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Linux 4.13.16
[linux/fpc-iii.git] / arch / sparc / kernel / signal_64.c
blob965d50e833e76dadc50b79ba24189a5884c7d9bc
1 /*
2 * arch/sparc64/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 */
10
11 #ifdef CONFIG_COMPAT
12 #include <linux/compat.h> /* for compat_old_sigset_t */
13 #endif
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/signal.h>
17 #include <linux/errno.h>
18 #include <linux/wait.h>
19 #include <linux/ptrace.h>
20 #include <linux/tracehook.h>
21 #include <linux/unistd.h>
22 #include <linux/mm.h>
23 #include <linux/tty.h>
24 #include <linux/binfmts.h>
25 #include <linux/bitops.h>
26 #include <linux/context_tracking.h>
27
28 #include <linux/uaccess.h>
29 #include <asm/ptrace.h>
30 #include <asm/pgtable.h>
31 #include <asm/fpumacro.h>
32 #include <asm/uctx.h>
33 #include <asm/siginfo.h>
34 #include <asm/visasm.h>
35 #include <asm/switch_to.h>
36 #include <asm/cacheflush.h>
37
38 #include "sigutil.h"
39 #include "systbls.h"
40 #include "kernel.h"
41 #include "entry.h"
42
43 /* {set, get}context() needed for 64-bit SparcLinux userland. */
44 asmlinkage void sparc64_set_context(struct pt_regs *regs)
45 {
46 struct ucontext __user *ucp = (struct ucontext __user *)
47 regs->u_regs[UREG_I0];
48 enum ctx_state prev_state = exception_enter();
49 mc_gregset_t __user *grp;
50 unsigned long pc, npc, tstate;
51 unsigned long fp, i7;
52 unsigned char fenab;
53 int err;
54
55 synchronize_user_stack();
56 if (get_thread_wsaved() ||
57 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
58 (!__access_ok(ucp, sizeof(*ucp))))
59 goto do_sigsegv;
60 grp = &ucp->uc_mcontext.mc_gregs;
61 err = __get_user(pc, &((*grp)[MC_PC]));
62 err |= __get_user(npc, &((*grp)[MC_NPC]));
63 if (err || ((pc | npc) & 3))
64 goto do_sigsegv;
65 if (regs->u_regs[UREG_I1]) {
66 sigset_t set;
67
68 if (_NSIG_WORDS == 1) {
69 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
70 goto do_sigsegv;
71 } else {
72 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
73 goto do_sigsegv;
74 }
75 set_current_blocked(&set);
76 }
77 if (test_thread_flag(TIF_32BIT)) {
78 pc &= 0xffffffff;
79 npc &= 0xffffffff;
80 }
81 regs->tpc = pc;
82 regs->tnpc = npc;
83 err |= __get_user(regs->y, &((*grp)[MC_Y]));
84 err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
85 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
86 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
87 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
88 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
89 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
90 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
91 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
92 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
93
94 /* Skip %g7 as that's the thread register in userspace. */
95
96 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
97 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
98 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
99 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
100 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
101 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
102 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
103 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
104
105 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
106 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
107 err |= __put_user(fp,
108 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
109 err |= __put_user(i7,
110 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
111
112 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
113 if (fenab) {
114 unsigned long *fpregs = current_thread_info()->fpregs;
115 unsigned long fprs;
116
117 fprs_write(0);
118 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
119 if (fprs & FPRS_DL)
120 err |= copy_from_user(fpregs,
121 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
122 (sizeof(unsigned int) * 32));
123 if (fprs & FPRS_DU)
124 err |= copy_from_user(fpregs+16,
125 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
126 (sizeof(unsigned int) * 32));
127 err |= __get_user(current_thread_info()->xfsr[0],
128 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
129 err |= __get_user(current_thread_info()->gsr[0],
130 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
131 regs->tstate &= ~TSTATE_PEF;
132 }
133 if (err)
134 goto do_sigsegv;
135 out:
136 exception_exit(prev_state);
137 return;
138 do_sigsegv:
139 force_sig(SIGSEGV, current);
140 goto out;
141 }
142
143 asmlinkage void sparc64_get_context(struct pt_regs *regs)
144 {
145 struct ucontext __user *ucp = (struct ucontext __user *)
146 regs->u_regs[UREG_I0];
147 enum ctx_state prev_state = exception_enter();
148 mc_gregset_t __user *grp;
149 mcontext_t __user *mcp;
150 unsigned long fp, i7;
151 unsigned char fenab;
152 int err;
153
154 synchronize_user_stack();
155 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
156 goto do_sigsegv;
157
158 #if 1
159 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
160 #else
161 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
162 #endif
163
164 mcp = &ucp->uc_mcontext;
165 grp = &mcp->mc_gregs;
166
167 /* Skip over the trap instruction, first. */
168 if (test_thread_flag(TIF_32BIT)) {
