xref: /freebsd/sys/amd64/ia32/ia32_signal.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2003 Peter Wemm
5  * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * William Jolitz.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 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. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/exec.h>
41 #include <sys/fcntl.h>
42 #include <sys/imgact.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mutex.h>
47 #include <sys/mman.h>
48 #include <sys/namei.h>
49 #include <sys/pioctl.h>
50 #include <sys/proc.h>
51 #include <sys/procfs.h>
52 #include <sys/resourcevar.h>
53 #include <sys/systm.h>
54 #include <sys/signalvar.h>
55 #include <sys/stat.h>
56 #include <sys/sx.h>
57 #include <sys/syscall.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/sysctl.h>
60 #include <sys/sysent.h>
61 #include <sys/vnode.h>
62 
63 #include <vm/vm.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_param.h>
66 #include <vm/pmap.h>
67 #include <vm/vm_map.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_extern.h>
70 
71 #include <compat/freebsd32/freebsd32_signal.h>
72 #include <compat/freebsd32/freebsd32_util.h>
73 #include <compat/freebsd32/freebsd32_proto.h>
74 #include <compat/freebsd32/freebsd32.h>
75 #include <compat/ia32/ia32_signal.h>
76 #include <machine/psl.h>
77 #include <machine/segments.h>
78 #include <machine/specialreg.h>
79 #include <machine/frame.h>
80 #include <machine/md_var.h>
81 #include <machine/pcb.h>
82 #include <machine/cpufunc.h>
83 #include <machine/trap.h>
84 
85 #ifdef COMPAT_FREEBSD4
86 static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *);
87 #endif
88 
89 #define	CS_SECURE(cs)		(ISPL(cs) == SEL_UPL)
90 #define	EFL_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
91 
92 static void
93 ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
94     char *xfpusave, size_t xfpusave_len)
95 {
96 	size_t max_len, len;
97 
98 	/*
99 	 * XXX Format of 64bit and 32bit FXSAVE areas differs. FXSAVE
100 	 * in 32bit mode saves %cs and %ds, while on 64bit it saves
101 	 * 64bit instruction and data pointers. Ignore the difference
102 	 * for now, it should be irrelevant for most applications.
103 	 */
104 	mcp->mc_ownedfp = fpugetregs(td);
105 	bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
106 	    sizeof(mcp->mc_fpstate));
107 	mcp->mc_fpformat = fpuformat();
108 	if (!use_xsave || xfpusave_len == 0)
109 		return;
110 	max_len = cpu_max_ext_state_size - sizeof(struct savefpu);
111 	len = xfpusave_len;
112 	if (len > max_len) {
113 		len = max_len;
114 		bzero(xfpusave + max_len, len - max_len);
115 	}
116 	mcp->mc_flags |= _MC_IA32_HASFPXSTATE;
117 	mcp->mc_xfpustate_len = len;
118 	bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len);
119 }
120 
121 static int
122 ia32_set_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
123     char *xfpustate, size_t xfpustate_len)
124 {
125 	int error;
126 
127 	if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
128 		return (0);
129 	else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
130 		return (EINVAL);
131 	else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
132 		/* We don't care what state is left in the FPU or PCB. */
133 		fpstate_drop(td);
134 		error = 0;
135 	} else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
136 	    mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
137 		error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate,
138 		    xfpustate, xfpustate_len);
139 	} else
140 		return (EINVAL);
141 	return (error);
142 }
143 
144 /*
145  * Get machine context.
