linux_sysvec.c revision 293575
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 293575 2016-01-09 17:29:08Z dchagin $");
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);
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 */
140static 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
154static 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)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \
189     _bsd_to_linux_trapcode[(code)]: \
190     LINUX_T_UNKNOWN)
191
192LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
193LINUX_VDSO_SYM_CHAR(linux_platform);
194
195/*
196 * If FreeBSD & Linux have a difference of opinion about what a trap
197 * means, deal with it here.
198 *
199 * MPSAFE
200 */
201static int
202translate_traps(int signal, int trap_code)
203{
204
205	if (signal != SIGBUS)
206		return signal;
207	switch (trap_code) {
208	case T_PROTFLT:
209	case T_TSSFLT:
210	case T_DOUBLEFLT:
211	case T_PAGEFLT:
212		return SIGSEGV;
213	default:
214		return signal;
215	}
216}
217
218static int
219linux_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
220{
221	struct proc *p;
222	struct trapframe *frame;
223
224	p = td->td_proc;
225	frame = td->td_frame;
226
227	sa->args[0] = frame->tf_rdi;
228	sa->args[1] = frame->tf_rsi;
229	sa->args[2] = frame->tf_rdx;
230	sa->args[3] = frame->tf_rcx;
231	sa->args[4] = frame->tf_r8;
232	sa->args[5] = frame->tf_r9;
233	sa->code = frame->tf_rax;
234
235	if (sa->code >= p->p_sysent->sv_size)
236		/* nosys */
237		sa->callp = &p->p_sysent->sv_table[LINUX_SYS_MAXSYSCALL];
238	else
239		sa->callp = &p->p_sysent->sv_table[sa->code];
240	sa->narg = sa->callp->sy_narg;
241
242	td->td_retval[0] = 0;
243	return (0);
244}
245
246static void
247linux_set_syscall_retval(struct thread *td, int error)
248{
249	struct trapframe *frame = td->td_frame;
250
251	/*
252	 * On Linux only %rcx and %r11 values are not preserved across
253	 * the syscall.
254	 * So, do not clobber %rdx and %r10
255	 */
256	td->td_retval[1] = frame->tf_rdx;
257	frame->tf_r10 = frame->tf_rcx;
258
259	cpu_set_syscall_retval(td, error);
260
261	 /* Restore all registers. */
262	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
263}
264
265static int
266elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
267{
268	Elf_Auxargs *args;
269	Elf_Addr *base;
270	Elf_Addr *pos;
271	struct ps_strings *arginfo;
272	struct proc *p;
273
274	p = imgp->proc;
275	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
276
277	KASSERT(curthread->td_proc == imgp->proc,
278	    ("unsafe elf_linux_fixup(), should be curproc"));
279	base = (Elf64_Addr *)*stack_base;
280	args = (Elf64_Auxargs *)imgp->auxargs;
281	pos = base + (imgp->args->argc + imgp->args->envc + 2);
282
283	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
284	    imgp->proc->p_sysent->sv_shared_page_base);
285	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
286	AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
287	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
288	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
289	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
290	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
291	AUXARGS_ENTRY(pos, AT_BASE, args->base);
292	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
293	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
294	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
295	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
296	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
297	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
298	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, 0);
299	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
300	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
301	if (imgp->execpathp != 0)
302		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
303	if (args->execfd != -1)
304		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
305	AUXARGS_ENTRY(pos, AT_NULL, 0);
306	free(imgp->auxargs, M_TEMP);
307	imgp->auxargs = NULL;
308
309	base--;
310	suword(base, (uint64_t)imgp->args->argc);
311
312	*stack_base = (register_t *)base;
313	return (0);
314}
315
316/*
317 * Copy strings out to the new process address space, constructing new arg
318 * and env vector tables. Return a pointer to the base so that it can be used
319 * as the initial stack pointer.
320 */
321static register_t *
322linux_copyout_strings(struct image_params *imgp)
323{
324	int argc, envc;
325	char **vectp;
326	char *stringp, *destp;
327	register_t *stack_base;
328	struct ps_strings *arginfo;
329	char canary[LINUX_AT_RANDOM_LEN];
330	size_t execpath_len;
331	struct proc *p;
332
333	/*
334	 * Calculate string base and vector table pointers.
