1 /*
2  *  linux/arch/m68k/kernel/signal.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive
8  * for more details.
9  */
10 
11 /*
12  * Linux/m68k support by Hamish Macdonald
13  *
14  * 68060 fixes by Jesper Skov
15  *
16  * 1997-12-01  Modified for POSIX.1b signals by Andreas Schwab
17  *
18  * mathemu support by Roman Zippel
19  *  (Note: fpstate in the signal context is completely ignored for the emulator
20  *         and the internal floating point format is put on stack)
21  */
22 
23 /*
24  * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
25  * Atari :-) Current limitation: Only one sigstack can be active at one time.
26  * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
27  * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
28  * signal handlers!
29  */
30 
31 #include <linux/sched.h>
32 #include <linux/mm.h>
33 #include <linux/kernel.h>
34 #include <linux/signal.h>
35 #include <linux/syscalls.h>
36 #include <linux/errno.h>
37 #include <linux/wait.h>
38 #include <linux/ptrace.h>
39 #include <linux/unistd.h>
40 #include <linux/stddef.h>
41 #include <linux/highuid.h>
42 #include <linux/personality.h>
43 #include <linux/tty.h>
44 #include <linux/binfmts.h>
45 #include <linux/module.h>
46 
47 #include <asm/setup.h>
48 #include <asm/uaccess.h>
49 #include <asm/pgtable.h>
50 #include <asm/traps.h>
51 #include <asm/ucontext.h>
52 
53 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
54 
55 static const int frame_extra_sizes[16] = {
56   [1]	= -1, /* sizeof(((struct frame *)0)->un.fmt1), */
57   [2]	= sizeof(((struct frame *)0)->un.fmt2),
58   [3]	= sizeof(((struct frame *)0)->un.fmt3),
59   [4]	= sizeof(((struct frame *)0)->un.fmt4),
60   [5]	= -1, /* sizeof(((struct frame *)0)->un.fmt5), */
61   [6]	= -1, /* sizeof(((struct frame *)0)->un.fmt6), */
62   [7]	= sizeof(((struct frame *)0)->un.fmt7),
63   [8]	= -1, /* sizeof(((struct frame *)0)->un.fmt8), */
64   [9]	= sizeof(((struct frame *)0)->un.fmt9),
65   [10]	= sizeof(((struct frame *)0)->un.fmta),
66   [11]	= sizeof(((struct frame *)0)->un.fmtb),
67   [12]	= -1, /* sizeof(((struct frame *)0)->un.fmtc), */
68   [13]	= -1, /* sizeof(((struct frame *)0)->un.fmtd), */
69   [14]	= -1, /* sizeof(((struct frame *)0)->un.fmte), */
70   [15]	= -1, /* sizeof(((struct frame *)0)->un.fmtf), */
71 };
72 
handle_kernel_fault(struct pt_regs * regs)73 int handle_kernel_fault(struct pt_regs *regs)
74 {
75 	const struct exception_table_entry *fixup;
76 	struct pt_regs *tregs;
77 
78 	/* Are we prepared to handle this kernel fault? */
79 	fixup = search_exception_tables(regs->pc);
80 	if (!fixup)
81 		return 0;
82 
83 	/* Create a new four word stack frame, discarding the old one. */
84 	regs->stkadj = frame_extra_sizes[regs->format];
85 	tregs =	(struct pt_regs *)((long)regs + regs->stkadj);
86 	tregs->vector = regs->vector;
87 	tregs->format = 0;
88 	tregs->pc = fixup->fixup;
89 	tregs->sr = regs->sr;
90 
91 	return 1;
92 }
93 
94 /*
95  * Atomically swap in the new signal mask, and wait for a signal.
96  */
97 asmlinkage int
sys_sigsuspend(int unused0,int unused1,old_sigset_t mask)98 sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
99 {
100 	mask &= _BLOCKABLE;
101 	spin_lock_irq(&current->sighand->siglock);
102 	current->saved_sigmask = current->blocked;
103 	siginitset(&current->blocked, mask);
104 	recalc_sigpending();
105 	spin_unlock_irq(&current->sighand->siglock);
106 
107 	current->state = TASK_INTERRUPTIBLE;
108 	schedule();
109 	set_restore_sigmask();
110 
111 	return -ERESTARTNOHAND;
112 }
113 
114 asmlinkage int
sys_sigaction(int sig,const struct old_sigaction __user * act,struct old_sigaction __user * oact)115 sys_sigaction(int sig, const struct old_sigaction __user *act,
116 	      struct old_sigaction __user *oact)
117 {
118 	struct k_sigaction new_ka, old_ka;
119 	int ret;
120 
121 	if (act) {
122 		old_sigset_t mask;
123 		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
124 		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
125 		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
126 		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
127 		    __get_user(mask, &act->sa_mask))
128 			return -EFAULT;
129 		siginitset(&new_ka.sa.sa_mask, mask);
130 	}
131 
132 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
133 
134 	if (!ret && oact) {
135 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
136 		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
137 		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
138 		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
139 		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
140 			return -EFAULT;
141 	}
142 
143 	return ret;
144 }
145 
146 asmlinkage int
sys_sigaltstack(const stack_t __user * uss,stack_t __user * uoss)147 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
148 {
149 	return do_sigaltstack(uss, uoss, rdusp());
150 }
151 
152 
153 /*
154  * Do a signal return; undo the signal stack.