146  */
147 static int
148 ia32_get_mcontext(struct thread *td, struct ia32_mcontext *mcp, int flags)
149 {
150 	struct pcb *pcb;
151 	struct trapframe *tp;
152 
153 	pcb = td->td_pcb;
154 	tp = td->td_frame;
155 
156 	PROC_LOCK(curthread->td_proc);
157 	mcp->mc_onstack = sigonstack(tp->tf_rsp);
158 	PROC_UNLOCK(curthread->td_proc);
159 	/* Entry into kernel always sets TF_HASSEGS */
160 	mcp->mc_gs = tp->tf_gs;
161 	mcp->mc_fs = tp->tf_fs;
162 	mcp->mc_es = tp->tf_es;
163 	mcp->mc_ds = tp->tf_ds;
164 	mcp->mc_edi = tp->tf_rdi;
165 	mcp->mc_esi = tp->tf_rsi;
166 	mcp->mc_ebp = tp->tf_rbp;
167 	mcp->mc_isp = tp->tf_rsp;
168 	mcp->mc_eflags = tp->tf_rflags;
169 	if (flags & GET_MC_CLEAR_RET) {
170 		mcp->mc_eax = 0;
171 		mcp->mc_edx = 0;
172 		mcp->mc_eflags &= ~PSL_C;
173 	} else {
174 		mcp->mc_eax = tp->tf_rax;
175 		mcp->mc_edx = tp->tf_rdx;
176 	}
177 	mcp->mc_ebx = tp->tf_rbx;
178 	mcp->mc_ecx = tp->tf_rcx;
179 	mcp->mc_eip = tp->tf_rip;
180 	mcp->mc_cs = tp->tf_cs;
181 	mcp->mc_esp = tp->tf_rsp;
182 	mcp->mc_ss = tp->tf_ss;
183 	mcp->mc_len = sizeof(*mcp);
184 	mcp->mc_flags = tp->tf_flags;
185 	ia32_get_fpcontext(td, mcp, NULL, 0);
186 	mcp->mc_fsbase = pcb->pcb_fsbase;
187 	mcp->mc_gsbase = pcb->pcb_gsbase;
188 	mcp->mc_xfpustate = 0;
189 	mcp->mc_xfpustate_len = 0;
190 	bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2));
191 	return (0);
192 }
193 
194 /*
195  * Set machine context.
196  *
197  * However, we don't set any but the user modifiable flags, and we won't
198  * touch the cs selector.
199  */
200 static int
201 ia32_set_mcontext(struct thread *td, struct ia32_mcontext *mcp)
202 {
203 	struct trapframe *tp;
204 	char *xfpustate;
205 	long rflags;
206 	int ret;
207 
208 	tp = td->td_frame;
209 	if (mcp->mc_len != sizeof(*mcp))
210 		return (EINVAL);
211 	rflags = (mcp->mc_eflags & PSL_USERCHANGE) |
212 	    (tp->tf_rflags & ~PSL_USERCHANGE);
213 	if (mcp->mc_flags & _MC_IA32_HASFPXSTATE) {
214 		if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
215 		    sizeof(struct savefpu))
216 			return (EINVAL);
217 		xfpustate = __builtin_alloca(mcp->mc_xfpustate_len);
218 		ret = copyin(PTRIN(mcp->mc_xfpustate), xfpustate,
219 		    mcp->mc_xfpustate_len);
220 		if (ret != 0)
221 			return (ret);
222 	} else
223 		xfpustate = NULL;
224 	ret = ia32_set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
225 	if (ret != 0)
226 		return (ret);
227 	tp->tf_gs = mcp->mc_gs;
228 	tp->tf_fs = mcp->mc_fs;
229 	tp->tf_es = mcp->mc_es;
230 	tp->tf_ds = mcp->mc_ds;
231 	tp->tf_flags = TF_HASSEGS;
232 	tp->tf_rdi = mcp->mc_edi;
233 	tp->tf_rsi = mcp->mc_esi;
234 	tp->tf_rbp = mcp->mc_ebp;
235 	tp->tf_rbx = mcp->mc_ebx;
236 	tp->tf_rdx = mcp->mc_edx;
237 	tp->tf_rcx = mcp->mc_ecx;
238 	tp->tf_rax = mcp->mc_eax;
239 	/* trapno, err */
240 	tp->tf_rip = mcp->mc_eip;
241 	tp->tf_rflags = rflags;
242 	tp->tf_rsp = mcp->mc_esp;
243 	tp->tf_ss = mcp->mc_ss;
244 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
245 	return (0);
246 }
247 
248 /*
249  * The first two fields of a ucontext_t are the signal mask and
250  * the machine context.  The next field is uc_link; we want to
251  * avoid destroying the link when copying out contexts.
