ia32_signal.c revision 340920
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: stable/11/sys/amd64/ia32/ia32_signal.c 340920 2018-11-25 17:44:30Z markj $");
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
85static 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
91static void
92ia32_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
120static int
121ia32_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 */
146static int
147ia32_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 */
199static int
200ia32_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
254int
255freebsd32_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		ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
264		PROC_LOCK(td->td_proc);
265		uc.uc_sigmask = td->td_sigmask;
266		PROC_UNLOCK(td->td_proc);
267		bzero(&uc.__spare__, sizeof(uc.__spare__));
268		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
269	}
270	return (ret);
271}
272
273int
274freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
275{
276	struct ia32_ucontext uc;
277	int ret;
278
279	if (uap->ucp == NULL)
280		ret = EINVAL;
281	else {
282		ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
283		if (ret == 0) {
284			ret = ia32_set_mcontext(td, &uc.uc_mcontext);
285			if (ret == 0) {
286				kern_sigprocmask(td, SIG_SETMASK,
287				    &uc.uc_sigmask, NULL, 0);
288			}
289		}
290	}
291	return (ret == 0 ? EJUSTRETURN : ret);
292}
293
294int
295freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
296{
297	struct ia32_ucontext uc;
298	int ret;
299
300	if (uap->oucp == NULL || uap->ucp == NULL)
301		ret = EINVAL;
302	else {
303		ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
304		PROC_LOCK(td->td_proc);
305		uc.uc_sigmask = td->td_sigmask;
306		PROC_UNLOCK(td->td_proc);
307		ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
308		if (ret == 0) {
309			ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
310			if (ret == 0) {
311				ret = ia32_set_mcontext(td, &uc.uc_mcontext);
312				if (ret == 0) {
313					kern_sigprocmask(td, SIG_SETMASK,
314					    &uc.uc_sigmask, NULL, 0);
315				}
316			}
317		}
318	}
319	return (ret == 0 ? EJUSTRETURN : ret);
320}
321
322/*
323 * Send an interrupt to process.
324 *
325 * Stack is set up to allow sigcode stored
326 * at top to call routine, followed by kcall
327 * to sigreturn routine below.  After sigreturn
328 * resets the signal mask, the stack, and the
329 * frame pointer, it returns to the user
330 * specified pc, psl.
331 */
332
333#ifdef COMPAT_43
334static void
335ia32_osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
336{
337	struct ia32_sigframe3 sf, *fp;
338	struct proc *p;
339	struct thread *td;
340	struct sigacts *psp;
341	struct trapframe *regs;
342	int sig;
343	int oonstack;
344
345	td = curthread;
346	p = td->td_proc;
347	PROC_LOCK_ASSERT(p, MA_OWNED);
348	sig = ksi->ksi_signo;
349	psp = p->p_sigacts;
350	mtx_assert(&psp->ps_mtx, MA_OWNED);
351	regs = td->td_frame;
352	oonstack = sigonstack(regs->tf_rsp);
353
354	/* Allocate space for the signal handler context. */
355	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
356	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
357		fp = (struct ia32_sigframe3 *)((uintptr_t)td->td_sigstk.ss_sp +
358		    td->td_sigstk.ss_size - sizeof(sf));
359		td->td_sigstk.ss_flags |= SS_ONSTACK;
360	} else
361		fp = (struct ia32_sigframe3 *)regs->tf_rsp - 1;
362
363	/* Build the argument list for the signal handler. */
364	sf.sf_signum = sig;
365	sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc;
366	bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo));
367	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
368		/* Signal handler installed with SA_SIGINFO. */
369		sf.sf_arg2 = (register_t)&fp->sf_siginfo;
370		sf.sf_siginfo.si_signo = sig;
371		sf.sf_siginfo.si_code = ksi->ksi_code;
372		sf.sf_ah = (uintptr_t)catcher;
373		sf.sf_addr = 0;
374	} else {
375		/* Old FreeBSD-style arguments. */
376		sf.sf_arg2 = ksi->ksi_code;
377		sf.sf_addr = (register_t)ksi->ksi_addr;
378		sf.sf_ah = (uintptr_t)catcher;
379	}
380	mtx_unlock(&psp->ps_mtx);
381	PROC_UNLOCK(p);
382
383	/* Save most if not all of trap frame. */
384	sf.sf_siginfo.si_sc.sc_eax = regs->tf_rax;
385	sf.sf_siginfo.si_sc.sc_ebx = regs->tf_rbx;
386	sf.sf_siginfo.si_sc.sc_ecx = regs->tf_rcx;
387	sf.sf_siginfo.si_sc.sc_edx = regs->tf_rdx;
388	sf.sf_siginfo.si_sc.sc_esi = regs->tf_rsi;
389	sf.sf_siginfo.si_sc.sc_edi = regs->tf_rdi;
390	sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs;
391	sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds;
392	sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss;
393	sf.sf_siginfo.si_sc.sc_es = regs->tf_es;
394	sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs;