335	 */
336	if (imgp->execpath != NULL && imgp->auxargs != NULL)
337		execpath_len = strlen(imgp->execpath) + 1;
338	else
339		execpath_len = 0;
340
341	p = imgp->proc;
342	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
343	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
344	    roundup(sizeof(canary), sizeof(char *)) -
345	    roundup(execpath_len, sizeof(char *)) -
346	    roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
347
348	if (execpath_len != 0) {
349		imgp->execpathp = (uintptr_t)arginfo - execpath_len;
350		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
351	}
352
353	/*
354	 * Prepare the canary for SSP.
355	 */
356	arc4rand(canary, sizeof(canary), 0);
357	imgp->canary = (uintptr_t)arginfo -
358	    roundup(execpath_len, sizeof(char *)) -
359	    roundup(sizeof(canary), sizeof(char *));
360	copyout(canary, (void *)imgp->canary, sizeof(canary));
361
362	/*
363	 * If we have a valid auxargs ptr, prepare some room
364	 * on the stack.
365	 */
366	if (imgp->auxargs) {
367		/*
368		 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
369		 * lower compatibility.
370		 */
371		imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
372		    (LINUX_AT_COUNT * 2);
373
374		/*
375		 * The '+ 2' is for the null pointers at the end of each of
376		 * the arg and env vector sets,and imgp->auxarg_size is room
377		 * for argument of Runtime loader.
378		 */
379		vectp = (char **)(destp - (imgp->args->argc +
380		    imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
381
382	} else {
383		/*
384		 * The '+ 2' is for the null pointers at the end of each of
385		 * the arg and env vector sets
386		 */
387		vectp = (char **)(destp - (imgp->args->argc +
388		    imgp->args->envc + 2) * sizeof(char *));
389	}
390
391	/*
392	 * vectp also becomes our initial stack base
393	 */
394	stack_base = (register_t *)vectp;
395
396	stringp = imgp->args->begin_argv;
397	argc = imgp->args->argc;
398	envc = imgp->args->envc;
399
400	/*
401	 * Copy out strings - arguments and environment.
402	 */
403	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
404
405	/*
406	 * Fill in "ps_strings" struct for ps, w, etc.
407	 */
408	suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
409	suword(&arginfo->ps_nargvstr, argc);
410
411	/*
412	 * Fill in argument portion of vector table.
413	 */
414	for (; argc > 0; --argc) {
415		suword(vectp++, (long)(intptr_t)destp);
416		while (*stringp++ != 0)
417			destp++;
418		destp++;
419	}
420
421	/* a null vector table pointer separates the argp's from the envp's */
422	suword(vectp++, 0);
423
424	suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
425	suword(&arginfo->ps_nenvstr, envc);
426
427	/*
428	 * Fill in environment portion of vector table.
429	 */
430	for (; envc > 0; --envc) {
431		suword(vectp++, (long)(intptr_t)destp);
432		while (*stringp++ != 0)
433			destp++;
434		destp++;
435	}
436
437	/* end of vector table is a null pointer */
438	suword(vectp, 0);
439	return (stack_base);
440}
441
442/*
443 * Reset registers to default values on exec.
444 */
445static void
446linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
447{
448	struct trapframe *regs = td->td_frame;
449	struct pcb *pcb = td->td_pcb;
450
451	mtx_lock(&dt_lock);
452	if (td->td_proc->p_md.md_ldt != NULL)
453		user_ldt_free(td);
454	else
455		mtx_unlock(&dt_lock);
456
457	pcb->pcb_fsbase = 0;
458	pcb->pcb_gsbase = 0;
459	clear_pcb_flags(pcb, PCB_32BIT);
460	pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
461	set_pcb_flags(pcb, PCB_FULL_IRET);
462
463	bzero((char *)regs, sizeof(struct trapframe));
464	regs->tf_rip = imgp->entry_addr;
465	regs->tf_rsp = stack;
466	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
467	regs->tf_ss = _udatasel;
468	regs->tf_cs = _ucodesel;
469	regs->tf_ds = _udatasel;
470	regs->tf_es = _udatasel;
471	regs->tf_fs = _ufssel;
472	regs->tf_gs = _ugssel;
473	regs->tf_flags = TF_HASSEGS;
474
475	/*
476	 * Reset the hardware debug registers if they were in use.
477	 * They won't have any meaning for the newly exec'd process.