155  *
156  * Keep the return code on the stack quadword aligned!
157  * That makes the cache flush below easier.
158  */
159 
160 struct sigframe
161 {
162 	char __user *pretcode;
163 	int sig;
164 	int code;
165 	struct sigcontext __user *psc;
166 	char retcode[8];
167 	unsigned long extramask[_NSIG_WORDS-1];
168 	struct sigcontext sc;
169 };
170 
171 struct rt_sigframe
172 {
173 	char __user *pretcode;
174 	int sig;
175 	struct siginfo __user *pinfo;
176 	void __user *puc;
177 	char retcode[8];
178 	struct siginfo info;
179 	struct ucontext uc;
180 };
181 
182 
183 static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
184 
restore_fpu_state(struct sigcontext * sc)185 static inline int restore_fpu_state(struct sigcontext *sc)
186 {
187 	int err = 1;
188 
189 	if (FPU_IS_EMU) {
190 	    /* restore registers */
191 	    memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
192 	    memcpy(current->thread.fp, sc->sc_fpregs, 24);
193 	    return 0;
194 	}
195 
196 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
197 	    /* Verify the frame format.  */
198 	    if (!CPU_IS_060 && (sc->sc_fpstate[0] != fpu_version))
199 		goto out;
200 	    if (CPU_IS_020_OR_030) {
201 		if (m68k_fputype & FPU_68881 &&
202 		    !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
203 		    goto out;
204 		if (m68k_fputype & FPU_68882 &&
205 		    !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
206 		    goto out;
207 	    } else if (CPU_IS_040) {
208 		if (!(sc->sc_fpstate[1] == 0x00 ||
209                       sc->sc_fpstate[1] == 0x28 ||
210                       sc->sc_fpstate[1] == 0x60))
211 		    goto out;
212 	    } else if (CPU_IS_060) {
213 		if (!(sc->sc_fpstate[3] == 0x00 ||
214                       sc->sc_fpstate[3] == 0x60 ||
215 		      sc->sc_fpstate[3] == 0xe0))
216 		    goto out;
217 	    } else
218 		goto out;
219 
220 	    __asm__ volatile (".chip 68k/68881\n\t"
221 			      "fmovemx %0,%%fp0-%%fp1\n\t"
222 			      "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
223 			      ".chip 68k"
224 			      : /* no outputs */
225 			      : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl));
226 	}
227 	__asm__ volatile (".chip 68k/68881\n\t"
228 			  "frestore %0\n\t"
229 			  ".chip 68k" : : "m" (*sc->sc_fpstate));
230 	err = 0;
231 
232 out:
233 	return err;
234 }
235 
236 #define FPCONTEXT_SIZE	216
237 #define uc_fpstate	uc_filler[0]
238 #define uc_formatvec	uc_filler[FPCONTEXT_SIZE/4]
239 #define uc_extra	uc_filler[FPCONTEXT_SIZE/4+1]
240 
rt_restore_fpu_state(struct ucontext __user * uc)241 static inline int rt_restore_fpu_state(struct ucontext __user *uc)
242 {
243 	unsigned char fpstate[FPCONTEXT_SIZE];
244 	int context_size = CPU_IS_060 ? 8 : 0;
245 	fpregset_t fpregs;
246 	int err = 1;
247 
248 	if (FPU_IS_EMU) {
249 		/* restore fpu control register */
250 		if (__copy_from_user(current->thread.fpcntl,
251 				uc->uc_mcontext.fpregs.f_fpcntl, 12))
252 			goto out;
253 		/* restore all other fpu register */
254 		if (__copy_from_user(current->thread.fp,
255 				uc->uc_mcontext.fpregs.f_fpregs, 96))
256 			goto out;
257 		return 0;
258 	}
259 
260 	if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
261 		goto out;
262 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
263 		if (!CPU_IS_060)
264 			context_size = fpstate[1];
265 		/* Verify the frame format.  */
266 		if (!CPU_IS_060 && (fpstate[0] != fpu_version))
267 			goto out;
268 		if (CPU_IS_020_OR_030) {
269 			if (m68k_fputype & FPU_68881 &&
270 			    !(context_size == 0x18 || context_size == 0xb4))
271 				goto out;
272 			if (m68k_fputype & FPU_68882 &&
273 			    !(context_size == 0x38 || context_size == 0xd4))
274 				goto out;
275 		} else if (CPU_IS_040) {
