xref: /freebsd/sys/amd64/ia32/ia32_signal.c (revision 5e3934b15a2741b2de6b217e77dc9d798d740804)
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/param.h>
37 #include <sys/exec.h>
38 #include <sys/fcntl.h>
39 #include <sys/imgact.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
44 #include <sys/mman.h>
45 #include <sys/namei.h>
46 #include <sys/proc.h>
47 #include <sys/procfs.h>
48 #include <sys/resourcevar.h>
49 #include <sys/systm.h>
50 #include <sys/signalvar.h>
51 #include <sys/stat.h>
52 #include <sys/sx.h>
53 #include <sys/syscall.h>
54 #include <sys/syscallsubr.h>
55 #include <sys/sysctl.h>
56 #include <sys/sysent.h>
57 #include <sys/vnode.h>
58 
59 #include <vm/vm.h>
60 #include <vm/vm_kern.h>
61 #include <vm/vm_param.h>
62 #include <vm/pmap.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_object.h>
65 #include <vm/vm_extern.h>
66 
67 #include <compat/freebsd32/freebsd32_signal.h>
68 #include <compat/freebsd32/freebsd32_util.h>
69 #include <compat/freebsd32/freebsd32_proto.h>
70 #include <compat/freebsd32/freebsd32.h>
71 #include <compat/ia32/ia32_signal.h>
72 #include <machine/psl.h>
73 #include <machine/segments.h>
74 #include <machine/specialreg.h>
75 #include <machine/frame.h>
76 #include <machine/md_var.h>
77 #include <machine/pcb.h>
78 #include <machine/cpufunc.h>
79 #include <machine/trap.h>
80 
81 #include "vdso_ia32_offsets.h"
82 
83 extern const char _binary_elf_vdso32_so_1_start[];
84 extern const char _binary_elf_vdso32_so_1_end[];
85 extern char _binary_elf_vdso32_so_1_size;
86 
87 #ifdef COMPAT_FREEBSD4
88 static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *);
89 #endif
90 
91 static void
92 ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
93     char **xfpusave, size_t *xfpusave_len)
94 {
95 	/*
96 	 * XXX Format of 64bit and 32bit FXSAVE areas differs. FXSAVE
97 	 * in 32bit mode saves %cs and %ds, while on 64bit it saves
98 	 * 64bit instruction and data pointers. Ignore the difference
99 	 * for now, it should be irrelevant for most applications.
100 	 */
101 	mcp->mc_ownedfp = fpugetregs(td);
102 	bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
103 	    sizeof(mcp->mc_fpstate));
104 	mcp->mc_fpformat = fpuformat();
105 	if (xfpusave == NULL)
106 		return;
107 	if (!use_xsave || cpu_max_ext_state_size <= sizeof(struct savefpu)) {
108 		*xfpusave_len = 0;
109 		*xfpusave = NULL;
110 	} else {
111 		mcp->mc_flags |= _MC_IA32_HASFPXSTATE;
112 		*xfpusave_len = mcp->mc_xfpustate_len =
113 		    cpu_max_ext_state_size - sizeof(struct savefpu);
114 		*xfpusave = (char *)(get_pcb_user_save_td(td) + 1);
115 	}
116 }
117 
118 static int
119 ia32_set_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
120     char *xfpustate, size_t xfpustate_len)
121 {
122 	int error;
123 
124 	if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
125 		return (0);
126 	else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
127 		return (EINVAL);
128 	else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
129 		/* We don't care what state is left in the FPU or PCB. */
130 		fpstate_drop(td);
131 		error = 0;
132 	} else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
133 	    mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
134 		error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate,
135 		    xfpustate, xfpustate_len);
136 	} else
137 		return (EINVAL);
138 	return (error);
139 }
140 
141 /*
142  * Get machine context.