252  */
253 #define	UC_COPY_SIZE	offsetof(struct ia32_ucontext, uc_link)
254 
255 int
256 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
257 {
258 	struct ia32_ucontext uc;
259 	int ret;
260 
261 	if (uap->ucp == NULL)
262 		ret = EINVAL;
263 	else {
264 		bzero(&uc, sizeof(uc));
265 		ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
266 		PROC_LOCK(td->td_proc);
267 		uc.uc_sigmask = td->td_sigmask;
268 		PROC_UNLOCK(td->td_proc);
269 		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
270 	}
271 	return (ret);
272 }
273 
274 int
275 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
276 {
277 	struct ia32_ucontext uc;
278 	int ret;
279 
280 	if (uap->ucp == NULL)
281 		ret = EINVAL;
282 	else {
283 		ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
284 		if (ret == 0) {
285 			ret = ia32_set_mcontext(td, &uc.uc_mcontext);
286 			if (ret == 0) {
287 				kern_sigprocmask(td, SIG_SETMASK,
288 				    &uc.uc_sigmask, NULL, 0);
289 			}
290 		}
291 	}
292 	return (ret == 0 ? EJUSTRETURN : ret);
293 }
294 
295 int
296 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
297 {
298 	struct ia32_ucontext uc;
299 	int ret;
300 
301 	if (uap->oucp == NULL || uap->ucp == NULL)
302 		ret = EINVAL;
303 	else {
304 		bzero(&uc, sizeof(uc));
305 		ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
306 		PROC_LOCK(td->td_proc);
307 		uc.uc_sigmask = td->td_sigmask;
308 		PROC_UNLOCK(td->td_proc);
309 		ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
310 		if (ret == 0) {
311 			ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
312 			if (ret == 0) {
313 				ret = ia32_set_mcontext(td, &uc.uc_mcontext);
314 				if (ret == 0) {
315 					kern_sigprocmask(td, SIG_SETMASK,
316 					    &uc.uc_sigmask, NULL, 0);
317 				}
318 			}
319 		}
320 	}
321 	return (ret == 0 ? EJUSTRETURN : ret);
322 }
323 
324 /*
325  * Send an interrupt to process.
326  *
327  * Stack is set up to allow sigcode stored
328  * at top to call routine, followed by kcall
329  * to sigreturn routine below.  After sigreturn
330  * resets the signal mask, the stack, and the
331  * frame pointer, it returns to the user
332  * specified pc, psl.
333  */
334 
335 #ifdef COMPAT_43
336 static void
337 ia32_osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
338 {
339 	struct ia32_sigframe3 sf, *fp;
340 	struct proc *p;
341 	struct thread *td;
342 	struct sigacts *psp;
343 	struct trapframe *regs;
344 	int sig;
345 	int oonstack;
346 
347 	td = curthread;
348 	p = td->td_proc;
349 	PROC_LOCK_ASSERT(p, MA_OWNED);
350 	sig = ksi->ksi_signo;
351 	psp = p->p_sigacts;
352 	mtx_assert(&psp->ps_mtx, MA_OWNED);
353 	regs = td->td_frame;
354 	oonstack = sigonstack(regs->tf_rsp);
355 
356 	/* Allocate space for the signal handler context. */
357 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
358 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
359 		fp = (struct ia32_sigframe3 *)((uintptr_t)td->td_sigstk.ss_sp +
360 		    td->td_sigstk.ss_size - sizeof(sf));
361 		td->td_sigstk.ss_flags |= SS_ONSTACK;
362 	} else
363 		fp = (struct ia32_sigframe3 *)regs->tf_rsp - 1;
364 
365 	/* Build the argument list for the signal handler. */
366 	sf.sf_signum = sig;
367 	sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc;
368 	bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo));
369 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
370 		/* Signal handler installed with SA_SIGINFO. */
371 		sf.sf_arg2 = (register_t)&fp->sf_siginfo;
372 		sf.sf_siginfo.si_signo = sig;
373 		sf.sf_siginfo.si_code = ksi->ksi_code;
374 		sf.sf_ah = (uintptr_t)catcher;
375 		sf.sf_addr = 0;
376 	} else {
377 		/* Old FreeBSD-style arguments. */
378 		sf.sf_arg2 = ksi->ksi_code;
379 		sf.sf_addr = (register_t)ksi->ksi_addr;
380 		sf.sf_ah = (uintptr_t)catcher;
381 	}
382 	mtx_unlock(&psp->ps_mtx);
383 	PROC_UNLOCK(p);
384 
385 	/* Save most if not all of trap frame. */
386 	sf.sf_siginfo.si_sc.sc_eax = regs->tf_rax;
387 	sf.sf_siginfo.si_sc.sc_ebx = regs->tf_rbx;
388 	sf.sf_siginfo.si_sc.sc_ecx = regs->tf_rcx;
389 	sf.sf_siginfo.si_sc.sc_edx = regs->tf_rdx;