276 			if (!(context_size == 0x00 ||
277 			      context_size == 0x28 ||
278 			      context_size == 0x60))
279 				goto out;
280 		} else if (CPU_IS_060) {
281 			if (!(fpstate[3] == 0x00 ||
282 			      fpstate[3] == 0x60 ||
283 			      fpstate[3] == 0xe0))
284 				goto out;
285 		} else
286 			goto out;
287 		if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
288 				     sizeof(fpregs)))
289 			goto out;
290 		__asm__ volatile (".chip 68k/68881\n\t"
291 				  "fmovemx %0,%%fp0-%%fp7\n\t"
292 				  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
293 				  ".chip 68k"
294 				  : /* no outputs */
295 				  : "m" (*fpregs.f_fpregs),
296 				    "m" (*fpregs.f_fpcntl));
297 	}
298 	if (context_size &&
299 	    __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
300 			     context_size))
301 		goto out;
302 	__asm__ volatile (".chip 68k/68881\n\t"
303 			  "frestore %0\n\t"
304 			  ".chip 68k" : : "m" (*fpstate));
305 	err = 0;
306 
307 out:
308 	return err;
309 }
310 
mangle_kernel_stack(struct pt_regs * regs,int formatvec,void __user * fp)311 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
312 			       void __user *fp)
313 {
314 	int fsize = frame_extra_sizes[formatvec >> 12];
315 	if (fsize < 0) {
316 		/*
317 		 * user process trying to return with weird frame format
318 		 */
319 #ifdef DEBUG
320 		printk("user process returning with weird frame format\n");
321 #endif
322 		return 1;
323 	}
324 	if (!fsize) {
325 		regs->format = formatvec >> 12;
326 		regs->vector = formatvec & 0xfff;
327 	} else {
328 		struct switch_stack *sw = (struct switch_stack *)regs - 1;
329 		unsigned long buf[fsize / 2]; /* yes, twice as much */
330 
331 		/* that'll make sure that expansion won't crap over data */
332 		if (copy_from_user(buf + fsize / 4, fp, fsize))
333 			return 1;
334 
335 		/* point of no return */
336 		regs->format = formatvec >> 12;
337 		regs->vector = formatvec & 0xfff;
338 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
339 		__asm__ __volatile__
340 			("   movel %0,%/a0\n\t"
341 			 "   subl %1,%/a0\n\t"     /* make room on stack */
342 			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
343 			 /* move switch_stack and pt_regs */
344 			 "1: movel %0@+,%/a0@+\n\t"
345 			 "   dbra %2,1b\n\t"
346 			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
347 			 "   lsrl  #2,%1\n\t"
348 			 "   subql #1,%1\n\t"
349 			 /* copy to the gap we'd made */
350 			 "2: movel %4@+,%/a0@+\n\t"
351 			 "   dbra %1,2b\n\t"
352 			 "   bral ret_from_signal\n"
353 			 : /* no outputs, it doesn't ever return */
354 			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
355 			   "n" (frame_offset), "a" (buf + fsize/4)
356 			 : "a0");
357 #undef frame_offset
358 	}
359 	return 0;
360 }
361 
362 static inline int
restore_sigcontext(struct pt_regs * regs,struct sigcontext __user * usc,void __user * fp)363 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
364 {
365 	int formatvec;
366 	struct sigcontext context;
367 	int err;
368 
369 	/* Always make any pending restarted system calls return -EINTR */
370 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
371 
372 	/* get previous context */
373 	if (copy_from_user(&context, usc, sizeof(context)))
374 		goto badframe;
375 
376 	/* restore passed registers */
377 	regs->d0 = context.sc_d0;
378 	regs->d1 = context.sc_d1;
379 	regs->a0 = context.sc_a0;
380 	regs->a1 = context.sc_a1;
381 	regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
382 	regs->pc = context.sc_pc;
383 	regs->orig_d0 = -1;		/* disable syscall checks */
384 	wrusp(context.sc_usp);
385 	formatvec = context.sc_formatvec;
386 
387 	err = restore_fpu_state(&context);
388 