143  */
144 static int
145 ia32_get_mcontext(struct thread *td, struct ia32_mcontext *mcp, int flags)
146 {
147 	struct pcb *pcb;
148 	struct trapframe *tp;
149 
150 	pcb = td->td_pcb;
151 	tp = td->td_frame;
152 
153 	PROC_LOCK(curthread->td_proc);
154 	mcp->mc_onstack = sigonstack(tp->tf_rsp);
155 	PROC_UNLOCK(curthread->td_proc);
156 	/* Entry into kernel always sets TF_HASSEGS */
157 	mcp->mc_gs = tp->tf_gs;
158 	mcp->mc_fs = tp->tf_fs;
159 	mcp->mc_es = tp->tf_es;
160 	mcp->mc_ds = tp->tf_ds;
161 	mcp->mc_edi = tp->tf_rdi;
162 	mcp->mc_esi = tp->tf_rsi;
163 	mcp->mc_ebp = tp->tf_rbp;
164 	mcp->mc_isp = tp->tf_rsp;
165 	mcp->mc_eflags = tp->tf_rflags;
166 	if (flags & GET_MC_CLEAR_RET) {
167 		mcp->mc_eax = 0;
168 		mcp->mc_edx = 0;
169 		mcp->mc_eflags &= ~PSL_C;
170 	} else {
171 		mcp->mc_eax = tp->tf_rax;
172 		mcp->mc_edx = tp->tf_rdx;
173 	}
174 	mcp->mc_ebx = tp->tf_rbx;
175 	mcp->mc_ecx = tp->tf_rcx;
176 	mcp->mc_eip = tp->tf_rip;
177 	mcp->mc_cs = tp->tf_cs;
178 	mcp->mc_esp = tp->tf_rsp;
179 	mcp->mc_ss = tp->tf_ss;
180 	mcp->mc_len = sizeof(*mcp);
181 	mcp->mc_flags = tp->tf_flags;
182 	ia32_get_fpcontext(td, mcp, NULL, 0);
183 	mcp->mc_fsbase = pcb->pcb_fsbase;
184 	mcp->mc_gsbase = pcb->pcb_gsbase;
185 	mcp->mc_xfpustate = 0;
186 	mcp->mc_xfpustate_len = 0;
187 	bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2));
188 	return (0);
189 }
190 
191 /*
192  * Set machine context.
193  *
194  * However, we don't set any but the user modifiable flags, and we won't
195  * touch the cs selector.
196  */
197 static int
198 ia32_set_mcontext(struct thread *td, struct ia32_mcontext *mcp)
199 {
200 	struct trapframe *tp;
201 	char *xfpustate;
202 	long rflags;
203 	int ret;
204 
205 	tp = td->td_frame;
206 	if (mcp->mc_len != sizeof(*mcp))
207 		return (EINVAL);
208 	rflags = (mcp->mc_eflags & PSL_USERCHANGE) |
209 	    (tp->tf_rflags & ~PSL_USERCHANGE);
210 	if (mcp->mc_flags & _MC_IA32_HASFPXSTATE) {
211 		if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
212 		    sizeof(struct savefpu))
213 			return (EINVAL);
214 		xfpustate = (char *)fpu_save_area_alloc();
215 		ret = copyin(PTRIN(mcp->mc_xfpustate), xfpustate,
216 		    mcp->mc_xfpustate_len);
217 		if (ret != 0) {
218 			fpu_save_area_free((struct savefpu *)xfpustate);
219 			return (ret);
220 		}
221 	} else
222 		xfpustate = NULL;
223 	ret = ia32_set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
224 	fpu_save_area_free((struct savefpu *)xfpustate);
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_osigframe 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_osigframe *)((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_osigframe *)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 = PROC_PS_STRINGS(p) -
423 	    (_binary_elf_vdso32_so_1_end - _binary_elf_vdso32_so_1_start) +
424 	    VDSO_IA32_OSIGCODE_OFFSET;
425 	regs->tf_rflags &= ~(PSL_T | PSL_D);
426 	regs->tf_cs = _ucode32sel;
427 	regs->tf_ds = _udatasel;
428 	regs->tf_es = _udatasel;
429 	regs->tf_fs = _udatasel;
430 	regs->tf_ss = _udatasel;
431 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
432 	PROC_LOCK(p);
433 	mtx_lock(&psp->ps_mtx);
434 }
435 #endif
436 
437 #ifdef COMPAT_FREEBSD4
438 static void
439 freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
440 {
441 	struct ia32_freebsd4_sigframe sf, *sfp;
442 	struct siginfo32 siginfo;
443 	struct proc *p;
444 	struct thread *td;
445 	struct sigacts *psp;
446 	struct trapframe *regs;
447 	int oonstack;
448 	int sig;
449 
450 	td = curthread;
451 	p = td->td_proc;
452 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
453 
454 	PROC_LOCK_ASSERT(p, MA_OWNED);
455 	sig = siginfo.si_signo;
456 	psp = p->p_sigacts;
457 	mtx_assert(&psp->ps_mtx, MA_OWNED);
458 	regs = td->td_frame;
459 	oonstack = sigonstack(regs->tf_rsp);
460 
461 	/* Save user context. */
462 	bzero(&sf, sizeof(sf));
463 	sf.sf_uc.uc_sigmask = *mask;
464 	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
465 	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
466 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
467 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
468 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
469 	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