478	 */
479	if (pcb->pcb_flags & PCB_DBREGS) {
480		pcb->pcb_dr0 = 0;
481		pcb->pcb_dr1 = 0;
482		pcb->pcb_dr2 = 0;
483		pcb->pcb_dr3 = 0;
484		pcb->pcb_dr6 = 0;
485		pcb->pcb_dr7 = 0;
486		if (pcb == curpcb) {
487			/*
488			 * Clear the debug registers on the running
489			 * CPU, otherwise they will end up affecting
490			 * the next process we switch to.
491			 */
492			reset_dbregs();
493		}
494		clear_pcb_flags(pcb, PCB_DBREGS);
495	}
496
497	/*
498	 * Drop the FP state if we hold it, so that the process gets a
499	 * clean FP state if it uses the FPU again.
500	 */
501	fpstate_drop(td);
502}
503
504/*
505 * Copied from amd64/amd64/machdep.c
506 *
507 * XXX fpu state need? don't think so
508 */
509int
510linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
511{
512	struct proc *p;
513	struct l_ucontext uc;
514	struct l_sigcontext *context;
515	struct trapframe *regs;
516	unsigned long rflags;
517	int error;
518	ksiginfo_t ksi;
519
520	regs = td->td_frame;
521	error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
522	if (error != 0)
523		return (error);
524
525	p = td->td_proc;
526	context = &uc.uc_mcontext;
527	rflags = context->sc_rflags;
528
529	/*
530	 * Don't allow users to change privileged or reserved flags.
531	 */
532	/*
533	 * XXX do allow users to change the privileged flag PSL_RF.
534	 * The cpu sets PSL_RF in tf_rflags for faults.  Debuggers
535	 * should sometimes set it there too.  tf_rflags is kept in
536	 * the signal context during signal handling and there is no
537	 * other place to remember it, so the PSL_RF bit may be
538	 * corrupted by the signal handler without us knowing.
539	 * Corruption of the PSL_RF bit at worst causes one more or
540	 * one less debugger trap, so allowing it is fairly harmless.
541	 */
542
543#define RFLAG_SECURE(ef, oef)     ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
544	if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
545		printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags);
546		return (EINVAL);
547	}
548
549	/*
550	 * Don't allow users to load a valid privileged %cs.  Let the
551	 * hardware check for invalid selectors, excess privilege in
552	 * other selectors, invalid %eip's and invalid %esp's.
553	 */
554#define CS_SECURE(cs)           (ISPL(cs) == SEL_UPL)
555	if (!CS_SECURE(context->sc_cs)) {
556		printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs);
557		ksiginfo_init_trap(&ksi);
558		ksi.ksi_signo = SIGBUS;
559		ksi.ksi_code = BUS_OBJERR;
560		ksi.ksi_trapno = T_PROTFLT;
561		ksi.ksi_addr = (void *)regs->tf_rip;
562		trapsignal(td, &ksi);
563		return (EINVAL);
564	}
565
566	PROC_LOCK(p);
567	linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
568	SIG_CANTMASK(td->td_sigmask);
569	signotify(td);
570	PROC_UNLOCK(p);
571
572	regs->tf_rdi    = context->sc_rdi;
573	regs->tf_rsi    = context->sc_rsi;
574	regs->tf_rdx    = context->sc_rdx;
575	regs->tf_rbp    = context->sc_rbp;
576	regs->tf_rbx    = context->sc_rbx;
577	regs->tf_rcx    = context->sc_rcx;
578	regs->tf_rax    = context->sc_rax;
579	regs->tf_rip    = context->sc_rip;
580	regs->tf_rsp    = context->sc_rsp;
581	regs->tf_r8     = context->sc_r8;
582	regs->tf_r9     = context->sc_r9;
583	regs->tf_r10    = context->sc_r10;
584	regs->tf_r11    = context->sc_r11;
585	regs->tf_r12    = context->sc_r12;
586	regs->tf_r13    = context->sc_r13;
587	regs->tf_r14    = context->sc_r14;
588	regs->tf_r15    = context->sc_r15;
589	regs->tf_cs     = context->sc_cs;
590	regs->tf_err    = context->sc_err;
591	regs->tf_rflags = rflags;
592
593	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
594	return (EJUSTRETURN);
595}
596
597/*
598 * copied from amd64/amd64/machdep.c
599 *
600 * Send an interrupt to process.