389 	if (err || mangle_kernel_stack(regs, formatvec, fp))
390 		goto badframe;
391 
392 	return 0;
393 
394 badframe:
395 	return 1;
396 }
397 
398 static inline int
rt_restore_ucontext(struct pt_regs * regs,struct switch_stack * sw,struct ucontext __user * uc)399 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
400 		    struct ucontext __user *uc)
401 {
402 	int temp;
403 	greg_t __user *gregs = uc->uc_mcontext.gregs;
404 	unsigned long usp;
405 	int err;
406 
407 	/* Always make any pending restarted system calls return -EINTR */
408 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
409 
410 	err = __get_user(temp, &uc->uc_mcontext.version);
411 	if (temp != MCONTEXT_VERSION)
412 		goto badframe;
413 	/* restore passed registers */
414 	err |= __get_user(regs->d0, &gregs[0]);
415 	err |= __get_user(regs->d1, &gregs[1]);
416 	err |= __get_user(regs->d2, &gregs[2]);
417 	err |= __get_user(regs->d3, &gregs[3]);
418 	err |= __get_user(regs->d4, &gregs[4]);
419 	err |= __get_user(regs->d5, &gregs[5]);
420 	err |= __get_user(sw->d6, &gregs[6]);
421 	err |= __get_user(sw->d7, &gregs[7]);
422 	err |= __get_user(regs->a0, &gregs[8]);
423 	err |= __get_user(regs->a1, &gregs[9]);
424 	err |= __get_user(regs->a2, &gregs[10]);
425 	err |= __get_user(sw->a3, &gregs[11]);
426 	err |= __get_user(sw->a4, &gregs[12]);
427 	err |= __get_user(sw->a5, &gregs[13]);
428 	err |= __get_user(sw->a6, &gregs[14]);
429 	err |= __get_user(usp, &gregs[15]);
430 	wrusp(usp);
431 	err |= __get_user(regs->pc, &gregs[16]);
432 	err |= __get_user(temp, &gregs[17]);
433 	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
434 	regs->orig_d0 = -1;		/* disable syscall checks */
435 	err |= __get_user(temp, &uc->uc_formatvec);
436 
437 	err |= rt_restore_fpu_state(uc);
438 
439 	if (err || do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
440 		goto badframe;
441 
442 	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
443 		goto badframe;
444 
445 	return 0;
446 
447 badframe:
448 	return 1;
449 }
450 
do_sigreturn(unsigned long __unused)451 asmlinkage int do_sigreturn(unsigned long __unused)
452 {
453 	struct switch_stack *sw = (struct switch_stack *) &__unused;
454 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
455 	unsigned long usp = rdusp();
456 	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
457 	sigset_t set;
458 
459 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
460 		goto badframe;
461 	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
462 	    (_NSIG_WORDS > 1 &&
463 	     __copy_from_user(&set.sig[1], &frame->extramask,
464 			      sizeof(frame->extramask))))
465 		goto badframe;
466 
467 	sigdelsetmask(&set, ~_BLOCKABLE);
468 	current->blocked = set;
469 	recalc_sigpending();
470 
471 	if (restore_sigcontext(regs, &frame->sc, frame + 1))
472 		goto badframe;
473 	return regs->d0;
474 
475 badframe:
476 	force_sig(SIGSEGV, current);
477 	return 0;
478 }
479 
do_rt_sigreturn(unsigned long __unused)480 asmlinkage int do_rt_sigreturn(unsigned long __unused)
481 {
482 	struct switch_stack *sw = (struct switch_stack *) &__unused;
483 	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
484 	unsigned long usp = rdusp();
485 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
486 	sigset_t set;
487 
488 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
489 		goto badframe;
490 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
491 		goto badframe;
492 
493 	sigdelsetmask(&set, ~_BLOCKABLE);
494 	current->blocked = set;
495 	recalc_sigpending();
496 
497 	if (rt_restore_ucontext(regs, sw, &frame->uc))
498 		goto badframe;
499 	return regs->d0;
500 
501 badframe:
502 	force_sig(SIGSEGV, current);
503 	return 0;
504 }
505 
506 /*
507  * Set up a signal frame.
