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signal32.c
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1 /*
2  * Based on arch/arm/kernel/signal.c
3  *
4  * Copyright (C) 1995-2009 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  * Modified by Will Deacon <[email protected]>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program. If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <linux/compat.h>
22 #include <linux/signal.h>
23 #include <linux/syscalls.h>
24 #include <linux/ratelimit.h>
25 
26 #include <asm/fpsimd.h>
27 #include <asm/signal32.h>
28 #include <asm/uaccess.h>
29 #include <asm/unistd32.h>
30 
31 struct compat_sigaction {
32  compat_uptr_t sa_handler;
33  compat_ulong_t sa_flags;
34  compat_uptr_t sa_restorer;
35  compat_sigset_t sa_mask;
36 };
37 
38 struct compat_old_sigaction {
39  compat_uptr_t sa_handler;
40  compat_old_sigset_t sa_mask;
41  compat_ulong_t sa_flags;
42  compat_uptr_t sa_restorer;
43 };
44 
45 typedef struct compat_sigaltstack {
46  compat_uptr_t ss_sp;
47  int ss_flags;
48  compat_size_t ss_size;
49 } compat_stack_t;
50 
51 struct compat_sigcontext {
52  /* We always set these two fields to 0 */
53  compat_ulong_t trap_no;
54  compat_ulong_t error_code;
55 
56  compat_ulong_t oldmask;
57  compat_ulong_t arm_r0;
58  compat_ulong_t arm_r1;
59  compat_ulong_t arm_r2;
60  compat_ulong_t arm_r3;
61  compat_ulong_t arm_r4;
62  compat_ulong_t arm_r5;
63  compat_ulong_t arm_r6;
64  compat_ulong_t arm_r7;
65  compat_ulong_t arm_r8;
66  compat_ulong_t arm_r9;
67  compat_ulong_t arm_r10;
68  compat_ulong_t arm_fp;
69  compat_ulong_t arm_ip;
70  compat_ulong_t arm_sp;
71  compat_ulong_t arm_lr;
72  compat_ulong_t arm_pc;
73  compat_ulong_t arm_cpsr;
74  compat_ulong_t fault_address;
75 };
76 
77 struct compat_ucontext {
78  compat_ulong_t uc_flags;
79  struct compat_ucontext *uc_link;
80  compat_stack_t uc_stack;
81  struct compat_sigcontext uc_mcontext;
82  compat_sigset_t uc_sigmask;
83  int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
84  compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
85 };
86 
87 struct compat_vfp_sigframe {
88  compat_ulong_t magic;
89  compat_ulong_t size;
90  struct compat_user_vfp {
91  compat_u64 fpregs[32];
92  compat_ulong_t fpscr;
93  } ufp;
94  struct compat_user_vfp_exc {
95  compat_ulong_t fpexc;
96  compat_ulong_t fpinst;
97  compat_ulong_t fpinst2;
98  } ufp_exc;
99 } __attribute__((__aligned__(8)));
100 
101 #define VFP_MAGIC 0x56465001
102 #define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
103 
104 struct compat_aux_sigframe {
105  struct compat_vfp_sigframe vfp;
106 
107  /* Something that isn't a valid magic number for any coprocessor. */
108  unsigned long end_magic;
109 } __attribute__((__aligned__(8)));
110 
111 struct compat_sigframe {
112  struct compat_ucontext uc;
113  compat_ulong_t retcode[2];
114 };
115 
116 struct compat_rt_sigframe {
117  struct compat_siginfo info;
118  struct compat_sigframe sig;
119 };
120 
121 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
122 
123 /*
124  * For ARM syscalls, the syscall number has to be loaded into r7.
125  * We do not support an OABI userspace.
126  */
127 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | __NR_compat_sigreturn)
128 #define SVC_SYS_SIGRETURN (0xef000000 | __NR_compat_sigreturn)
129 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | __NR_compat_rt_sigreturn)
130 #define SVC_SYS_RT_SIGRETURN (0xef000000 | __NR_compat_rt_sigreturn)
131 
132 /*
133  * For Thumb syscalls, we also pass the syscall number via r7. We therefore
134  * need two 16-bit instructions.
