xref: /freebsd-11-stable/sys/amd64/ia32/ia32_signal.c (revision e2cf125b0a9d0c0b91ceb9f7d2c8c1df5fcd56f4)
1 /*-
2  * Copyright (c) 2003 Peter Wemm
3  * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * William Jolitz.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_compat.h"
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 
84 #ifdef COMPAT_FREEBSD4
85 static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *);
86 #endif
87 
88 #define	CS_SECURE(cs)		(ISPL(cs) == SEL_UPL)
89 #define	EFL_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
90 
91 static void
ia32_get_fpcontext(struct thread * td,struct ia32_mcontext * mcp,char * xfpusave,size_t xfpusave_len)92 ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
93     char *xfpusave, size_t xfpusave_len)
94 {
95 	size_t max_len, len;
96 
97 	/*
98 	 * XXX Format of 64bit and 32bit FXSAVE areas differs. FXSAVE
99 	 * in 32bit mode saves %cs and %ds, while on 64bit it saves
100 	 * 64bit instruction and data pointers. Ignore the difference
101 	 * for now, it should be irrelevant for most applications.
102 	 */
103 	mcp->mc_ownedfp = fpugetregs(td);
104 	bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
105 	    sizeof(mcp->mc_fpstate));
106 	mcp->mc_fpformat = fpuformat();
107 	if (!use_xsave || xfpusave_len == 0)
108 		return;
109 	max_len = cpu_max_ext_state_size - sizeof(struct savefpu);
110 	len = xfpusave_len;
111 	if (len > max_len) {
112 		len = max_len;
113 		bzero(xfpusave + max_len, len - max_len);
114 	}
115 	mcp->mc_flags |= _MC_IA32_HASFPXSTATE;
116 	mcp->mc_xfpustate_len = len;
117 	bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len);
118 }
119 
120 static int
ia32_set_fpcontext(struct thread * td,struct ia32_mcontext * mcp,char * xfpustate,size_t xfpustate_len)121 ia32_set_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
122     char *xfpustate, size_t xfpustate_len)
123 {
124 	int error;
125 
126 	if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
127 		return (0);
128 	else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
129 		return (EINVAL);
130 	else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
131 		/* We don't care what state is left in the FPU or PCB. */
132 		fpstate_drop(td);
133 		error = 0;
134 	} else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
135 	    mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
136 		error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate,
137 		    xfpustate, xfpustate_len);
138 	} else
139 		return (EINVAL);
140 	return (error);
141 }
142 
143 /*
144  * Get machine context.
145  */
146 static int
ia32_get_mcontext(struct thread * td,struct ia32_mcontext * mcp,int flags)147 ia32_get_mcontext(struct thread *td, struct ia32_mcontext *mcp, int flags)
148 {
149 	struct pcb *pcb;
150 	struct trapframe *tp;
151 
152 	pcb = td->td_pcb;
153 	tp = td->td_frame;
154 
155 	PROC_LOCK(curthread->td_proc);
156 	mcp->mc_onstack = sigonstack(tp->tf_rsp);
157 	PROC_UNLOCK(curthread->td_proc);
158 	/* Entry into kernel always sets TF_HASSEGS */
159 	mcp->mc_gs = tp->tf_gs;
160 	mcp->mc_fs = tp->tf_fs;
161 	mcp->mc_es = tp->tf_es;
162 	mcp->mc_ds = tp->tf_ds;
163 	mcp->mc_edi = tp->tf_rdi;
164 	mcp->mc_esi = tp->tf_rsi;
165 	mcp->mc_ebp = tp->tf_rbp;
166 	mcp->mc_isp = tp->tf_rsp;
167 	mcp->mc_eflags = tp->tf_rflags;
168 	if (flags & GET_MC_CLEAR_RET) {
169 		mcp->mc_eax = 0;
170 		mcp->mc_edx = 0;
171 		mcp->mc_eflags &= ~PSL_C;
172 	} else {
173 		mcp->mc_eax = tp->tf_rax;
174 		mcp->mc_edx = tp->tf_rdx;
175 	}
176 	mcp->mc_ebx = tp->tf_rbx;
177 	mcp->mc_ecx = tp->tf_rcx;
178 	mcp->mc_eip = tp->tf_rip;
179 	mcp->mc_cs = tp->tf_cs;
180 	mcp->mc_esp = tp->tf_rsp;
181 	mcp->mc_ss = tp->tf_ss;
182 	mcp->mc_len = sizeof(*mcp);
183 	mcp->mc_flags = tp->tf_flags;
184 	ia32_get_fpcontext(td, mcp, NULL, 0);
185 	mcp->mc_fsbase = pcb->pcb_fsbase;
186 	mcp->mc_gsbase = pcb->pcb_gsbase;
187 	mcp->mc_xfpustate = 0;
188 	mcp->mc_xfpustate_len = 0;
189 	bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2));
190 	return (0);
191 }
192 
193 /*
194  * Set machine context.
