1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2003 Peter Wemm
5 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/param.h>
40 #include <sys/exec.h>
41 #include <sys/fcntl.h>
42 #include <sys/imgact.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mutex.h>
47 #include <sys/mman.h>
48 #include <sys/namei.h>
49 #include <sys/proc.h>
50 #include <sys/procfs.h>
51 #include <sys/resourcevar.h>
52 #include <sys/systm.h>
53 #include <sys/signalvar.h>
54 #include <sys/stat.h>
55 #include <sys/sx.h>
56 #include <sys/syscall.h>
57 #include <sys/syscallsubr.h>
58 #include <sys/sysctl.h>
59 #include <sys/sysent.h>
60 #include <sys/vnode.h>
61
62 #include <vm/vm.h>
63 #include <vm/vm_kern.h>
64 #include <vm/vm_param.h>
65 #include <vm/pmap.h>
66 #include <vm/vm_map.h>
67 #include <vm/vm_object.h>
68 #include <vm/vm_extern.h>
69
70 #include <compat/freebsd32/freebsd32_signal.h>
71 #include <compat/freebsd32/freebsd32_util.h>
72 #include <compat/freebsd32/freebsd32_proto.h>
73 #include <compat/freebsd32/freebsd32.h>
74 #include <compat/ia32/ia32_signal.h>
75 #include <machine/psl.h>
76 #include <machine/segments.h>
77 #include <machine/specialreg.h>
78 #include <machine/frame.h>
79 #include <machine/md_var.h>
80 #include <machine/pcb.h>
81 #include <machine/cpufunc.h>
82 #include <machine/trap.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 ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
269 }
270 return (ret);
271 }
272
273 int
freebsd32_setcontext(struct thread * td,struct freebsd32_setcontext_args * uap)274 freebsd32_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
294 int
freebsd32_swapcontext(struct thread * td,struct freebsd32_swapcontext_args * uap)295 freebsd32_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 bzero(&uc, sizeof(uc));
304 ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
305 PROC_LOCK(td->td_proc);
306 uc.uc_sigmask = td->td_sigmask;
307 PROC_UNLOCK(td->td_proc);
308 ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
309 if (ret == 0) {
310 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
311 if (ret == 0) {
312 ret = ia32_set_mcontext(td, &uc.uc_mcontext);
313 if (ret == 0) {
314 kern_sigprocmask(td, SIG_SETMASK,
315 &uc.uc_sigmask, NULL, 0);
316 }
317 }
318 }
319 }
320 return (ret == 0 ? EJUSTRETURN : ret);
321 }
322
323 /*
324 * Send an interrupt to process.
325 *
326 * Stack is set up to allow sigcode stored
327 * at top to call routine, followed by kcall
328 * to sigreturn routine below. After sigreturn
329 * resets the signal mask, the stack, and the
330 * frame pointer, it returns to the user
331 * specified pc, psl.
332 */
333
334 #ifdef COMPAT_43
335 static void
ia32_osendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)336 ia32_osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
337 {
338 struct ia32_sigframe3 sf, *fp;
339 struct proc *p;
340 struct thread *td;
341 struct sigacts *psp;
342 struct trapframe *regs;
343 int sig;
344 int oonstack;
345
346 td = curthread;
347 p = td->td_proc;
348 PROC_LOCK_ASSERT(p, MA_OWNED);
349 sig = ksi->ksi_signo;
350 psp = p->p_sigacts;
351 mtx_assert(&psp->ps_mtx, MA_OWNED);
352 regs = td->td_frame;
353 oonstack = sigonstack(regs->tf_rsp);
354
355 /* Allocate space for the signal handler context. */
356 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
357 SIGISMEMBER(psp->ps_sigonstack, sig)) {
358 fp = (struct ia32_sigframe3 *)((uintptr_t)td->td_sigstk.ss_sp +
359 td->td_sigstk.ss_size - sizeof(sf));
360 td->td_sigstk.ss_flags |= SS_ONSTACK;
361 } else
362 fp = (struct ia32_sigframe3 *)regs->tf_rsp - 1;
363
364 /* Build the argument list for the signal handler. */
365 sf.sf_signum = sig;
366 sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc;
367 bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo));
368 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
369 /* Signal handler installed with SA_SIGINFO. */
370 sf.sf_arg2 = (register_t)&fp->sf_siginfo;
371 sf.sf_siginfo.si_signo = sig;
372 sf.sf_siginfo.si_code = ksi->ksi_code;
373 sf.sf_ah = (uintptr_t)catcher;
374 sf.sf_addr = 0;
375 } else {
376 /* Old FreeBSD-style arguments. */
377 sf.sf_arg2 = ksi->ksi_code;
378 sf.sf_addr = (register_t)ksi->ksi_addr;
379 sf.sf_ah = (uintptr_t)catcher;
380 }
381 mtx_unlock(&psp->ps_mtx);
382 PROC_UNLOCK(p);
383
384 /* Save most if not all of trap frame. */
385 sf.sf_siginfo.si_sc.sc_eax = regs->tf_rax;
386 sf.sf_siginfo.si_sc.sc_ebx = regs->tf_rbx;
387 sf.sf_siginfo.si_sc.sc_ecx = regs->tf_rcx;
388 sf.sf_siginfo.si_sc.sc_edx = regs->tf_rdx;
389 sf.sf_siginfo.si_sc.sc_esi = regs->tf_rsi;
390 sf.sf_siginfo.si_sc.sc_edi = regs->tf_rdi;
391 sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs;
392 sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds;
393 sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss;
394 sf.sf_siginfo.si_sc.sc_es = regs->tf_es;
