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signal_64.c
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1 /*
2  * arch/sparc64/kernel/signal.c
3  *
4  * Copyright (C) 1991, 1992 Linus Torvalds
5  * Copyright (C) 1995, 2008 David S. Miller ([email protected])
6  * Copyright (C) 1996 Miguel de Icaza ([email protected])
7  * Copyright (C) 1997 Eddie C. Dost ([email protected])
8  * Copyright (C) 1997,1998 Jakub Jelinek ([email protected])
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 
27 #include <asm/uaccess.h>
28 #include <asm/ptrace.h>
29 #include <asm/pgtable.h>
30 #include <asm/fpumacro.h>
31 #include <asm/uctx.h>
32 #include <asm/siginfo.h>
33 #include <asm/visasm.h>
34 #include <asm/switch_to.h>
35 #include <asm/cacheflush.h>
36 
37 #include "entry.h"
38 #include "systbls.h"
39 #include "sigutil.h"
40 
41 /* {set, get}context() needed for 64-bit SparcLinux userland. */
43 {
44  struct ucontext __user *ucp = (struct ucontext __user *)
45  regs->u_regs[UREG_I0];
46  mc_gregset_t __user *grp;
47  unsigned long pc, npc, tstate;
48  unsigned long fp, i7;
49  unsigned char fenab;
50  int err;
51 
53  if (get_thread_wsaved() ||
54  (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
55  (!__access_ok(ucp, sizeof(*ucp))))
56  goto do_sigsegv;
57  grp = &ucp->uc_mcontext.mc_gregs;
58  err = __get_user(pc, &((*grp)[MC_PC]));
59  err |= __get_user(npc, &((*grp)[MC_NPC]));
60  if (err || ((pc | npc) & 3))
61  goto do_sigsegv;
62  if (regs->u_regs[UREG_I1]) {
63  sigset_t set;
64 
65  if (_NSIG_WORDS == 1) {
66  if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
67  goto do_sigsegv;
68  } else {
69  if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
70  goto do_sigsegv;
71  }
72  set_current_blocked(&set);
73  }
74  if (test_thread_flag(TIF_32BIT)) {
75  pc &= 0xffffffff;
76  npc &= 0xffffffff;
77  }
78  regs->tpc = pc;
79  regs->tnpc = npc;
80  err |= __get_user(regs->y, &((*grp)[MC_Y]));
81  err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
82  regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
83  regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
84  err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
85  err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
86  err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
87  err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
88  err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
89  err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
90 
91  /* Skip %g7 as that's the thread register in userspace. */
92 
93  err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
94  err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
95  err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
96  err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
97  err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
98  err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
99  err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
100  err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
101 
102  err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
103  err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
104  err |= __put_user(fp,
105  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
106  err |= __put_user(i7,
107  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
108 
109  err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
110  if (fenab) {
111  unsigned long *fpregs = current_thread_info()->fpregs;
112  unsigned long fprs;
113 
114  fprs_write(0);
115  err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
116  if (fprs & FPRS_DL)
117  err |= copy_from_user(fpregs,
118  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
119  (sizeof(unsigned int) * 32));
120  if (fprs & FPRS_DU)
121  err |= copy_from_user(fpregs+16,
122  ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
123  (sizeof(unsigned int) * 32));
124  err |= __get_user(current_thread_info()->xfsr[0],
125  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
126  err |= __get_user(current_thread_info()->gsr[0],
127  &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
128  regs->tstate &= ~TSTATE_PEF;
129  }
130  if (err)
131  goto do_sigsegv;
132 
133  return;
134 do_sigsegv:
136 }
137 
139 {
140  struct ucontext __user *ucp = (struct ucontext __user *)
141  regs->u_regs[UREG_I0];
142  mc_gregset_t __user *grp;
143  mcontext_t __user *mcp;
144  unsigned long fp, i7;
145  unsigned char fenab;
146  int err;
147 
149  if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
150  goto do_sigsegv;
151 
152 #if 1
153  fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
154 #else
155  fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
156 #endif
157 
158  mcp = &ucp->uc_mcontext;
159  grp = &mcp->mc_gregs;
160 
161  /* Skip over the trap instruction, first. */
162  if (test_thread_flag(TIF_32BIT)) {
163  regs->tpc = (regs->tnpc & 0xffffffff);
164  regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
165  } else {
166  regs->tpc = regs->tnpc;
167  regs->tnpc += 4;
168  }
169  err = 0;