195  *
196  * However, we don't set any but the user modifiable flags, and we won't
197  * touch the cs selector.
198  */
199 static int
ia32_set_mcontext(struct thread * td,struct ia32_mcontext * mcp)200 ia32_set_mcontext(struct thread *td, struct ia32_mcontext *mcp)
201 {
202 	struct trapframe *tp;
203 	char *xfpustate;
204 	long rflags;
205 	int ret;
206 
207 	tp = td->td_frame;
208 	if (mcp->mc_len != sizeof(*mcp))
209 		return (EINVAL);
210 	rflags = (mcp->mc_eflags & PSL_USERCHANGE) |
211 	    (tp->tf_rflags & ~PSL_USERCHANGE);
212 	if (mcp->mc_flags & _MC_IA32_HASFPXSTATE) {
213 		if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
214 		    sizeof(struct savefpu))
215 			return (EINVAL);
216 		xfpustate = __builtin_alloca(mcp->mc_xfpustate_len);
217 		ret = copyin(PTRIN(mcp->mc_xfpustate), xfpustate,
218 		    mcp->mc_xfpustate_len);
219 		if (ret != 0)
220 			return (ret);
221 	} else
222 		xfpustate = NULL;
223 	ret = ia32_set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
224 	if (ret != 0)
225 		return (ret);
226 	tp->tf_gs = mcp->mc_gs;
227 	tp->tf_fs = mcp->mc_fs;
228 	tp->tf_es = mcp->mc_es;
229 	tp->tf_ds = mcp->mc_ds;
230 	tp->tf_flags = TF_HASSEGS;
231 	tp->tf_rdi = mcp->mc_edi;
232 	tp->tf_rsi = mcp->mc_esi;
233 	tp->tf_rbp = mcp->mc_ebp;
234 	tp->tf_rbx = mcp->mc_ebx;
235 	tp->tf_rdx = mcp->mc_edx;
236 	tp->tf_rcx = mcp->mc_ecx;
237 	tp->tf_rax = mcp->mc_eax;
238 	/* trapno, err */
239 	tp->tf_rip = mcp->mc_eip;
240 	tp->tf_rflags = rflags;
241 	tp->tf_rsp = mcp->mc_esp;
242 	tp->tf_ss = mcp->mc_ss;
243 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
244 	return (0);
245 }
246 
247 /*
248  * The first two fields of a ucontext_t are the signal mask and
249  * the machine context.  The next field is uc_link; we want to
250  * avoid destroying the link when copying out contexts.