395	sf.sf_siginfo.si_sc.sc_gs = regs->tf_gs;
396	sf.sf_siginfo.si_sc.sc_isp = regs->tf_rsp;
397
398	/* Build the signal context to be used by osigreturn(). */
399	sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0;
400	SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask);
401	sf.sf_siginfo.si_sc.sc_esp = regs->tf_rsp;
402	sf.sf_siginfo.si_sc.sc_ebp = regs->tf_rbp;
403	sf.sf_siginfo.si_sc.sc_eip = regs->tf_rip;
404	sf.sf_siginfo.si_sc.sc_eflags = regs->tf_rflags;
405	sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno;
406	sf.sf_siginfo.si_sc.sc_err = regs->tf_err;
407
408	/*
409	 * Copy the sigframe out to the user's stack.
410	 */
411	if (copyout(&sf, fp, sizeof(*fp)) != 0) {
412#ifdef DEBUG
413		printf("process %ld has trashed its stack\n", (long)p->p_pid);
414#endif
415		PROC_LOCK(p);
416		sigexit(td, SIGILL);
417	}
418
419	regs->tf_rsp = (uintptr_t)fp;
420	regs->tf_rip = p->p_sysent->sv_psstrings - sz_ia32_osigcode;
421	regs->tf_rflags &= ~(PSL_T | PSL_D);
422	regs->tf_cs = _ucode32sel;
423	regs->tf_ds = _udatasel;
424	regs->tf_es = _udatasel;
425	regs->tf_fs = _udatasel;
426	regs->tf_ss = _udatasel;
427	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
428	PROC_LOCK(p);
429	mtx_lock(&psp->ps_mtx);
430}
431#endif
432
433#ifdef COMPAT_FREEBSD4
434static void
435freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
436{
437	struct ia32_sigframe4 sf, *sfp;
438	struct siginfo32 siginfo;
439	struct proc *p;
440	struct thread *td;
441	struct sigacts *psp;
442	struct trapframe *regs;
443	int oonstack;
444	int sig;
445
446	td = curthread;
447	p = td->td_proc;
448	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
449
450	PROC_LOCK_ASSERT(p, MA_OWNED);
451	sig = siginfo.si_signo;
452	psp = p->p_sigacts;
453	mtx_assert(&psp->ps_mtx, MA_OWNED);
454	regs = td->td_frame;
455	oonstack = sigonstack(regs->tf_rsp);
456
457	/* Save user context. */
458	bzero(&sf, sizeof(sf));
459	sf.sf_uc.uc_sigmask = *mask;
460	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
461	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
462	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
463	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
464	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
465	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
466	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
467	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
468	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
469	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
470	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
471	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
472	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
473	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
474	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
475	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
476	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
477	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
478	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
479	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
480	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
481	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
482	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
483	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
484	bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
485	    sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
486	bzero(sf.sf_uc.uc_mcontext.__spare__,
487	    sizeof(sf.sf_uc.uc_mcontext.__spare__));
488	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
489
490	/* Allocate space for the signal handler context. */
491	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
492	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
493		sfp = (struct ia32_sigframe4 *)((uintptr_t)td->td_sigstk.ss_sp +
494		    td->td_sigstk.ss_size - sizeof(sf));
495	} else
496		sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1;
497	PROC_UNLOCK(p);
498
499	/* Build the argument list for the signal handler. */
500	sf.sf_signum = sig;
501	sf.sf_ucontext = (register_t)&sfp->sf_uc;
502	bzero(&sf.sf_si, sizeof(sf.sf_si));
503	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
504		/* Signal handler installed with SA_SIGINFO. */
505		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
506		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
507
508		/* Fill in POSIX parts */
509		sf.sf_si = siginfo;
510		sf.sf_si.si_signo = sig;
511	} else {
512		/* Old FreeBSD-style arguments. */
513		sf.sf_siginfo = siginfo.si_code;
514		sf.sf_addr = (u_int32_t)siginfo.si_addr;
515		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
516	}
517	mtx_unlock(&psp->ps_mtx);
518
519	/*
520	 * Copy the sigframe out to the user's stack.