470 	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
471 	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
472 	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
473 	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
474 	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
475 	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
476 	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
477 	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
478 	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
479 	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
480 	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
481 	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
482 	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
483 	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
484 	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
485 	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
486 	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
487 	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
488 	bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
489 	    sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
490 	bzero(sf.sf_uc.uc_mcontext.__spare__,
491 	    sizeof(sf.sf_uc.uc_mcontext.__spare__));
492 	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
493 
494 	/* Allocate space for the signal handler context. */
495 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
496 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
497 		sfp = (struct ia32_freebsd4_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
498 		    td->td_sigstk.ss_size - sizeof(sf));
499 	} else
500 		sfp = (struct ia32_freebsd4_sigframe *)regs->tf_rsp - 1;
501 	PROC_UNLOCK(p);
502 
503 	/* Build the argument list for the signal handler. */
504 	sf.sf_signum = sig;
505 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
506 	bzero(&sf.sf_si, sizeof(sf.sf_si));
507 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
508 		/* Signal handler installed with SA_SIGINFO. */
509 		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
510 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
511 
512 		/* Fill in POSIX parts */
513 		sf.sf_si = siginfo;
514 		sf.sf_si.si_signo = sig;
515 	} else {
516 		/* Old FreeBSD-style arguments. */
517 		sf.sf_siginfo = siginfo.si_code;
518 		sf.sf_addr = (u_int32_t)siginfo.si_addr;
519 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
520 	}
521 	mtx_unlock(&psp->ps_mtx);
522 
523 	/*
524 	 * Copy the sigframe out to the user's stack.
525 	 */
526 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
527 #ifdef DEBUG
528 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
529 #endif
530 		PROC_LOCK(p);
531 		sigexit(td, SIGILL);
532 	}
533 
534 	regs->tf_rsp = (uintptr_t)sfp;
535 	regs->tf_rip = PROC_SIGCODE(p) +
536 	    VDSO_FREEBSD4_IA32_SIGCODE_OFFSET - VDSO_IA32_SIGCODE_OFFSET;
537 	regs->tf_rflags &= ~(PSL_T | PSL_D);
538 	regs->tf_cs = _ucode32sel;
539 	regs->tf_ss = _udatasel;
540 	regs->tf_ds = _udatasel;
541 	regs->tf_es = _udatasel;
542 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
543 	/* leave user %fs and %gs untouched */
544 	PROC_LOCK(p);
545 	mtx_lock(&psp->ps_mtx);
546 }
547 #endif	/* COMPAT_FREEBSD4 */
548 
549 void
550 ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
551 {
552 	struct ia32_sigframe sf, *sfp;
553 	struct siginfo32 siginfo;
554 	struct proc *p;
555 	struct thread *td;
556 	struct sigacts *psp;
557 	char *sp;
558 	struct trapframe *regs;
559 	char *xfpusave;
560 	size_t xfpusave_len;
561 	int oonstack;
562 	int sig;
563 
564 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
565 	td = curthread;
566 	p = td->td_proc;
567 	PROC_LOCK_ASSERT(p, MA_OWNED);
568 	sig = siginfo.si_signo;
569 	psp = p->p_sigacts;
570 #ifdef COMPAT_FREEBSD4
571 	if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
572 		freebsd4_ia32_sendsig(catcher, ksi, mask);
573 		return;
574 	}
575 #endif
576 #ifdef COMPAT_43
577 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
578 		ia32_osendsig(catcher, ksi, mask);
579 		return;
580 	}
581 #endif
582 	mtx_assert(&psp->ps_mtx, MA_OWNED);
583 	regs = td->td_frame;
584 	oonstack = sigonstack(regs->tf_rsp);
585 
586 	/* Save user context. */
