arch/m32r/kernel/signal.c

   1 /*
   2  *  linux/arch/m32r/kernel/signal.c
   3  *
   4  *  Copyright (c) 2003  Hitoshi Yamamoto
   5  *
   6  *  Taken from i386 version.
   7  *  Copyright (C) 1991, 1992  Linus Torvalds
   8  *
   9  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  10  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
  11  */
  12
  13 #include <linux/sched.h>
  14 #include <linux/mm.h>
  15 #include <linux/smp.h>
  16 #include <linux/kernel.h>
  17 #include <linux/signal.h>
  18 #include <linux/errno.h>
  19 #include <linux/wait.h>
  20 #include <linux/unistd.h>
  21 #include <linux/stddef.h>
  22 #include <linux/personality.h>
  23 #include <linux/freezer.h>
  24 #include <linux/tracehook.h>
  25 #include <asm/cacheflush.h>
  26 #include <asm/ucontext.h>
  27 #include <asm/uaccess.h>
  28
  29 #define DEBUG_SIG 0
  30
  31 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  32
  33 int do_signal(struct pt_regs *, sigset_t *);
  34
  35 asmlinkage int
  36 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize,
  37                   unsigned long r2, unsigned long r3, unsigned long r4,
  38                   unsigned long r5, unsigned long r6, struct pt_regs *regs)
  39 {
  40         sigset_t newset;
  41
  42         /* XXX: Don't preclude handling different sized sigset_t's.  */
  43         if (sigsetsize != sizeof(sigset_t))
  44                 return -EINVAL;
  45
  46         if (copy_from_user(&newset, unewset, sizeof(newset)))
  47                 return -EFAULT;
  48         sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
  49
  50         spin_lock_irq(&current->sighand->siglock);
  51         current->saved_sigmask = current->blocked;
  52         current->blocked = newset;
  53         recalc_sigpending();
  54         spin_unlock_irq(&current->sighand->siglock);
  55
  56         current->state = TASK_INTERRUPTIBLE;
  57         schedule();
  58         set_thread_flag(TIF_RESTORE_SIGMASK);
  59         return -ERESTARTNOHAND;
  60 }
  61
  62 asmlinkage int
  63 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  64                 unsigned long r2, unsigned long r3, unsigned long r4,
  65                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
  66 {
  67         return do_sigaltstack(uss, uoss, regs->spu);
  68 }
  69
  70
  71 /*
  72  * Do a signal return; undo the signal stack.
  73  */
  74
  75 struct rt_sigframe
  76 {
  77         int sig;
  78         struct siginfo __user *pinfo;
  79         void __user *puc;
  80         struct siginfo info;
  81         struct ucontext uc;
  82 //      struct _fpstate fpstate;
  83 };
  84
  85 static int
  86 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  87                    int *r0_p)
  88 {
  89         unsigned int err = 0;
  90
  91         /* Always make any pending restarted system calls return -EINTR */
  92         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  93
  94 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
  95         COPY(r4);
  96         COPY(r5);
  97         COPY(r6);
  98         COPY(pt_regs);
  99         /* COPY(r0); Skip r0 */
 100         COPY(r1);
 101         COPY(r2);
 102         COPY(r3);
 103         COPY(r7);
 104         COPY(r8);
 105         COPY(r9);
 106         COPY(r10);
 107         COPY(r11);
 108         COPY(r12);
 109         COPY(acc0h);
 110         COPY(acc0l);
 111         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 112         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 113         COPY(psw);
 114         COPY(bpc);
 115         COPY(bbpsw);
 116         COPY(bbpc);
 117         COPY(spu);
 118         COPY(fp);
 119         COPY(lr);
 120         COPY(spi);
 121 #undef COPY
 122
 123         regs->syscall_nr = -1;  /* disable syscall checks */
 124         err |= __get_user(*r0_p, &sc->sc_r0);
 125
 126         return err;
 127 }
 128
 129 asmlinkage int
 130 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 131                  unsigned long r2, unsigned long r3, unsigned long r4,
 132                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
 133 {
 134         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 135         sigset_t set;
 136         int result;
 137
 138         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 139                 goto badframe;
 140         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 141                 goto badframe;
 142
 143         sigdelsetmask(&set, ~_BLOCKABLE);
 144         spin_lock_irq(&current->sighand->siglock);
 145         current->blocked = set;
 146         recalc_sigpending();
 147         spin_unlock_irq(&current->sighand->siglock);
 148
 149         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 150                 goto badframe;
 151
 152         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 153                 goto badframe;
 154
 155         return result;
 156
 157 badframe:
 158         force_sig(SIGSEGV, current);
 159         return 0;
 160 }
 161
 162 /*
 163  * Set up a signal frame.
