1/*-
2 * Copyright (c) 2013 Dmitry Chagin
3 * Copyright (c) 2004 Tim J. Robbins
4 * Copyright (c) 2003 Peter Wemm
5 * Copyright (c) 2002 Doug Rabson
6 * Copyright (c) 1998-1999 Andrew Gallatin
7 * Copyright (c) 1994-1996 S��ren Schmidt
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer
15 *    in this position and unchanged.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: stable/10/sys/amd64/linux/linux_sysvec.c 326814 2017-12-12 22:10:12Z pfg $");
36
37#include "opt_compat.h"
38
39#define	__ELF_WORD_SIZE	64
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/exec.h>
44#include <sys/fcntl.h>
45#include <sys/imgact.h>
46#include <sys/imgact_elf.h>
47#include <sys/kernel.h>
48#include <sys/ktr.h>
49#include <sys/lock.h>
50#include <sys/malloc.h>
51#include <sys/module.h>
52#include <sys/mutex.h>
53#include <sys/proc.h>
54#include <sys/resourcevar.h>
55#include <sys/signalvar.h>
56#include <sys/sysctl.h>
57#include <sys/syscallsubr.h>
58#include <sys/sysent.h>
59#include <sys/sysproto.h>
60#include <sys/vnode.h>
61#include <sys/eventhandler.h>
62
63#include <vm/vm.h>
64#include <vm/pmap.h>
65#include <vm/vm_extern.h>
66#include <vm/vm_map.h>
67#include <vm/vm_object.h>
68#include <vm/vm_page.h>
69#include <vm/vm_param.h>
70
71#include <machine/cpu.h>
72#include <machine/md_var.h>
73#include <machine/pcb.h>
74#include <machine/specialreg.h>
75
76#include <amd64/linux/linux.h>
77#include <amd64/linux/linux_proto.h>
78#include <compat/linux/linux_emul.h>
79#include <compat/linux/linux_futex.h>
80#include <compat/linux/linux_ioctl.h>
81#include <compat/linux/linux_mib.h>
82#include <compat/linux/linux_misc.h>
83#include <compat/linux/linux_signal.h>
84#include <compat/linux/linux_sysproto.h>
85#include <compat/linux/linux_util.h>
86#include <compat/linux/linux_vdso.h>
87
88MODULE_VERSION(linux64, 1);
89
90#if BYTE_ORDER == LITTLE_ENDIAN
91#define SHELLMAGIC      0x2123 /* #! */
92#else
93#define SHELLMAGIC      0x2321
94#endif
95
96#if defined(DEBUG)
97SYSCTL_PROC(_compat_linux, OID_AUTO, debug,
98	    CTLTYPE_STRING | CTLFLAG_RW,
99	    0, 0, linux_sysctl_debug, "A",
100	    "Linux 64 debugging control");
101#endif
102
103/*
104 * Allow the this functions to use the ldebug() facility
105 * even though they are not syscalls themselves. Map them
106 * to syscall 0. This is slightly less bogus than using
107 * ldebug(sigreturn).