135  */
136 #define SVC_THUMB_SIGRETURN (((0xdf00 | __NR_compat_sigreturn) << 16) | \
137  0x2700 | __NR_compat_sigreturn)
138 #define SVC_THUMB_RT_SIGRETURN (((0xdf00 | __NR_compat_rt_sigreturn) << 16) | \
139  0x2700 | __NR_compat_rt_sigreturn)
140 
141 const compat_ulong_t aarch32_sigret_code[6] = {
142  /*
143  * AArch32 sigreturn code.
144  * We don't construct an OABI SWI - instead we just set the imm24 field
145  * to the EABI syscall number so that we create a sane disassembly.
146  */
147  MOV_R7_NR_SIGRETURN, SVC_SYS_SIGRETURN, SVC_THUMB_SIGRETURN,
148  MOV_R7_NR_RT_SIGRETURN, SVC_SYS_RT_SIGRETURN, SVC_THUMB_RT_SIGRETURN,
149 };
150 
151 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
152 {
153  compat_sigset_t cset;
154 
155  cset.sig[0] = set->sig[0] & 0xffffffffull;
156  cset.sig[1] = set->sig[0] >> 32;
157 
158  return copy_to_user(uset, &cset, sizeof(*uset));
159 }
160 
161 static inline int get_sigset_t(sigset_t *set,
162  const compat_sigset_t __user *uset)
163 {
164  compat_sigset_t s32;
165 
166  if (copy_from_user(&s32, uset, sizeof(*uset)))
167  return -EFAULT;
168 
169  set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
170  return 0;
171 }
172 
173 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
174 {
175  int err;
176 
177  if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
178  return -EFAULT;
179 
180  /* If you change siginfo_t structure, please be sure
181  * this code is fixed accordingly.
182  * It should never copy any pad contained in the structure
183  * to avoid security leaks, but must copy the generic
184  * 3 ints plus the relevant union member.
185  * This routine must convert siginfo from 64bit to 32bit as well
186  * at the same time.
187  */
188  err = __put_user(from->si_signo, &to->si_signo);
189  err |= __put_user(from->si_errno, &to->si_errno);
190  err |= __put_user((short)from->si_code, &to->si_code);
191  if (from->si_code < 0)
192  err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
193  SI_PAD_SIZE);
194  else switch (from->si_code & __SI_MASK) {
195  case __SI_KILL:
196  err |= __put_user(from->si_pid, &to->si_pid);
197  err |= __put_user(from->si_uid, &to->si_uid);
198  break;
199  case __SI_TIMER:
200  err |= __put_user(from->si_tid, &to->si_tid);
201  err |= __put_user(from->si_overrun, &to->si_overrun);
202  err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
203  &to->si_ptr);
204  break;
205  case __SI_POLL:
206  err |= __put_user(from->si_band, &to->si_band);
207  err |= __put_user(from->si_fd, &to->si_fd);
208  break;
209  case __SI_FAULT:
210  err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
211  &to->si_addr);
212 #ifdef BUS_MCEERR_AO
213  /*
214  * Other callers might not initialize the si_lsb field,
215  * so check explicitely for the right codes here.
216  */
217  if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
218  err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
219 #endif
220  break;
221  case __SI_CHLD:
222  err |= __put_user(from->si_pid, &to->si_pid);
223  err |= __put_user(from->si_uid, &to->si_uid);
224  err |= __put_user(from->si_status, &to->si_status);
225  err |= __put_user(from->si_utime, &to->si_utime);
226  err |= __put_user(from->si_stime, &to->si_stime);
227  break;
228  case __SI_RT: /* This is not generated by the kernel as of now. */
229  case __SI_MESGQ: /* But this is */
230  err |= __put_user(from->si_pid, &to->si_pid);
231  err |= __put_user(from->si_uid, &to->si_uid);
232  err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
233  break;
234  default: /* this is just in case for now ... */
235  err |= __put_user(from->si_pid, &to->si_pid);
236  err |= __put_user(from->si_uid, &to->si_uid);
237  break;
238  }
239  return err;
240 }
241 
242 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
243 {
244  memset(to, 0, sizeof *to);
245 
246  if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
247  copy_from_user(to->_sifields._pad,
248  from->_sifields._pad, SI_PAD_SIZE))
249  return -EFAULT;
250 
251  return 0;
252 }
253 
254 /*
255  * VFP save/restore code.