169 regs->tpc = (regs->tnpc & 0xffffffff);
170 regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
171 } else {
172 regs->tpc = regs->tnpc;
173 regs->tnpc += 4;
174 }
175 err = 0;
176 if (_NSIG_WORDS == 1)
177 err |= __put_user(current->blocked.sig[0],
178 (unsigned long __user *)&ucp->uc_sigmask);
179 else
180 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
181 sizeof(sigset_t));
182
183 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
184 err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
185 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
186 err |= __put_user(regs->y, &((*grp)[MC_Y]));
187 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
188 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
189 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
190 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
191 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
192 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
193 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
194 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
195 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
196 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
197 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
198 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
199 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
200 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
201 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
202
203 err |= __get_user(fp,
204 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
205 err |= __get_user(i7,
206 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
207 err |= __put_user(fp, &(mcp->mc_fp));
208 err |= __put_user(i7, &(mcp->mc_i7));
209
210 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
211 if (fenab) {
212 unsigned long *fpregs = current_thread_info()->fpregs;
213 unsigned long fprs;
214
215 fprs = current_thread_info()->fpsaved[0];
216 if (fprs & FPRS_DL)
217 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
218 (sizeof(unsigned int) * 32));
219 if (fprs & FPRS_DU)
220 err |= copy_to_user(
221 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
222 (sizeof(unsigned int) * 32));
223 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
224 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
225 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
226 }
227 if (err)
228 goto do_sigsegv;
229 out:
230 exception_exit(prev_state);
231 return;
232 do_sigsegv:
233 force_sig(SIGSEGV, current);
234 goto out;
235 }
236
237 /* Checks if the fp is valid. We always build rt signal frames which
238 * are 16-byte aligned, therefore we can always enforce that the
239 * restore frame has that property as well.
240 */
241 static bool invalid_frame_pointer(void __user *fp)
242 {
243 if (((unsigned long) fp) & 15)
244 return true;
245 return false;
246 }
247
248 struct rt_signal_frame {
249 struct sparc_stackf ss;
250 siginfo_t info;
251 struct pt_regs regs;
252 __siginfo_fpu_t __user *fpu_save;
253 stack_t stack;
254 sigset_t mask;
255 __siginfo_rwin_t *rwin_save;
256 };
257
258 void do_rt_sigreturn(struct pt_regs *regs)
259 {
260 unsigned long tpc, tnpc, tstate, ufp;
261 struct rt_signal_frame __user *sf;
262 __siginfo_fpu_t __user *fpu_save;
263 __siginfo_rwin_t __user *rwin_save;
264 sigset_t set;
265 int err;
266
267 /* Always make any pending restarted system calls return -EINTR */
268 current->restart_block.fn = do_no_restart_syscall;
269
270 synchronize_user_stack ();
271 sf = (struct rt_signal_frame __user *)
272 (regs->u_regs [UREG_FP] + STACK_BIAS);
273
274 /* 1. Make sure we are not getting garbage from the user */
275 if (invalid_frame_pointer(sf))
276 goto segv;
277
278 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
279 goto segv;
280
281 if ((ufp + STACK_BIAS) & 0x7)
282 goto segv;
283
284 err = __get_user(tpc, &sf->regs.tpc);
285 err |= __get_user(tnpc, &sf->regs.tnpc);
286 if (test_thread_flag(TIF_32BIT)) {
287 tpc &= 0xffffffff;
288 tnpc &= 0xffffffff;
289 }
290 err |= ((tpc | tnpc) & 3);
291
292 /* 2. Restore the state */
293 err |= __get_user(regs->y, &sf->regs.y);
294 err |= __get_user(tstate, &sf->regs.tstate);
295 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
296
297 /* User can only change condition codes and %asi in %tstate. */
298 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
299 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
300
301 err |= __get_user(fpu_save, &sf->fpu_save);
302 if (!err && fpu_save)
303 err |= restore_fpu_state(regs, fpu_save);
304
305 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
306 err |= restore_altstack(&sf->stack);
307 if (err)
308 goto segv;
309
310 err |= __get_user(rwin_save, &sf->rwin_save);
311 if (!err && rwin_save) {
312 if (restore_rwin_state(rwin_save))
313 goto segv;
314 }
315
316 regs->tpc = tpc;
317 regs->tnpc = tnpc;
318
319 /* Prevent syscall restart. */
320 pt_regs_clear_syscall(regs);
321
322 set_current_blocked(&set);
323 return;
324 segv:
325 force_sig(SIGSEGV, current);
326 }
327
328 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
329 {
330 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
331
332 /*
333 * If we are on the alternate signal stack and would overflow it, don't.