390 	sf.sf_siginfo.si_sc.sc_esi = regs->tf_rsi;
391 	sf.sf_siginfo.si_sc.sc_edi = regs->tf_rdi;
392 	sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs;
393 	sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds;
394 	sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss;
395 	sf.sf_siginfo.si_sc.sc_es = regs->tf_es;
396 	sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs;
397 	sf.sf_siginfo.si_sc.sc_gs = regs->tf_gs;
398 	sf.sf_siginfo.si_sc.sc_isp = regs->tf_rsp;
399 
400 	/* Build the signal context to be used by osigreturn(). */
401 	sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0;
402 	SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask);
403 	sf.sf_siginfo.si_sc.sc_esp = regs->tf_rsp;
404 	sf.sf_siginfo.si_sc.sc_ebp = regs->tf_rbp;
405 	sf.sf_siginfo.si_sc.sc_eip = regs->tf_rip;
406 	sf.sf_siginfo.si_sc.sc_eflags = regs->tf_rflags;
407 	sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno;
408 	sf.sf_siginfo.si_sc.sc_err = regs->tf_err;
409 
410 	/*
411 	 * Copy the sigframe out to the user's stack.
412 	 */
413 	if (copyout(&sf, fp, sizeof(*fp)) != 0) {
414 #ifdef DEBUG
415 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
416 #endif
417 		PROC_LOCK(p);
418 		sigexit(td, SIGILL);
419 	}
420 
421 	regs->tf_rsp = (uintptr_t)fp;
422 	regs->tf_rip = p->p_sysent->sv_psstrings - sz_ia32_osigcode;
423 	regs->tf_rflags &= ~(PSL_T | PSL_D);
424 	regs->tf_cs = _ucode32sel;
425 	regs->tf_ds = _udatasel;
426 	regs->tf_es = _udatasel;
427 	regs->tf_fs = _udatasel;
428 	regs->tf_ss = _udatasel;
429 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
430 	PROC_LOCK(p);
431 	mtx_lock(&psp->ps_mtx);
432 }
433 #endif
434 
435 #ifdef COMPAT_FREEBSD4
436 static void
437 freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
438 {
439 	struct ia32_sigframe4 sf, *sfp;
440 	struct siginfo32 siginfo;
441 	struct proc *p;
442 	struct thread *td;
443 	struct sigacts *psp;
444 	struct trapframe *regs;
445 	int oonstack;
446 	int sig;
447 
448 	td = curthread;
449 	p = td->td_proc;
450 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
451 
452 	PROC_LOCK_ASSERT(p, MA_OWNED);
453 	sig = siginfo.si_signo;
454 	psp = p->p_sigacts;
455 	mtx_assert(&psp->ps_mtx, MA_OWNED);
456 	regs = td->td_frame;
457 	oonstack = sigonstack(regs->tf_rsp);
458 
459 	/* Save user context. */
460 	bzero(&sf, sizeof(sf));
461 	sf.sf_uc.uc_sigmask = *mask;
462 	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
463 	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
464 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
465 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
466 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
467 	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
468 	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
469 	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
470 	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
471 	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
472 	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
473 	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
474 	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
475 	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
476 	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
477 	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
478 	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
479 	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
480 	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
481 	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
482 	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
483 	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
484 	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
485 	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
486 	bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
487 	    sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
488 	bzero(sf.sf_uc.uc_mcontext.__spare__,
489 	    sizeof(sf.sf_uc.uc_mcontext.__spare__));
490 	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
491 
492 	/* Allocate space for the signal handler context. */