256  */
257 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
258 {
259  struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
260  compat_ulong_t magic = VFP_MAGIC;
261  compat_ulong_t size = VFP_STORAGE_SIZE;
262  compat_ulong_t fpscr, fpexc;
263  int err = 0;
264 
265  /*
266  * Save the hardware registers to the fpsimd_state structure.
267  * Note that this also saves V16-31, which aren't visible
268  * in AArch32.
269  */
270  fpsimd_save_state(fpsimd);
271 
272  /* Place structure header on the stack */
273  __put_user_error(magic, &frame->magic, err);
274  __put_user_error(size, &frame->size, err);
275 
276  /*
277  * Now copy the FP registers. Since the registers are packed,
278  * we can copy the prefix we want (V0-V15) as it is.
279  * FIXME: Won't work if big endian.
280  */
281  err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
282  sizeof(frame->ufp.fpregs));
283 
284  /* Create an AArch32 fpscr from the fpsr and the fpcr. */
285  fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
286  (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
287  __put_user_error(fpscr, &frame->ufp.fpscr, err);
288 
289  /*
290  * The exception register aren't available so we fake up a
291  * basic FPEXC and zero everything else.
292  */
293  fpexc = (1 << 30);
294  __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
295  __put_user_error(0, &frame->ufp_exc.fpinst, err);
296  __put_user_error(0, &frame->ufp_exc.fpinst2, err);
297 
298  return err ? -EFAULT : 0;
299 }
300 
301 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
302 {
303  struct fpsimd_state fpsimd;
304  compat_ulong_t magic = VFP_MAGIC;
305  compat_ulong_t size = VFP_STORAGE_SIZE;
306  compat_ulong_t fpscr;
307  int err = 0;
308 
309  __get_user_error(magic, &frame->magic, err);
310  __get_user_error(size, &frame->size, err);
311 
312  if (err)
313  return -EFAULT;
314  if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
315  return -EINVAL;
316 
317  /*
318  * Copy the FP registers into the start of the fpsimd_state.
319  * FIXME: Won't work if big endian.
320  */
321  err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
322  sizeof(frame->ufp.fpregs));
323 
324  /* Extract the fpsr and the fpcr from the fpscr */
325  __get_user_error(fpscr, &frame->ufp.fpscr, err);
326  fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
327  fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
328 
329  /*
330  * We don't need to touch the exception register, so
331  * reload the hardware state.
332  */
333  if (!err) {
334  preempt_disable();
335  fpsimd_load_state(&fpsimd);
336  preempt_enable();
337  }
338 
339  return err ? -EFAULT : 0;
340 }
341 
342 /*
343  * atomically swap in the new signal mask, and wait for a signal.
344  */
345 asmlinkage int compat_sys_sigsuspend(int restart, compat_ulong_t oldmask,
346  compat_old_sigset_t mask)
347 {
348  sigset_t blocked;
349 
350  siginitset(&current->blocked, mask);
351  return sigsuspend(&blocked);
352 }
353 
354 asmlinkage int compat_sys_sigaction(int sig,
355  const struct compat_old_sigaction __user *act,
356  struct compat_old_sigaction __user *oact)
357 {
358  struct k_sigaction new_ka, old_ka;
359  int ret;
360  compat_old_sigset_t mask;
361  compat_uptr_t handler, restorer;
362 
363  if (act) {
364  if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
365  __get_user(handler, &act->sa_handler) ||
366  __get_user(restorer, &act->sa_restorer) ||
367  __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
368  __get_user(mask, &act->sa_mask))
369  return -EFAULT;
370 
371  new_ka.sa.sa_handler = compat_ptr(handler);
372  new_ka.sa.sa_restorer = compat_ptr(restorer);
373  siginitset(&new_ka.sa.sa_mask, mask);
374  }
375 
376  ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
377 
378  if (!ret && oact) {
379  if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
380  __put_user(ptr_to_compat(old_ka.sa.sa_handler),
381  &oact->sa_handler) ||
382  __put_user(ptr_to_compat(old_ka.sa.sa_restorer),
383  &oact->sa_restorer) ||
384  __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
385  __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
386  return -EFAULT;
387  }
388 
389  return ret;
390 }
391 
392 asmlinkage int compat_sys_rt_sigaction(int sig,
393  const struct compat_sigaction __user *act,
394  struct compat_sigaction __user *oact,