251  */
252 #define	UC_COPY_SIZE	offsetof(struct ia32_ucontext, uc_link)
253 
254 int
freebsd32_getcontext(struct thread * td,struct freebsd32_getcontext_args * uap)255 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
256 {
257 	struct ia32_ucontext uc;
258 	int ret;
259 
260 	if (uap->ucp == NULL)
261 		ret = EINVAL;
262 	else {
263 		bzero(&uc, sizeof(uc));
264 		ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
265 		PROC_LOCK(td->td_proc);
266 		uc.uc_sigmask = td->td_sigmask;
267 		PROC_UNLOCK(td->td_proc);
268 		bzero(&uc.__spare__, sizeof(uc.__spare__));
269 		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
270 	}
271 	return (ret);
272 }
273 
274 int
freebsd32_setcontext(struct thread * td,struct freebsd32_setcontext_args * uap)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
freebsd32_swapcontext(struct thread * td,struct freebsd32_swapcontext_args * uap)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
ia32_osendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)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
freebsd4_ia32_sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)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
ia32_sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)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 	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
625 
626 	/* Allocate space for the signal handler context. */
627 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
628 	    SIGISMEMBER(psp->ps_sigonstack, sig))
629 		sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
630 	else
631 		sp = (char *)regs->tf_rsp;
632 	if (xfpusave != NULL) {
633 		sp -= xfpusave_len;
634 		sp = (char *)((unsigned long)sp & ~0x3Ful);
635 		sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
636 	}
637 	sp -= sizeof(sf);
638 	/* Align to 16 bytes. */
639 	sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
640 	PROC_UNLOCK(p);
641 
642 	/* Build the argument list for the signal handler. */
643 	sf.sf_signum = sig;
644 	sf.sf_ucontext = (register_t)&sfp->sf_uc;
645 	bzero(&sf.sf_si, sizeof(sf.sf_si));
646 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
647 		/* Signal handler installed with SA_SIGINFO. */
648 		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
649 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
650 
651 		/* Fill in POSIX parts */
652 		sf.sf_si = siginfo;
653 		sf.sf_si.si_signo = sig;
654 	} else {
655 		/* Old FreeBSD-style arguments. */
656 		sf.sf_siginfo = siginfo.si_code;
657 		sf.sf_addr = (u_int32_t)siginfo.si_addr;
658 		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
659 	}
660 	mtx_unlock(&psp->ps_mtx);
661 
662 	/*
663 	 * Copy the sigframe out to the user's stack.
664 	 */
665 	if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
666 	    (xfpusave != NULL && copyout(xfpusave,
667 	    PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len)
668 	    != 0)) {
669 #ifdef DEBUG
670 		printf("process %ld has trashed its stack\n", (long)p->p_pid);
671 #endif
672 		PROC_LOCK(p);
673 		sigexit(td, SIGILL);
674 	}
675 
676 	regs->tf_rsp = (uintptr_t)sfp;
677 	regs->tf_rip = p->p_sysent->sv_sigcode_base;
678 	regs->tf_rflags &= ~(PSL_T | PSL_D);
679 	regs->tf_cs = _ucode32sel;
680 	regs->tf_ss = _udatasel;
681 	regs->tf_ds = _udatasel;
682 	regs->tf_es = _udatasel;
683 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
684 	/* XXXKIB leave user %fs and %gs untouched */
685 	PROC_LOCK(p);
686 	mtx_lock(&psp->ps_mtx);
687 }
688 
689 /*
690  * System call to cleanup state after a signal
691  * has been taken.  Reset signal mask and
692  * stack state from context left by sendsig (above).
693  * Return to previous pc and psl as specified by
694  * context left by sendsig. Check carefully to
695  * make sure that the user has not modified the
696  * state to gain improper privileges.
697  */
698 
699 #ifdef COMPAT_43
700 int
ofreebsd32_sigreturn(struct thread * td,struct ofreebsd32_sigreturn_args * uap)701 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
702 {
703 	struct ia32_sigcontext3 sc, *scp;
704 	struct trapframe *regs;
705 	int eflags, error;
706 	ksiginfo_t ksi;
707 
708 	regs = td->td_frame;
709 	error = copyin(uap->sigcntxp, &sc, sizeof(sc));
710 	if (error != 0)
711 		return (error);
712 	scp = &sc;
713 	eflags = scp->sc_eflags;
714 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
715 		return (EINVAL);
716 	}
717 	if (!CS_SECURE(scp->sc_cs)) {
718 		ksiginfo_init_trap(&ksi);
719 		ksi.ksi_signo = SIGBUS;
720 		ksi.ksi_code = BUS_OBJERR;
721 		ksi.ksi_trapno = T_PROTFLT;
722 		ksi.ksi_addr = (void *)regs->tf_rip;
723 		trapsignal(td, &ksi);
724 		return (EINVAL);