601 */
602static void
603linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
604{
605	struct l_rt_sigframe sf, *sfp;
606	struct proc *p;
607	struct thread *td;
608	struct sigacts *psp;
609	caddr_t sp;
610	struct trapframe *regs;
611	int sig, code;
612	int oonstack;
613
614	td = curthread;
615	p = td->td_proc;
616	PROC_LOCK_ASSERT(p, MA_OWNED);
617	sig = ksi->ksi_signo;
618	psp = p->p_sigacts;
619	code = ksi->ksi_code;
620	mtx_assert(&psp->ps_mtx, MA_OWNED);
621	regs = td->td_frame;
622	oonstack = sigonstack(regs->tf_rsp);
623
624	LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
625	    catcher, sig, mask, code);
626
627	/* Allocate space for the signal handler context. */
628	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
629	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
630		sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size -
631		    sizeof(struct l_rt_sigframe);
632	} else
633		sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128;
634	/* Align to 16 bytes. */
635	sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
636	mtx_unlock(&psp->ps_mtx);
637
638	/* Translate the signal. */
639	sig = bsd_to_linux_signal(sig);
640
641	/* Save user context. */
642	bzero(&sf, sizeof(sf));
643	bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask);
644	bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask);
645
646	sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
647	sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
648	sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
649	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
650	PROC_UNLOCK(p);
651
652	sf.sf_sc.uc_mcontext.sc_rdi    = regs->tf_rdi;
653	sf.sf_sc.uc_mcontext.sc_rsi    = regs->tf_rsi;
654	sf.sf_sc.uc_mcontext.sc_rdx    = regs->tf_rdx;
655	sf.sf_sc.uc_mcontext.sc_rbp    = regs->tf_rbp;
656	sf.sf_sc.uc_mcontext.sc_rbx    = regs->tf_rbx;
657	sf.sf_sc.uc_mcontext.sc_rcx    = regs->tf_rcx;
658	sf.sf_sc.uc_mcontext.sc_rax    = regs->tf_rax;
659	sf.sf_sc.uc_mcontext.sc_rip    = regs->tf_rip;
660	sf.sf_sc.uc_mcontext.sc_rsp    = regs->tf_rsp;
661	sf.sf_sc.uc_mcontext.sc_r8     = regs->tf_r8;
662	sf.sf_sc.uc_mcontext.sc_r9     = regs->tf_r9;
663	sf.sf_sc.uc_mcontext.sc_r10    = regs->tf_r10;
664	sf.sf_sc.uc_mcontext.sc_r11    = regs->tf_r11;
665	sf.sf_sc.uc_mcontext.sc_r12    = regs->tf_r12;
666	sf.sf_sc.uc_mcontext.sc_r13    = regs->tf_r13;
667	sf.sf_sc.uc_mcontext.sc_r14    = regs->tf_r14;
668	sf.sf_sc.uc_mcontext.sc_r15    = regs->tf_r15;
669	sf.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
670	sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags;
671	sf.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
672	sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
673	sf.sf_sc.uc_mcontext.sc_cr2    = (register_t)ksi->ksi_addr;
674
675	/* Build the argument list for the signal handler. */
676	regs->tf_rdi = sig;			/* arg 1 in %rdi */
677	regs->tf_rax = 0;
678	regs->tf_rsi = (register_t)&sfp->sf_si;	/* arg 2 in %rsi */
679	regs->tf_rdx = (register_t)&sfp->sf_sc;	/* arg 3 in %rdx */
680
681	sf.sf_handler = catcher;
682	/* Fill in POSIX parts */
683	ksiginfo_to_lsiginfo(ksi, &sf.sf_si, sig);
684
685	/*
686	 * Copy the sigframe out to the user's stack.
687	 */
688	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
689#ifdef DEBUG
690		printf("process %ld has trashed its stack\n", (long)p->p_pid);
691#endif
692		PROC_LOCK(p);
693		sigexit(td, SIGILL);
694	}
695
696	regs->tf_rsp = (long)sfp;
697	regs->tf_rip = linux_rt_sigcode;
698	regs->tf_rflags &= ~(PSL_T | PSL_D);
699	regs->tf_cs = _ucodesel;
700	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
701	PROC_LOCK(p);
702	mtx_lock(&psp->ps_mtx);
703}
704
705/*
706 * If a linux binary is exec'ing something, try this image activator
707 * first.  We override standard shell script execution in order to
708 * be able to modify the interpreter path.  We only do this if a linux
709 * binary is doing the exec, so we do not create an EXEC module for it.