395  compat_size_t sigsetsize)
396 {
397  struct k_sigaction new_ka, old_ka;
398  int ret;
399 
400  /* XXX: Don't preclude handling different sized sigset_t's. */
401  if (sigsetsize != sizeof(compat_sigset_t))
402  return -EINVAL;
403 
404  if (act) {
405  compat_uptr_t handler, restorer;
406 
407  ret = get_user(handler, &act->sa_handler);
408  new_ka.sa.sa_handler = compat_ptr(handler);
409  ret |= get_user(restorer, &act->sa_restorer);
410  new_ka.sa.sa_restorer = compat_ptr(restorer);
411  ret |= get_sigset_t(&new_ka.sa.sa_mask, &act->sa_mask);
412  ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
413  if (ret)
414  return -EFAULT;
415  }
416 
417  ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
418  if (!ret && oact) {
419  ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), &oact->sa_handler);
420  ret |= put_sigset_t(&oact->sa_mask, &old_ka.sa.sa_mask);
421  ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
422  }
423  return ret;
424 }
425 
426 int compat_do_sigaltstack(compat_uptr_t compat_uss, compat_uptr_t compat_uoss,
427  compat_ulong_t sp)
428 {
429  compat_stack_t __user *newstack = compat_ptr(compat_uss);
430  compat_stack_t __user *oldstack = compat_ptr(compat_uoss);
431  compat_uptr_t ss_sp;
432  int ret;
433  mm_segment_t old_fs;
434  stack_t uss, uoss;
435 
436  /* Marshall the compat new stack into a stack_t */
437  if (newstack) {
438  if (get_user(ss_sp, &newstack->ss_sp) ||
439  __get_user(uss.ss_flags, &newstack->ss_flags) ||
440  __get_user(uss.ss_size, &newstack->ss_size))
441  return -EFAULT;
442  uss.ss_sp = compat_ptr(ss_sp);
443  }
444 
445  old_fs = get_fs();
446  set_fs(KERNEL_DS);
447  /* The __user pointer casts are valid because of the set_fs() */
448  ret = do_sigaltstack(
449  newstack ? (stack_t __user *) &uss : NULL,
450  oldstack ? (stack_t __user *) &uoss : NULL,
451  (unsigned long)sp);
452  set_fs(old_fs);
453 
454  /* Convert the old stack_t into a compat stack. */
455  if (!ret && oldstack &&
456  (put_user(ptr_to_compat(uoss.ss_sp), &oldstack->ss_sp) ||
457  __put_user(uoss.ss_flags, &oldstack->ss_flags) ||
458  __put_user(uoss.ss_size, &oldstack->ss_size)))
459  return -EFAULT;
460  return ret;
461 }
462 
463 static int compat_restore_sigframe(struct pt_regs *regs,
464  struct compat_sigframe __user *sf)
465 {
466  int err;
467  sigset_t set;
468  struct compat_aux_sigframe __user *aux;
469 
470  err = get_sigset_t(&set, &sf->uc.uc_sigmask);
471  if (err == 0) {
472  sigdelsetmask(&set, ~_BLOCKABLE);
473  set_current_blocked(&set);
474  }
475 
476  __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
477  __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
478  __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
479  __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
480  __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
481  __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
482  __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
483  __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
484  __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
485  __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
486  __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
487  __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
488  __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
489  __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
490  __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
491  __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
492  __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
493 
494  /*
495  * Avoid compat_sys_sigreturn() restarting.
496  */
497  regs->syscallno = ~0UL;
498 
499  err |= !valid_user_regs(&regs->user_regs);
500 
501  aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
502  if (err == 0)
503  err |= compat_restore_vfp_context(&aux->vfp);
504 
505  return err;
506 }
507 
508 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
509 {
510  struct compat_sigframe __user *frame;
511 
512  /* Always make any pending restarted system calls return -EINTR */
513  current_thread_info()->restart_block.fn = do_no_restart_syscall;
514 
515  /*
516  * Since we stacked the signal on a 64-bit boundary,
517  * then 'sp' should be word aligned here. If it's
518  * not, then the user is trying to mess with us.