108 */
109#define	LINUX_SYS_linux_rt_sendsig	0
110
111const char *linux_kplatform;
112static int linux_szsigcode;
113static vm_object_t linux_shared_page_obj;
114static char *linux_shared_page_mapping;
115extern char _binary_linux_locore_o_start;
116extern char _binary_linux_locore_o_end;
117
118extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
119
120SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
121
122static register_t * linux_copyout_strings(struct image_params *imgp);
123static int	elf_linux_fixup(register_t **stack_base,
124		    struct image_params *iparams);
125static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
126static void	linux_vdso_install(void *param);
127static void	linux_vdso_deinstall(void *param);
128static void	linux_set_syscall_retval(struct thread *td, int error);
129static int	linux_fetch_syscall_args(struct thread *td, struct syscall_args *sa);
130static void	linux_exec_setregs(struct thread *td, struct image_params *imgp,
131		    u_long stack);
132static int	linux_vsyscall(struct thread *td);
133
134/*
135 * Linux syscalls return negative errno's, we do positive and map them
136 * Reference:
137 *   FreeBSD: src/sys/sys/errno.h
138 *   Linux:   linux-2.6.17.8/include/asm-generic/errno-base.h
139 *            linux-2.6.17.8/include/asm-generic/errno.h
140 */
141static int bsd_to_linux_errno[ELAST + 1] = {
142	-0,  -1,  -2,  -3,  -4,  -5,  -6,  -7,  -8,  -9,
143	-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
144	-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
145	-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
146	-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
147	-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
148	-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
149	-116, -66,  -6,  -6,  -6,  -6,  -6, -37, -38,  -9,
150	  -6,  -6, -43, -42, -75,-125, -84, -61, -16, -74,
151	 -72, -67, -71
152};
153
154#define LINUX_T_UNKNOWN  255
155static int _bsd_to_linux_trapcode[] = {
156	LINUX_T_UNKNOWN,	/* 0 */
157	6,			/* 1  T_PRIVINFLT */
158	LINUX_T_UNKNOWN,	/* 2 */
159	3,			/* 3  T_BPTFLT */
160	LINUX_T_UNKNOWN,	/* 4 */
161	LINUX_T_UNKNOWN,	/* 5 */
162	16,			/* 6  T_ARITHTRAP */
163	254,			/* 7  T_ASTFLT */
164	LINUX_T_UNKNOWN,	/* 8 */
165	13,			/* 9  T_PROTFLT */
166	1,			/* 10 T_TRCTRAP */
167	LINUX_T_UNKNOWN,	/* 11 */
168	14,			/* 12 T_PAGEFLT */
169	LINUX_T_UNKNOWN,	/* 13 */
170	17,			/* 14 T_ALIGNFLT */
171	LINUX_T_UNKNOWN,	/* 15 */
172	LINUX_T_UNKNOWN,	/* 16 */
173	LINUX_T_UNKNOWN,	/* 17 */
174	0,			/* 18 T_DIVIDE */
175	2,			/* 19 T_NMI */
176	4,			/* 20 T_OFLOW */
177	5,			/* 21 T_BOUND */
178	7,			/* 22 T_DNA */
179	8,			/* 23 T_DOUBLEFLT */
180	9,			/* 24 T_FPOPFLT */
181	10,			/* 25 T_TSSFLT */
182	11,			/* 26 T_SEGNPFLT */
183	12,			/* 27 T_STKFLT */
184	18,			/* 28 T_MCHK */
185	19,			/* 29 T_XMMFLT */
186	15			/* 30 T_RESERVED */
187};
188#define bsd_to_linux_trapcode(code) \
189    ((code)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \
190     _bsd_to_linux_trapcode[(code)]: \
191     LINUX_T_UNKNOWN)
192
193LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
194LINUX_VDSO_SYM_CHAR(linux_platform);
195
196/*
197 * If FreeBSD & Linux have a difference of opinion about what a trap
198 * means, deal with it here.
199 *
200 * MPSAFE
201 */
202static int
203translate_traps(int signal, int trap_code)
204{
205
206	if (signal != SIGBUS)
207		return signal;
208	switch (trap_code) {
209	case T_PROTFLT:
210	case T_TSSFLT:
211	case T_DOUBLEFLT:
212	case T_PAGEFLT:
213		return SIGSEGV;
214	default:
215		return signal;
216	}
217}
218
219static int
220linux_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
221{
222	struct proc *p;
223	struct trapframe *frame;
224
225	p = td->td_proc;
226	frame = td->td_frame;
227
228	sa->args[0] = frame->tf_rdi;
229	sa->args[1] = frame->tf_rsi;
230	sa->args[2] = frame->tf_rdx;
231	sa->args[3] = frame->tf_rcx;
232	sa->args[4] = frame->tf_r8;
233	sa->args[5] = frame->tf_r9;
234	sa->code = frame->tf_rax;
235
236	if (sa->code >= p->p_sysent->sv_size)
237		/* nosys */
238		sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
239	else
240		sa->callp = &p->p_sysent->sv_table[sa->code];
241	sa->narg = sa->callp->sy_narg;
242
243	td->td_retval[0] = 0;
244	return (0);
245}
246
247static void
248linux_set_syscall_retval(struct thread *td, int error)
249{
250	struct trapframe *frame = td->td_frame;
251
252	/*
253	 * On Linux only %rcx and %r11 values are not preserved across
254	 * the syscall.