493 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
494 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
495 		sfp = (struct ia32_sigframe4 *)((uintptr_t)td->td_sigstk.ss_sp +
496 		    td->td_sigstk.ss_size - sizeof(sf));
497 	} else
498 		sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1;
499 	PROC_UNLOCK(p);
500 
501 	/* Build the argument list for the signal handler. */
502 	sf.sf_signum = sig;
503 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
504 	bzero(&sf.sf_si, sizeof(sf.sf_si));
505 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
506 		/* Signal handler installed with SA_SIGINFO. */
507 		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
508 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
509 
510 		/* Fill in POSIX parts */
511 		sf.sf_si = siginfo;
512 		sf.sf_si.si_signo = sig;
513 	} else {
514 		/* Old FreeBSD-style arguments. */
515 		sf.sf_siginfo = siginfo.si_code;
516 		sf.sf_addr = (u_int32_t)siginfo.si_addr;
517 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
518 	}
519 	mtx_unlock(&psp->ps_mtx);
520 
521 	/*
522 	 * Copy the sigframe out to the user's stack.
523 	 */
524 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
525 #ifdef DEBUG
526 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
527 #endif
528 		PROC_LOCK(p);
529 		sigexit(td, SIGILL);
530 	}
531 
532 	regs->tf_rsp = (uintptr_t)sfp;
533 	regs->tf_rip = p->p_sysent->sv_sigcode_base + sz_ia32_sigcode -
534 	    sz_freebsd4_ia32_sigcode;
535 	regs->tf_rflags &= ~(PSL_T | PSL_D);
536 	regs->tf_cs = _ucode32sel;
537 	regs->tf_ss = _udatasel;
538 	regs->tf_ds = _udatasel;
539 	regs->tf_es = _udatasel;
540 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
541 	/* leave user %fs and %gs untouched */
542 	PROC_LOCK(p);
543 	mtx_lock(&psp->ps_mtx);
544 }
545 #endif	/* COMPAT_FREEBSD4 */
546 
547 void
548 ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
549 {
550 	struct ia32_sigframe sf, *sfp;
551 	struct siginfo32 siginfo;
552 	struct proc *p;
553 	struct thread *td;
554 	struct sigacts *psp;
555 	char *sp;
556 	struct trapframe *regs;
557 	char *xfpusave;
558 	size_t xfpusave_len;
559 	int oonstack;
560 	int sig;
561 
562 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
563 	td = curthread;
564 	p = td->td_proc;
565 	PROC_LOCK_ASSERT(p, MA_OWNED);
566 	sig = siginfo.si_signo;
567 	psp = p->p_sigacts;
568 #ifdef COMPAT_FREEBSD4
569 	if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
570 		freebsd4_ia32_sendsig(catcher, ksi, mask);
571 		return;
572 	}
573 #endif
574 #ifdef COMPAT_43
575 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
576 		ia32_osendsig(catcher, ksi, mask);
577 		return;
578 	}
579 #endif
580 	mtx_assert(&psp->ps_mtx, MA_OWNED);
581 	regs = td->td_frame;
582 	oonstack = sigonstack(regs->tf_rsp);
583 
584 	if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
585 		xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
586 		xfpusave = __builtin_alloca(xfpusave_len);
587 	} else {
588 		xfpusave_len = 0;
589 		xfpusave = NULL;
590 	}
591 
592 	/* Save user context. */
593 	bzero(&sf, sizeof(sf));
594 	sf.sf_uc.uc_sigmask = *mask;
595 	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
596 	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
597 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
598 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
599 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
600 	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
601 	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
602 	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
603 	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
604 	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
605 	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
606 	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
607 	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
608 	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
609 	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
610 	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