587 	bzero(&sf, sizeof(sf));
588 	sf.sf_uc.uc_sigmask = *mask;
589 	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
590 	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
591 	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
592 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
593 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
594 	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
595 	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
596 	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
597 	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
598 	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
599 	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
600 	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
601 	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
602 	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
603 	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
604 	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
605 	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
606 	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
607 	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
608 	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
609 	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
610 	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
611 	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
612 	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
613 	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
614 	ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, &xfpusave, &xfpusave_len);
615 	sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase;
616 	sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase;
617 
618 	/* Allocate space for the signal handler context. */
619 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
620 	    SIGISMEMBER(psp->ps_sigonstack, sig))
621 		sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
622 	else
623 		sp = (char *)regs->tf_rsp;
624 	if (xfpusave != NULL) {
625 		sp -= xfpusave_len;
626 		sp = (char *)((unsigned long)sp & ~0x3Ful);
627 		sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
628 	}
629 	sp -= sizeof(sf);
630 	/* Align to 16 bytes. */
631 	sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
632 	PROC_UNLOCK(p);
633 
634 	/* Build the argument list for the signal handler. */
635 	sf.sf_signum = sig;
636 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
637 	bzero(&sf.sf_si, sizeof(sf.sf_si));
638 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
639 		/* Signal handler installed with SA_SIGINFO. */
640 		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
641 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
642 
643 		/* Fill in POSIX parts */
644 		sf.sf_si = siginfo;
645 		sf.sf_si.si_signo = sig;
646 	} else {
647 		/* Old FreeBSD-style arguments. */
648 		sf.sf_siginfo = siginfo.si_code;
649 		sf.sf_addr = (u_int32_t)siginfo.si_addr;
650 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
651 	}
652 	mtx_unlock(&psp->ps_mtx);
653 
654 	/*
655 	 * Copy the sigframe out to the user's stack.
656 	 */
657 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
658 	    (xfpusave != NULL && copyout(xfpusave,
659 	    PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len)
660 	    != 0)) {
661 #ifdef DEBUG
662 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
663 #endif
664 		PROC_LOCK(p);
665 		sigexit(td, SIGILL);
666 	}
667 
668 	fpstate_drop(td);
669 	regs->tf_rsp = (uintptr_t)sfp;
670 	regs->tf_rip = PROC_SIGCODE(p);
671 	regs->tf_rflags &= ~(PSL_T | PSL_D);
672 	regs->tf_cs = _ucode32sel;
673 	regs->tf_ss = _udatasel;
674 	regs->tf_ds = _udatasel;
675 	regs->tf_es = _udatasel;
676 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
677 	/* XXXKIB leave user %fs and %gs untouched */
678 	PROC_LOCK(p);
679 	mtx_lock(&psp->ps_mtx);
680 }
681 
682 /*
683  * System call to cleanup state after a signal
684  * has been taken.  Reset signal mask and
685  * stack state from context left by sendsig (above).
686  * Return to previous pc and psl as specified by
687  * context left by sendsig. Check carefully to
688  * make sure that the user has not modified the
689  * state to gain improper privileges.
