	0
110 
111 const char *linux_kplatform;
112 static int linux_szsigcode;
113 static vm_object_t linux_shared_page_obj;
114 static char *linux_shared_page_mapping;
115 extern char _binary_linux32_locore_o_start;
116 extern char _binary_linux32_locore_o_end;
117 
118 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL];
119 
120 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
121 
122 static int	elf_linux_fixup(register_t **stack_base,
123 		    struct image_params *iparams);
124 static register_t *linux_copyout_strings(struct image_params *imgp);
125 static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
126 static void	exec_linux_setregs(struct thread *td,
127 				   struct image_params *imgp, u_long stack);
128 static void	linux32_fixlimit(struct rlimit *rl, int which);
129 static boolean_t linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
130 static void	linux_vdso_install(void *param);
131 static void	linux_vdso_deinstall(void *param);
132 
133 /*
134  * Linux syscalls return negative errno's, we do positive and map them
135  * Reference:
136  *   FreeBSD: src/sys/sys/errno.h
137  *   Linux:   linux-2.6.17.8/include/asm-generic/errno-base.h
138  *            linux-2.6.17.8/include/asm-generic/errno.h
139  */
140 static int bsd_to_linux_errno[ELAST + 1] = {
141 	-0,  -1,  -2,  -3,  -4,  -5,  -6,  -7,  -8,  -9,
142 	-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
143 	-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
144 	-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
145 	-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
146 	-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
147 	-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
148 	-116, -66,  -6,  -6,  -6,  -6,  -6, -37, -38,  -9,
149 	  -6,  -6, -43, -42, -75,-125, -84, -95, -16, -74,
150 	 -72, -67, -71
151 };
152 
153 #define LINUX_T_UNKNOWN  255
154 static int _bsd_to_linux_trapcode[] = {
155 	LINUX_T_UNKNOWN,	/* 0 */
156 	6,			/* 1  T_PRIVINFLT */
157 	LINUX_T_UNKNOWN,	/* 2 */
158 	3,			/* 3  T_BPTFLT */
159 	LINUX_T_UNKNOWN,	/* 4 */
160 	LINUX_T_UNKNOWN,	/* 5 */
161 	16,			/* 6  T_ARITHTRAP */
162 	254,			/* 7  T_ASTFLT */
163 	LINUX_T_UNKNOWN,	/* 8 */
164 	13,			/* 9  T_PROTFLT */
165 	1,			/* 10 T_TRCTRAP */
166 	LINUX_T_UNKNOWN,	/* 11 */
167 	14,			/* 12 T_PAGEFLT */
168 	LINUX_T_UNKNOWN,	/* 13 */
169 	17,			/* 14 T_ALIGNFLT */
170 	LINUX_T_UNKNOWN,	/* 15 */
171 	LINUX_T_UNKNOWN,	/* 16 */
172 	LINUX_T_UNKNOWN,	/* 17 */
173 	0,			/* 18 T_DIVIDE */
174 	2,			/* 19 T_NMI */
175 	4,			/* 20 T_OFLOW */
176 	5,			/* 21 T_BOUND */
177 	7,			/* 22 T_DNA */
178 	8,			/* 23 T_DOUBLEFLT */
179 	9,			/* 24 T_FPOPFLT */
180 	10,			/* 25 T_TSSFLT */
181 	11,			/* 26 T_SEGNPFLT */
182 	12,			/* 27 T_STKFLT */
183 	18,			/* 28 T_MCHK */
184 	19,			/* 29 T_XMMFLT */
185 	15			/* 30 T_RESERVED */
186 };
187 #define bsd_to_linux_trapcode(code) \
188     ((code)<nitems(_bsd_to_linux_trapcode)? \
189      _bsd_to_linux_trapcode[(code)]: \
190      LINUX_T_UNKNOWN)
191 
192 struct linux32_ps_strings {
193 	u_int32_t ps_argvstr;	/* first of 0 or more argument strings */
194 	u_int ps_nargvstr;	/* the number of argument strings */
195 	u_int32_t ps_envstr;	/* first of 0 or more environment strings */
196 	u_int ps_nenvstr;	/* the number of environment strings */
197 };
198 
199 LINUX_VDSO_SYM_INTPTR(linux32_sigcode);
200 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode);
201 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall);
202 LINUX_VDSO_SYM_CHAR(linux_platform);
203 
204 /*
205  * If FreeBSD & Linux have a difference of opinion about what a trap
206  * means, deal with it here.
207  *
208  * MPSAFE
209  */
210 static int
211 translate_traps(int signal, int trap_code)
212 {
213 	if (signal != SIGBUS)
214 		return signal;
215 	switch (trap_code) {
216 	case T_PROTFLT:
217 	case T_TSSFLT:
218 	case T_DOUBLEFLT:
219 	case T_PAGEFLT:
220 		return SIGSEGV;
221 	default:
222 		return signal;
223 	}
224 }
225 
226 static int
227 elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
228 {
229 	Elf32_Auxargs *args;
230 	Elf32_Addr *base;
231 	Elf32_Addr *pos;
232 	struct linux32_ps_strings *arginfo;
233 	int issetugid;
234 
235 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
236 
237 	KASSERT(curthread->td_proc == imgp->proc,
238 	    ("unsafe elf_linux_fixup(), should be curproc"));
239 	base = (Elf32_Addr *)*stack_base;
240 	args = (Elf32_Auxargs *)imgp->auxargs;
241 	pos = base + (imgp->args->argc + imgp->args->envc + 2);
242 
243 	issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
244 	AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO_EHDR,
245 	    imgp->proc->p_sysent->sv_shared_page_base);
246 	AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
247 	AUXARGS_ENTRY_32(pos, LINUX_AT_HWCAP, cpu_feature);
248 
249 	/*
250 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
251 	 * as it has appeared in the 2.4.0-rc7 first time.