611 	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
612 	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
613 	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
614 	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
615 	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
616 	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
617 	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
618 	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
619 	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
620 	ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
621 	fpstate_drop(td);
622 	sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase;
623 	sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase;
624 
625 	/* Allocate space for the signal handler context. */
626 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
627 	    SIGISMEMBER(psp->ps_sigonstack, sig))
628 		sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
629 	else
630 		sp = (char *)regs->tf_rsp;
631 	if (xfpusave != NULL) {
632 		sp -= xfpusave_len;
633 		sp = (char *)((unsigned long)sp & ~0x3Ful);
634 		sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
635 	}
636 	sp -= sizeof(sf);
637 	/* Align to 16 bytes. */
638 	sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
639 	PROC_UNLOCK(p);
640 
641 	/* Build the argument list for the signal handler. */
642 	sf.sf_signum = sig;
643 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
644 	bzero(&sf.sf_si, sizeof(sf.sf_si));
645 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
646 		/* Signal handler installed with SA_SIGINFO. */
647 		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
648 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
649 
650 		/* Fill in POSIX parts */
651 		sf.sf_si = siginfo;
652 		sf.sf_si.si_signo = sig;
653 	} else {
654 		/* Old FreeBSD-style arguments. */
655 		sf.sf_siginfo = siginfo.si_code;
656 		sf.sf_addr = (u_int32_t)siginfo.si_addr;
657 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
658 	}
659 	mtx_unlock(&psp->ps_mtx);
660 
661 	/*
662 	 * Copy the sigframe out to the user's stack.
663 	 */
664 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
665 	    (xfpusave != NULL && copyout(xfpusave,
666 	    PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len)
667 	    != 0)) {
668 #ifdef DEBUG
669 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
670 #endif
671 		PROC_LOCK(p);
672 		sigexit(td, SIGILL);
673 	}
674 
675 	regs->tf_rsp = (uintptr_t)sfp;
676 	regs->tf_rip = p->p_sysent->sv_sigcode_base;
677 	regs->tf_rflags &= ~(PSL_T | PSL_D);
678 	regs->tf_cs = _ucode32sel;
679 	regs->tf_ss = _udatasel;
680 	regs->tf_ds = _udatasel;
681 	regs->tf_es = _udatasel;
682 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
683 	/* XXXKIB leave user %fs and %gs untouched */
684 	PROC_LOCK(p);
685 	mtx_lock(&psp->ps_mtx);
686 }
687 
688 /*
689  * System call to cleanup state after a signal
690  * has been taken.  Reset signal mask and
691  * stack state from context left by sendsig (above).
692  * Return to previous pc and psl as specified by
693  * context left by sendsig. Check carefully to
694  * make sure that the user has not modified the
695  * state to gain improper privileges.
696  */
697 
698 #ifdef COMPAT_43
699 int
700 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
701 {
702 	struct ia32_sigcontext3 sc, *scp;
703 	struct trapframe *regs;
704 	int eflags, error;
705 	ksiginfo_t ksi;
706 
707 	regs = td->td_frame;
708 	error = copyin(uap->sigcntxp, &sc, sizeof(sc));
709 	if (error != 0)
710 		return (error);
711 	scp = &sc;
712 	eflags = scp->sc_eflags;
713 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
714 		return (EINVAL);
715 	}
716 	if (!CS_SECURE(scp->sc_cs)) {
717 		ksiginfo_init_trap(&ksi);
718 		ksi.ksi_signo = SIGBUS;
719 		ksi.ksi_code = BUS_OBJERR;
720 		ksi.ksi_trapno = T_PROTFLT;
721 		ksi.ksi_addr = (void *)regs->tf_rip;
722 		trapsignal(td, &ksi);
723 		return (EINVAL);
724 	}
725 	regs->tf_ds = scp->sc_ds;
726 	regs->tf_es = scp->sc_es;
727 	regs->tf_fs = scp->sc_fs;