710 */
711static int exec_linux_imgact_try(struct image_params *iparams);
712
713static int
714exec_linux_imgact_try(struct image_params *imgp)
715{
716	const char *head = (const char *)imgp->image_header;
717	char *rpath;
718	int error = -1, len;
719
720	/*
721	 * The interpreter for shell scripts run from a linux binary needs
722	 * to be located in /compat/linux if possible in order to recursively
723	 * maintain linux path emulation.
724	 */
725	if (((const short *)head)[0] == SHELLMAGIC) {
726		/*
727		 * Run our normal shell image activator.  If it succeeds
728		 * attempt to use the alternate path for the interpreter.
729		 * If an alternate path is found, use our stringspace
730		 * to store it.
731		 */
732		if ((error = exec_shell_imgact(imgp)) == 0) {
733			linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
734			    imgp->interpreter_name, UIO_SYSSPACE,
735			    &rpath, 0, AT_FDCWD);
736			if (rpath != NULL) {
737				len = strlen(rpath) + 1;
738
739				if (len <= MAXSHELLCMDLEN)
740					memcpy(imgp->interpreter_name,
741					    rpath, len);
742				free(rpath, M_TEMP);
743			}
744		}
745	}
746	return(error);
747}
748
749struct sysentvec elf_linux_sysvec = {
750	.sv_size	= LINUX_SYS_MAXSYSCALL,
751	.sv_table	= linux_sysent,
752	.sv_mask	= 0,
753	.sv_sigsize	= 0,
754	.sv_sigtbl	= NULL,
755	.sv_errsize	= ELAST + 1,
756	.sv_errtbl	= bsd_to_linux_errno,
757	.sv_transtrap	= translate_traps,
758	.sv_fixup	= elf_linux_fixup,
759	.sv_sendsig	= linux_rt_sendsig,
760	.sv_sigcode	= &_binary_linux_locore_o_start,
761	.sv_szsigcode	= &linux_szsigcode,
762	.sv_prepsyscall	= NULL,
763	.sv_name	= "Linux ELF64",
764	.sv_coredump	= elf64_coredump,
765	.sv_imgact_try	= exec_linux_imgact_try,
766	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
767	.sv_pagesize	= PAGE_SIZE,
768	.sv_minuser	= VM_MIN_ADDRESS,
769	.sv_maxuser	= VM_MAXUSER_ADDRESS,
770	.sv_usrstack	= USRSTACK,
771	.sv_psstrings	= PS_STRINGS,
772	.sv_stackprot	= VM_PROT_ALL,
773	.sv_copyout_strings = linux_copyout_strings,
774	.sv_setregs	= linux_exec_setregs,
775	.sv_fixlimit	= NULL,
776	.sv_maxssiz	= NULL,
777	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP,
778	.sv_set_syscall_retval = linux_set_syscall_retval,
779	.sv_fetch_syscall_args = linux_fetch_syscall_args,
780	.sv_syscallnames = NULL,
781	.sv_shared_page_base = SHAREDPAGE,
782	.sv_shared_page_len = PAGE_SIZE,
783	.sv_schedtail	= linux_schedtail,
784	.sv_thread_detach = linux_thread_detach
785};
786
787static void
788linux_vdso_install(void *param)
789{
790
791	linux_szsigcode = (&_binary_linux_locore_o_end -
792	    &_binary_linux_locore_o_start);
793
794	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
795		panic("Linux invalid vdso size\n");
796
797	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
798
799	linux_shared_page_obj = __elfN(linux_shared_page_init)
800	    (&linux_shared_page_mapping);
801
802	__elfN(linux_vdso_reloc)(&elf_linux_sysvec, SHAREDPAGE);
803
804	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
805	    linux_szsigcode);
806	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
807
808	linux_kplatform = linux_shared_page_mapping +
809	    (linux_platform - (caddr_t)SHAREDPAGE);
810}
811SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
812    (sysinit_cfunc_t)linux_vdso_install, NULL);
813
814static void
815linux_vdso_deinstall(void *param)
816{
817
818	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
819};
820SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
821    (sysinit_cfunc_t)linux_vdso_deinstall, NULL);
822
823static char GNULINUX_ABI_VENDOR[] = "GNU";
824static int GNULINUX_ABI_DESC = 0;
825
826static boolean_t
827linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
828{
829	const Elf32_Word *desc;
830	uintptr_t p;
831
832	p = (uintptr_t)(note + 1);
833	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
834
835	desc = (const Elf32_Word *)p;
836	if (desc[0] != GNULINUX_ABI_DESC)
837		return (FALSE);
838
839	/*
840	 * For linux we encode osrel as follows (see linux_mib.c):
841	 * VVVMMMIII (version, major, minor), see linux_mib.c.