255	 * So, do not clobber %rdx and %r10
256	 */
257	td->td_retval[1] = frame->tf_rdx;
258	frame->tf_r10 = frame->tf_rcx;
259
260	cpu_set_syscall_retval(td, error);
261
262	 /* Restore all registers. */
263	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
264}
265
266static int
267elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
268{
269	Elf_Auxargs *args;
270	Elf_Addr *base;
271	Elf_Addr *pos;
272	struct ps_strings *arginfo;
273	struct proc *p;
274	int issetugid;
275
276	p = imgp->proc;
277	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
278
279	KASSERT(curthread->td_proc == imgp->proc,
280	    ("unsafe elf_linux_fixup(), should be curproc"));
281	base = (Elf64_Addr *)*stack_base;
282	args = (Elf64_Auxargs *)imgp->auxargs;
283	pos = base + (imgp->args->argc + imgp->args->envc + 2);
284
285	issetugid = p->p_flag & P_SUGID ? 1 : 0;
286	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
287	    imgp->proc->p_sysent->sv_shared_page_base);
288	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
289	AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
290	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
291	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
292	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
293	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
294	AUXARGS_ENTRY(pos, AT_BASE, args->base);
295	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
296	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
297	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
298	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
299	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
300	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
301	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
302	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
303	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
304	if (imgp->execpathp != 0)
305		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
306	if (args->execfd != -1)
307		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
308	AUXARGS_ENTRY(pos, AT_NULL, 0);
309	free(imgp->auxargs, M_TEMP);
310	imgp->auxargs = NULL;
311
312	base--;
313	suword(base, (uint64_t)imgp->args->argc);
314
315	*stack_base = (register_t *)base;
316	return (0);
317}
318
319/*
320 * Copy strings out to the new process address space, constructing new arg
321 * and env vector tables. Return a pointer to the base so that it can be used
322 * as the initial stack pointer.
323 */
324static register_t *
325linux_copyout_strings(struct image_params *imgp)
326{
327	int argc, envc;
328	char **vectp;
329	char *stringp, *destp;
330	register_t *stack_base;
331	struct ps_strings *arginfo;
332	char canary[LINUX_AT_RANDOM_LEN];
333	size_t execpath_len;
334	struct proc *p;
335
336	/*
337	 * Calculate string base and vector table pointers.
338	 */
339	if (imgp->execpath != NULL && imgp->auxargs != NULL)
340		execpath_len = strlen(imgp->execpath) + 1;
341	else
342		execpath_len = 0;
343
344	p = imgp->proc;
345	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
346	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
347	    roundup(sizeof(canary), sizeof(char *)) -
348	    roundup(execpath_len, sizeof(char *)) -
349	    roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
350
351	if (execpath_len != 0) {
352		imgp->execpathp = (uintptr_t)arginfo - execpath_len;
353		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
354	}
355
356	/*
357	 * Prepare the canary for SSP.
358	 */
359	arc4rand(canary, sizeof(canary), 0);
360	imgp->canary = (uintptr_t)arginfo -
361	    roundup(execpath_len, sizeof(char *)) -
362	    roundup(sizeof(canary), sizeof(char *));
363	copyout(canary, (void *)imgp->canary, sizeof(canary));
364
365	/*
366	 * If we have a valid auxargs ptr, prepare some room
367	 * on the stack.
368	 */
369	if (imgp->auxargs) {
370		/*
371		 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
372		 * lower compatibility.
373		 */
374		imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
375		    (LINUX_AT_COUNT * 2);
376
377		/*
378		 * The '+ 2' is for the null pointers at the end of each of
379		 * the arg and env vector sets,and imgp->auxarg_size is room
380		 * for argument of Runtime loader.
381		 */
382		vectp = (char **)(destp - (imgp->args->argc +
383		    imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
384
385	} else {
386		/*
387		 * The '+ 2' is for the null pointers at the end of each of
388		 * the arg and env vector sets
389		 */
390		vectp = (char **)(destp - (imgp->args->argc +
391		    imgp->args->envc + 2) * sizeof(char *));
392	}
393
394	/*
395	 * vectp also becomes our initial stack base
396	 */
397	stack_base = (register_t *)vectp;
398
399	stringp = imgp->args->begin_argv;
400	argc = imgp->args->argc;
401	envc = imgp->args->envc;
402
403	/*
404	 * Copy out strings - arguments and environment.