728 	regs->tf_gs = scp->sc_gs;
729 
730 	regs->tf_rax = scp->sc_eax;
731 	regs->tf_rbx = scp->sc_ebx;
732 	regs->tf_rcx = scp->sc_ecx;
733 	regs->tf_rdx = scp->sc_edx;
734 	regs->tf_rsi = scp->sc_esi;
735 	regs->tf_rdi = scp->sc_edi;
736 	regs->tf_cs = scp->sc_cs;
737 	regs->tf_ss = scp->sc_ss;
738 	regs->tf_rbp = scp->sc_ebp;
739 	regs->tf_rsp = scp->sc_esp;
740 	regs->tf_rip = scp->sc_eip;
741 	regs->tf_rflags = eflags;
742 
743 	if (scp->sc_onstack & 1)
744 		td->td_sigstk.ss_flags |= SS_ONSTACK;
745 	else
746 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
747 
748 	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
749 	    SIGPROCMASK_OLD);
750 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
751 	return (EJUSTRETURN);
752 }
753 #endif
754 
755 #ifdef COMPAT_FREEBSD4
756 /*
757  * MPSAFE
758  */
759 int
760 freebsd4_freebsd32_sigreturn(td, uap)
761 	struct thread *td;
762 	struct freebsd4_freebsd32_sigreturn_args /* {
763 		const struct freebsd4_freebsd32_ucontext *sigcntxp;
764 	} */ *uap;
765 {
766 	struct ia32_ucontext4 uc;
767 	struct trapframe *regs;
768 	struct ia32_ucontext4 *ucp;
769 	int cs, eflags, error;
770 	ksiginfo_t ksi;
771 
772 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
773 	if (error != 0)
774 		return (error);
775 	ucp = &uc;
776 	regs = td->td_frame;
777 	eflags = ucp->uc_mcontext.mc_eflags;
778 	/*
779 	 * Don't allow users to change privileged or reserved flags.
780 	 */
781 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
782 		uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n",
783 		    td->td_proc->p_pid, td->td_name, eflags);
784 		return (EINVAL);
785 	}
786 
787 	/*
788 	 * Don't allow users to load a valid privileged %cs.  Let the
789 	 * hardware check for invalid selectors, excess privilege in
790 	 * other selectors, invalid %eip's and invalid %esp's.
791 	 */
792 	cs = ucp->uc_mcontext.mc_cs;
793 	if (!CS_SECURE(cs)) {
794 		uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n",
795 		    td->td_proc->p_pid, td->td_name, cs);
796 		ksiginfo_init_trap(&ksi);
797 		ksi.ksi_signo = SIGBUS;
798 		ksi.ksi_code = BUS_OBJERR;
799 		ksi.ksi_trapno = T_PROTFLT;
800 		ksi.ksi_addr = (void *)regs->tf_rip;
801 		trapsignal(td, &ksi);
802 		return (EINVAL);
803 	}
804 
805 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
806 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
807 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
808 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
809 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
810 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
811 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
812 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
813 	regs->tf_err = ucp->uc_mcontext.mc_err;
814 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
815 	regs->tf_cs = cs;
816 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
817 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
818 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
819 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
820 	regs->tf_es = ucp->uc_mcontext.mc_es;
821 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
822 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
823 
824 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
825 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
826 	return (EJUSTRETURN);
827 }
828 #endif	/* COMPAT_FREEBSD4 */
829 
830 /*
831  * MPSAFE
832  */
833 int
834 freebsd32_sigreturn(td, uap)
835 	struct thread *td;
836 	struct freebsd32_sigreturn_args /* {
837 		const struct freebsd32_ucontext *sigcntxp;
838 	} */ *uap;
839 {
840 	struct ia32_ucontext uc;
841 	struct trapframe *regs;
842 	struct ia32_ucontext *ucp;
843 	char *xfpustate;
844 	size_t xfpustate_len;
845 	int cs, eflags, error, ret;
846 	ksiginfo_t ksi;
847 
848 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
849 	if (error != 0)
850 		return (error);
851 	ucp = &uc;
852 	regs = td->td_frame;
853 	eflags = ucp->uc_mcontext.mc_eflags;
854 	/*
855 	 * Don't allow users to change privileged or reserved flags.