395 sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs;
396 sf.sf_siginfo.si_sc.sc_gs = regs->tf_gs;
397 sf.sf_siginfo.si_sc.sc_isp = regs->tf_rsp;
398
399 /* Build the signal context to be used by osigreturn(). */
400 sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0;
401 SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask);
402 sf.sf_siginfo.si_sc.sc_esp = regs->tf_rsp;
403 sf.sf_siginfo.si_sc.sc_ebp = regs->tf_rbp;
404 sf.sf_siginfo.si_sc.sc_eip = regs->tf_rip;
405 sf.sf_siginfo.si_sc.sc_eflags = regs->tf_rflags;
406 sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno;
407 sf.sf_siginfo.si_sc.sc_err = regs->tf_err;
408
409 /*
410 * Copy the sigframe out to the user's stack.
411 */
412 if (copyout(&sf, fp, sizeof(*fp)) != 0) {
413 #ifdef DEBUG
414 printf("process %ld has trashed its stack\n", (long)p->p_pid);
415 #endif
416 PROC_LOCK(p);
417 sigexit(td, SIGILL);
418 }
419
420 regs->tf_rsp = (uintptr_t)fp;
421 regs->tf_rip = p->p_sysent->sv_psstrings - sz_ia32_osigcode;
422 regs->tf_rflags &= ~(PSL_T | PSL_D);
423 regs->tf_cs = _ucode32sel;
424 regs->tf_ds = _udatasel;
425 regs->tf_es = _udatasel;
426 regs->tf_fs = _udatasel;
427 regs->tf_ss = _udatasel;
428 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
429 PROC_LOCK(p);
430 mtx_lock(&psp->ps_mtx);
431 }
432 #endif
433
434 #ifdef COMPAT_FREEBSD4
435 static void
freebsd4_ia32_sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)436 freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
437 {
438 struct ia32_sigframe4 sf, *sfp;
439 struct siginfo32 siginfo;
440 struct proc *p;
441 struct thread *td;
442 struct sigacts *psp;
443 struct trapframe *regs;
444 int oonstack;
445 int sig;
446
447 td = curthread;
448 p = td->td_proc;
449 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
450
451 PROC_LOCK_ASSERT(p, MA_OWNED);
452 sig = siginfo.si_signo;
453 psp = p->p_sigacts;
454 mtx_assert(&psp->ps_mtx, MA_OWNED);
455 regs = td->td_frame;
456 oonstack = sigonstack(regs->tf_rsp);
457
458 /* Save user context. */
459 bzero(&sf, sizeof(sf));
460 sf.sf_uc.uc_sigmask = *mask;
461 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
462 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
463 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
464 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
465 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
466 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
467 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
468 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
469 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
470 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
471 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
472 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
473 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
474 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
475 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
476 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
477 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
478 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
479 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
480 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
481 sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
482 sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
483 sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
484 sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
485 bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
486 sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
487 bzero(sf.sf_uc.uc_mcontext.__spare__,
488 sizeof(sf.sf_uc.uc_mcontext.__spare__));
489 bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
490
491 /* Allocate space for the signal handler context. */
492 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
493 SIGISMEMBER(psp->ps_sigonstack, sig)) {
494 sfp = (struct ia32_sigframe4 *)((uintptr_t)td->td_sigstk.ss_sp +
495 td->td_sigstk.ss_size - sizeof(sf));
496 } else
497 sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1;
498 PROC_UNLOCK(p);
499
500 /* Build the argument list for the signal handler. */
501 sf.sf_signum = sig;
502 sf.sf_ucontext = (register_t)&sfp->sf_uc;
503 bzero(&sf.sf_si, sizeof(sf.sf_si));
504 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
505 /* Signal handler installed with SA_SIGINFO. */
506 sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
507 sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
508
509 /* Fill in POSIX parts */
510 sf.sf_si = siginfo;
511 sf.sf_si.si_signo = sig;
512 } else {
513 /* Old FreeBSD-style arguments. */
514 sf.sf_siginfo = siginfo.si_code;
515 sf.sf_addr = (u_int32_t)siginfo.si_addr;
516 sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
517 }
518 mtx_unlock(&psp->ps_mtx);
519
520 /*
521 * Copy the sigframe out to the user's stack.