521	 */
522	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
523#ifdef DEBUG
524		printf("process %ld has trashed its stack\n", (long)p->p_pid);
525#endif
526		PROC_LOCK(p);
527		sigexit(td, SIGILL);
528	}
529
530	regs->tf_rsp = (uintptr_t)sfp;
531	regs->tf_rip = p->p_sysent->sv_sigcode_base + sz_ia32_sigcode -
532	    sz_freebsd4_ia32_sigcode;
533	regs->tf_rflags &= ~(PSL_T | PSL_D);
534	regs->tf_cs = _ucode32sel;
535	regs->tf_ss = _udatasel;
536	regs->tf_ds = _udatasel;
537	regs->tf_es = _udatasel;
538	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
539	/* leave user %fs and %gs untouched */
540	PROC_LOCK(p);
541	mtx_lock(&psp->ps_mtx);
542}
543#endif	/* COMPAT_FREEBSD4 */
544
545void
546ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
547{
548	struct ia32_sigframe sf, *sfp;
549	struct siginfo32 siginfo;
550	struct proc *p;
551	struct thread *td;
552	struct sigacts *psp;
553	char *sp;
554	struct trapframe *regs;
555	char *xfpusave;
556	size_t xfpusave_len;
557	int oonstack;
558	int sig;
559
560	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
561	td = curthread;
562	p = td->td_proc;
563	PROC_LOCK_ASSERT(p, MA_OWNED);
564	sig = siginfo.si_signo;
565	psp = p->p_sigacts;
566#ifdef COMPAT_FREEBSD4
567	if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
568		freebsd4_ia32_sendsig(catcher, ksi, mask);
569		return;
570	}
571#endif
572#ifdef COMPAT_43
573	if (SIGISMEMBER(psp->ps_osigset, sig)) {
574		ia32_osendsig(catcher, ksi, mask);
575		return;
576	}
577#endif
578	mtx_assert(&psp->ps_mtx, MA_OWNED);
579	regs = td->td_frame;
580	oonstack = sigonstack(regs->tf_rsp);
581
582	if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
583		xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
584		xfpusave = __builtin_alloca(xfpusave_len);
585	} else {
586		xfpusave_len = 0;
587		xfpusave = NULL;
588	}
589
590	/* Save user context. */
591	bzero(&sf, sizeof(sf));
592	sf.sf_uc.uc_sigmask = *mask;
593	sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
594	sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
595	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
596	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
597	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
598	sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
599	sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
600	sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
601	sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
602	sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
603	sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
604	sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
605	sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
606	sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
607	sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
608	sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
609	sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
610	sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
611	sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
612	sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
613	sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
614	sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
615	sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
616	sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
617	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
618	ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
619	fpstate_drop(td);
620	sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase;
621	sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase;
622	bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
623
624	/* Allocate space for the signal handler context. */
625	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
626	    SIGISMEMBER(psp->ps_sigonstack, sig))
627		sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
628	else
629		sp = (char *)regs->tf_rsp;
630	if (xfpusave != NULL) {
631		sp -= xfpusave_len;
632		sp = (char *)((unsigned long)sp & ~0x3Ful);
633		sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
634	}
635	sp -= sizeof(sf);
636	/* Align to 16 bytes. */
637	sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
638	PROC_UNLOCK(p);
639
640	/* Build the argument list for the signal handler. */
641	sf.sf_signum = sig;
642	sf.sf_ucontext = (register_t)&sfp->sf_uc;
643	bzero(&sf.sf_si, sizeof(sf.sf_si));
644	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
645		/* Signal handler installed with SA_SIGINFO. */
646		sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
647		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
648
649		/* Fill in POSIX parts */
650		sf.sf_si = siginfo;
651		sf.sf_si.si_signo = sig;
652	} else {
653		/* Old FreeBSD-style arguments. */
654		sf.sf_siginfo = siginfo.si_code;
655		sf.sf_addr = (u_int32_t)siginfo.si_addr;
656		sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
657	}
658	mtx_unlock(&psp->ps_mtx);
659
660	/*
661	 * Copy the sigframe out to the user's stack.