405	 */
406	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
407
408	/*
409	 * Fill in "ps_strings" struct for ps, w, etc.
410	 */
411	suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
412	suword(&arginfo->ps_nargvstr, argc);
413
414	/*
415	 * Fill in argument portion of vector table.
416	 */
417	for (; argc > 0; --argc) {
418		suword(vectp++, (long)(intptr_t)destp);
419		while (*stringp++ != 0)
420			destp++;
421		destp++;
422	}
423
424	/* a null vector table pointer separates the argp's from the envp's */
425	suword(vectp++, 0);
426
427	suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
428	suword(&arginfo->ps_nenvstr, envc);
429
430	/*
431	 * Fill in environment portion of vector table.
432	 */
433	for (; envc > 0; --envc) {
434		suword(vectp++, (long)(intptr_t)destp);
435		while (*stringp++ != 0)
436			destp++;
437		destp++;
438	}
439
440	/* end of vector table is a null pointer */
441	suword(vectp, 0);
442	return (stack_base);
443}
444
445/*
446 * Reset registers to default values on exec.
447 */
448static void
449linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
450{
451	struct trapframe *regs = td->td_frame;
452	struct pcb *pcb = td->td_pcb;
453
454	mtx_lock(&dt_lock);
455	if (td->td_proc->p_md.md_ldt != NULL)
456		user_ldt_free(td);
457	else
458		mtx_unlock(&dt_lock);
459
460	pcb->pcb_fsbase = 0;
461	pcb->pcb_gsbase = 0;
462	clear_pcb_flags(pcb, PCB_32BIT);
463	pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
464	set_pcb_flags(pcb, PCB_FULL_IRET);
465
466	bzero((char *)regs, sizeof(struct trapframe));
467	regs->tf_rip = imgp->entry_addr;
468	regs->tf_rsp = stack;
469	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
470	regs->tf_ss = _udatasel;
471	regs->tf_cs = _ucodesel;
472	regs->tf_ds = _udatasel;
473	regs->tf_es = _udatasel;
474	regs->tf_fs = _ufssel;
475	regs->tf_gs = _ugssel;
476	regs->tf_flags = TF_HASSEGS;
477
478	/*
479	 * Reset the hardware debug registers if they were in use.
480	 * They won't have any meaning for the newly exec'd process.
481	 */
482	if (pcb->pcb_flags & PCB_DBREGS) {
483		pcb->pcb_dr0 = 0;
484		pcb->pcb_dr1 = 0;
485		pcb->pcb_dr2 = 0;
486		pcb->pcb_dr3 = 0;
487		pcb->pcb_dr6 = 0;
488		pcb->pcb_dr7 = 0;
489		if (pcb == curpcb) {
490			/*
491			 * Clear the debug registers on the running
492			 * CPU, otherwise they will end up affecting
493			 * the next process we switch to.
494			 */
495			reset_dbregs();
496		}
497		clear_pcb_flags(pcb, PCB_DBREGS);
498	}
499
500	/*
501	 * Drop the FP state if we hold it, so that the process gets a
502	 * clean FP state if it uses the FPU again.
503	 */
504	fpstate_drop(td);
505}
506
507/*
508 * Copied from amd64/amd64/machdep.c
509 *
510 * XXX fpu state need? don't think so
511 */
512int
513linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
514{
515	struct proc *p;
516	struct l_ucontext uc;
517	struct l_sigcontext *context;
518	struct trapframe *regs;
519	unsigned long rflags;
520	int error;
521	ksiginfo_t ksi;
522
523	regs = td->td_frame;
524	error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
525	if (error != 0)
526		return (error);
527
528	p = td->td_proc;
529	context = &uc.uc_mcontext;
530	rflags = context->sc_rflags;
531
532	/*
533	 * Don't allow users to change privileged or reserved flags.
534	 */
535	/*
536	 * XXX do allow users to change the privileged flag PSL_RF.
