1 /* $NetBSD: compat_16_machdep.c,v 1.18 2021/10/27 04:14:59 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: Utah Hdr: machdep.c 1.74 92/12/20
37 * from: @(#)machdep.c 8.10 (Berkeley) 4/20/94
38 */
39
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: compat_16_machdep.c,v 1.18 2021/10/27 04:14:59 thorpej Exp $");
42
43 #ifdef _KERNEL_OPT
44 #include "opt_compat_netbsd.h"
45 #endif
46
47 #define __M68K_SIGNAL_PRIVATE
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/proc.h>
53 #include <sys/ras.h>
54 #include <sys/signal.h>
55 #include <sys/signalvar.h>
56 #include <sys/ucontext.h>
57
58 #include <sys/mount.h>
59 #include <sys/syscallargs.h>
60
61 #ifdef COMPAT_13
62 #include <compat/sys/signal.h>
63 #include <compat/sys/signalvar.h>
64 #endif
65
66 #include <machine/cpu.h>
67 #include <machine/reg.h>
68 #include <machine/frame.h>
69
70 extern short exframesize[];
71
72 #ifdef DEBUG
73 extern int sigdebug;
74 extern int sigpid;
75 #define SDB_FOLLOW 0x01
76 #define SDB_KSTACK 0x02
77 #define SDB_FPSTATE 0x04
78 #endif
79
80 #ifdef COMPAT_16
81 /*
82 * Send an interrupt to process.
83 */
84 void
sendsig_sigcontext(const ksiginfo_t * ksi,const sigset_t * mask)85 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
86 {
87 struct lwp *l = curlwp;
88 struct proc *p = l->l_proc;
89 struct sigacts *ps = p->p_sigacts;
90 struct frame *frame = (struct frame *)l->l_md.md_regs;
91 int onstack, error;
92 int sig = ksi->ksi_signo;
93 u_long code = KSI_TRAPCODE(ksi);
94 struct sigframe_sigcontext *fp = getframe(l, sig, &onstack), kf;
95 sig_t catcher = SIGACTION(p, sig).sa_handler;
96 short ft = frame->f_format;
97
98 fp--;
99
100 #ifdef DEBUG
101 if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
102 printf("sendsig(%d): sig %d ssp %p usp %p scp %p ft %d\n",
103 p->p_pid, sig, &onstack, fp, &fp->sf_sc, ft);
104 #endif
105
106 /* Build stack frame for signal trampoline. */
107 switch (ps->sa_sigdesc[sig].sd_vers) {
108 case __SIGTRAMP_SIGCODE_VERSION: /* legacy on-stack sigtramp */
109 kf.sf_ra = (int)p->p_sigctx.ps_sigcode;
110 break;
111
112 case __SIGTRAMP_SIGCONTEXT_VERSION:
113 kf.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp;
114 break;
115
116 default:
117 /* Don't know what trampoline version; kill it. */
118 sigexit(l, SIGILL);
119 }
120
121 kf.sf_signum = sig;
122 kf.sf_code = code;
123 kf.sf_scp = &fp->sf_sc;
124
125 /*
126 * Save necessary hardware state. Currently this includes:
127 * - general registers
128 * - original exception frame (if not a "normal" frame)
129 * - FP coprocessor state
130 */
131 kf.sf_state.ss_flags = SS_USERREGS;
132 memcpy(kf.sf_state.ss_frame.f_regs, frame->f_regs,
133 sizeof(frame->f_regs));
134 if (ft >= FMT4) {
135 #ifdef DEBUG
136 if (ft > 15 || exframesize[ft] < 0)
137 panic("sendsig: bogus frame type");
138 #endif
139 kf.sf_state.ss_flags |= SS_RTEFRAME;
140 kf.sf_state.ss_frame.f_format = frame->f_format;
141 kf.sf_state.ss_frame.f_vector = frame->f_vector;
142 memcpy(&kf.sf_state.ss_frame.F_u, &frame->F_u,
143 (size_t) exframesize[ft]);
144 /*
145 * Leave an indicator that we need to clean up the kernel
146 * stack. We do this by setting the "pad word" above the
147 * hardware stack frame to the amount the stack must be
148 * adjusted by.
149 *
150 * N.B. we increment rather than just set f_stackadj in
151 * case we are called from syscall when processing a
152 * sigreturn. In that case, f_stackadj may be non-zero.