662	 */
663	if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
664	    (xfpusave != NULL && copyout(xfpusave,
665	    PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len)
666	    != 0)) {
667#ifdef DEBUG
668		printf("process %ld has trashed its stack\n", (long)p->p_pid);
669#endif
670		PROC_LOCK(p);
671		sigexit(td, SIGILL);
672	}
673
674	regs->tf_rsp = (uintptr_t)sfp;
675	regs->tf_rip = p->p_sysent->sv_sigcode_base;
676	regs->tf_rflags &= ~(PSL_T | PSL_D);
677	regs->tf_cs = _ucode32sel;
678	regs->tf_ss = _udatasel;
679	regs->tf_ds = _udatasel;
680	regs->tf_es = _udatasel;
681	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
682	/* XXXKIB leave user %fs and %gs untouched */
683	PROC_LOCK(p);
684	mtx_lock(&psp->ps_mtx);
685}
686
687/*
688 * System call to cleanup state after a signal
689 * has been taken.  Reset signal mask and
690 * stack state from context left by sendsig (above).
691 * Return to previous pc and psl as specified by
692 * context left by sendsig. Check carefully to
693 * make sure that the user has not modified the
694 * state to gain improper privileges.
695 */
696
697#ifdef COMPAT_43
698int
699ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
700{
701	struct ia32_sigcontext3 sc, *scp;
702	struct trapframe *regs;
703	int eflags, error;
704	ksiginfo_t ksi;
705
706	regs = td->td_frame;
707	error = copyin(uap->sigcntxp, &sc, sizeof(sc));
708	if (error != 0)
709		return (error);
710	scp = &sc;
711	eflags = scp->sc_eflags;
712	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
713		return (EINVAL);
714	}
715	if (!CS_SECURE(scp->sc_cs)) {
716		ksiginfo_init_trap(&ksi);
717		ksi.ksi_signo = SIGBUS;
718		ksi.ksi_code = BUS_OBJERR;
719		ksi.ksi_trapno = T_PROTFLT;
720		ksi.ksi_addr = (void *)regs->tf_rip;
721		trapsignal(td, &ksi);
722		return (EINVAL);
723	}
724	regs->tf_ds = scp->sc_ds;
725	regs->tf_es = scp->sc_es;
726	regs->tf_fs = scp->sc_fs;
727	regs->tf_gs = scp->sc_gs;
728
729	regs->tf_rax = scp->sc_eax;
730	regs->tf_rbx = scp->sc_ebx;
731	regs->tf_rcx = scp->sc_ecx;
732	regs->tf_rdx = scp->sc_edx;
733	regs->tf_rsi = scp->sc_esi;
734	regs->tf_rdi = scp->sc_edi;
735	regs->tf_cs = scp->sc_cs;
736	regs->tf_ss = scp->sc_ss;
737	regs->tf_rbp = scp->sc_ebp;
738	regs->tf_rsp = scp->sc_esp;
739	regs->tf_rip = scp->sc_eip;
740	regs->tf_rflags = eflags;
741
742	if (scp->sc_onstack & 1)
743		td->td_sigstk.ss_flags |= SS_ONSTACK;
744	else
745		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
746
747	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
748	    SIGPROCMASK_OLD);
749	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
750	return (EJUSTRETURN);
751}
752#endif
753
754#ifdef COMPAT_FREEBSD4
755/*
756 * MPSAFE
757 */
758int
759freebsd4_freebsd32_sigreturn(td, uap)
760	struct thread *td;
761	struct freebsd4_freebsd32_sigreturn_args /* {
762		const struct freebsd4_freebsd32_ucontext *sigcntxp;
763	} */ *uap;
764{
765	struct ia32_ucontext4 uc;
766	struct trapframe *regs;
767	struct ia32_ucontext4 *ucp;
768	int cs, eflags, error;
769	ksiginfo_t ksi;
770
771	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
772	if (error != 0)
773		return (error);
774	ucp = &uc;
775	regs = td->td_frame;
776	eflags = ucp->uc_mcontext.mc_eflags;
777	/*
778	 * Don't allow users to change privileged or reserved flags.