252 	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
253 	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
254 	 * is not present.
255 	 * Also see linux_times() implementation.
256 	 */
257 	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
258 		AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz);
259 	AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr);
260 	AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent);
261 	AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum);
262 	AUXARGS_ENTRY_32(pos, AT_PAGESZ, args->pagesz);
263 	AUXARGS_ENTRY_32(pos, AT_FLAGS, args->flags);
264 	AUXARGS_ENTRY_32(pos, AT_ENTRY, args->entry);
265 	AUXARGS_ENTRY_32(pos, AT_BASE, args->base);
266 	AUXARGS_ENTRY_32(pos, LINUX_AT_SECURE, issetugid);
267 	AUXARGS_ENTRY_32(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
268 	AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
269 	AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
270 	AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
271 	AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
272 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary));
273 	if (imgp->execpathp != 0)
274 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp));
275 	if (args->execfd != -1)
276 		AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd);
277 	AUXARGS_ENTRY_32(pos, AT_NULL, 0);
278 
279 	free(imgp->auxargs, M_TEMP);
280 	imgp->auxargs = NULL;
281 
282 	base--;
283 	suword32(base, (uint32_t)imgp->args->argc);
284 	*stack_base = (register_t *)base;
285 	return (0);
286 }
287 
288 static void
289 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
290 {
291 	struct thread *td = curthread;
292 	struct proc *p = td->td_proc;
293 	struct sigacts *psp;
294 	struct trapframe *regs;
295 	struct l_rt_sigframe *fp, frame;
296 	int oonstack;
297 	int sig;
298 	int code;
299 
300 	sig = ksi->ksi_signo;
301 	code = ksi->ksi_code;
302 	PROC_LOCK_ASSERT(p, MA_OWNED);
303 	psp = p->p_sigacts;
304 	mtx_assert(&psp->ps_mtx, MA_OWNED);
305 	regs = td->td_frame;
306 	oonstack = sigonstack(regs->tf_rsp);
307 
308 #ifdef DEBUG
309 	if (ldebug(rt_sendsig))
310 		printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
311 		    catcher, sig, (void*)mask, code);
312 #endif
313 	/*
314 	 * Allocate space for the signal handler context.
315 	 */
316 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
317 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
318 		fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
319 		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
320 	} else
321 		fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
322 	mtx_unlock(&psp->ps_mtx);
323 
324 	/*
325 	 * Build the argument list for the signal handler.
326 	 */
327 	sig = bsd_to_linux_signal(sig);
328 
329 	bzero(&frame, sizeof(frame));
330 
331 	frame.sf_handler = PTROUT(catcher);
332 	frame.sf_sig = sig;
333 	frame.sf_siginfo = PTROUT(&fp->sf_si);
334 	frame.sf_ucontext = PTROUT(&fp->sf_sc);
335 
336 	/* Fill in POSIX parts */
337 	ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
338 
339 	/*
340 	 * Build the signal context to be used by sigreturn
341 	 * and libgcc unwind.
342 	 */
343 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
344 	frame.sf_sc.uc_link = 0;		/* XXX ??? */
345 
346 	frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
347 	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
348 	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
349 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
350 	PROC_UNLOCK(p);
351 
352 	bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
353 
354 	frame.sf_sc.uc_mcontext.sc_mask   = frame.sf_sc.uc_sigmask.__mask;
355 	frame.sf_sc.uc_mcontext.sc_edi    = regs->tf_rdi;
356 	frame.sf_sc.uc_mcontext.sc_esi    = regs->tf_rsi;
357 	frame.sf_sc.uc_mcontext.sc_ebp    = regs->tf_rbp;
358 	frame.sf_sc.uc_mcontext.sc_ebx    = regs->tf_rbx;
359 	frame.sf_sc.uc_mcontext.sc_esp    = regs->tf_rsp;
360 	frame.sf_sc.uc_mcontext.sc_edx    = regs->tf_rdx;
361 	frame.sf_sc.uc_mcontext.sc_ecx    = regs->tf_rcx;
362 	frame.sf_sc.uc_mcontext.sc_eax    = regs->tf_rax;
363 	frame.sf_sc.uc_mcontext.sc_eip    = regs->tf_rip;
364 	frame.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
365 	frame.sf_sc.uc_mcontext.sc_gs     = regs->tf_gs;
366 	frame.sf_sc.uc_mcontext.sc_fs     = regs->tf_fs;
367 	frame.sf_sc.uc_mcontext.sc_es     = regs->tf_es;
368 	frame.sf_sc.uc_mcontext.sc_ds     = regs->tf_ds;
369 	frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags;
370 	frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
371 	frame.sf_sc.uc_mcontext.sc_ss     = regs->tf_ss;
372 	frame.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
373 	frame.sf_sc.uc_mcontext.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
374 	frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
375 
376 #ifdef DEBUG
377 	if (ldebug(rt_sendsig))
378 		printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
379 		    frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
380 		    td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
381 #endif
382 
383 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
384 		/*
385 		 * Process has trashed its stack; give it an illegal
386 		 * instruction to halt it in its tracks.