522 */
523 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
524 #ifdef DEBUG
525 printf("process %ld has trashed its stack\n", (long)p->p_pid);
526 #endif
527 PROC_LOCK(p);
528 sigexit(td, SIGILL);
529 }
530
531 regs->tf_rsp = (uintptr_t)sfp;
532 regs->tf_rip = p->p_sysent->sv_sigcode_base + sz_ia32_sigcode -
533 sz_freebsd4_ia32_sigcode;
534 regs->tf_rflags &= ~(PSL_T | PSL_D);
535 regs->tf_cs = _ucode32sel;
536 regs->tf_ss = _udatasel;
537 regs->tf_ds = _udatasel;
538 regs->tf_es = _udatasel;
539 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
540 /* leave user %fs and %gs untouched */
541 PROC_LOCK(p);
542 mtx_lock(&psp->ps_mtx);
543 }
544 #endif /* COMPAT_FREEBSD4 */
545
546 void
ia32_sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)547 ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
548 {
549 struct ia32_sigframe sf, *sfp;
550 struct siginfo32 siginfo;
551 struct proc *p;
552 struct thread *td;
553 struct sigacts *psp;
554 char *sp;
555 struct trapframe *regs;
556 char *xfpusave;
557 size_t xfpusave_len;
558 int oonstack;
559 int sig;
560
561 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
562 td = curthread;
563 p = td->td_proc;
564 PROC_LOCK_ASSERT(p, MA_OWNED);
565 sig = siginfo.si_signo;
566 psp = p->p_sigacts;
567 #ifdef COMPAT_FREEBSD4
568 if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
569 freebsd4_ia32_sendsig(catcher, ksi, mask);
570 return;
571 }
572 #endif
573 #ifdef COMPAT_43
574 if (SIGISMEMBER(psp->ps_osigset, sig)) {
575 ia32_osendsig(catcher, ksi, mask);
576 return;
577 }
578 #endif
579 mtx_assert(&psp->ps_mtx, MA_OWNED);
580 regs = td->td_frame;
581 oonstack = sigonstack(regs->tf_rsp);
582
583 if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
584 xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
585 xfpusave = __builtin_alloca(xfpusave_len);
586 } else {
587 xfpusave_len = 0;
588 xfpusave = NULL;
589 }
590
591 /* Save user context. */
592 bzero(&sf, sizeof(sf));
593 sf.sf_uc.uc_sigmask = *mask;
594 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
595 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
596 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
597 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
598 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
599 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
600 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
601 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
602 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
603 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
604 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
605 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
606 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
607 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
608 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
609 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
610 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
611 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
612 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
613 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
614 sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
615 sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
616 sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
617 sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
618 sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
619 ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
620 fpstate_drop(td);
621 sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase;
622 sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase;
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
698 int
ofreebsd32_sigreturn(struct thread * td,struct ofreebsd32_sigreturn_args * uap)699 ofreebsd32_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 = ≻
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 */
758 int
freebsd4_freebsd32_sigreturn(td,uap)759 freebsd4_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 */
832 int
freebsd32_sigreturn(td,uap)833 freebsd32_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 */
937 void
ia32_setregs(struct thread * td,struct image_params * imgp,uintptr_t stack)938 ia32_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
939 {
940 struct trapframe *regs;
941 struct pcb *pcb;
942 register_t saved_rflags;
943
944 regs = td->td_frame;
945 pcb = td->td_pcb;
946
947 if (td->td_proc->p_md.md_ldt != NULL)
948 user_ldt_free(td);
949 #ifdef COMPAT_43
950 setup_lcall_gate();
951 #endif
952
953 pcb->pcb_fsbase = 0;
954 pcb->pcb_gsbase = 0;
955 pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
956
957 saved_rflags = regs->tf_rflags & PSL_T;
958 bzero((char *)regs, sizeof(struct trapframe));
959 regs->tf_rip = imgp->entry_addr;
960 regs->tf_rsp = stack;
961 regs->tf_rflags = PSL_USER | saved_rflags;
962 regs->tf_ss = _udatasel;
963 regs->tf_cs = _ucode32sel;
964 regs->tf_rbx = (register_t)imgp->ps_strings;
965 regs->tf_ds = _udatasel;
966 regs->tf_es = _udatasel;
967 regs->tf_fs = _ufssel;
968 regs->tf_gs = _ugssel;
969 regs->tf_flags = TF_HASSEGS;
970
971 fpstate_drop(td);
972
973 /* Return via doreti so that we can change to a different %cs */
974 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
975 }
976