519  */
520  if (regs->compat_sp & 7)
521  goto badframe;
522 
523  frame = (struct compat_sigframe __user *)regs->compat_sp;
524 
525  if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
526  goto badframe;
527 
528  if (compat_restore_sigframe(regs, frame))
529  goto badframe;
530 
531  return regs->regs[0];
532 
533 badframe:
534  if (show_unhandled_signals)
535  pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
536  current->comm, task_pid_nr(current), __func__,
537  regs->pc, regs->sp);
538  force_sig(SIGSEGV, current);
539  return 0;
540 }
541 
542 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
543 {
544  struct compat_rt_sigframe __user *frame;
545 
546  /* Always make any pending restarted system calls return -EINTR */
547  current_thread_info()->restart_block.fn = do_no_restart_syscall;
548 
549  /*
550  * Since we stacked the signal on a 64-bit boundary,
551  * then 'sp' should be word aligned here. If it's
552  * not, then the user is trying to mess with us.
553  */
554  if (regs->compat_sp & 7)
555  goto badframe;
556 
557  frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
558 
559  if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
560  goto badframe;
561 
562  if (compat_restore_sigframe(regs, &frame->sig))
563  goto badframe;
564 
565  if (compat_do_sigaltstack(ptr_to_compat(&frame->sig.uc.uc_stack),
566  ptr_to_compat((void __user *)NULL),
567  regs->compat_sp) == -EFAULT)
568  goto badframe;
569 
570  return regs->regs[0];
571 
572 badframe:
573  if (show_unhandled_signals)
574  pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
575  current->comm, task_pid_nr(current), __func__,
576  regs->pc, regs->sp);
577  force_sig(SIGSEGV, current);
578  return 0;
579 }
580 
581 static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
582  struct pt_regs *regs,
583  int framesize)
584 {
585  compat_ulong_t sp = regs->compat_sp;
586  void __user *frame;
587 
588  /*
589  * This is the X/Open sanctioned signal stack switching.
590  */
591  if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
592  sp = current->sas_ss_sp + current->sas_ss_size;
593 
594  /*
595  * ATPCS B01 mandates 8-byte alignment
596  */
597  frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
598 
599  /*
600  * Check that we can actually write to the signal frame.
601  */
602  if (!access_ok(VERIFY_WRITE, frame, framesize))
603  frame = NULL;
604 
605  return frame;
606 }
607 
608 static int compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
609  compat_ulong_t __user *rc, void __user *frame,
610  int usig)
611 {
612  compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
613  compat_ulong_t retcode;
614  compat_ulong_t spsr = regs->pstate & ~PSR_f;
615  int thumb;
616 
617  /* Check if the handler is written for ARM or Thumb */
618  thumb = handler & 1;
619 
620  if (thumb) {
621  spsr |= COMPAT_PSR_T_BIT;
622  spsr &= ~COMPAT_PSR_IT_MASK;
623  } else {
624  spsr &= ~COMPAT_PSR_T_BIT;
625  }
626 
627  if (ka->sa.sa_flags & SA_RESTORER) {
628  retcode = ptr_to_compat(ka->sa.sa_restorer);
629  } else {
630  /* Set up sigreturn pointer */
631  unsigned int idx = thumb << 1;
632 
633  if (ka->sa.sa_flags & SA_SIGINFO)
634  idx += 3;
635 
636  retcode = AARCH32_VECTORS_BASE +
637  AARCH32_KERN_SIGRET_CODE_OFFSET +
638  (idx << 2) + thumb;
639  }
640 
641  regs->regs[0] = usig;
642  regs->compat_sp = ptr_to_compat(frame);
643  regs->compat_lr = retcode;
644  regs->pc = handler;
645  regs->pstate = spsr;
646 
647  return 0;
648 }
649 
650 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
651  struct pt_regs *regs, sigset_t *set)
652 {
653  struct compat_aux_sigframe __user *aux;
654  int err = 0;
655 
656  __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
657  __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
658  __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
659  __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
660  __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
661  __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
662  __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
663  __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
664  __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
665  __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
666  __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
667  __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
