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Merge tag 'xtensa-next-20140721' of git://github.com/czankel/xtensa-linux
[deliverable/linux.git] / arch / sparc / kernel / signal_64.c
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 <asm/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 flush_user_windows();
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 struct rt_signal_frame {
238 struct sparc_stackf ss;
239 siginfo_t info;
240 struct pt_regs regs;
241 __siginfo_fpu_t __user *fpu_save;
242 stack_t stack;
243 sigset_t mask;
244 __siginfo_rwin_t *rwin_save;
245 };
246
247 void do_rt_sigreturn(struct pt_regs *regs)
248 {
249 struct rt_signal_frame __user *sf;
250 unsigned long tpc, tnpc, tstate;
251 __siginfo_fpu_t __user *fpu_save;
252 __siginfo_rwin_t __user *rwin_save;
253 sigset_t set;
254 int err;
255
256 /* Always make any pending restarted system calls return -EINTR */
257 current_thread_info()->restart_block.fn = do_no_restart_syscall;
258
259 synchronize_user_stack ();
260 sf = (struct rt_signal_frame __user *)
261 (regs->u_regs [UREG_FP] + STACK_BIAS);
262
263 /* 1. Make sure we are not getting garbage from the user */
264 if (((unsigned long) sf) & 3)
265 goto segv;
266
267 err = get_user(tpc, &sf->regs.tpc);
268 err |= __get_user(tnpc, &sf->regs.tnpc);
269 if (test_thread_flag(TIF_32BIT)) {
270 tpc &= 0xffffffff;
271 tnpc &= 0xffffffff;
272 }
273 err |= ((tpc | tnpc) & 3);
274
275 /* 2. Restore the state */
276 err |= __get_user(regs->y, &sf->regs.y);
277 err |= __get_user(tstate, &sf->regs.tstate);
278 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
279
280 /* User can only change condition codes and %asi in %tstate. */
281 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
282 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
283
284 err |= __get_user(fpu_save, &sf->fpu_save);
285 if (!err && fpu_save)
286 err |= restore_fpu_state(regs, fpu_save);
287
288 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
289 err |= restore_altstack(&sf->stack);
290 if (err)
291 goto segv;
292
293 err |= __get_user(rwin_save, &sf->rwin_save);
294 if (!err && rwin_save) {
295 if (restore_rwin_state(rwin_save))
296 goto segv;
297 }
298
299 regs->tpc = tpc;
300 regs->tnpc = tnpc;
301
302 /* Prevent syscall restart. */
303 pt_regs_clear_syscall(regs);
304
305 set_current_blocked(&set);
306 return;
307 segv:
308 force_sig(SIGSEGV, current);
309 }
310
311 /* Checks if the fp is valid */
312 static int invalid_frame_pointer(void __user *fp)
313 {
314 if (((unsigned long) fp) & 15)
315 return 1;
316 return 0;
317 }
318
319 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
320 {
321 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
322
323 /*
324 * If we are on the alternate signal stack and would overflow it, don't.
325 * Return an always-bogus address instead so we will die with SIGSEGV.
326 */
327 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
328 return (void __user *) -1L;
329
330 /* This is the X/Open sanctioned signal stack switching. */
331 sp = sigsp(sp, ksig) - framesize;
332
333 /* Always align the stack frame. This handles two cases. First,
334 * sigaltstack need not be mindful of platform specific stack
335 * alignment. Second, if we took this signal because the stack
336 * is not aligned properly, we'd like to take the signal cleanly
337 * and report that.
338 */
339 sp &= ~15UL;
340
341 return (void __user *) sp;
342 }
343
344 static inline int
345 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
346 {
347 struct rt_signal_frame __user *sf;
348 int wsaved, err, sf_size;
349 void __user *tail;
350
351 /* 1. Make sure everything is clean */
352 synchronize_user_stack();
353 save_and_clear_fpu();
354
355 wsaved = get_thread_wsaved();
356
357 sf_size = sizeof(struct rt_signal_frame);
358 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
359 sf_size += sizeof(__siginfo_fpu_t);
360 if (wsaved)
361 sf_size += sizeof(__siginfo_rwin_t);
362 sf = (struct rt_signal_frame __user *)
363 get_sigframe(ksig, regs, sf_size);
364
365 if (invalid_frame_pointer (sf)) {
366 do_exit(SIGILL); /* won't return, actually */
367 return -EINVAL;
368 }
369
370 tail = (sf + 1);
371
372 /* 2. Save the current process state */
373 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
374
375 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
376 __siginfo_fpu_t __user *fpu_save = tail;
377 tail += sizeof(__siginfo_fpu_t);
378 err |= save_fpu_state(regs, fpu_save);
379 err |= __put_user((u64)fpu_save, &sf->fpu_save);
380 } else {
381 err |= __put_user(0, &sf->fpu_save);
382 }
383 if (wsaved) {
384 __siginfo_rwin_t __user *rwin_save = tail;
385 tail += sizeof(__siginfo_rwin_t);
386 err |= save_rwin_state(wsaved, rwin_save);
387 err |= __put_user((u64)rwin_save, &sf->rwin_save);
388 set_thread_wsaved(0);
389 } else {
390 err |= __put_user(0, &sf->rwin_save);
391 }
392
393 /* Setup sigaltstack */
394 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
395
396 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
397
398 if (!wsaved) {
399 err |= copy_in_user((u64 __user *)sf,
400 (u64 __user *)(regs->u_regs[UREG_FP] +
401 STACK_BIAS),
402 sizeof(struct reg_window));
403 } else {
404 struct reg_window *rp;
405
406 rp = &current_thread_info()->reg_window[wsaved - 1];
407 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
408 }
409 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
410 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
411 else {
412 err |= __put_user(ksig->sig, &sf->info.si_signo);
413 err |= __put_user(SI_NOINFO, &sf->info.si_code);
414 }
415 if (err)
416 return err;
417
418 /* 3. signal handler back-trampoline and parameters */
419 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
420 regs->u_regs[UREG_I0] = ksig->sig;
421 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
422
423 /* The sigcontext is passed in this way because of how it
424 * is defined in GLIBC's /usr/include/bits/sigcontext.h
425 * for sparc64. It includes the 128 bytes of siginfo_t.