170  if (_NSIG_WORDS == 1)
171  err |= __put_user(current->blocked.sig[0],
172  (unsigned long __user *)&ucp->uc_sigmask);
173  else
174  err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
175  sizeof(sigset_t));
176 
177  err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
178  err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
179  err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
180  err |= __put_user(regs->y, &((*grp)[MC_Y]));
181  err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
182  err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
183  err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
184  err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
185  err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
186  err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
187  err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
188  err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
189  err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
190  err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
191  err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
192  err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
193  err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
194  err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
195  err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
196 
197  err |= __get_user(fp,
198  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
199  err |= __get_user(i7,
200  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
201  err |= __put_user(fp, &(mcp->mc_fp));
202  err |= __put_user(i7, &(mcp->mc_i7));
203 
204  err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
205  if (fenab) {
206  unsigned long *fpregs = current_thread_info()->fpregs;
207  unsigned long fprs;
208 
209  fprs = current_thread_info()->fpsaved[0];
210  if (fprs & FPRS_DL)
211  err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
212  (sizeof(unsigned int) * 32));
213  if (fprs & FPRS_DU)
214  err |= copy_to_user(
215  ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
216  (sizeof(unsigned int) * 32));
217  err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
218  err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
219  err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
220  }
221  if (err)
222  goto do_sigsegv;
223 
224  return;
225 do_sigsegv:
227 }
228 
229 struct rt_signal_frame {
230  struct sparc_stackf ss;
231  siginfo_t info;
232  struct pt_regs regs;
234  stack_t stack;
235  sigset_t mask;
237 };
238 
239 static long _sigpause_common(old_sigset_t set)
240 {
241  sigset_t blocked;
242  siginitset(&blocked, set);
243  return sigsuspend(&blocked);
244 }
245 
246 asmlinkage long sys_sigpause(unsigned int set)
247 {
248  return _sigpause_common(set);
249 }
250 
252 {
253  return _sigpause_common(set);
254 }
255 
257 {
258  struct rt_signal_frame __user *sf;
259  unsigned long tpc, tnpc, tstate;
260  __siginfo_fpu_t __user *fpu_save;
261  __siginfo_rwin_t __user *rwin_save;
262  sigset_t set;
263  int err;
264 
265  /* Always make any pending restarted system calls return -EINTR */
266  current_thread_info()->restart_block.fn = do_no_restart_syscall;
267 
269  sf = (struct rt_signal_frame __user *)
270  (regs->u_regs [UREG_FP] + STACK_BIAS);
271 
272  /* 1. Make sure we are not getting garbage from the user */
273  if (((unsigned long) sf) & 3)
274  goto segv;
275 
276  err = get_user(tpc, &sf->regs.tpc);
277  err |= __get_user(tnpc, &sf->regs.tnpc);
278  if (test_thread_flag(TIF_32BIT)) {
279  tpc &= 0xffffffff;
280  tnpc &= 0xffffffff;
281  }
282  err |= ((tpc | tnpc) & 3);
283 
284  /* 2. Restore the state */
285  err |= __get_user(regs->y, &sf->regs.y);
286  err |= __get_user(tstate, &sf->regs.tstate);
287  err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
288 
289  /* User can only change condition codes and %asi in %tstate. */
290  regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
291  regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
292 
293  err |= __get_user(fpu_save, &sf->fpu_save);
294  if (!err && fpu_save)
295  err |= restore_fpu_state(regs, fpu_save);
296 
297  err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
298  if (err || do_sigaltstack(&sf->stack, NULL, (unsigned long)sf) == -EFAULT)
299  goto segv;
300 
301  err |= __get_user(rwin_save, &sf->rwin_save);
302  if (!err && rwin_save) {
303  if (restore_rwin_state(rwin_save))
304  goto segv;
305  }
306 
307  regs->tpc = tpc;
308  regs->tnpc = tnpc;
309 
310  /* Prevent syscall restart. */
311  pt_regs_clear_syscall(regs);
312 
313  set_current_blocked(&set);
314  return;
315 segv:
317 }
318 
319 /* Checks if the fp is valid */
320 static int invalid_frame_pointer(void __user *fp)
321 {
322  if (((unsigned long) fp) & 15)
323  return 1;
324  return 0;
325 }
326 
327 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
328 {
329  unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
330 
331  /*
332  * If we are on the alternate signal stack and would overflow it, don't.