387 		 */
388 #ifdef DEBUG
389 		if (ldebug(rt_sendsig))
390 			printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
391 			    fp, oonstack);
392 #endif
393 		PROC_LOCK(p);
394 		sigexit(td, SIGILL);
395 	}
396 
397 	/*
398 	 * Build context to run handler in.
399 	 */
400 	regs->tf_rsp = PTROUT(fp);
401 	regs->tf_rip = linux32_rt_sigcode;
402 	regs->tf_rflags &= ~(PSL_T | PSL_D);
403 	regs->tf_cs = _ucode32sel;
404 	regs->tf_ss = _udatasel;
405 	regs->tf_ds = _udatasel;
406 	regs->tf_es = _udatasel;
407 	regs->tf_fs = _ufssel;
408 	regs->tf_gs = _ugssel;
409 	regs->tf_flags = TF_HASSEGS;
410 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
411 	PROC_LOCK(p);
412 	mtx_lock(&psp->ps_mtx);
413 }
414 
415 
416 /*
417  * Send an interrupt to process.
418  *
419  * Stack is set up to allow sigcode stored
420  * in u. to call routine, followed by kcall
421  * to sigreturn routine below.  After sigreturn
422  * resets the signal mask, the stack, and the
423  * frame pointer, it returns to the user
424  * specified pc, psl.
425  */
426 static void
427 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
428 {
429 	struct thread *td = curthread;
430 	struct proc *p = td->td_proc;
431 	struct sigacts *psp;
432 	struct trapframe *regs;
433 	struct l_sigframe *fp, frame;
434 	l_sigset_t lmask;
435 	int oonstack;
436 	int sig, code;
437 
438 	sig = ksi->ksi_signo;
439 	code = ksi->ksi_code;
440 	PROC_LOCK_ASSERT(p, MA_OWNED);
441 	psp = p->p_sigacts;
442 	mtx_assert(&psp->ps_mtx, MA_OWNED);
443 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
444 		/* Signal handler installed with SA_SIGINFO. */
445 		linux_rt_sendsig(catcher, ksi, mask);
446 		return;
447 	}
448 
449 	regs = td->td_frame;
450 	oonstack = sigonstack(regs->tf_rsp);
451 
452 #ifdef DEBUG
453 	if (ldebug(sendsig))
454 		printf(ARGS(sendsig, "%p, %d, %p, %u"),
455 		    catcher, sig, (void*)mask, code);
456 #endif
457 
458 	/*
459 	 * Allocate space for the signal handler context.
460 	 */
461 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
462 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
463 		fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
464 		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
465 	} else
466 		fp = (struct l_sigframe *)regs->tf_rsp - 1;
467 	mtx_unlock(&psp->ps_mtx);
468 	PROC_UNLOCK(p);
469 
470 	/*
471 	 * Build the argument list for the signal handler.
472 	 */
473 	sig = bsd_to_linux_signal(sig);
474 
475 	bzero(&frame, sizeof(frame));
476 
477 	frame.sf_handler = PTROUT(catcher);
478 	frame.sf_sig = sig;
479 
480 	bsd_to_linux_sigset(mask, &lmask);
481 
482 	/*
483 	 * Build the signal context to be used by sigreturn.
484 	 */
485 	frame.sf_sc.sc_mask   = lmask.__mask;
486 	frame.sf_sc.sc_gs     = regs->tf_gs;
487 	frame.sf_sc.sc_fs     = regs->tf_fs;
488 	frame.sf_sc.sc_es     = regs->tf_es;
489 	frame.sf_sc.sc_ds     = regs->tf_ds;
490 	frame.sf_sc.sc_edi    = regs->tf_rdi;
491 	frame.sf_sc.sc_esi    = regs->tf_rsi;
492 	frame.sf_sc.sc_ebp    = regs->tf_rbp;
493 	frame.sf_sc.sc_ebx    = regs->tf_rbx;
494 	frame.sf_sc.sc_esp    = regs->tf_rsp;
495 	frame.sf_sc.sc_edx    = regs->tf_rdx;
496 	frame.sf_sc.sc_ecx    = regs->tf_rcx;
497 	frame.sf_sc.sc_eax    = regs->tf_rax;
498 	frame.sf_sc.sc_eip    = regs->tf_rip;
499 	frame.sf_sc.sc_cs     = regs->tf_cs;
500 	frame.sf_sc.sc_eflags = regs->tf_rflags;
501 	frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
502 	frame.sf_sc.sc_ss     = regs->tf_ss;
503 	frame.sf_sc.sc_err    = regs->tf_err;
504 	frame.sf_sc.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
505 	frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
506 
507 	frame.sf_extramask[0] = lmask.__mask;
508 
509 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
510 		/*
511 		 * Process has trashed its stack; give it an illegal
512 		 * instruction to halt it in its tracks.
