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Merge tag 'stable/for-linus-3.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kerne...
[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 "entry.h"
39 #include "systbls.h"
40 #include "sigutil.h"
41
42 /* {set, get}context() needed for 64-bit SparcLinux userland. */
43 asmlinkage void sparc64_set_context(struct pt_regs *regs)
44 {
45 struct ucontext __user *ucp = (struct ucontext __user *)
46 regs->u_regs[UREG_I0];
47 enum ctx_state prev_state = exception_enter();
48 mc_gregset_t __user *grp;
49 unsigned long pc, npc, tstate;
50 unsigned long fp, i7;
51 unsigned char fenab;
52 int err;
53
54 flush_user_windows();
55 if (get_thread_wsaved() ||
56 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
57 (!__access_ok(ucp, sizeof(*ucp))))
58 goto do_sigsegv;
59 grp = &ucp->uc_mcontext.mc_gregs;
60 err = __get_user(pc, &((*grp)[MC_PC]));
61 err |= __get_user(npc, &((*grp)[MC_NPC]));
62 if (err || ((pc | npc) & 3))
63 goto do_sigsegv;
64 if (regs->u_regs[UREG_I1]) {
65 sigset_t set;
66
67 if (_NSIG_WORDS == 1) {
68 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
69 goto do_sigsegv;
70 } else {
71 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
72 goto do_sigsegv;
73 }
74 set_current_blocked(&set);
75 }
76 if (test_thread_flag(TIF_32BIT)) {
77 pc &= 0xffffffff;
78 npc &= 0xffffffff;
79 }
80 regs->tpc = pc;
81 regs->tnpc = npc;
82 err |= __get_user(regs->y, &((*grp)[MC_Y]));
83 err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
84 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
85 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
86 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
87 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
88 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
89 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
90 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
91 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
92
93 /* Skip %g7 as that's the thread register in userspace. */
94
95 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
96 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
97 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
98 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
99 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
100 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
101 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
102 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
103
104 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
105 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
106 err |= __put_user(fp,
107 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
108 err |= __put_user(i7,
109 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
110
111 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
112 if (fenab) {
113 unsigned long *fpregs = current_thread_info()->fpregs;
114 unsigned long fprs;
115
116 fprs_write(0);
117 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
118 if (fprs & FPRS_DL)
119 err |= copy_from_user(fpregs,
120 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
121 (sizeof(unsigned int) * 32));
122 if (fprs & FPRS_DU)
123 err |= copy_from_user(fpregs+16,
124 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
125 (sizeof(unsigned int) * 32));
126 err |= __get_user(current_thread_info()->xfsr[0],
127 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
128 err |= __get_user(current_thread_info()->gsr[0],
129 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
130 regs->tstate &= ~TSTATE_PEF;
131 }
132 if (err)
133 goto do_sigsegv;
134 out:
135 exception_exit(prev_state);
136 return;
137 do_sigsegv:
138 force_sig(SIGSEGV, current);
139 goto out;
140 }
141
142 asmlinkage void sparc64_get_context(struct pt_regs *regs)
143 {
144 struct ucontext __user *ucp = (struct ucontext __user *)
145 regs->u_regs[UREG_I0];
146 enum ctx_state prev_state = exception_enter();
147 mc_gregset_t __user *grp;
148 mcontext_t __user *mcp;
149 unsigned long fp, i7;
150 unsigned char fenab;
151 int err;
152
153 synchronize_user_stack();
154 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
155 goto do_sigsegv;
156
157 #if 1
158 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
159 #else
160 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
161 #endif
162
163 mcp = &ucp->uc_mcontext;
164 grp = &mcp->mc_gregs;
165
166 /* Skip over the trap instruction, first. */
167 if (test_thread_flag(TIF_32BIT)) {
168 regs->tpc = (regs->tnpc & 0xffffffff);
169 regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
170 } else {
171 regs->tpc = regs->tnpc;
172 regs->tnpc += 4;
173 }
174 err = 0;
175 if (_NSIG_WORDS == 1)
176 err |= __put_user(current->blocked.sig[0],
177 (unsigned long __user *)&ucp->uc_sigmask);
178 else
179 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
180 sizeof(sigset_t));
181
182 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
183 err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