334 * Return an always-bogus address instead so we will die with SIGSEGV.
335 */
336 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
337 return (void __user *) -1L;
338
339 /* This is the X/Open sanctioned signal stack switching. */
340 sp = sigsp(sp, ksig) - framesize;
341
342 /* Always align the stack frame. This handles two cases. First,
343 * sigaltstack need not be mindful of platform specific stack
344 * alignment. Second, if we took this signal because the stack
345 * is not aligned properly, we'd like to take the signal cleanly
346 * and report that.
347 */
348 sp &= ~15UL;
349
350 return (void __user *) sp;
351 }
352
353 static inline int
354 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
355 {
356 struct rt_signal_frame __user *sf;
357 int wsaved, err, sf_size;
358 void __user *tail;
359
360 /* 1. Make sure everything is clean */
361 synchronize_user_stack();
362 save_and_clear_fpu();
363
364 wsaved = get_thread_wsaved();
365
366 sf_size = sizeof(struct rt_signal_frame);
367 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
368 sf_size += sizeof(__siginfo_fpu_t);
369 if (wsaved)
370 sf_size += sizeof(__siginfo_rwin_t);
371 sf = (struct rt_signal_frame __user *)
372 get_sigframe(ksig, regs, sf_size);
373
374 if (invalid_frame_pointer (sf)) {
375 do_exit(SIGILL); /* won't return, actually */
376 return -EINVAL;
377 }
378
379 tail = (sf + 1);
380
381 /* 2. Save the current process state */
382 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
383
384 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
385 __siginfo_fpu_t __user *fpu_save = tail;
386 tail += sizeof(__siginfo_fpu_t);
387 err |= save_fpu_state(regs, fpu_save);
388 err |= __put_user((u64)fpu_save, &sf->fpu_save);
389 } else {
390 err |= __put_user(0, &sf->fpu_save);
391 }
392 if (wsaved) {
393 __siginfo_rwin_t __user *rwin_save = tail;
394 tail += sizeof(__siginfo_rwin_t);
395 err |= save_rwin_state(wsaved, rwin_save);
396 err |= __put_user((u64)rwin_save, &sf->rwin_save);
397 set_thread_wsaved(0);
398 } else {
399 err |= __put_user(0, &sf->rwin_save);
400 }
401
402 /* Setup sigaltstack */
403 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
404
405 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
406
407 if (!wsaved) {
408 err |= copy_in_user((u64 __user *)sf,
409 (u64 __user *)(regs->u_regs[UREG_FP] +
410 STACK_BIAS),
411 sizeof(struct reg_window));
412 } else {
413 struct reg_window *rp;
414
415 rp = &current_thread_info()->reg_window[wsaved - 1];
416 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
417 }
418 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
419 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
420 else {
421 err |= __put_user(ksig->sig, &sf->info.si_signo);
422 err |= __put_user(SI_NOINFO, &sf->info.si_code);
423 }
424 if (err)
425 return err;
426
427 /* 3. signal handler back-trampoline and parameters */
428 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
429 regs->u_regs[UREG_I0] = ksig->sig;
430 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
431
432 /* The sigcontext is passed in this way because of how it
433 * is defined in GLIBC's /usr/include/bits/sigcontext.h
434 * for sparc64. It includes the 128 bytes of siginfo_t.