537	 * The cpu sets PSL_RF in tf_rflags for faults.  Debuggers
538	 * should sometimes set it there too.  tf_rflags is kept in
539	 * the signal context during signal handling and there is no
540	 * other place to remember it, so the PSL_RF bit may be
541	 * corrupted by the signal handler without us knowing.
542	 * Corruption of the PSL_RF bit at worst causes one more or
543	 * one less debugger trap, so allowing it is fairly harmless.
544	 */
545
546#define RFLAG_SECURE(ef, oef)     ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
547	if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
548		printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags);
549		return (EINVAL);
550	}
551
552	/*
553	 * Don't allow users to load a valid privileged %cs.  Let the
554	 * hardware check for invalid selectors, excess privilege in
555	 * other selectors, invalid %eip's and invalid %esp's.
556	 */
557#define CS_SECURE(cs)           (ISPL(cs) == SEL_UPL)
558	if (!CS_SECURE(context->sc_cs)) {
559		printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs);
560		ksiginfo_init_trap(&ksi);
561		ksi.ksi_signo = SIGBUS;
562		ksi.ksi_code = BUS_OBJERR;
563		ksi.ksi_trapno = T_PROTFLT;
564		ksi.ksi_addr = (void *)regs->tf_rip;
565		trapsignal(td, &ksi);
566		return (EINVAL);
567	}
568
569	PROC_LOCK(p);
570	linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
571	SIG_CANTMASK(td->td_sigmask);
572	signotify(td);
573	PROC_UNLOCK(p);
574
575	regs->tf_rdi    = context->sc_rdi;
576	regs->tf_rsi    = context->sc_rsi;
577	regs->tf_rdx    = context->sc_rdx;
578	regs->tf_rbp    = context->sc_rbp;
579	regs->tf_rbx    = context->sc_rbx;
580	regs->tf_rcx    = context->sc_rcx;
581	regs->tf_rax    = context->sc_rax;
582	regs->tf_rip    = context->sc_rip;
583	regs->tf_rsp    = context->sc_rsp;
584	regs->tf_r8     = context->sc_r8;
585	regs->tf_r9     = context->sc_r9;
586	regs->tf_r10    = context->sc_r10;
587	regs->tf_r11    = context->sc_r11;
588	regs->tf_r12    = context->sc_r12;
589	regs->tf_r13    = context->sc_r13;
590	regs->tf_r14    = context->sc_r14;
591	regs->tf_r15    = context->sc_r15;
592	regs->tf_cs     = context->sc_cs;
593	regs->tf_err    = context->sc_err;
594	regs->tf_rflags = rflags;
595
596	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
597	return (EJUSTRETURN);
598}
599
600/*
601 * copied from amd64/amd64/machdep.c
602 *
603 * Send an interrupt to process.
604 */
605static void
606linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
607{
608	struct l_rt_sigframe sf, *sfp;
609	struct proc *p;
610	struct thread *td;
611	struct sigacts *psp;
612	caddr_t sp;
613	struct trapframe *regs;
614	int sig, code;
615	int oonstack;
616
617	td = curthread;
618	p = td->td_proc;
619	PROC_LOCK_ASSERT(p, MA_OWNED);
620	sig = ksi->ksi_signo;
621	psp = p->p_sigacts;
622	code = ksi->ksi_code;
623	mtx_assert(&psp->ps_mtx, MA_OWNED);
624	regs = td->td_frame;
625	oonstack = sigonstack(regs->tf_rsp);
626
627	LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
628	    catcher, sig, mask, code);
629
630	/* Allocate space for the signal handler context. */
631	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
632	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
633		sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size -
634		    sizeof(struct l_rt_sigframe);
635	} else
636		sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128;
637	/* Align to 16 bytes. */
638	sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
639	mtx_unlock(&psp->ps_mtx);
640
641	/* Translate the signal. */