333  * Return an always-bogus address instead so we will die with SIGSEGV.
334  */
335  if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
336  return (void __user *) -1L;
337 
338  /* This is the X/Open sanctioned signal stack switching. */
339  if (ka->sa.sa_flags & SA_ONSTACK) {
340  if (sas_ss_flags(sp) == 0)
341  sp = current->sas_ss_sp + current->sas_ss_size;
342  }
343 
344  sp -= framesize;
345 
346  /* Always align the stack frame. This handles two cases. First,
347  * sigaltstack need not be mindful of platform specific stack
348  * alignment. Second, if we took this signal because the stack
349  * is not aligned properly, we'd like to take the signal cleanly
350  * and report that.
351  */
352  sp &= ~15UL;
353 
354  return (void __user *) sp;
355 }
356 
357 static inline int
358 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
359  int signo, sigset_t *oldset, siginfo_t *info)
360 {
361  struct rt_signal_frame __user *sf;
362  int wsaved, err, sf_size;
363  void __user *tail;
364 
365  /* 1. Make sure everything is clean */
367  save_and_clear_fpu();
368 
369  wsaved = get_thread_wsaved();
370 
371  sf_size = sizeof(struct rt_signal_frame);
372  if (current_thread_info()->fpsaved[0] & FPRS_FEF)
373  sf_size += sizeof(__siginfo_fpu_t);
374  if (wsaved)
375  sf_size += sizeof(__siginfo_rwin_t);
376  sf = (struct rt_signal_frame __user *)
377  get_sigframe(ka, regs, sf_size);
378 
379  if (invalid_frame_pointer (sf))
380  goto sigill;
381 
382  tail = (sf + 1);
383 
384  /* 2. Save the current process state */
385  err = copy_to_user(&sf->regs, regs, sizeof (*regs));
386 
387  if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
389  tail += sizeof(__siginfo_fpu_t);
390  err |= save_fpu_state(regs, fpu_save);
391  err |= __put_user((u64)fpu_save, &sf->fpu_save);
392  } else {
393  err |= __put_user(0, &sf->fpu_save);
394  }
395  if (wsaved) {
397  tail += sizeof(__siginfo_rwin_t);
398  err |= save_rwin_state(wsaved, rwin_save);
399  err |= __put_user((u64)rwin_save, &sf->rwin_save);
400  set_thread_wsaved(0);
401  } else {
402  err |= __put_user(0, &sf->rwin_save);
403  }
404 
405  /* Setup sigaltstack */
406  err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
407  err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
408  err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
409 
410  err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
411 
412  if (!wsaved) {
413  err |= copy_in_user((u64 __user *)sf,
414  (u64 __user *)(regs->u_regs[UREG_FP] +
415  STACK_BIAS),
416  sizeof(struct reg_window));
417  } else {
418  struct reg_window *rp;
419 
420  rp = &current_thread_info()->reg_window[wsaved - 1];
421  err |= copy_to_user(sf, rp, sizeof(struct reg_window));
422  }
423  if (info)
424  err |= copy_siginfo_to_user(&sf->info, info);
425  else {
426  err |= __put_user(signo, &sf->info.si_signo);
427  err |= __put_user(SI_NOINFO, &sf->info.si_code);
428  }
429  if (err)
430  goto sigsegv;
431 
432  /* 3. signal handler back-trampoline and parameters */
433  regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
434  regs->u_regs[UREG_I0] = signo;
435  regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
436 
437  /* The sigcontext is passed in this way because of how it
438  * is defined in GLIBC's /usr/include/bits/sigcontext.h
439  * for sparc64. It includes the 128 bytes of siginfo_t.