513 		 */
514 		PROC_LOCK(p);
515 		sigexit(td, SIGILL);
516 	}
517 
518 	/*
519 	 * Build context to run handler in.
520 	 */
521 	regs->tf_rsp = PTROUT(fp);
522 	regs->tf_rip = linux32_sigcode;
523 	regs->tf_rflags &= ~(PSL_T | PSL_D);
524 	regs->tf_cs = _ucode32sel;
525 	regs->tf_ss = _udatasel;
526 	regs->tf_ds = _udatasel;
527 	regs->tf_es = _udatasel;
528 	regs->tf_fs = _ufssel;
529 	regs->tf_gs = _ugssel;
530 	regs->tf_flags = TF_HASSEGS;
531 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
532 	PROC_LOCK(p);
533 	mtx_lock(&psp->ps_mtx);
534 }
535 
536 /*
537  * System call to cleanup state after a signal
538  * has been taken.  Reset signal mask and
539  * stack state from context left by sendsig (above).
540  * Return to previous pc and psl as specified by
541  * context left by sendsig. Check carefully to
542  * make sure that the user has not modified the
543  * psl to gain improper privileges or to cause
544  * a machine fault.
545  */
546 int
547 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
548 {
549 	struct l_sigframe frame;
550 	struct trapframe *regs;
551 	sigset_t bmask;
552 	l_sigset_t lmask;
553 	int eflags;
554 	ksiginfo_t ksi;
555 
556 	regs = td->td_frame;
557 
558 #ifdef DEBUG
559 	if (ldebug(sigreturn))
560 		printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
561 #endif
562 	/*
563 	 * The trampoline code hands us the sigframe.
564 	 * It is unsafe to keep track of it ourselves, in the event that a
565 	 * program jumps out of a signal handler.
566 	 */
567 	if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
568 		return (EFAULT);
569 
570 	/*
571 	 * Check for security violations.
572 	 */
573 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
574 	eflags = frame.sf_sc.sc_eflags;
575 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
576 		return(EINVAL);
577 
578 	/*
579 	 * Don't allow users to load a valid privileged %cs.  Let the
580 	 * hardware check for invalid selectors, excess privilege in
581 	 * other selectors, invalid %eip's and invalid %esp's.
582 	 */
583 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
584 	if (!CS_SECURE(frame.sf_sc.sc_cs)) {
585 		ksiginfo_init_trap(&ksi);
586 		ksi.ksi_signo = SIGBUS;
587 		ksi.ksi_code = BUS_OBJERR;
588 		ksi.ksi_trapno = T_PROTFLT;
589 		ksi.ksi_addr = (void *)regs->tf_rip;
590 		trapsignal(td, &ksi);
591 		return(EINVAL);
592 	}
593 
594 	lmask.__mask = frame.sf_sc.sc_mask;
595 	lmask.__mask = frame.sf_extramask[0];
596 	linux_to_bsd_sigset(&lmask, &bmask);
597 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
598 
599 	/*
600 	 * Restore signal context.
601 	 */
602 	regs->tf_rdi    = frame.sf_sc.sc_edi;
603 	regs->tf_rsi    = frame.sf_sc.sc_esi;
604 	regs->tf_rbp    = frame.sf_sc.sc_ebp;
605 	regs->tf_rbx    = frame.sf_sc.sc_ebx;
606 	regs->tf_rdx    = frame.sf_sc.sc_edx;
607 	regs->tf_rcx    = frame.sf_sc.sc_ecx;
608 	regs->tf_rax    = frame.sf_sc.sc_eax;
609 	regs->tf_rip    = frame.sf_sc.sc_eip;
610 	regs->tf_cs     = frame.sf_sc.sc_cs;
611 	regs->tf_ds     = frame.sf_sc.sc_ds;
612 	regs->tf_es     = frame.sf_sc.sc_es;
613 	regs->tf_fs     = frame.sf_sc.sc_fs;
614 	regs->tf_gs     = frame.sf_sc.sc_gs;
615 	regs->tf_rflags = eflags;
616 	regs->tf_rsp    = frame.sf_sc.sc_esp_at_signal;
617 	regs->tf_ss     = frame.sf_sc.sc_ss;
618 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
619 
620 	return (EJUSTRETURN);
621 }
622 
623 /*
624  * System call to cleanup state after a signal
625  * has been taken.  Reset signal mask and
626  * stack state from context left by rt_sendsig (above).
627  * Return to previous pc and psl as specified by
628  * context left by sendsig. Check carefully to
629  * make sure that the user has not modified the
630  * psl to gain improper privileges or to cause
631  * a machine fault.
632  */
633 int
634 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
635 {
636 	struct l_ucontext uc;
637 	struct l_sigcontext *context;
638 	sigset_t bmask;
639 	l_stack_t *lss;
640 	stack_t ss;
641 	struct trapframe *regs;
642 	int eflags;
643 	ksiginfo_t ksi;
644 
645 	regs = td->td_frame;
646 
647 #ifdef DEBUG
648 	if (ldebug(rt_sigreturn))
649 		printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
650 #endif
651 	/*
652 	 * The trampoline code hands us the ucontext.