642	sig = bsd_to_linux_signal(sig);
643
644	/* Save user context. */
645	bzero(&sf, sizeof(sf));
646	bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask);
647	bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask);
648
649	sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
650	sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
651	sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
652	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
653	PROC_UNLOCK(p);
654
655	sf.sf_sc.uc_mcontext.sc_rdi    = regs->tf_rdi;
656	sf.sf_sc.uc_mcontext.sc_rsi    = regs->tf_rsi;
657	sf.sf_sc.uc_mcontext.sc_rdx    = regs->tf_rdx;
658	sf.sf_sc.uc_mcontext.sc_rbp    = regs->tf_rbp;
659	sf.sf_sc.uc_mcontext.sc_rbx    = regs->tf_rbx;
660	sf.sf_sc.uc_mcontext.sc_rcx    = regs->tf_rcx;
661	sf.sf_sc.uc_mcontext.sc_rax    = regs->tf_rax;
662	sf.sf_sc.uc_mcontext.sc_rip    = regs->tf_rip;
663	sf.sf_sc.uc_mcontext.sc_rsp    = regs->tf_rsp;
664	sf.sf_sc.uc_mcontext.sc_r8     = regs->tf_r8;
665	sf.sf_sc.uc_mcontext.sc_r9     = regs->tf_r9;
666	sf.sf_sc.uc_mcontext.sc_r10    = regs->tf_r10;
667	sf.sf_sc.uc_mcontext.sc_r11    = regs->tf_r11;
668	sf.sf_sc.uc_mcontext.sc_r12    = regs->tf_r12;
669	sf.sf_sc.uc_mcontext.sc_r13    = regs->tf_r13;
670	sf.sf_sc.uc_mcontext.sc_r14    = regs->tf_r14;
671	sf.sf_sc.uc_mcontext.sc_r15    = regs->tf_r15;
672	sf.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
673	sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags;
674	sf.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
675	sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
676	sf.sf_sc.uc_mcontext.sc_cr2    = (register_t)ksi->ksi_addr;
677
678	/* Build the argument list for the signal handler. */
679	regs->tf_rdi = sig;			/* arg 1 in %rdi */
680	regs->tf_rax = 0;
681	regs->tf_rsi = (register_t)&sfp->sf_si;	/* arg 2 in %rsi */
682	regs->tf_rdx = (register_t)&sfp->sf_sc;	/* arg 3 in %rdx */
683
684	sf.sf_handler = catcher;
685	/* Fill in POSIX parts */
686	ksiginfo_to_lsiginfo(ksi, &sf.sf_si, sig);
687
688	/*
689	 * Copy the sigframe out to the user's stack.
690	 */
691	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
692#ifdef DEBUG
693		printf("process %ld has trashed its stack\n", (long)p->p_pid);
694#endif
695		PROC_LOCK(p);
696		sigexit(td, SIGILL);
697	}
698
699	regs->tf_rsp = (long)sfp;
700	regs->tf_rip = linux_rt_sigcode;
701	regs->tf_rflags &= ~(PSL_T | PSL_D);
702	regs->tf_cs = _ucodesel;
703	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
704	PROC_LOCK(p);
705	mtx_lock(&psp->ps_mtx);
706}
707
708/*
709 * If a linux binary is exec'ing something, try this image activator
710 * first.  We override standard shell script execution in order to
711 * be able to modify the interpreter path.  We only do this if a linux
712 * binary is doing the exec, so we do not create an EXEC module for it.
713 */
714static int exec_linux_imgact_try(struct image_params *iparams);
715
716static int
717exec_linux_imgact_try(struct image_params *imgp)
718{
719	const char *head = (const char *)imgp->image_header;
720	char *rpath;
721	int error = -1;
722
723	/*
724	 * The interpreter for shell scripts run from a linux binary needs
725	 * to be located in /compat/linux if possible in order to recursively
726	 * maintain linux path emulation.
727	 */
728	if (((const short *)head)[0] == SHELLMAGIC) {
729		/*
730		 * Run our normal shell image activator.  If it succeeds
731		 * attempt to use the alternate path for the interpreter.
732		 * If an alternate path is found, use our stringspace
733		 * to store it.