508  */
509 
save_fpu_state(struct sigcontext * sc,struct pt_regs * regs)510 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
511 {
512 	if (FPU_IS_EMU) {
513 		/* save registers */
514 		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
515 		memcpy(sc->sc_fpregs, current->thread.fp, 24);
516 		return;
517 	}
518 
519 	__asm__ volatile (".chip 68k/68881\n\t"
520 			  "fsave %0\n\t"
521 			  ".chip 68k"
522 			  : : "m" (*sc->sc_fpstate) : "memory");
523 
524 	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
525 		fpu_version = sc->sc_fpstate[0];
526 		if (CPU_IS_020_OR_030 &&
527 		    regs->vector >= (VEC_FPBRUC * 4) &&
528 		    regs->vector <= (VEC_FPNAN * 4)) {
529 			/* Clear pending exception in 68882 idle frame */
530 			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
531 				sc->sc_fpstate[0x38] |= 1 << 3;
532 		}
533 		__asm__ volatile (".chip 68k/68881\n\t"
534 				  "fmovemx %%fp0-%%fp1,%0\n\t"
535 				  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
536 				  ".chip 68k"
537 				  : "=m" (*sc->sc_fpregs),
538 				    "=m" (*sc->sc_fpcntl)
539 				  : /* no inputs */
540 				  : "memory");
541 	}
542 }
543 
rt_save_fpu_state(struct ucontext __user * uc,struct pt_regs * regs)544 static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
545 {
546 	unsigned char fpstate[FPCONTEXT_SIZE];
547 	int context_size = CPU_IS_060 ? 8 : 0;
548 	int err = 0;
549 
550 	if (FPU_IS_EMU) {
551 		/* save fpu control register */
552 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
553 				current->thread.fpcntl, 12);
554 		/* save all other fpu register */
555 		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
556 				current->thread.fp, 96);
557 		return err;
558 	}
559 
560 	__asm__ volatile (".chip 68k/68881\n\t"
561 			  "fsave %0\n\t"
562 			  ".chip 68k"
563 			  : : "m" (*fpstate) : "memory");
564 
565 	err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
566 	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
567 		fpregset_t fpregs;
568 		if (!CPU_IS_060)
569 			context_size = fpstate[1];
570 		fpu_version = fpstate[0];
571 		if (CPU_IS_020_OR_030 &&
572 		    regs->vector >= (VEC_FPBRUC * 4) &&
573 		    regs->vector <= (VEC_FPNAN * 4)) {
574 			/* Clear pending exception in 68882 idle frame */
575 			if (*(unsigned short *) fpstate == 0x1f38)
576 				fpstate[0x38] |= 1 << 3;
577 		}
578 		__asm__ volatile (".chip 68k/68881\n\t"
579 				  "fmovemx %%fp0-%%fp7,%0\n\t"
580 				  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
581 				  ".chip 68k"
582 				  : "=m" (*fpregs.f_fpregs),
583 				    "=m" (*fpregs.f_fpcntl)
584 				  : /* no inputs */
585 				  : "memory");
586 		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
587 				    sizeof(fpregs));
588 	}
589 	if (context_size)
590 		err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
591 				    context_size);
592 	return err;
593 }
594 
setup_sigcontext(struct sigcontext * sc,struct pt_regs * regs,unsigned long mask)595 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
596 			     unsigned long mask)
597 {
598 	sc->sc_mask = mask;
599 	sc->sc_usp = rdusp();
600 	sc->sc_d0 = regs->d0;
601 	sc->sc_d1 = regs->d1;
602 	sc->sc_a0 = regs->a0;
603 	sc->sc_a1 = regs->a1;
604 	sc->sc_sr = regs->sr;
605 	sc->sc_pc = regs->pc;
606 	sc->sc_formatvec = regs->format << 12 | regs->vector;
607 	save_fpu_state(sc, regs);
608 }
609 
rt_setup_ucontext(struct ucontext __user * uc,struct pt_regs * regs)610 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
611 {
612 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
613 	greg_t __user *gregs = uc->uc_mcontext.gregs;
614 	int err = 0;
615 
616 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
617 	err |= __put_user(regs->d0, &gregs[0]);
618 	err |= __put_user(regs->d1, &gregs[1]);
619 	err |= __put_user(regs->d2, &gregs[2]);
620 	err |= __put_user(regs->d3, &gregs[3]);
621 	err |= __put_user(regs->d4, &gregs[4]);
622 	err |= __put_user(regs->d5, &gregs[5]);
623 	err |= __put_user(sw->d6, &gregs[6]);
624 	err |= __put_user(sw->d7, &gregs[7]);
625 	err |= __put_user(regs->a0, &gregs[8]);
626 	err |= __put_user(regs->a1, &gregs[9]);
627 	err |= __put_user(regs->a2, &gregs[10]);
628 	err |= __put_user(sw->a3, &gregs[11]);
629 	err |= __put_user(sw->a4, &gregs[12]);
630 	err |= __put_user(sw->a5, &gregs[13]);
631 	err |= __put_user(sw->a6, &gregs[14]);
632 	err |= __put_user(rdusp(), &gregs[15]);
633 	err |= __put_user(regs->pc, &gregs[16]);
634 	err |= __put_user(regs->sr, &gregs[17]);
635 	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
636 	err |= rt_save_fpu_state(uc, regs);
637 	return err;
638 }
639 
push_cache(unsigned long vaddr)640 static inline void push_cache (unsigned long vaddr)
641 {
642 	/*
643 	 * Using the old cache_push_v() was really a big waste.