653 	 * It is unsafe to keep track of it ourselves, in the event that a
654 	 * program jumps out of a signal handler.
655 	 */
656 	if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
657 		return (EFAULT);
658 
659 	context = &uc.uc_mcontext;
660 
661 	/*
662 	 * Check for security violations.
663 	 */
664 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
665 	eflags = context->sc_eflags;
666 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
667 		return(EINVAL);
668 
669 	/*
670 	 * Don't allow users to load a valid privileged %cs.  Let the
671 	 * hardware check for invalid selectors, excess privilege in
672 	 * other selectors, invalid %eip's and invalid %esp's.
673 	 */
674 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
675 	if (!CS_SECURE(context->sc_cs)) {
676 		ksiginfo_init_trap(&ksi);
677 		ksi.ksi_signo = SIGBUS;
678 		ksi.ksi_code = BUS_OBJERR;
679 		ksi.ksi_trapno = T_PROTFLT;
680 		ksi.ksi_addr = (void *)regs->tf_rip;
681 		trapsignal(td, &ksi);
682 		return(EINVAL);
683 	}
684 
685 	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
686 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
687 
688 	/*
689 	 * Restore signal context
690 	 */
691 	regs->tf_gs	= context->sc_gs;
692 	regs->tf_fs	= context->sc_fs;
693 	regs->tf_es	= context->sc_es;
694 	regs->tf_ds	= context->sc_ds;
695 	regs->tf_rdi    = context->sc_edi;
696 	regs->tf_rsi    = context->sc_esi;
697 	regs->tf_rbp    = context->sc_ebp;
698 	regs->tf_rbx    = context->sc_ebx;
699 	regs->tf_rdx    = context->sc_edx;
700 	regs->tf_rcx    = context->sc_ecx;
701 	regs->tf_rax    = context->sc_eax;
702 	regs->tf_rip    = context->sc_eip;
703 	regs->tf_cs     = context->sc_cs;
704 	regs->tf_rflags = eflags;
705 	regs->tf_rsp    = context->sc_esp_at_signal;
706 	regs->tf_ss     = context->sc_ss;
707 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
708 
709 	/*
710 	 * call sigaltstack & ignore results..
711 	 */
712 	lss = &uc.uc_stack;
713 	ss.ss_sp = PTRIN(lss->ss_sp);
714 	ss.ss_size = lss->ss_size;
715 	ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
716 
717 #ifdef DEBUG
718 	if (ldebug(rt_sigreturn))
719 		printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
720 		    ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
721 #endif
722 	(void)kern_sigaltstack(td, &ss, NULL);
723 
724 	return (EJUSTRETURN);
725 }
726 
727 static int
728 linux32_fetch_syscall_args(struct thread *td)
729 {
730 	struct proc *p;
731 	struct trapframe *frame;
732 	struct syscall_args *sa;
733 
734 	p = td->td_proc;
735 	frame = td->td_frame;
736 	sa = &td->td_sa;
737 
738 	sa->args[0] = frame->tf_rbx;
739 	sa->args[1] = frame->tf_rcx;
740 	sa->args[2] = frame->tf_rdx;
741 	sa->args[3] = frame->tf_rsi;
742 	sa->args[4] = frame->tf_rdi;
743 	sa->args[5] = frame->tf_rbp;	/* Unconfirmed */
744 	sa->code = frame->tf_rax;
745 
746 	if (sa->code >= p->p_sysent->sv_size)
747 		/* nosys */
748 		sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
749 	else
750 		sa->callp = &p->p_sysent->sv_table[sa->code];
751 	sa->narg = sa->callp->sy_narg;
752 
753 	td->td_retval[0] = 0;
754 	td->td_retval[1] = frame->tf_rdx;
755 
756 	return (0);
757 }
758 
759 /*
760  * If a linux binary is exec'ing something, try this image activator
761  * first.  We override standard shell script execution in order to
762  * be able to modify the interpreter path.  We only do this if a linux
763  * binary is doing the exec, so we do not create an EXEC module for it.
764  */
765 static int	exec_linux_imgact_try(struct image_params *iparams);
766 
767 static int
768 exec_linux_imgact_try(struct image_params *imgp)
769 {
770 	const char *head = (const char *)imgp->image_header;
771 	char *rpath;
772 	int error = -1;
773 
774 	/*
775 	* The interpreter for shell scripts run from a linux binary needs
776 	* to be located in /compat/linux if possible in order to recursively
777 	* maintain linux path emulation.
778 	*/
779 	if (((const short *)head)[0] == SHELLMAGIC) {
780 		/*
781 		* Run our normal shell image activator.  If it succeeds attempt
782 		* to use the alternate path for the interpreter.  If an
783 		* alternate * path is found, use our stringspace to store it.