734		 */
735		if ((error = exec_shell_imgact(imgp)) == 0) {
736			linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
737			    imgp->interpreter_name, UIO_SYSSPACE,
738			    &rpath, 0, AT_FDCWD);
739			if (rpath != NULL)
740				imgp->args->fname_buf =
741				    imgp->interpreter_name = rpath;
742		}
743	}
744	return (error);
745}
746
747#define	LINUX_VSYSCALL_START		(-10UL << 20)
748#define	LINUX_VSYSCALL_SZ		1024
749
750const unsigned long linux_vsyscall_vector[] = {
751	LINUX_SYS_gettimeofday,
752	LINUX_SYS_linux_time,
753				/* getcpu not implemented */
754};
755
756static int
757linux_vsyscall(struct thread *td)
758{
759	struct trapframe *frame;
760	uint64_t retqaddr;
761	int code, traced;
762	int error;
763
764	frame = td->td_frame;
765
766	/* Check %rip for vsyscall area */
767	if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START))
768		return (EINVAL);
769	if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0)
770		return (EINVAL);
771	code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ;
772	if (code >= nitems(linux_vsyscall_vector))
773		return (EINVAL);
774
775	/*
776	 * vsyscall called as callq *(%rax), so we must
777	 * use return address from %rsp and also fixup %rsp
778	 */
779	error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr));
780	if (error)
781		return (error);
782
783	frame->tf_rip = retqaddr;
784	frame->tf_rax = linux_vsyscall_vector[code];
785	frame->tf_rsp += 8;
786
787	traced = (frame->tf_flags & PSL_T);
788
789	amd64_syscall(td, traced);
790
791	return (0);
792}
793
794struct sysentvec elf_linux_sysvec = {
795	.sv_size	= LINUX_SYS_MAXSYSCALL,
796	.sv_table	= linux_sysent,
797	.sv_mask	= 0,
798	.sv_sigsize	= 0,
799	.sv_sigtbl	= NULL,
800	.sv_errsize	= ELAST + 1,
801	.sv_errtbl	= bsd_to_linux_errno,
802	.sv_transtrap	= translate_traps,
803	.sv_fixup	= elf_linux_fixup,
804	.sv_sendsig	= linux_rt_sendsig,
805	.sv_sigcode	= &_binary_linux_locore_o_start,
806	.sv_szsigcode	= &linux_szsigcode,
807	.sv_prepsyscall	= NULL,
808	.sv_name	= "Linux ELF64",
809	.sv_coredump	= elf64_coredump,
810	.sv_imgact_try	= exec_linux_imgact_try,
811	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
812	.sv_pagesize	= PAGE_SIZE,
813	.sv_minuser	= VM_MIN_ADDRESS,
814	.sv_maxuser	= VM_MAXUSER_ADDRESS,
815	.sv_usrstack	= USRSTACK,
816	.sv_psstrings	= PS_STRINGS,
817	.sv_stackprot	= VM_PROT_ALL,
818	.sv_copyout_strings = linux_copyout_strings,
819	.sv_setregs	= linux_exec_setregs,
820	.sv_fixlimit	= NULL,
821	.sv_maxssiz	= NULL,
822	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP,
823	.sv_set_syscall_retval = linux_set_syscall_retval,
824	.sv_fetch_syscall_args = linux_fetch_syscall_args,
825	.sv_syscallnames = NULL,
826	.sv_shared_page_base = SHAREDPAGE,
827	.sv_shared_page_len = PAGE_SIZE,
828	.sv_schedtail	= linux_schedtail,
829	.sv_thread_detach = linux_thread_detach,
830	.sv_trap	= linux_vsyscall,
831};
832
833static void
834linux_vdso_install(void *param)
835{
836
837	linux_szsigcode = (&_binary_linux_locore_o_end -
838	    &_binary_linux_locore_o_start);
839
840	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
841		panic("Linux invalid vdso size\n");
842
843	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
844
845	linux_shared_page_obj = __elfN(linux_shared_page_init)
846	    (&linux_shared_page_mapping);
847
848	__elfN(linux_vdso_reloc)(&elf_linux_sysvec, SHAREDPAGE);
849
850	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
851	    linux_szsigcode);
852	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
853
854	linux_kplatform = linux_shared_page_mapping +
855	    (linux_platform - (caddr_t)SHAREDPAGE);
856}
857SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
858    (sysinit_cfunc_t)linux_vdso_install, NULL);
859
860static void
861linux_vdso_deinstall(void *param)
862{
863
864	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
865};
866SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
867    (sysinit_cfunc_t)linux_vdso_deinstall, NULL);
868
869static char GNULINUX_ABI_VENDOR[] = "GNU";
870static int GNULINUX_ABI_DESC = 0;
871
872static boolean_t
873linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
874{
875	const Elf32_Word *desc;
876	uintptr_t p;
877
878	p = (uintptr_t)(note + 1);
879	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
880
881	desc = (const Elf32_Word *)p;
882	if (desc[0] != GNULINUX_ABI_DESC)
883		return (FALSE);
884
885	/*
886	 * For linux we encode osrel as follows (see linux_mib.c):
887	 * VVVMMMIII (version, major, minor), see linux_mib.c.