668  __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
669  __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
670  __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
671  __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
672  __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
673 
674  __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
675  __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
676  __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
677  __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
678 
679  err |= put_sigset_t(&sf->uc.uc_sigmask, set);
680 
681  aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
682 
683  if (err == 0)
684  err |= compat_preserve_vfp_context(&aux->vfp);
685  __put_user_error(0, &aux->end_magic, err);
686 
687  return err;
688 }
689 
690 /*
691  * 32-bit signal handling routines called from signal.c
692  */
693 int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
694  sigset_t *set, struct pt_regs *regs)
695 {
696  struct compat_rt_sigframe __user *frame;
697  compat_stack_t stack;
698  int err = 0;
699 
700  frame = compat_get_sigframe(ka, regs, sizeof(*frame));
701 
702  if (!frame)
703  return 1;
704 
705  err |= copy_siginfo_to_user32(&frame->info, info);
706 
707  __put_user_error(0, &frame->sig.uc.uc_flags, err);
708  __put_user_error(NULL, &frame->sig.uc.uc_link, err);
709 
710  memset(&stack, 0, sizeof(stack));
711  stack.ss_sp = (compat_uptr_t)current->sas_ss_sp;
712  stack.ss_flags = sas_ss_flags(regs->compat_sp);
713  stack.ss_size = current->sas_ss_size;
714  err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
715 
716  err |= compat_setup_sigframe(&frame->sig, regs, set);
717  if (err == 0)
718  err = compat_setup_return(regs, ka, frame->sig.retcode, frame,
719  usig);
720 
721  if (err == 0) {
722  regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
723  regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
724  }
725 
726  return err;
727 }
728 
729 int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
730  struct pt_regs *regs)
731 {
732  struct compat_sigframe __user *frame;
733  int err = 0;
734 
735  frame = compat_get_sigframe(ka, regs, sizeof(*frame));
736 
737  if (!frame)
738  return 1;
739 
740  __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
741 
742  err |= compat_setup_sigframe(frame, regs, set);
743  if (err == 0)
744  err = compat_setup_return(regs, ka, frame->retcode, frame, usig);
745 
746  return err;
747 }
748 
749 /*
750  * RT signals don't have generic compat wrappers.
751  * See arch/powerpc/kernel/signal_32.c
752  */
753 asmlinkage int compat_sys_rt_sigprocmask(int how, compat_sigset_t __user *set,
754  compat_sigset_t __user *oset,
755  compat_size_t sigsetsize)
756 {
757  sigset_t s;
758  sigset_t __user *up;
759  int ret;
760  mm_segment_t old_fs = get_fs();
761 
762  if (set) {
763  if (get_sigset_t(&s, set))
764  return -EFAULT;
765  }
766 
767  set_fs(KERNEL_DS);
768  /* This is valid because of the set_fs() */
769  up = (sigset_t __user *) &s;
770  ret = sys_rt_sigprocmask(how, set ? up : NULL, oset ? up : NULL,
771  sigsetsize);
772  set_fs(old_fs);
773  if (ret)
774  return ret;
775  if (oset) {
776  if (put_sigset_t(oset, &s))
777  return -EFAULT;
778  }
779  return 0;
780 }
781 
782 asmlinkage int compat_sys_rt_sigpending(compat_sigset_t __user *set,
783  compat_size_t sigsetsize)
784 {
785  sigset_t s;
786  int ret;
787  mm_segment_t old_fs = get_fs();
788 
789  set_fs(KERNEL_DS);
790  /* The __user pointer cast is valid because of the set_fs() */
791  ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize);
792  set_fs(old_fs);
793  if (!ret) {
794  if (put_sigset_t(set, &s))
795  return -EFAULT;
796  }
797  return ret;
798 }
799 
800 asmlinkage int compat_sys_rt_sigqueueinfo(int pid, int sig,
801  compat_siginfo_t __user *uinfo)
802 {
803  siginfo_t info;
804  int ret;
805  mm_segment_t old_fs = get_fs();
806 
807  ret = copy_siginfo_from_user32(&info, uinfo);
808  if (unlikely(ret))
809  return ret;
810 
811  set_fs (KERNEL_DS);
812  /* The __user pointer cast is valid because of the set_fs() */
813  ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __user *) &info);
814  set_fs (old_fs);
815  return ret;
816 }
817 
818 void compat_setup_restart_syscall(struct pt_regs *regs)
819 {
820  regs->regs[7] = __NR_compat_restart_syscall;
821 }
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