644 	 *
645 	 * What we are trying to do is to flush 8 bytes to ram.
646 	 * Flushing 2 cache lines of 16 bytes is much cheaper than
647 	 * flushing 1 or 2 pages, as previously done in
648 	 * cache_push_v().
649 	 *                                                     Jes
650 	 */
651 	if (CPU_IS_040) {
652 		unsigned long temp;
653 
654 		__asm__ __volatile__ (".chip 68040\n\t"
655 				      "nop\n\t"
656 				      "ptestr (%1)\n\t"
657 				      "movec %%mmusr,%0\n\t"
658 				      ".chip 68k"
659 				      : "=r" (temp)
660 				      : "a" (vaddr));
661 
662 		temp &= PAGE_MASK;
663 		temp |= vaddr & ~PAGE_MASK;
664 
665 		__asm__ __volatile__ (".chip 68040\n\t"
666 				      "nop\n\t"
667 				      "cpushl %%bc,(%0)\n\t"
668 				      ".chip 68k"
669 				      : : "a" (temp));
670 	}
671 	else if (CPU_IS_060) {
672 		unsigned long temp;
673 		__asm__ __volatile__ (".chip 68060\n\t"
674 				      "plpar (%0)\n\t"
675 				      ".chip 68k"
676 				      : "=a" (temp)
677 				      : "0" (vaddr));
678 		__asm__ __volatile__ (".chip 68060\n\t"
679 				      "cpushl %%bc,(%0)\n\t"
680 				      ".chip 68k"
681 				      : : "a" (temp));
682 	}
683 	else {
684 		/*
685 		 * 68030/68020 have no writeback cache;
686 		 * still need to clear icache.
687 		 * Note that vaddr is guaranteed to be long word aligned.
688 		 */
689 		unsigned long temp;
690 		asm volatile ("movec %%cacr,%0" : "=r" (temp));
691 		temp += 4;
692 		asm volatile ("movec %0,%%caar\n\t"
693 			      "movec %1,%%cacr"
694 			      : : "r" (vaddr), "r" (temp));
695 		asm volatile ("movec %0,%%caar\n\t"
696 			      "movec %1,%%cacr"
697 			      : : "r" (vaddr + 4), "r" (temp));
698 	}
699 }
700 
701 static inline void __user *
get_sigframe(struct k_sigaction * ka,struct pt_regs * regs,size_t frame_size)702 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
703 {
704 	unsigned long usp;
705 
706 	/* Default to using normal stack.  */
707 	usp = rdusp();
708 
709 	/* This is the X/Open sanctioned signal stack switching.  */
710 	if (ka->sa.sa_flags & SA_ONSTACK) {
711 		if (!sas_ss_flags(usp))
712 			usp = current->sas_ss_sp + current->sas_ss_size;
713 	}
714 	return (void __user *)((usp - frame_size) & -8UL);
715 }
716 
setup_frame(int sig,struct k_sigaction * ka,sigset_t * set,struct pt_regs * regs)717 static int setup_frame (int sig, struct k_sigaction *ka,
718 			 sigset_t *set, struct pt_regs *regs)
719 {
720 	struct sigframe __user *frame;
721 	int fsize = frame_extra_sizes[regs->format];
722 	struct sigcontext context;
723 	int err = 0;
724 
725 	if (fsize < 0) {
726 #ifdef DEBUG
727 		printk ("setup_frame: Unknown frame format %#x\n",
728 			regs->format);
729 #endif
730 		goto give_sigsegv;
731 	}
732 
733 	frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
734 
735 	if (fsize)
736 		err |= copy_to_user (frame + 1, regs + 1, fsize);
737 
738 	err |= __put_user((current_thread_info()->exec_domain
739 			   && current_thread_info()->exec_domain->signal_invmap
740 			   && sig < 32
741 			   ? current_thread_info()->exec_domain->signal_invmap[sig]
742 			   : sig),
743 			  &frame->sig);
744 
745 	err |= __put_user(regs->vector, &frame->code);
746 	err |= __put_user(&frame->sc, &frame->psc);
747 
748 	if (_NSIG_WORDS > 1)
749 		err |= copy_to_user(frame->extramask, &set->sig[1],
750 				    sizeof(frame->extramask));
751 
752 	setup_sigcontext(&context, regs, set->sig[0]);
753 	err |= copy_to_user (&frame->sc, &context, sizeof(context));
754 
755 	/* Set up to return from userspace.  */
756 	err |= __put_user(frame->retcode, &frame->pretcode);
757 	/* moveq #,d0; trap #0 */
758 	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
759 			  (long __user *)(frame->retcode));
760 
761 	if (err)
762 		goto give_sigsegv;
763 
764 	push_cache ((unsigned long) &frame->retcode);
765 
766 	/*
767 	 * Set up registers for signal handler.  All the state we are about
768 	 * to destroy is successfully copied to sigframe.