842	 */
843	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
844
845	return (TRUE);
846}
847
848static Elf_Brandnote linux64_brandnote = {
849	.hdr.n_namesz	= sizeof(GNULINUX_ABI_VENDOR),
850	.hdr.n_descsz	= 16,
851	.hdr.n_type	= 1,
852	.vendor		= GNULINUX_ABI_VENDOR,
853	.flags		= BN_TRANSLATE_OSREL,
854	.trans_osrel	= linux_trans_osrel
855};
856
857static Elf64_Brandinfo linux_glibc2brand = {
858	.brand		= ELFOSABI_LINUX,
859	.machine	= EM_X86_64,
860	.compat_3_brand	= "Linux",
861	.emul_path	= "/compat/linux",
862	.interp_path	= "/lib64/ld-linux-x86-64.so.2",
863	.sysvec		= &elf_linux_sysvec,
864	.interp_newpath	= NULL,
865	.brand_note	= &linux64_brandnote,
866	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
867};
868
869static Elf64_Brandinfo linux_glibc2brandshort = {
870	.brand		= ELFOSABI_LINUX,
871	.machine	= EM_X86_64,
872	.compat_3_brand	= "Linux",
873	.emul_path	= "/compat/linux",
874	.interp_path	= "/lib64/ld-linux.so.2",
875	.sysvec		= &elf_linux_sysvec,
876	.interp_newpath	= NULL,
877	.brand_note	= &linux64_brandnote,
878	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
879};
880
881Elf64_Brandinfo *linux_brandlist[] = {
882	&linux_glibc2brand,
883	&linux_glibc2brandshort,
884	NULL
885};
886
887static int
888linux64_elf_modevent(module_t mod, int type, void *data)
889{
890	Elf64_Brandinfo **brandinfo;
891	int error;
892	struct linux_ioctl_handler **lihp;
893
894	error = 0;
895
896	switch(type) {
897	case MOD_LOAD:
898		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
899		     ++brandinfo)
900			if (elf64_insert_brand_entry(*brandinfo) < 0)
901				error = EINVAL;
902		if (error == 0) {
903			SET_FOREACH(lihp, linux_ioctl_handler_set)
904				linux_ioctl_register_handler(*lihp);
905			LIST_INIT(&futex_list);
906			mtx_init(&futex_mtx, "ftllk64", NULL, MTX_DEF);
907			stclohz = (stathz ? stathz : hz);
908			if (bootverbose)
909				printf("Linux x86-64 ELF exec handler installed\n");
910		} else
911			printf("cannot insert Linux x86-64 ELF brand handler\n");
912		break;
913	case MOD_UNLOAD:
914		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
915		     ++brandinfo)
916			if (elf64_brand_inuse(*brandinfo))
917				error = EBUSY;
918		if (error == 0) {
919			for (brandinfo = &linux_brandlist[0];
920			     *brandinfo != NULL; ++brandinfo)
921				if (elf64_remove_brand_entry(*brandinfo) < 0)
922					error = EINVAL;
923		}
924		if (error == 0) {
925			SET_FOREACH(lihp, linux_ioctl_handler_set)
926				linux_ioctl_unregister_handler(*lihp);
927			mtx_destroy(&futex_mtx);
928			if (bootverbose)
929				printf("Linux ELF exec handler removed\n");
930		} else
931			printf("Could not deinstall ELF interpreter entry\n");
932		break;
933	default:
934		return (EOPNOTSUPP);
935	}
936	return (error);
937}
938
939static moduledata_t linux64_elf_mod = {
940	"linux64elf",
941	linux64_elf_modevent,
942	0
943};
944
945DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
946MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
947