779	 */
780	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
781		uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n",
782		    td->td_proc->p_pid, td->td_name, eflags);
783		return (EINVAL);
784	}
785
786	/*
787	 * Don't allow users to load a valid privileged %cs.  Let the
788	 * hardware check for invalid selectors, excess privilege in
789	 * other selectors, invalid %eip's and invalid %esp's.
790	 */
791	cs = ucp->uc_mcontext.mc_cs;
792	if (!CS_SECURE(cs)) {
793		uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n",
794		    td->td_proc->p_pid, td->td_name, cs);
795		ksiginfo_init_trap(&ksi);
796		ksi.ksi_signo = SIGBUS;
797		ksi.ksi_code = BUS_OBJERR;
798		ksi.ksi_trapno = T_PROTFLT;
799		ksi.ksi_addr = (void *)regs->tf_rip;
800		trapsignal(td, &ksi);
801		return (EINVAL);
802	}
803
804	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
805	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
806	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
807	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
808	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
809	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
810	regs->tf_rax = ucp->uc_mcontext.mc_eax;
811	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
812	regs->tf_err = ucp->uc_mcontext.mc_err;
813	regs->tf_rip = ucp->uc_mcontext.mc_eip;
814	regs->tf_cs = cs;
815	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
816	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
817	regs->tf_ss = ucp->uc_mcontext.mc_ss;
818	regs->tf_ds = ucp->uc_mcontext.mc_ds;
819	regs->tf_es = ucp->uc_mcontext.mc_es;
820	regs->tf_fs = ucp->uc_mcontext.mc_fs;
821	regs->tf_gs = ucp->uc_mcontext.mc_gs;
822
823	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
824	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
825	return (EJUSTRETURN);
826}
827#endif	/* COMPAT_FREEBSD4 */
828
829/*
830 * MPSAFE
831 */
832int
833freebsd32_sigreturn(td, uap)
834	struct thread *td;
835	struct freebsd32_sigreturn_args /* {
836		const struct freebsd32_ucontext *sigcntxp;
837	} */ *uap;
838{
839	struct ia32_ucontext uc;
840	struct trapframe *regs;
841	struct ia32_ucontext *ucp;
842	char *xfpustate;
843	size_t xfpustate_len;
844	int cs, eflags, error, ret;
845	ksiginfo_t ksi;
846
847	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
848	if (error != 0)
849		return (error);
850	ucp = &uc;
851	regs = td->td_frame;
852	eflags = ucp->uc_mcontext.mc_eflags;
853	/*
854	 * Don't allow users to change privileged or reserved flags.
855	 */
856	if (!EFL_SECURE(eflags, regs->tf_rflags)) {
857		uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n",
858		    td->td_proc->p_pid, td->td_name, eflags);
859		return (EINVAL);
860	}
861
862	/*
863	 * Don't allow users to load a valid privileged %cs.  Let the
864	 * hardware check for invalid selectors, excess privilege in
865	 * other selectors, invalid %eip's and invalid %esp's.