440  */
441  regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
442 
443  /* 5. signal handler */
444  regs->tpc = (unsigned long) ka->sa.sa_handler;
445  regs->tnpc = (regs->tpc + 4);
446  if (test_thread_flag(TIF_32BIT)) {
447  regs->tpc &= 0xffffffff;
448  regs->tnpc &= 0xffffffff;
449  }
450  /* 4. return to kernel instructions */
451  regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
452  return 0;
453 
454 sigill:
455  do_exit(SIGILL);
456  return -EINVAL;
457 
458 sigsegv:
459  force_sigsegv(signo, current);
460  return -EFAULT;
461 }
462 
463 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
464  siginfo_t *info,
465  sigset_t *oldset, struct pt_regs *regs)
466 {
467  int err;
468 
469  err = setup_rt_frame(ka, regs, signr, oldset,
470  (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
471  if (err)
472  return;
473 
474  signal_delivered(signr, info, ka, regs, 0);
475 }
476 
477 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
478  struct sigaction *sa)
479 {
480  switch (regs->u_regs[UREG_I0]) {
482  case ERESTARTNOHAND:
483  no_system_call_restart:
484  regs->u_regs[UREG_I0] = EINTR;
485  regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
486  break;
487  case ERESTARTSYS:
488  if (!(sa->sa_flags & SA_RESTART))
489  goto no_system_call_restart;
490  /* fallthrough */
491  case ERESTARTNOINTR:
492  regs->u_regs[UREG_I0] = orig_i0;
493  regs->tpc -= 4;
494  regs->tnpc -= 4;
495  }
496 }
497 
498 /* Note that 'init' is a special process: it doesn't get signals it doesn't
499  * want to handle. Thus you cannot kill init even with a SIGKILL even by
500  * mistake.
501  */
502 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
503 {
504  struct k_sigaction ka;
505  int restart_syscall;
506  sigset_t *oldset = sigmask_to_save();
507  siginfo_t info;
508  int signr;
509 
510  /* It's a lot of work and synchronization to add a new ptrace
511  * register for GDB to save and restore in order to get
512  * orig_i0 correct for syscall restarts when debugging.
513  *
514  * Although it should be the case that most of the global
515  * registers are volatile across a system call, glibc already
516  * depends upon that fact that we preserve them. So we can't
517  * just use any global register to save away the orig_i0 value.
518  *
519  * In particular %g2, %g3, %g4, and %g5 are all assumed to be
520  * preserved across a system call trap by various pieces of
521  * code in glibc.
522  *
523  * %g7 is used as the "thread register". %g6 is not used in
524  * any fixed manner. %g6 is used as a scratch register and
525  * a compiler temporary, but it's value is never used across
526  * a system call. Therefore %g6 is usable for orig_i0 storage.
527  */
528  if (pt_regs_is_syscall(regs) &&
529  (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
530  regs->u_regs[UREG_G6] = orig_i0;
531 
532 #ifdef CONFIG_COMPAT
533  if (test_thread_flag(TIF_32BIT)) {
534  extern void do_signal32(sigset_t *, struct pt_regs *);
535  do_signal32(oldset, regs);
536  return;
537  }
538 #endif
539 
540  signr = get_signal_to_deliver(&info, &ka, regs, NULL);
541 
542  restart_syscall = 0;
543  if (pt_regs_is_syscall(regs) &&
544  (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
545  restart_syscall = 1;
546  orig_i0 = regs->u_regs[UREG_G6];
547  }
548 
549  if (signr > 0) {
550  if (restart_syscall)
551  syscall_restart(orig_i0, regs, &ka.sa);
552  handle_signal(signr, &ka, &info, oldset, regs);
553  return;
554  }
555  if (restart_syscall &&
556  (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
557  regs->u_regs[UREG_I0] == ERESTARTSYS ||
558  regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
559  /* replay the system call when we are done */
560  regs->u_regs[UREG_I0] = orig_i0;
561  regs->tpc -= 4;
562  regs->tnpc -= 4;
563  pt_regs_clear_syscall(regs);
564  }
565  if (restart_syscall &&
568  regs->tpc -= 4;
569  regs->tnpc -= 4;
570  pt_regs_clear_syscall(regs);
571  }
572 
573  /* If there's no signal to deliver, we just put the saved sigmask
574  * back
575  */
576  restore_saved_sigmask();
577 }
578 
579 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
580 {
581  if (thread_info_flags & _TIF_SIGPENDING)
582  do_signal(regs, orig_i0);
583  if (thread_info_flags & _TIF_NOTIFY_RESUME) {
584  clear_thread_flag(TIF_NOTIFY_RESUME);
585  tracehook_notify_resume(regs);
586  }
587 }
588