784 		*/
785 		if ((error = exec_shell_imgact(imgp)) == 0) {
786 			linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
787 			    imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0,
788 			    AT_FDCWD);
789 			if (rpath != NULL)
790 				imgp->args->fname_buf =
791 				    imgp->interpreter_name = rpath;
792 		}
793 	}
794 	return (error);
795 }
796 
797 /*
798  * Clear registers on exec
799  * XXX copied from ia32_signal.c.
800  */
801 static void
802 exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
803 {
804 	struct trapframe *regs = td->td_frame;
805 	struct pcb *pcb = td->td_pcb;
806 
807 	mtx_lock(&dt_lock);
808 	if (td->td_proc->p_md.md_ldt != NULL)
809 		user_ldt_free(td);
810 	else
811 		mtx_unlock(&dt_lock);
812 
813 	critical_enter();
814 	wrmsr(MSR_FSBASE, 0);
815 	wrmsr(MSR_KGSBASE, 0);	/* User value while we're in the kernel */
816 	pcb->pcb_fsbase = 0;
817 	pcb->pcb_gsbase = 0;
818 	critical_exit();
819 	pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
820 
821 	bzero((char *)regs, sizeof(struct trapframe));
822 	regs->tf_rip = imgp->entry_addr;
823 	regs->tf_rsp = stack;
824 	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
825 	regs->tf_gs = _ugssel;
826 	regs->tf_fs = _ufssel;
827 	regs->tf_es = _udatasel;
828 	regs->tf_ds = _udatasel;
829 	regs->tf_ss = _udatasel;
830 	regs->tf_flags = TF_HASSEGS;
831 	regs->tf_cs = _ucode32sel;
832 	regs->tf_rbx = imgp->ps_strings;
833 
834 	fpstate_drop(td);
835 
836 	/* Do full restore on return so that we can change to a different %cs */
837 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
838 	td->td_retval[1] = 0;
839 }
840 
841 /*
842  * XXX copied from ia32_sysvec.c.
843  */
844 static register_t *
845 linux_copyout_strings(struct image_params *imgp)
846 {
847 	int argc, envc;
848 	u_int32_t *vectp;
849 	char *stringp, *destp;
850 	u_int32_t *stack_base;
851 	struct linux32_ps_strings *arginfo;
852 	char canary[LINUX_AT_RANDOM_LEN];
853 	size_t execpath_len;
854 
855 	/*
856 	 * Calculate string base and vector table pointers.
857 	 */
858 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
859 		execpath_len = strlen(imgp->execpath) + 1;
860 	else
861 		execpath_len = 0;
862 
863 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
864 	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
865 	    roundup(sizeof(canary), sizeof(char *)) -
866 	    roundup(execpath_len, sizeof(char *)) -
867 	    roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
868 
869 	if (execpath_len != 0) {
870 		imgp->execpathp = (uintptr_t)arginfo - execpath_len;
871 		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
872 	}
873 
874 	/*
875 	 * Prepare the canary for SSP.
876 	 */
877 	arc4rand(canary, sizeof(canary), 0);
878 	imgp->canary = (uintptr_t)arginfo -
879 	    roundup(execpath_len, sizeof(char *)) -
880 	    roundup(sizeof(canary), sizeof(char *));
881 	copyout(canary, (void *)imgp->canary, sizeof(canary));
882 
883 	/*
884 	 * If we have a valid auxargs ptr, prepare some room
885 	 * on the stack.
886 	 */
887 	if (imgp->auxargs) {
888 		/*
889 		 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
890 		 * lower compatibility.
891 		 */
892 		imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
893 		    (LINUX_AT_COUNT * 2);
894 		/*
895 		 * The '+ 2' is for the null pointers at the end of each of
896 		 * the arg and env vector sets,and imgp->auxarg_size is room
897 		 * for argument of Runtime loader.
898 		 */
899 		vectp = (u_int32_t *) (destp - (imgp->args->argc +
900 		    imgp->args->envc + 2 + imgp->auxarg_size) *
901 		    sizeof(u_int32_t));
902 
903 	} else
904 		/*
905 		 * The '+ 2' is for the null pointers at the end of each of
906 		 * the arg and env vector sets
907 		 */
908 		vectp = (u_int32_t *)(destp - (imgp->args->argc +
909 		    imgp->args->envc + 2) * sizeof(u_int32_t));
910 
911 	/*
912 	 * vectp also becomes our initial stack base
913 	 */
914 	stack_base = vectp;
915 
916 	stringp = imgp->args->begin_argv;
917 	argc = imgp->args->argc;
918 	envc = imgp->args->envc;
919 	/*
920 	 * Copy out strings - arguments and environment.
921 	 */
922 	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
923 
924 	/*
925 	 * Fill in "ps_strings" struct for ps, w, etc.
926 	 */
927 	suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp);
928 	suword32(&arginfo->ps_nargvstr, argc);
929 
930 	/*
931 	 * Fill in argument portion of vector table.
932 	 */
933 	for (; argc > 0; --argc) {
934 		suword32(vectp++, (uint32_t)(intptr_t)destp);
935 		while (*stringp++ != 0)
936 			destp++;
937 		destp++;
938 	}
939 
940 	/* a null vector table pointer separates the argp's from the envp's */
941 	suword32(vectp++, 0);
942 
943 	suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp);
944 	suword32(&arginfo->ps_nenvstr, envc);
945 
946 	/*
947 	 * Fill in environment portion of vector table.