435 */
436 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
437
438 /* 5. signal handler */
439 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
440 regs->tnpc = (regs->tpc + 4);
441 if (test_thread_flag(TIF_32BIT)) {
442 regs->tpc &= 0xffffffff;
443 regs->tnpc &= 0xffffffff;
444 }
445 /* 4. return to kernel instructions */
446 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
447 return 0;
448 }
449
450 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
451 struct sigaction *sa)
452 {
453 switch (regs->u_regs[UREG_I0]) {
454 case ERESTART_RESTARTBLOCK:
455 case ERESTARTNOHAND:
456 no_system_call_restart:
457 regs->u_regs[UREG_I0] = EINTR;
458 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
459 break;
460 case ERESTARTSYS:
461 if (!(sa->sa_flags & SA_RESTART))
462 goto no_system_call_restart;
463 /* fallthrough */
464 case ERESTARTNOINTR:
465 regs->u_regs[UREG_I0] = orig_i0;
466 regs->tpc -= 4;
467 regs->tnpc -= 4;
468 }
469 }
470
471 /* Note that 'init' is a special process: it doesn't get signals it doesn't
472 * want to handle. Thus you cannot kill init even with a SIGKILL even by
473 * mistake.
474 */
475 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
476 {
477 struct ksignal ksig;
478 int restart_syscall;
479 bool has_handler;
480
481 /* It's a lot of work and synchronization to add a new ptrace
482 * register for GDB to save and restore in order to get
483 * orig_i0 correct for syscall restarts when debugging.
484 *
485 * Although it should be the case that most of the global
486 * registers are volatile across a system call, glibc already
487 * depends upon that fact that we preserve them. So we can't
488 * just use any global register to save away the orig_i0 value.
489 *
490 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
491 * preserved across a system call trap by various pieces of
492 * code in glibc.
493 *
494 * %g7 is used as the "thread register". %g6 is not used in
495 * any fixed manner. %g6 is used as a scratch register and
496 * a compiler temporary, but it's value is never used across
497 * a system call. Therefore %g6 is usable for orig_i0 storage.
498 */
499 if (pt_regs_is_syscall(regs) &&
500 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
501 regs->u_regs[UREG_G6] = orig_i0;
502
503 #ifdef CONFIG_COMPAT
504 if (test_thread_flag(TIF_32BIT)) {
505 do_signal32(regs);
506 return;
507 }
508 #endif
509
510 has_handler = get_signal(&ksig);
511
512 restart_syscall = 0;
513 if (pt_regs_is_syscall(regs) &&
514 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
515 restart_syscall = 1;
516 orig_i0 = regs->u_regs[UREG_G6];
517 }
518
519 if (has_handler) {
520 if (restart_syscall)
521 syscall_restart(orig_i0, regs, &ksig.ka.sa);
522 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
523 } else {
524 if (restart_syscall) {
525 switch (regs->u_regs[UREG_I0]) {
526 case ERESTARTNOHAND:
527 case ERESTARTSYS:
528 case ERESTARTNOINTR:
529 /* replay the system call when we are done */
530 regs->u_regs[UREG_I0] = orig_i0;
531 regs->tpc -= 4;
532 regs->tnpc -= 4;
533 pt_regs_clear_syscall(regs);
534 case ERESTART_RESTARTBLOCK:
535 regs->u_regs[UREG_G1] = __NR_restart_syscall;
536 regs->tpc -= 4;
537 regs->tnpc -= 4;
538 pt_regs_clear_syscall(regs);
539 }
540 }
541 restore_saved_sigmask();
542 }
543 }
544
545 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
546 {
547 user_exit();
548 if (thread_info_flags & _TIF_UPROBE)
549 uprobe_notify_resume(regs);
550 if (thread_info_flags & _TIF_SIGPENDING)
551 do_signal(regs, orig_i0);
552 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
553 clear_thread_flag(TIF_NOTIFY_RESUME);
554 tracehook_notify_resume(regs);
555 }
556 user_enter();
557 }
558
Linux with added FPC-III support