184 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
185 err |= __put_user(regs->y, &((*grp)[MC_Y]));
186 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
187 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
188 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
189 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
190 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
191 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
192 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
193 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
194 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
195 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
196 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
197 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
198 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
199 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
200 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
201
202 err |= __get_user(fp,
203 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
204 err |= __get_user(i7,
205 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
206 err |= __put_user(fp, &(mcp->mc_fp));
207 err |= __put_user(i7, &(mcp->mc_i7));
208
209 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
210 if (fenab) {
211 unsigned long *fpregs = current_thread_info()->fpregs;
212 unsigned long fprs;
213
214 fprs = current_thread_info()->fpsaved[0];
215 if (fprs & FPRS_DL)
216 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
217 (sizeof(unsigned int) * 32));
218 if (fprs & FPRS_DU)
219 err |= copy_to_user(
220 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
221 (sizeof(unsigned int) * 32));
222 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
223 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
224 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
225 }
226 if (err)
227 goto do_sigsegv;
228 out:
229 exception_exit(prev_state);
230 return;
231 do_sigsegv:
232 force_sig(SIGSEGV, current);
233 goto out;
234 }
235
236 struct rt_signal_frame {
237 struct sparc_stackf ss;
238 siginfo_t info;
239 struct pt_regs regs;
240 __siginfo_fpu_t __user *fpu_save;
241 stack_t stack;
242 sigset_t mask;
243 __siginfo_rwin_t *rwin_save;
244 };
245
246 void do_rt_sigreturn(struct pt_regs *regs)
247 {
248 struct rt_signal_frame __user *sf;
249 unsigned long tpc, tnpc, tstate;
250 __siginfo_fpu_t __user *fpu_save;
251 __siginfo_rwin_t __user *rwin_save;
252 sigset_t set;
253 int err;
254
255 /* Always make any pending restarted system calls return -EINTR */
256 current_thread_info()->restart_block.fn = do_no_restart_syscall;
257
258 synchronize_user_stack ();
259 sf = (struct rt_signal_frame __user *)
260 (regs->u_regs [UREG_FP] + STACK_BIAS);
261
262 /* 1. Make sure we are not getting garbage from the user */
263 if (((unsigned long) sf) & 3)
264 goto segv;
265
266 err = get_user(tpc, &sf->regs.tpc);
267 err |= __get_user(tnpc, &sf->regs.tnpc);
268 if (test_thread_flag(TIF_32BIT)) {
269 tpc &= 0xffffffff;
270 tnpc &= 0xffffffff;
271 }
272 err |= ((tpc | tnpc) & 3);
273
274 /* 2. Restore the state */
275 err |= __get_user(regs->y, &sf->regs.y);
276 err |= __get_user(tstate, &sf->regs.tstate);
277 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
278
279 /* User can only change condition codes and %asi in %tstate. */
280 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
281 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
282
283 err |= __get_user(fpu_save, &sf->fpu_save);
284 if (!err && fpu_save)
285 err |= restore_fpu_state(regs, fpu_save);
286
287 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
288 err |= restore_altstack(&sf->stack);
289 if (err)
290 goto segv;
291
292 err |= __get_user(rwin_save, &sf->rwin_save);
293 if (!err && rwin_save) {
294 if (restore_rwin_state(rwin_save))
295 goto segv;
296 }
297
298 regs->tpc = tpc;
299 regs->tnpc = tnpc;
300
301 /* Prevent syscall restart. */
302 pt_regs_clear_syscall(regs);
303
304 set_current_blocked(&set);
305 return;
306 segv:
307 force_sig(SIGSEGV, current);
308 }
309
310 /* Checks if the fp is valid */
311 static int invalid_frame_pointer(void __user *fp)
312 {
313 if (((unsigned long) fp) & 15)
314 return 1;
315 return 0;
316 }
317
318 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
319 {
320 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
321
322 /*
323 * If we are on the alternate signal stack and would overflow it, don't.
324 * Return an always-bogus address instead so we will die with SIGSEGV.
325 */
326 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
327 return (void __user *) -1L;
328
329 /* This is the X/Open sanctioned signal stack switching. */
330 sp = sigsp(sp, ksig) - framesize;
331
332 /* Always align the stack frame. This handles two cases. First,
333 * sigaltstack need not be mindful of platform specific stack
334 * alignment. Second, if we took this signal because the stack
335 * is not aligned properly, we'd like to take the signal cleanly
336 * and report that.