690  */
691 
692 #ifdef COMPAT_43
693 int
694 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
695 {
696 	struct ia32_osigcontext sc, *scp;
697 	struct trapframe *regs;
698 	int eflags, error;
699 	ksiginfo_t ksi;
700 
701 	regs = td->td_frame;
702 	error = copyin(uap->sigcntxp, &sc, sizeof(sc));
703 	if (error != 0)
704 		return (error);
705 	scp = &sc;
706 	eflags = scp->sc_eflags;
707 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
708 		return (EINVAL);
709 	}
710 	if (!CS_SECURE(scp->sc_cs)) {
711 		ksiginfo_init_trap(&ksi);
712 		ksi.ksi_signo = SIGBUS;
713 		ksi.ksi_code = BUS_OBJERR;
714 		ksi.ksi_trapno = T_PROTFLT;
715 		ksi.ksi_addr = (void *)regs->tf_rip;
716 		trapsignal(td, &ksi);
717 		return (EINVAL);
718 	}
719 	regs->tf_ds = scp->sc_ds;
720 	regs->tf_es = scp->sc_es;
721 	regs->tf_fs = scp->sc_fs;
722 	regs->tf_gs = scp->sc_gs;
723 
724 	regs->tf_rax = scp->sc_eax;
725 	regs->tf_rbx = scp->sc_ebx;
726 	regs->tf_rcx = scp->sc_ecx;
727 	regs->tf_rdx = scp->sc_edx;
728 	regs->tf_rsi = scp->sc_esi;
729 	regs->tf_rdi = scp->sc_edi;
730 	regs->tf_cs = scp->sc_cs;
731 	regs->tf_ss = scp->sc_ss;
732 	regs->tf_rbp = scp->sc_ebp;
733 	regs->tf_rsp = scp->sc_esp;
734 	regs->tf_rip = scp->sc_eip;
735 	regs->tf_rflags = eflags;
736 
737 	if (scp->sc_onstack & 1)
738 		td->td_sigstk.ss_flags |= SS_ONSTACK;
739 	else
740 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
741 
742 	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
743 	    SIGPROCMASK_OLD);
744 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
745 	return (EJUSTRETURN);
746 }
747 #endif
748 
749 #ifdef COMPAT_FREEBSD4
750 int
751 freebsd4_freebsd32_sigreturn(struct thread *td,
752     struct freebsd4_freebsd32_sigreturn_args *uap)
753 {
754 	struct ia32_freebsd4_ucontext uc;
755 	struct trapframe *regs;
756 	struct ia32_freebsd4_ucontext *ucp;
757 	int cs, eflags, error;
758 	ksiginfo_t ksi;
759 
760 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
761 	if (error != 0)
762 		return (error);
763 	ucp = &uc;
764 	regs = td->td_frame;
765 	eflags = ucp->uc_mcontext.mc_eflags;
766 	/*
767 	 * Don't allow users to change privileged or reserved flags.
768 	 */
769 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
770 		uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n",
771 		    td->td_proc->p_pid, td->td_name, eflags);
772 		return (EINVAL);
773 	}
774 
775 	/*
776 	 * Don't allow users to load a valid privileged %cs.  Let the
777 	 * hardware check for invalid selectors, excess privilege in
778 	 * other selectors, invalid %eip's and invalid %esp's.
779 	 */
780 	cs = ucp->uc_mcontext.mc_cs;
781 	if (!CS_SECURE(cs)) {
782 		uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n",
783 		    td->td_proc->p_pid, td->td_name, cs);
784 		ksiginfo_init_trap(&ksi);
785 		ksi.ksi_signo = SIGBUS;
786 		ksi.ksi_code = BUS_OBJERR;
787 		ksi.ksi_trapno = T_PROTFLT;
788 		ksi.ksi_addr = (void *)regs->tf_rip;
789 		trapsignal(td, &ksi);
790 		return (EINVAL);
791 	}
792 
793 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
794 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
795 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
796 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
797 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
798 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
799 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
800 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
801 	regs->tf_err = ucp->uc_mcontext.mc_err;
802 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
803 	regs->tf_cs = cs;
804 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
805 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
806 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
807 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
808 	regs->tf_es = ucp->uc_mcontext.mc_es;
809 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
810 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
811 
812 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
813 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
814 	return (EJUSTRETURN);
815 }
816 #endif	/* COMPAT_FREEBSD4 */
817 
818 int
819 freebsd32_sigreturn(struct thread *td, struct freebsd32_sigreturn_args *uap)
820 {
821 	struct ia32_ucontext uc;
822 	struct trapframe *regs;
823 	struct ia32_ucontext *ucp;
824 	char *xfpustate;
825 	size_t xfpustate_len;
826 	int cs, eflags, error, ret;
827 	ksiginfo_t ksi;
828 
829 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
830 	if (error != 0)
831 		return (error);
832 	ucp = &uc;
833 	regs = td->td_frame;
834 	eflags = ucp->uc_mcontext.mc_eflags;
835 	/*
836 	 * Don't allow users to change privileged or reserved flags.