725 	}
726 	regs->tf_ds = scp->sc_ds;
727 	regs->tf_es = scp->sc_es;
728 	regs->tf_fs = scp->sc_fs;
729 	regs->tf_gs = scp->sc_gs;
730 
731 	regs->tf_rax = scp->sc_eax;
732 	regs->tf_rbx = scp->sc_ebx;
733 	regs->tf_rcx = scp->sc_ecx;
734 	regs->tf_rdx = scp->sc_edx;
735 	regs->tf_rsi = scp->sc_esi;
736 	regs->tf_rdi = scp->sc_edi;
737 	regs->tf_cs = scp->sc_cs;
738 	regs->tf_ss = scp->sc_ss;
739 	regs->tf_rbp = scp->sc_ebp;
740 	regs->tf_rsp = scp->sc_esp;
741 	regs->tf_rip = scp->sc_eip;
742 	regs->tf_rflags = eflags;
743 
744 	if (scp->sc_onstack & 1)
745 		td->td_sigstk.ss_flags |= SS_ONSTACK;
746 	else
747 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
748 
749 	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
750 	    SIGPROCMASK_OLD);
751 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
752 	return (EJUSTRETURN);
753 }
754 #endif
755 
756 #ifdef COMPAT_FREEBSD4
757 /*
758  * MPSAFE
759  */
760 int
freebsd4_freebsd32_sigreturn(td,uap)761 freebsd4_freebsd32_sigreturn(td, uap)
762 	struct thread *td;
763 	struct freebsd4_freebsd32_sigreturn_args /* {
764 		const struct freebsd4_freebsd32_ucontext *sigcntxp;
765 	} */ *uap;
766 {
767 	struct ia32_ucontext4 uc;
768 	struct trapframe *regs;
769 	struct ia32_ucontext4 *ucp;
770 	int cs, eflags, error;
771 	ksiginfo_t ksi;
772 
773 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
774 	if (error != 0)
775 		return (error);
776 	ucp = &uc;
777 	regs = td->td_frame;
778 	eflags = ucp->uc_mcontext.mc_eflags;
779 	/*
780 	 * Don't allow users to change privileged or reserved flags.
781 	 */
782 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
783 		uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n",
784 		    td->td_proc->p_pid, td->td_name, eflags);
785 		return (EINVAL);
786 	}
787 
788 	/*
789 	 * Don't allow users to load a valid privileged %cs.  Let the
790 	 * hardware check for invalid selectors, excess privilege in
791 	 * other selectors, invalid %eip's and invalid %esp's.
792 	 */
793 	cs = ucp->uc_mcontext.mc_cs;
794 	if (!CS_SECURE(cs)) {
795 		uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n",
796 		    td->td_proc->p_pid, td->td_name, cs);
797 		ksiginfo_init_trap(&ksi);
798 		ksi.ksi_signo = SIGBUS;
799 		ksi.ksi_code = BUS_OBJERR;
800 		ksi.ksi_trapno = T_PROTFLT;
801 		ksi.ksi_addr = (void *)regs->tf_rip;
802 		trapsignal(td, &ksi);
803 		return (EINVAL);
804 	}
805 
806 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
807 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
808 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
809 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
810 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
811 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
812 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
813 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
814 	regs->tf_err = ucp->uc_mcontext.mc_err;
815 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
816 	regs->tf_cs = cs;
817 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
818 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
819 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
820 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
821 	regs->tf_es = ucp->uc_mcontext.mc_es;
822 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
823 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
824 
825 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
826 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
827 	return (EJUSTRETURN);
828 }
829 #endif	/* COMPAT_FREEBSD4 */
830 
831 /*
832  * MPSAFE
833  */
834 int
freebsd32_sigreturn(td,uap)835 freebsd32_sigreturn(td, uap)
836 	struct thread *td;
837 	struct freebsd32_sigreturn_args /* {
838 		const struct freebsd32_ucontext *sigcntxp;
839 	} */ *uap;
840 {
841 	struct ia32_ucontext uc;
842 	struct trapframe *regs;
843 	struct ia32_ucontext *ucp;
844 	char *xfpustate;
845 	size_t xfpustate_len;
846 	int cs, eflags, error, ret;
847 	ksiginfo_t ksi;
848 
849 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
850 	if (error != 0)
851 		return (error);
852 	ucp = &uc;
853 	regs = td->td_frame;
854 	eflags = ucp->uc_mcontext.mc_eflags;
855 	/*
856 	 * Don't allow users to change privileged or reserved flags.
857 	 */
858 	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
859 		uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n",
860 		    td->td_proc->p_pid, td->td_name, eflags);
861 		return (EINVAL);
862 	}
863 
864 	/*
865 	 * Don't allow users to load a valid privileged %cs.  Let the
866 	 * hardware check for invalid selectors, excess privilege in
867 	 * other selectors, invalid %eip's and invalid %esp's.