856 	 */
857 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
858 		uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n",
859 		    td->td_proc->p_pid, td->td_name, eflags);
860 		return (EINVAL);
861 	}
862 
863 	/*
864 	 * Don't allow users to load a valid privileged %cs.  Let the
865 	 * hardware check for invalid selectors, excess privilege in
866 	 * other selectors, invalid %eip's and invalid %esp's.
867 	 */
868 	cs = ucp->uc_mcontext.mc_cs;
869 	if (!CS_SECURE(cs)) {
870 		uprintf("pid %d (%s): sigreturn cs = 0x%x\n",
871 		    td->td_proc->p_pid, td->td_name, cs);
872 		ksiginfo_init_trap(&ksi);
873 		ksi.ksi_signo = SIGBUS;
874 		ksi.ksi_code = BUS_OBJERR;
875 		ksi.ksi_trapno = T_PROTFLT;
876 		ksi.ksi_addr = (void *)regs->tf_rip;
877 		trapsignal(td, &ksi);
878 		return (EINVAL);
879 	}
880 
881 	if ((ucp->uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
882 		xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
883 		if (xfpustate_len > cpu_max_ext_state_size -
884 		    sizeof(struct savefpu)) {
885 			uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
886 			    td->td_proc->p_pid, td->td_name, xfpustate_len);
887 			return (EINVAL);
888 		}
889 		xfpustate = __builtin_alloca(xfpustate_len);
890 		error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate),
891 		    xfpustate, xfpustate_len);
892 		if (error != 0) {
893 			uprintf(
894 	"pid %d (%s): sigreturn copying xfpustate failed\n",
895 			    td->td_proc->p_pid, td->td_name);
896 			return (error);
897 		}
898 	} else {
899 		xfpustate = NULL;
900 		xfpustate_len = 0;
901 	}
902 	ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
903 	    xfpustate_len);
904 	if (ret != 0) {
905 		uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
906 		    td->td_proc->p_pid, td->td_name, ret);
907 		return (ret);
908 	}
909 
910 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
911 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
912 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
913 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
914 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
915 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
916 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
917 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
918 	regs->tf_err = ucp->uc_mcontext.mc_err;
919 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
920 	regs->tf_cs = cs;
921 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
922 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
923 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
924 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
925 	regs->tf_es = ucp->uc_mcontext.mc_es;
926 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
927 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
928 	regs->tf_flags = TF_HASSEGS;
929 
930 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
931 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
932 	return (EJUSTRETURN);
933 }
934 
935 /*
936  * Clear registers on exec
937  */
938 void
939 ia32_setregs(struct thread *td, struct image_params *imgp, u_long stack)
940 {
941 	struct trapframe *regs;
942 	struct pcb *pcb;
943 	register_t saved_rflags;
944 
945 	regs = td->td_frame;
946 	pcb = td->td_pcb;
947 
948 	if (td->td_proc->p_md.md_ldt != NULL)
949 		user_ldt_free(td);
950 #ifdef COMPAT_43
951 	setup_lcall_gate();
952 #endif
953 
954 	pcb->pcb_fsbase = 0;
955 	pcb->pcb_gsbase = 0;
956 	pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
957 
958 	saved_rflags = regs->tf_rflags & PSL_T;
959 	bzero((char *)regs, sizeof(struct trapframe));
960 	regs->tf_rip = imgp->entry_addr;
961 	regs->tf_rsp = stack;
962 	regs->tf_rflags = PSL_USER | saved_rflags;
963 	regs->tf_ss = _udatasel;
964 	regs->tf_cs = _ucode32sel;
965 	regs->tf_rbx = imgp->ps_strings;
966 	regs->tf_ds = _udatasel;
967 	regs->tf_es = _udatasel;
968 	regs->tf_fs = _ufssel;
969 	regs->tf_gs = _ugssel;
970 	regs->tf_flags = TF_HASSEGS;
971 
972 	fpstate_drop(td);
973 
974 	/* Return via doreti so that we can change to a different %cs */
975 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
976 }
977