837 	 */
838 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
839 		uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n",
840 		    td->td_proc->p_pid, td->td_name, eflags);
841 		return (EINVAL);
842 	}
843 
844 	/*
845 	 * Don't allow users to load a valid privileged %cs.  Let the
846 	 * hardware check for invalid selectors, excess privilege in
847 	 * other selectors, invalid %eip's and invalid %esp's.
848 	 */
849 	cs = ucp->uc_mcontext.mc_cs;
850 	if (!CS_SECURE(cs)) {
851 		uprintf("pid %d (%s): sigreturn cs = 0x%x\n",
852 		    td->td_proc->p_pid, td->td_name, cs);
853 		ksiginfo_init_trap(&ksi);
854 		ksi.ksi_signo = SIGBUS;
855 		ksi.ksi_code = BUS_OBJERR;
856 		ksi.ksi_trapno = T_PROTFLT;
857 		ksi.ksi_addr = (void *)regs->tf_rip;
858 		trapsignal(td, &ksi);
859 		return (EINVAL);
860 	}
861 
862 	if ((ucp->uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
863 		xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
864 		if (xfpustate_len > cpu_max_ext_state_size -
865 		    sizeof(struct savefpu)) {
866 			uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
867 			    td->td_proc->p_pid, td->td_name, xfpustate_len);
868 			return (EINVAL);
869 		}
870 		xfpustate = (char *)fpu_save_area_alloc();
871 		error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate),
872 		    xfpustate, xfpustate_len);
873 		if (error != 0) {
874 			fpu_save_area_free((struct savefpu *)xfpustate);
875 			uprintf(
876 	"pid %d (%s): sigreturn copying xfpustate failed\n",
877 			    td->td_proc->p_pid, td->td_name);
878 			return (error);
879 		}
880 	} else {
881 		xfpustate = NULL;
882 		xfpustate_len = 0;
883 	}
884 	ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
885 	    xfpustate_len);
886 	fpu_save_area_free((struct savefpu *)xfpustate);
887 	if (ret != 0) {
888 		uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
889 		    td->td_proc->p_pid, td->td_name, ret);
890 		return (ret);
891 	}
892 
893 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
894 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
895 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
896 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
897 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
898 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
899 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
900 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
901 	regs->tf_err = ucp->uc_mcontext.mc_err;
902 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
903 	regs->tf_cs = cs;
904 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
905 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
906 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
907 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
908 	regs->tf_es = ucp->uc_mcontext.mc_es;
909 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
910 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
911 	regs->tf_flags = TF_HASSEGS;
912 
913 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
914 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
915 	return (EJUSTRETURN);
916 }
917 
918 /*
919  * Clear registers on exec
920  */
921 void
922 ia32_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
923 {
924 	struct trapframe *regs;
925 	struct pcb *pcb;
926 	register_t saved_rflags;
927 
928 	regs = td->td_frame;
929 	pcb = td->td_pcb;
930 
931 	if (td->td_proc->p_md.md_ldt != NULL)
932 		user_ldt_free(td);
933 #ifdef COMPAT_43
934 	setup_lcall_gate();
935 #endif
936 
937 	pcb->pcb_fsbase = 0;
938 	pcb->pcb_gsbase = 0;
939 	pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
940 
941 	saved_rflags = regs->tf_rflags & PSL_T;
942 	bzero((char *)regs, sizeof(struct trapframe));
943 	regs->tf_rip = imgp->entry_addr;
944 	regs->tf_rsp = stack;
945 	regs->tf_rflags = PSL_USER | saved_rflags;
946 	regs->tf_ss = _udatasel;
947 	regs->tf_cs = _ucode32sel;
948 	regs->tf_rbx = (register_t)imgp->ps_strings;
949 	regs->tf_ds = _udatasel;
950 	regs->tf_es = _udatasel;
951 	regs->tf_fs = _ufssel;
952 	regs->tf_gs = _ugssel;
953 	regs->tf_flags = TF_HASSEGS;
954 
955 	x86_clear_dbregs(pcb);
956 
957 	fpstate_drop(td);
958 
959 	/* Return via doreti so that we can change to a different %cs */
960 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
961 }
962