948 	 */
949 	for (; envc > 0; --envc) {
950 		suword32(vectp++, (uint32_t)(intptr_t)destp);
951 		while (*stringp++ != 0)
952 			destp++;
953 		destp++;
954 	}
955 
956 	/* end of vector table is a null pointer */
957 	suword32(vectp, 0);
958 
959 	return ((register_t *)stack_base);
960 }
961 
962 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0,
963     "32-bit Linux emulation");
964 
965 static u_long	linux32_maxdsiz = LINUX32_MAXDSIZ;
966 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
967     &linux32_maxdsiz, 0, "");
968 static u_long	linux32_maxssiz = LINUX32_MAXSSIZ;
969 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
970     &linux32_maxssiz, 0, "");
971 static u_long	linux32_maxvmem = LINUX32_MAXVMEM;
972 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
973     &linux32_maxvmem, 0, "");
974 
975 #if defined(DEBUG)
976 SYSCTL_PROC(_compat_linux32, OID_AUTO, debug,
977             CTLTYPE_STRING | CTLFLAG_RW,
978             0, 0, linux_sysctl_debug, "A",
979             "Linux debugging control");
980 #endif
981 
982 static void
983 linux32_fixlimit(struct rlimit *rl, int which)
984 {
985 
986 	switch (which) {
987 	case RLIMIT_DATA:
988 		if (linux32_maxdsiz != 0) {
989 			if (rl->rlim_cur > linux32_maxdsiz)
990 				rl->rlim_cur = linux32_maxdsiz;
991 			if (rl->rlim_max > linux32_maxdsiz)
992 				rl->rlim_max = linux32_maxdsiz;
993 		}
994 		break;
995 	case RLIMIT_STACK:
996 		if (linux32_maxssiz != 0) {
997 			if (rl->rlim_cur > linux32_maxssiz)
998 				rl->rlim_cur = linux32_maxssiz;
999 			if (rl->rlim_max > linux32_maxssiz)
1000 				rl->rlim_max = linux32_maxssiz;
1001 		}
1002 		break;
1003 	case RLIMIT_VMEM:
1004 		if (linux32_maxvmem != 0) {
1005 			if (rl->rlim_cur > linux32_maxvmem)
1006 				rl->rlim_cur = linux32_maxvmem;
1007 			if (rl->rlim_max > linux32_maxvmem)
1008 				rl->rlim_max = linux32_maxvmem;
1009 		}
1010 		break;
1011 	}
1012 }
1013 
1014 struct sysentvec elf_linux_sysvec = {
1015 	.sv_size	= LINUX32_SYS_MAXSYSCALL,
1016 	.sv_table	= linux32_sysent,
1017 	.sv_mask	= 0,
1018 	.sv_errsize	= ELAST + 1,
1019 	.sv_errtbl	= bsd_to_linux_errno,
1020 	.sv_transtrap	= translate_traps,
1021 	.sv_fixup	= elf_linux_fixup,
1022 	.sv_sendsig	= linux_sendsig,
1023 	.sv_sigcode	= &_binary_linux32_locore_o_start,
1024 	.sv_szsigcode	= &linux_szsigcode,
1025 	.sv_name	= "Linux ELF32",
1026 	.sv_coredump	= elf32_coredump,
1027 	.sv_imgact_try	= exec_linux_imgact_try,
1028 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
1029 	.sv_pagesize	= PAGE_SIZE,
1030 	.sv_minuser	= VM_MIN_ADDRESS,
1031 	.sv_maxuser	= LINUX32_MAXUSER,
1032 	.sv_usrstack	= LINUX32_USRSTACK,
1033 	.sv_psstrings	= LINUX32_PS_STRINGS,
1034 	.sv_stackprot	= VM_PROT_ALL,
1035 	.sv_copyout_strings = linux_copyout_strings,
1036 	.sv_setregs	= exec_linux_setregs,
1037 	.sv_fixlimit	= linux32_fixlimit,
1038 	.sv_maxssiz	= &linux32_maxssiz,
1039 	.sv_flags	= SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP,
1040 	.sv_set_syscall_retval = cpu_set_syscall_retval,
1041 	.sv_fetch_syscall_args = linux32_fetch_syscall_args,
1042 	.sv_syscallnames = NULL,
1043 	.sv_shared_page_base = LINUX32_SHAREDPAGE,
1044 	.sv_shared_page_len = PAGE_SIZE,
1045 	.sv_schedtail	= linux_schedtail,
1046 	.sv_thread_detach = linux_thread_detach,
1047 	.sv_trap	= NULL,
1048 };
1049 
1050 static void
1051 linux_vdso_install(void *param)
1052 {
1053 
1054 	linux_szsigcode = (&_binary_linux32_locore_o_end -
1055 	    &_binary_linux32_locore_o_start);
1056 
1057 	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
1058 		panic("Linux invalid vdso size\n");
1059 
1060 	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
1061 
1062 	linux_shared_page_obj = __elfN(linux_shared_page_init)
1063 	    (&linux_shared_page_mapping);
1064 
1065 	__elfN(linux_vdso_reloc)(&elf_linux_sysvec, LINUX32_SHAREDPAGE);
1066 
1067 	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
1068 	    linux_szsigcode);
1069 	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
1070 
1071 	linux_kplatform = linux_shared_page_mapping +
1072 	    (linux_platform - (caddr_t)LINUX32_SHAREDPAGE);
1073 }
1074 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
1075     (sysinit_cfunc_t)linux_vdso_install, NULL);
1076 
1077 static void
1078 linux_vdso_deinstall(void *param)
1079 {
1080 
1081 	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
1082 };
1083 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
1084     (sysinit_cfunc_t)linux_vdso_deinstall, NULL);
1085 
1086 static char GNU_ABI_VENDOR[] = "GNU";
1087 static int GNULINUX_ABI_DESC = 0;
1088 
1089 static boolean_t
1090 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
1091 {
1092 	const Elf32_Word *desc;
1093 	uintptr_t p;
1094 
1095 	p = (uintptr_t)(note + 1);
1096 	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1097 
1098 	desc = (const Elf32_Word *)p;
1099 	if (desc[0] != GNULINUX_ABI_DESC)
1100 		return (FALSE);
1101 
1102 	/*
1103 	 * For linux we encode osrel as follows (see linux_mib.c):
1104 	 * VVVMMMIII (version, major, minor), see linux_mib.c.