337 */
338 sp &= ~15UL;
339
340 return (void __user *) sp;
341 }
342
343 static inline int
344 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
345 {
346 struct rt_signal_frame __user *sf;
347 int wsaved, err, sf_size;
348 void __user *tail;
349
350 /* 1. Make sure everything is clean */
351 synchronize_user_stack();
352 save_and_clear_fpu();
353
354 wsaved = get_thread_wsaved();
355
356 sf_size = sizeof(struct rt_signal_frame);
357 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
358 sf_size += sizeof(__siginfo_fpu_t);
359 if (wsaved)
360 sf_size += sizeof(__siginfo_rwin_t);
361 sf = (struct rt_signal_frame __user *)
362 get_sigframe(ksig, regs, sf_size);
363
364 if (invalid_frame_pointer (sf)) {
365 do_exit(SIGILL); /* won't return, actually */
366 return -EINVAL;
367 }
368
369 tail = (sf + 1);
370
371 /* 2. Save the current process state */
372 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
373
374 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
375 __siginfo_fpu_t __user *fpu_save = tail;
376 tail += sizeof(__siginfo_fpu_t);
377 err |= save_fpu_state(regs, fpu_save);
378 err |= __put_user((u64)fpu_save, &sf->fpu_save);
379 } else {
380 err |= __put_user(0, &sf->fpu_save);
381 }
382 if (wsaved) {
383 __siginfo_rwin_t __user *rwin_save = tail;
384 tail += sizeof(__siginfo_rwin_t);
385 err |= save_rwin_state(wsaved, rwin_save);
386 err |= __put_user((u64)rwin_save, &sf->rwin_save);
387 set_thread_wsaved(0);
388 } else {
389 err |= __put_user(0, &sf->rwin_save);
390 }
391
392 /* Setup sigaltstack */
393 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
394
395 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
396
397 if (!wsaved) {
398 err |= copy_in_user((u64 __user *)sf,
399 (u64 __user *)(regs->u_regs[UREG_FP] +
400 STACK_BIAS),
401 sizeof(struct reg_window));
402 } else {
403 struct reg_window *rp;
404
405 rp = &current_thread_info()->reg_window[wsaved - 1];
406 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
407 }
408 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
409 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
410 else {
411 err |= __put_user(ksig->sig, &sf->info.si_signo);
412 err |= __put_user(SI_NOINFO, &sf->info.si_code);
413 }
414 if (err)
415 return err;
416
417 /* 3. signal handler back-trampoline and parameters */
418 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
419 regs->u_regs[UREG_I0] = ksig->sig;
420 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
421
422 /* The sigcontext is passed in this way because of how it
423 * is defined in GLIBC's /usr/include/bits/sigcontext.h
424 * for sparc64. It includes the 128 bytes of siginfo_t.
425 */
426 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
427
428 /* 5. signal handler */
429 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
430 regs->tnpc = (regs->tpc + 4);
431 if (test_thread_flag(TIF_32BIT)) {
432 regs->tpc &= 0xffffffff;
433 regs->tnpc &= 0xffffffff;
434 }
435 /* 4. return to kernel instructions */
436 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
437 return 0;
438 }
439
440 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
441 struct sigaction *sa)
442 {
443 switch (regs->u_regs[UREG_I0]) {
444 case ERESTART_RESTARTBLOCK:
445 case ERESTARTNOHAND:
446 no_system_call_restart:
447 regs->u_regs[UREG_I0] = EINTR;
448 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
449 break;
450 case ERESTARTSYS:
451 if (!(sa->sa_flags & SA_RESTART))
452 goto no_system_call_restart;
453 /* fallthrough */
454 case ERESTARTNOINTR:
455 regs->u_regs[UREG_I0] = orig_i0;
456 regs->tpc -= 4;
457 regs->tnpc -= 4;
458 }
459 }
460
461 /* Note that 'init' is a special process: it doesn't get signals it doesn't
462 * want to handle. Thus you cannot kill init even with a SIGKILL even by
463 * mistake.
464 */
465 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
466 {
467 struct ksignal ksig;
468 int restart_syscall;
469 bool has_handler;
470
471 /* It's a lot of work and synchronization to add a new ptrace
472 * register for GDB to save and restore in order to get
473 * orig_i0 correct for syscall restarts when debugging.
474 *
475 * Although it should be the case that most of the global
476 * registers are volatile across a system call, glibc already
477 * depends upon that fact that we preserve them. So we can't
478 * just use any global register to save away the orig_i0 value.
479 *
480 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
481 * preserved across a system call trap by various pieces of
482 * code in glibc.
483 *
484 * %g7 is used as the "thread register". %g6 is not used in
485 * any fixed manner. %g6 is used as a scratch register and
486 * a compiler temporary, but it's value is never used across
487 * a system call. Therefore %g6 is usable for orig_i0 storage.
488 */
489 if (pt_regs_is_syscall(regs) &&
490 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
491 regs->u_regs[UREG_G6] = orig_i0;
492
493 #ifdef CONFIG_COMPAT
494 if (test_thread_flag(TIF_32BIT)) {
495 extern void do_signal32(struct pt_regs *);
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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