426 */
427 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
428
429 /* 5. signal handler */
430 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
431 regs->tnpc = (regs->tpc + 4);
432 if (test_thread_flag(TIF_32BIT)) {
433 regs->tpc &= 0xffffffff;
434 regs->tnpc &= 0xffffffff;
435 }
436 /* 4. return to kernel instructions */
437 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
438 return 0;
439 }
440
441 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
442 struct sigaction *sa)
443 {
444 switch (regs->u_regs[UREG_I0]) {
445 case ERESTART_RESTARTBLOCK:
446 case ERESTARTNOHAND:
447 no_system_call_restart:
448 regs->u_regs[UREG_I0] = EINTR;
449 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
450 break;
451 case ERESTARTSYS:
452 if (!(sa->sa_flags & SA_RESTART))
453 goto no_system_call_restart;
454 /* fallthrough */
455 case ERESTARTNOINTR:
456 regs->u_regs[UREG_I0] = orig_i0;
457 regs->tpc -= 4;
458 regs->tnpc -= 4;
459 }
460 }
461
462 /* Note that 'init' is a special process: it doesn't get signals it doesn't
463 * want to handle. Thus you cannot kill init even with a SIGKILL even by
464 * mistake.
465 */
466 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
467 {
468 struct ksignal ksig;
469 int restart_syscall;
470 bool has_handler;
471
472 /* It's a lot of work and synchronization to add a new ptrace
473 * register for GDB to save and restore in order to get
474 * orig_i0 correct for syscall restarts when debugging.
475 *
476 * Although it should be the case that most of the global
477 * registers are volatile across a system call, glibc already
478 * depends upon that fact that we preserve them. So we can't
479 * just use any global register to save away the orig_i0 value.
480 *
481 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
482 * preserved across a system call trap by various pieces of
483 * code in glibc.
484 *
485 * %g7 is used as the "thread register". %g6 is not used in
486 * any fixed manner. %g6 is used as a scratch register and
487 * a compiler temporary, but it's value is never used across
488 * a system call. Therefore %g6 is usable for orig_i0 storage.
489 */
490 if (pt_regs_is_syscall(regs) &&
491 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
492 regs->u_regs[UREG_G6] = orig_i0;
493
494 #ifdef CONFIG_COMPAT
495 if (test_thread_flag(TIF_32BIT)) {
496 do_signal32(regs);
497 return;
498 }
499 #endif
500
501 has_handler = get_signal(&ksig);
502
503 restart_syscall = 0;
504 if (pt_regs_is_syscall(regs) &&
505 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
506 restart_syscall = 1;
507 orig_i0 = regs->u_regs[UREG_G6];
508 }
509
510 if (has_handler) {
511 if (restart_syscall)
512 syscall_restart(orig_i0, regs, &ksig.ka.sa);
513 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
514 } else {
515 if (restart_syscall) {
516 switch (regs->u_regs[UREG_I0]) {
517 case ERESTARTNOHAND:
518 case ERESTARTSYS:
519 case ERESTARTNOINTR:
520 /* replay the system call when we are done */
521 regs->u_regs[UREG_I0] = orig_i0;
522 regs->tpc -= 4;
523 regs->tnpc -= 4;
524 pt_regs_clear_syscall(regs);
525 case ERESTART_RESTARTBLOCK:
526 regs->u_regs[UREG_G1] = __NR_restart_syscall;
527 regs->tpc -= 4;
528 regs->tnpc -= 4;
529 pt_regs_clear_syscall(regs);
530 }
531 }
532 restore_saved_sigmask();
533 }
534 }
535
536 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
537 {
538 user_exit();
539 if (thread_info_flags & _TIF_SIGPENDING)
540 do_signal(regs, orig_i0);
541 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
542 clear_thread_flag(TIF_NOTIFY_RESUME);
543 tracehook_notify_resume(regs);
544 }
545 user_enter();
546 }
547
Linux kernel - Deliverables
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