153 */
154 frame->f_stackadj += exframesize[ft];
155 frame->f_format = frame->f_vector = 0;
156 #ifdef DEBUG
157 if (sigdebug & SDB_FOLLOW)
158 printf("sendsig(%d): copy out %d of frame %d\n",
159 p->p_pid, exframesize[ft], ft);
160 #endif
161 }
162
163 if (fputype) {
164 kf.sf_state.ss_flags |= SS_FPSTATE;
165 m68881_save(&kf.sf_state.ss_fpstate);
166 }
167 #ifdef DEBUG
168 if ((sigdebug & SDB_FPSTATE) && *(char *)&kf.sf_state.ss_fpstate)
169 printf("sendsig(%d): copy out FP state (%x) to %p\n",
170 p->p_pid, *(u_int *)&kf.sf_state.ss_fpstate,
171 &kf.sf_state.ss_fpstate);
172 #endif
173
174 /* Build the signal context to be used by sigreturn. */
175 kf.sf_sc.sc_sp = frame->f_regs[SP];
176 kf.sf_sc.sc_fp = frame->f_regs[A6];
177 kf.sf_sc.sc_ap = (int)&fp->sf_state;
178 kf.sf_sc.sc_pc = frame->f_pc;
179 kf.sf_sc.sc_ps = frame->f_sr;
180
181 /* Save signal stack. */
182 kf.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
183
184 /* Save signal mask. */
185 kf.sf_sc.sc_mask = *mask;
186
187 #ifdef COMPAT_13
188 /*
189 * XXX We always have to save an old style signal mask because
190 * XXX we might be delivering a signal to a process which will
191 * XXX escape from the signal in a non-standard way and invoke
192 * XXX sigreturn() directly.
193 */
194 native_sigset_to_sigset13(mask, &kf.sf_sc.__sc_mask13);
195 #endif
196 sendsig_reset(l, sig);
197 mutex_exit(p->p_lock);
198 error = copyout(&kf, fp, sizeof(kf));
199 mutex_enter(p->p_lock);
200
201 if (error != 0) {
202 #ifdef DEBUG
203 if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
204 printf("sendsig(%d): copyout failed on sig %d\n",
205 p->p_pid, sig);
206 #endif
207 /*
208 * Process has trashed its stack; give it an illegal
209 * instruction to halt it in its tracks.
210 */
211 sigexit(l, SIGILL);
212 /* NOTREACHED */
213 }
214 #ifdef DEBUG
215 if (sigdebug & SDB_FOLLOW)
216 printf("sendsig(%d): sig %d scp %p fp %p sc_sp %x sc_ap %x\n",
217 p->p_pid, sig, kf.sf_scp, fp,
218 kf.sf_sc.sc_sp, kf.sf_sc.sc_ap);
219 #endif
220
221 buildcontext(l, catcher, fp);
222
223 /* Remember that we're now on the signal stack. */
224 if (onstack)
225 l->l_sigstk.ss_flags |= SS_ONSTACK;
226
227 #ifdef DEBUG
228 if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
229 printf("sendsig(%d): sig %d returns\n",
230 p->p_pid, sig);
231 #endif
232 }
233 #endif
234
235 #ifdef COMPAT_16
236 /*
237 * System call to cleanup state after a signal
238 * has been taken. Reset signal mask and
239 * stack state from context left by sendsig (above).
240 * Return to previous pc and psl as specified by
241 * context left by sendsig. Check carefully to
242 * make sure that the user has not modified the
243 * psl to gain improper privileges or to cause
244 * a machine fault.
245 */
246 int
compat_16_sys___sigreturn14(struct lwp * l,const struct compat_16_sys___sigreturn14_args * uap,register_t * retval)247 compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
248 {
249 /* {
250 syscallarg(struct sigcontext *) sigcntxp;
251 } */
252 struct proc *p = l->l_proc;
253 struct sigcontext *scp;
254 struct frame *frame;
255 struct sigcontext tsigc;
256 struct sigstate tstate;
257 int rf, flags, error;
258
259 /*
260 * The trampoline code hands us the context.
261 * It is unsafe to keep track of it ourselves, in the event that a
262 * program jumps out of a signal handler.