888	 */
889	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
890
891	return (TRUE);
892}
893
894static Elf_Brandnote linux64_brandnote = {
895	.hdr.n_namesz	= sizeof(GNULINUX_ABI_VENDOR),
896	.hdr.n_descsz	= 16,
897	.hdr.n_type	= 1,
898	.vendor		= GNULINUX_ABI_VENDOR,
899	.flags		= BN_TRANSLATE_OSREL,
900	.trans_osrel	= linux_trans_osrel
901};
902
903static Elf64_Brandinfo linux_glibc2brand = {
904	.brand		= ELFOSABI_LINUX,
905	.machine	= EM_X86_64,
906	.compat_3_brand	= "Linux",
907	.emul_path	= "/compat/linux",
908	.interp_path	= "/lib64/ld-linux-x86-64.so.2",
909	.sysvec		= &elf_linux_sysvec,
910	.interp_newpath	= NULL,
911	.brand_note	= &linux64_brandnote,
912	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
913};
914
915static Elf64_Brandinfo linux_glibc2brandshort = {
916	.brand		= ELFOSABI_LINUX,
917	.machine	= EM_X86_64,
918	.compat_3_brand	= "Linux",
919	.emul_path	= "/compat/linux",
920	.interp_path	= "/lib64/ld-linux.so.2",
921	.sysvec		= &elf_linux_sysvec,
922	.interp_newpath	= NULL,
923	.brand_note	= &linux64_brandnote,
924	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
925};
926
927Elf64_Brandinfo *linux_brandlist[] = {
928	&linux_glibc2brand,
929	&linux_glibc2brandshort,
930	NULL
931};
932
933static int
934linux64_elf_modevent(module_t mod, int type, void *data)
935{
936	Elf64_Brandinfo **brandinfo;
937	int error;
938	struct linux_ioctl_handler **lihp;
939
940	error = 0;
941
942	switch(type) {
943	case MOD_LOAD:
944		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
945		     ++brandinfo)
946			if (elf64_insert_brand_entry(*brandinfo) < 0)
947				error = EINVAL;
948		if (error == 0) {
949			SET_FOREACH(lihp, linux_ioctl_handler_set)
950				linux_ioctl_register_handler(*lihp);
951			LIST_INIT(&futex_list);
952			mtx_init(&futex_mtx, "ftllk64", NULL, MTX_DEF);
953			stclohz = (stathz ? stathz : hz);
954			if (bootverbose)
955				printf("Linux x86-64 ELF exec handler installed\n");
956		} else
957			printf("cannot insert Linux x86-64 ELF brand handler\n");
958		break;
959	case MOD_UNLOAD:
960		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
961		     ++brandinfo)
962			if (elf64_brand_inuse(*brandinfo))
963				error = EBUSY;
964		if (error == 0) {
965			for (brandinfo = &linux_brandlist[0];
966			     *brandinfo != NULL; ++brandinfo)
967				if (elf64_remove_brand_entry(*brandinfo) < 0)
968					error = EINVAL;
969		}
970		if (error == 0) {
971			SET_FOREACH(lihp, linux_ioctl_handler_set)
972				linux_ioctl_unregister_handler(*lihp);
973			mtx_destroy(&futex_mtx);
974			if (bootverbose)
975				printf("Linux ELF exec handler removed\n");
976		} else
977			printf("Could not deinstall ELF interpreter entry\n");
978		break;
979	default:
980		return (EOPNOTSUPP);
981	}
982	return (error);
983}
984
985static moduledata_t linux64_elf_mod = {
986	"linux64elf",
987	linux64_elf_modevent,
988	0
989};
990
991DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
992MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
993FEATURE(linux64, "Linux 64bit support");
994