769 	 */
770 	wrusp ((unsigned long) frame);
771 	regs->pc = (unsigned long) ka->sa.sa_handler;
772 
773 	/*
774 	 * This is subtle; if we build more than one sigframe, all but the
775 	 * first one will see frame format 0 and have fsize == 0, so we won't
776 	 * screw stkadj.
777 	 */
778 	if (fsize)
779 		regs->stkadj = fsize;
780 
781 	/* Prepare to skip over the extra stuff in the exception frame.  */
782 	if (regs->stkadj) {
783 		struct pt_regs *tregs =
784 			(struct pt_regs *)((ulong)regs + regs->stkadj);
785 #ifdef DEBUG
786 		printk("Performing stackadjust=%04x\n", regs->stkadj);
787 #endif
788 		/* This must be copied with decreasing addresses to
789                    handle overlaps.  */
790 		tregs->vector = 0;
791 		tregs->format = 0;
792 		tregs->pc = regs->pc;
793 		tregs->sr = regs->sr;
794 	}
795 	return 0;
796 
797 give_sigsegv:
798 	force_sigsegv(sig, current);
799 	return err;
800 }
801 
setup_rt_frame(int sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * set,struct pt_regs * regs)802 static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
803 			    sigset_t *set, struct pt_regs *regs)
804 {
805 	struct rt_sigframe __user *frame;
806 	int fsize = frame_extra_sizes[regs->format];
807 	int err = 0;
808 
809 	if (fsize < 0) {
810 #ifdef DEBUG
811 		printk ("setup_frame: Unknown frame format %#x\n",
812 			regs->format);
813 #endif
814 		goto give_sigsegv;
815 	}
816 
817 	frame = get_sigframe(ka, regs, sizeof(*frame));
818 
819 	if (fsize)
820 		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
821 
822 	err |= __put_user((current_thread_info()->exec_domain
823 			   && current_thread_info()->exec_domain->signal_invmap
824 			   && sig < 32
825 			   ? current_thread_info()->exec_domain->signal_invmap[sig]
826 			   : sig),
827 			  &frame->sig);
828 	err |= __put_user(&frame->info, &frame->pinfo);
829 	err |= __put_user(&frame->uc, &frame->puc);
830 	err |= copy_siginfo_to_user(&frame->info, info);
831 
832 	/* Create the ucontext.  */
833 	err |= __put_user(0, &frame->uc.uc_flags);
834 	err |= __put_user(NULL, &frame->uc.uc_link);
835 	err |= __put_user((void __user *)current->sas_ss_sp,
836 			  &frame->uc.uc_stack.ss_sp);
837 	err |= __put_user(sas_ss_flags(rdusp()),
838 			  &frame->uc.uc_stack.ss_flags);
839 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
840 	err |= rt_setup_ucontext(&frame->uc, regs);
841 	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
842 
843 	/* Set up to return from userspace.  */
844 	err |= __put_user(frame->retcode, &frame->pretcode);
845 #ifdef __mcoldfire__
846 	/* movel #__NR_rt_sigreturn,d0; trap #0 */
847 	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
848 	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
849 			  (long __user *)(frame->retcode + 4));
850 #else
851 	/* moveq #,d0; notb d0; trap #0 */
852 	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
853 			  (long __user *)(frame->retcode + 0));
854 	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
855 #endif
856 
857 	if (err)
858 		goto give_sigsegv;
859 
860 	push_cache ((unsigned long) &frame->retcode);
861 
862 	/*
863 	 * Set up registers for signal handler.  All the state we are about
864 	 * to destroy is successfully copied to sigframe.
865 	 */
866 	wrusp ((unsigned long) frame);
867 	regs->pc = (unsigned long) ka->sa.sa_handler;
868 
869 	/*
870 	 * This is subtle; if we build more than one sigframe, all but the
871 	 * first one will see frame format 0 and have fsize == 0, so we won't
872 	 * screw stkadj.