263 */
264 scp = SCARG(uap, sigcntxp);
265 #ifdef DEBUG
266 if (sigdebug & SDB_FOLLOW)
267 printf("sigreturn: pid %d, scp %p\n", p->p_pid, scp);
268 #endif
269 if ((int)scp & 1)
270 return EINVAL;
271
272 if (copyin(scp, &tsigc, sizeof(tsigc)) != 0)
273 return EFAULT;
274 scp = &tsigc;
275
276 /* Make sure the user isn't pulling a fast one on us! */
277 if ((scp->sc_ps & (PSL_MBZ|PSL_IPL|PSL_S)) != 0)
278 return EINVAL;
279
280 /* Restore register context. */
281 frame = (struct frame *) l->l_md.md_regs;
282
283 /*
284 * Grab pointer to hardware state information.
285 * If zero, the user is probably doing a longjmp.
286 */
287 if ((rf = scp->sc_ap) == 0)
288 goto restore;
289
290 /*
291 * See if there is anything to do before we go to the
292 * expense of copying in close to 1/2K of data
293 */
294 error = ufetch_int((void *)rf, (u_int *)&flags);
295 #ifdef DEBUG
296 if (sigdebug & SDB_FOLLOW)
297 printf("sigreturn(%d): sc_ap %x flags %x\n",
298 p->p_pid, rf, error ? -1 : flags);
299 #endif
300 /* ufetch_int() failed (bogus sc_ap value). */
301 if (error)
302 return EINVAL;
303
304 if (flags == 0 || copyin((void *)rf, &tstate, sizeof(tstate)) != 0)
305 goto restore;
306 #ifdef DEBUG
307 if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
308 printf("sigreturn(%d): ssp %p usp %x scp %p ft %d\n",
309 p->p_pid, &flags, scp->sc_sp, SCARG(uap, sigcntxp),
310 (flags & SS_RTEFRAME) ? tstate.ss_frame.f_format : -1);
311 #endif
312 /*
313 * Restore long stack frames. Note that we do not copy
314 * back the saved SR or PC, they were picked up above from
315 * the sigcontext structure.
316 */
317 if (flags & SS_RTEFRAME) {
318 register int sz;
319
320 /* grab frame type and validate */
321 sz = tstate.ss_frame.f_format;
322 if (sz > 15 || (sz = exframesize[sz]) < 0
323 || frame->f_stackadj < sz)
324 return EINVAL;
325 frame->f_stackadj -= sz;
326 frame->f_format = tstate.ss_frame.f_format;
327 frame->f_vector = tstate.ss_frame.f_vector;
328 memcpy(&frame->F_u, &tstate.ss_frame.F_u, sz);
329 #ifdef DEBUG
330 if (sigdebug & SDB_FOLLOW)
331 printf("sigreturn(%d): copy in %d of frame type %d\n",
332 p->p_pid, sz, tstate.ss_frame.f_format);
333 #endif
334 }
335
336 /*
337 * Restore most of the users registers except for A6 and SP
338 * which will be handled below.
339 */
340 if (flags & SS_USERREGS)
341 memcpy(frame->f_regs, tstate.ss_frame.f_regs,
342 sizeof(frame->f_regs) - (2 * NBPW));
343
344 /*
345 * Restore the original FP context
346 */
347 if (fputype && (flags & SS_FPSTATE))
348 m68881_restore(&tstate.ss_fpstate);
349
350 restore:
351 /*
352 * Restore the user supplied information.
353 * This should be at the last so that the error (EINVAL)
354 * is reported to the sigreturn caller, not to the
355 * jump destination.
356 */
357
358 frame->f_regs[SP] = scp->sc_sp;
359 frame->f_regs[A6] = scp->sc_fp;
360 frame->f_pc = scp->sc_pc;
361 frame->f_sr = scp->sc_ps;
362
363 mutex_enter(p->p_lock);
364
365 /* Restore signal stack. */
366 if (scp->sc_onstack & SS_ONSTACK)
367 l->l_sigstk.ss_flags |= SS_ONSTACK;
368 else
369 l->l_sigstk.ss_flags &= ~SS_ONSTACK;
370
371 /* Restore signal mask. */
372 (void) sigprocmask1(l, SIG_SETMASK, &scp->sc_mask, 0);
373
374 mutex_exit(p->p_lock);
375
376 #ifdef DEBUG
377 if ((sigdebug & SDB_FPSTATE) && *(char *)&tstate.ss_fpstate)
378 printf("sigreturn(%d): copied in FP state (%x) at %p\n",
379 p->p_pid, *(u_int *)&tstate.ss_fpstate,
380 &tstate.ss_fpstate);
381 if ((sigdebug & SDB_FOLLOW) ||
382 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid))
383 printf("sigreturn(%d): returns\n", p->p_pid);
384 #endif
385 return EJUSTRETURN;
386 }
387 #endif
388