1105 	 */
1106 	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
1107 
1108 	return (TRUE);
1109 }
1110 
1111 static Elf_Brandnote linux32_brandnote = {
1112 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
1113 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
1114 	.hdr.n_type	= 1,
1115 	.vendor		= GNU_ABI_VENDOR,
1116 	.flags		= BN_TRANSLATE_OSREL,
1117 	.trans_osrel	= linux32_trans_osrel
1118 };
1119 
1120 static Elf32_Brandinfo linux_brand = {
1121 	.brand		= ELFOSABI_LINUX,
1122 	.machine	= EM_386,
1123 	.compat_3_brand	= "Linux",
1124 	.emul_path	= "/compat/linux",
1125 	.interp_path	= "/lib/ld-linux.so.1",
1126 	.sysvec		= &elf_linux_sysvec,
1127 	.interp_newpath	= NULL,
1128 	.brand_note	= &linux32_brandnote,
1129 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1130 };
1131 
1132 static Elf32_Brandinfo linux_glibc2brand = {
1133 	.brand		= ELFOSABI_LINUX,
1134 	.machine	= EM_386,
1135 	.compat_3_brand	= "Linux",
1136 	.emul_path	= "/compat/linux",
1137 	.interp_path	= "/lib/ld-linux.so.2",
1138 	.sysvec		= &elf_linux_sysvec,
1139 	.interp_newpath	= NULL,
1140 	.brand_note	= &linux32_brandnote,
1141 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1142 };
1143 
1144 Elf32_Brandinfo *linux_brandlist[] = {
1145 	&linux_brand,
1146 	&linux_glibc2brand,
1147 	NULL
1148 };
1149 
1150 static int
1151 linux_elf_modevent(module_t mod, int type, void *data)
1152 {
1153 	Elf32_Brandinfo **brandinfo;
1154 	int error;
1155 	struct linux_ioctl_handler **lihp;
1156 
1157 	error = 0;
1158 
1159 	switch(type) {
1160 	case MOD_LOAD:
1161 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1162 		     ++brandinfo)
1163 			if (elf32_insert_brand_entry(*brandinfo) < 0)
1164 				error = EINVAL;
1165 		if (error == 0) {
1166 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1167 				linux_ioctl_register_handler(*lihp);
1168 			LIST_INIT(&futex_list);
1169 			mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1170 			stclohz = (stathz ? stathz : hz);
1171 			if (bootverbose)
1172 				printf("Linux ELF exec handler installed\n");
1173 		} else
1174 			printf("cannot insert Linux ELF brand handler\n");
1175 		break;
1176 	case MOD_UNLOAD:
1177 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1178 		     ++brandinfo)
1179 			if (elf32_brand_inuse(*brandinfo))
1180 				error = EBUSY;
1181 		if (error == 0) {
1182 			for (brandinfo = &linux_brandlist[0];
1183 			     *brandinfo != NULL; ++brandinfo)
1184 				if (elf32_remove_brand_entry(*brandinfo) < 0)
1185 					error = EINVAL;
1186 		}
1187 		if (error == 0) {
1188 			SET_FOREACH(lihp, linux_ioctl_handler_set)
1189 				linux_ioctl_unregister_handler(*lihp);
1190 			mtx_destroy(&futex_mtx);
1191 			if (bootverbose)
1192 				printf("Linux ELF exec handler removed\n");
1193 		} else
1194 			printf("Could not deinstall ELF interpreter entry\n");
1195 		break;
1196 	default:
1197 		return (EOPNOTSUPP);
1198 	}
1199 	return (error);
1200 }
1201 
1202 static moduledata_t linux_elf_mod = {
1203 	"linuxelf",
1204 	linux_elf_modevent,
1205 	0
1206 };
1207 
1208 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1209 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1);
1210 FEATURE(linux, "Linux 32bit support");
1211