873 	 */
874 	if (fsize)
875 		regs->stkadj = fsize;
876 
877 	/* Prepare to skip over the extra stuff in the exception frame.  */
878 	if (regs->stkadj) {
879 		struct pt_regs *tregs =
880 			(struct pt_regs *)((ulong)regs + regs->stkadj);
881 #ifdef DEBUG
882 		printk("Performing stackadjust=%04x\n", regs->stkadj);
883 #endif
884 		/* This must be copied with decreasing addresses to
885                    handle overlaps.  */
886 		tregs->vector = 0;
887 		tregs->format = 0;
888 		tregs->pc = regs->pc;
889 		tregs->sr = regs->sr;
890 	}
891 	return 0;
892 
893 give_sigsegv:
894 	force_sigsegv(sig, current);
895 	return err;
896 }
897 
898 static inline void
handle_restart(struct pt_regs * regs,struct k_sigaction * ka,int has_handler)899 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
900 {
901 	switch (regs->d0) {
902 	case -ERESTARTNOHAND:
903 		if (!has_handler)
904 			goto do_restart;
905 		regs->d0 = -EINTR;
906 		break;
907 
908 	case -ERESTART_RESTARTBLOCK:
909 		if (!has_handler) {
910 			regs->d0 = __NR_restart_syscall;
911 			regs->pc -= 2;
912 			break;
913 		}
914 		regs->d0 = -EINTR;
915 		break;
916 
917 	case -ERESTARTSYS:
918 		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
919 			regs->d0 = -EINTR;
920 			break;
921 		}
922 	/* fallthrough */
923 	case -ERESTARTNOINTR:
924 	do_restart:
925 		regs->d0 = regs->orig_d0;
926 		regs->pc -= 2;
927 		break;
928 	}
929 }
930 
ptrace_signal_deliver(struct pt_regs * regs,void * cookie)931 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
932 {
933 	if (regs->orig_d0 < 0)
934 		return;
935 	switch (regs->d0) {
936 	case -ERESTARTNOHAND:
937 	case -ERESTARTSYS:
938 	case -ERESTARTNOINTR:
939 		regs->d0 = regs->orig_d0;
940 		regs->orig_d0 = -1;
941 		regs->pc -= 2;
942 		break;
943 	}
944 }
945 
946 /*
947  * OK, we're invoking a handler
948  */
949 static void
handle_signal(int sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * oldset,struct pt_regs * regs)950 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
951 	      sigset_t *oldset, struct pt_regs *regs)
952 {
953 	int err;
954 	/* are we from a system call? */
955 	if (regs->orig_d0 >= 0)
956 		/* If so, check system call restarting.. */
957 		handle_restart(regs, ka, 1);
958 
959 	/* set up the stack frame */
960 	if (ka->sa.sa_flags & SA_SIGINFO)
961 		err = setup_rt_frame(sig, ka, info, oldset, regs);
962 	else
963 		err = setup_frame(sig, ka, oldset, regs);
964 
965 	if (err)
966 		return;
967 
968 	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
969 	if (!(ka->sa.sa_flags & SA_NODEFER))
970 		sigaddset(&current->blocked,sig);
971 	recalc_sigpending();
972 
973 	if (test_thread_flag(TIF_DELAYED_TRACE)) {
974 		regs->sr &= ~0x8000;
975 		send_sig(SIGTRAP, current, 1);
976 	}
977 
978 	clear_thread_flag(TIF_RESTORE_SIGMASK);
979 }
980 
981 /*
982  * Note that 'init' is a special process: it doesn't get signals it doesn't
983  * want to handle. Thus you cannot kill init even with a SIGKILL even by
984  * mistake.
985  */
do_signal(struct pt_regs * regs)986 asmlinkage void do_signal(struct pt_regs *regs)
987 {
988 	siginfo_t info;
989 	struct k_sigaction ka;
990 	int signr;
991 	sigset_t *oldset;
992 
993 	current->thread.esp0 = (unsigned long) regs;
994 
995 	if (test_thread_flag(TIF_RESTORE_SIGMASK))
996 		oldset = &current->saved_sigmask;
997 	else
998 		oldset = &current->blocked;
999 
1000 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1001 	if (signr > 0) {
1002 		/* Whee!  Actually deliver the signal.  */
1003 		handle_signal(signr, &ka, &info, oldset, regs);
1004 		return;
1005 	}
1006 
1007 	/* Did we come from a system call? */
1008 	if (regs->orig_d0 >= 0)
1009 		/* Restart the system call - no handlers present */
1010 		handle_restart(regs, NULL, 0);
1011 
1012 	/* If there's no signal to deliver, we just restore the saved mask.  */
1013 	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
1014 		clear_thread_flag(TIF_RESTORE_SIGMASK);
1015 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
1016 	}
1017 }
1018