868 	 */
869 	cs = ucp->uc_mcontext.mc_cs;
870 	if (!CS_SECURE(cs)) {
871 		uprintf("pid %d (%s): sigreturn cs = 0x%x\n",
872 		    td->td_proc->p_pid, td->td_name, cs);
873 		ksiginfo_init_trap(&ksi);
874 		ksi.ksi_signo = SIGBUS;
875 		ksi.ksi_code = BUS_OBJERR;
876 		ksi.ksi_trapno = T_PROTFLT;
877 		ksi.ksi_addr = (void *)regs->tf_rip;
878 		trapsignal(td, &ksi);
879 		return (EINVAL);
880 	}
881 
882 	if ((ucp->uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
883 		xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
884 		if (xfpustate_len > cpu_max_ext_state_size -
885 		    sizeof(struct savefpu)) {
886 			uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
887 			    td->td_proc->p_pid, td->td_name, xfpustate_len);
888 			return (EINVAL);
889 		}
890 		xfpustate = __builtin_alloca(xfpustate_len);
891 		error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate),
892 		    xfpustate, xfpustate_len);
893 		if (error != 0) {
894 			uprintf(
895 	"pid %d (%s): sigreturn copying xfpustate failed\n",
896 			    td->td_proc->p_pid, td->td_name);
897 			return (error);
898 		}
899 	} else {
900 		xfpustate = NULL;
901 		xfpustate_len = 0;
902 	}
903 	ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
904 	    xfpustate_len);
905 	if (ret != 0) {
906 		uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
907 		    td->td_proc->p_pid, td->td_name, ret);
908 		return (ret);
909 	}
910 
911 	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
912 	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
913 	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
914 	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
915 	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
916 	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
917 	regs->tf_rax = ucp->uc_mcontext.mc_eax;
918 	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
919 	regs->tf_err = ucp->uc_mcontext.mc_err;
920 	regs->tf_rip = ucp->uc_mcontext.mc_eip;
921 	regs->tf_cs = cs;
922 	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
923 	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
924 	regs->tf_ss = ucp->uc_mcontext.mc_ss;
925 	regs->tf_ds = ucp->uc_mcontext.mc_ds;
926 	regs->tf_es = ucp->uc_mcontext.mc_es;
927 	regs->tf_fs = ucp->uc_mcontext.mc_fs;
928 	regs->tf_gs = ucp->uc_mcontext.mc_gs;
929 	regs->tf_flags = TF_HASSEGS;
930 
931 	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
932 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
933 	return (EJUSTRETURN);
934 }
935 
936 /*
937  * Clear registers on exec
938  */
939 void
ia32_setregs(struct thread * td,struct image_params * imgp,u_long stack)940 ia32_setregs(struct thread *td, struct image_params *imgp, u_long stack)
941 {
942 	struct trapframe *regs;
943 	struct pcb *pcb;
944 	register_t saved_rflags;
945 
946 	mtx_lock(&dt_lock);
947 	regs = td->td_frame;
948 	pcb = td->td_pcb;
949 
950 	if (td->td_proc->p_md.md_ldt != NULL)
951 		user_ldt_free(td);
952 	else
953 		mtx_unlock(&dt_lock);
954 #ifdef COMPAT_43
955 	setup_lcall_gate();
956 #endif
957 
958 	pcb->pcb_fsbase = 0;
959 	pcb->pcb_gsbase = 0;
960 	pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
961 
962 	saved_rflags = regs->tf_rflags & PSL_T;
963 	bzero((char *)regs, sizeof(struct trapframe));
964 	regs->tf_rip = imgp->entry_addr;
965 	regs->tf_rsp = stack;
966 	regs->tf_rflags = PSL_USER | saved_rflags;
967 	regs->tf_ss = _udatasel;
968 	regs->tf_cs = _ucode32sel;
969 	regs->tf_rbx = imgp->ps_strings;
970 	regs->tf_ds = _udatasel;
971 	regs->tf_es = _udatasel;
972 	regs->tf_fs = _ufssel;
973 	regs->tf_gs = _ugssel;
974 	regs->tf_flags = TF_HASSEGS;
975 
976 	fpstate_drop(td);
977 
978 	/* Return via doreti so that we can change to a different %cs */
979 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
980 	td->td_retval[1] = 0;
981 }
982