866	 */
867	cs = ucp->uc_mcontext.mc_cs;
868	if (!CS_SECURE(cs)) {
869		uprintf("pid %d (%s): sigreturn cs = 0x%x\n",
870		    td->td_proc->p_pid, td->td_name, cs);
871		ksiginfo_init_trap(&ksi);
872		ksi.ksi_signo = SIGBUS;
873		ksi.ksi_code = BUS_OBJERR;
874		ksi.ksi_trapno = T_PROTFLT;
875		ksi.ksi_addr = (void *)regs->tf_rip;
876		trapsignal(td, &ksi);
877		return (EINVAL);
878	}
879
880	if ((ucp->uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
881		xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
882		if (xfpustate_len > cpu_max_ext_state_size -
883		    sizeof(struct savefpu)) {
884			uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
885			    td->td_proc->p_pid, td->td_name, xfpustate_len);
886			return (EINVAL);
887		}
888		xfpustate = __builtin_alloca(xfpustate_len);
889		error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate),
890		    xfpustate, xfpustate_len);
891		if (error != 0) {
892			uprintf(
893	"pid %d (%s): sigreturn copying xfpustate failed\n",
894			    td->td_proc->p_pid, td->td_name);
895			return (error);
896		}
897	} else {
898		xfpustate = NULL;
899		xfpustate_len = 0;
900	}
901	ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
902	    xfpustate_len);
903	if (ret != 0) {
904		uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
905		    td->td_proc->p_pid, td->td_name, ret);
906		return (ret);
907	}
908
909	regs->tf_rdi = ucp->uc_mcontext.mc_edi;
910	regs->tf_rsi = ucp->uc_mcontext.mc_esi;
911	regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
912	regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
913	regs->tf_rdx = ucp->uc_mcontext.mc_edx;
914	regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
915	regs->tf_rax = ucp->uc_mcontext.mc_eax;
916	regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
917	regs->tf_err = ucp->uc_mcontext.mc_err;
918	regs->tf_rip = ucp->uc_mcontext.mc_eip;
919	regs->tf_cs = cs;
920	regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
921	regs->tf_rsp = ucp->uc_mcontext.mc_esp;
922	regs->tf_ss = ucp->uc_mcontext.mc_ss;
923	regs->tf_ds = ucp->uc_mcontext.mc_ds;
924	regs->tf_es = ucp->uc_mcontext.mc_es;
925	regs->tf_fs = ucp->uc_mcontext.mc_fs;
926	regs->tf_gs = ucp->uc_mcontext.mc_gs;
927	regs->tf_flags = TF_HASSEGS;
928
929	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
930	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
931	return (EJUSTRETURN);
932}
933
934/*
935 * Clear registers on exec
936 */
937void
938ia32_setregs(struct thread *td, struct image_params *imgp, u_long stack)
939{
940	struct trapframe *regs;
941	struct pcb *pcb;
942	register_t saved_rflags;
943
944	mtx_lock(&dt_lock);
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	else
951		mtx_unlock(&dt_lock);
952#ifdef COMPAT_43
953	setup_lcall_gate();
954#endif
955
956	pcb->pcb_fsbase = 0;
957	pcb->pcb_gsbase = 0;
958	pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
959
960	saved_rflags = regs->tf_rflags & PSL_T;
961	bzero((char *)regs, sizeof(struct trapframe));
962	regs->tf_rip = imgp->entry_addr;
963	regs->tf_rsp = stack;
964	regs->tf_rflags = PSL_USER | saved_rflags;
965	regs->tf_ss = _udatasel;
966	regs->tf_cs = _ucode32sel;
967	regs->tf_rbx = imgp->ps_strings;
968	regs->tf_ds = _udatasel;
969	regs->tf_es = _udatasel;
970	regs->tf_fs = _ufssel;
971	regs->tf_gs = _ugssel;
972	regs->tf_flags = TF_HASSEGS;
973
974	fpstate_drop(td);
975
976	/* Return via doreti so that we can change to a different %cs */
977	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
978	td->td_retval[1] = 0;
979}
980