 164  */
 165
 166 static int
 167 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 168                  unsigned long mask)
 169 {
 170         int err = 0;
 171
 172 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 173         COPY(r4);
 174         COPY(r5);
 175         COPY(r6);
 176         COPY(pt_regs);
 177         COPY(r0);
 178         COPY(r1);
 179         COPY(r2);
 180         COPY(r3);
 181         COPY(r7);
 182         COPY(r8);
 183         COPY(r9);
 184         COPY(r10);
 185         COPY(r11);
 186         COPY(r12);
 187         COPY(acc0h);
 188         COPY(acc0l);
 189         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 190         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 191         COPY(psw);
 192         COPY(bpc);
 193         COPY(bbpsw);
 194         COPY(bbpc);
 195         COPY(spu);
 196         COPY(fp);
 197         COPY(lr);
 198         COPY(spi);
 199 #undef COPY
 200
 201         err |= __put_user(mask, &sc->oldmask);
 202
 203         return err;
 204 }
 205
 206 /*
 207  * Determine which stack to use..
 208  */
 209 static inline void __user *
 210 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 211 {
 212         /* This is the X/Open sanctioned signal stack switching.  */
 213         if (ka->sa.sa_flags & SA_ONSTACK) {
 214                 if (sas_ss_flags(sp) == 0)
 215                         sp = current->sas_ss_sp + current->sas_ss_size;
 216         }
 217
 218         return (void __user *)((sp - frame_size) & -8ul);
 219 }
 220
 221 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 222                            sigset_t *set, struct pt_regs *regs)
 223 {
 224         struct rt_sigframe __user *frame;
 225         int err = 0;
 226         int signal;
 227
 228         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 229
 230         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 231                 goto give_sigsegv;
 232
 233         signal = current_thread_info()->exec_domain
 234                 && current_thread_info()->exec_domain->signal_invmap
 235                 && sig < 32
 236                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 237                 : sig;
 238
 239         err |= __put_user(signal, &frame->sig);
 240         if (err)
 241                 goto give_sigsegv;
 242
 243         err |= __put_user(&frame->info, &frame->pinfo);
 244         err |= __put_user(&frame->uc, &frame->puc);
 245         err |= copy_siginfo_to_user(&frame->info, info);
 246         if (err)
 247                 goto give_sigsegv;
 248
 249         /* Create the ucontext.  */
 250         err |= __put_user(0, &frame->uc.uc_flags);
 251         err |= __put_user(0, &frame->uc.uc_link);
 252         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 253         err |= __put_user(sas_ss_flags(regs->spu),
 254                           &frame->uc.uc_stack.ss_flags);
 255         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 256         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 257         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 258         if (err)
 259                 goto give_sigsegv;
 260
 261         /* Set up to return from userspace.  */
 262         regs->lr = (unsigned long)ka->sa.sa_restorer;
 263
 264         /* Set up registers for signal handler */
 265         regs->spu = (unsigned long)frame;
 266         regs->r0 = signal;      /* Arg for signal handler */
 267         regs->r1 = (unsigned long)&frame->info;
 268         regs->r2 = (unsigned long)&frame->uc;
 269         regs->bpc = (unsigned long)ka->sa.sa_handler;
 270
 271         set_fs(USER_DS);
 272
 273 #if DEBUG_SIG
 274         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 275                 current->comm, current->pid, frame, regs->pc);
 276 #endif
 277
 278         return;
 279
 280 give_sigsegv:
 281         force_sigsegv(sig, current);
 282 }
 283
 284 /*
 285  * OK, we're invoking a handler
 286  */
 287
 288 static void
 289 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 290               sigset_t *oldset, struct pt_regs *regs)
 291 {
 292         unsigned short inst;
 293
 294         /* Are we from a system call? */
 295         if (regs->syscall_nr >= 0) {
 296                 /* If so, check system call restarting.. */
 297                 switch (regs->r0) {
 298                         case -ERESTART_RESTARTBLOCK:
 299                         case -ERESTARTNOHAND:
 300                                 regs->r0 = -EINTR;
 301                                 break;
 302
 303                         case -ERESTARTSYS:
 304                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 305                                         regs->r0 = -EINTR;
 306                                         break;
 307                                 }
 308                         /* fallthrough */
 309                         case -ERESTARTNOINTR:
 310                                 regs->r0 = regs->orig_r0;
 311                                 inst = *(unsigned short *)(regs->bpc - 2);
 312                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 313                                         regs->bpc -= 2;
 314                                 else
 315                                         regs->bpc -= 4;
 316                 }
 317         }
 318
 319         /* Set up the stack frame */
 320         setup_rt_frame(sig, ka, info, oldset, regs);
 321
 322         spin_lock_irq(&current->sighand->siglock);
 323         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 324         if (!(ka->sa.sa_flags & SA_NODEFER))
 325                 sigaddset(&current->blocked,sig);
 326         recalc_sigpending();
 327         spin_unlock_irq(&current->sighand->siglock);
 328 }
 329
 330 /*
 331  * Note that 'init' is a special process: it doesn't get signals it doesn't
 332  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 333  * mistake.
 334  */
 335 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 336 {
 337         siginfo_t info;
 338         int signr;
 339         struct k_sigaction ka;
 340         unsigned short inst;
 341
 342         /*
 343          * We want the common case to go fast, which
 344          * is why we may in certain cases get here from
 345          * kernel mode. Just return without doing anything
 346          * if so.
 347          */
 348         if (!user_mode(regs))
 349                 return 1;
 350
 351         if (try_to_freeze())
 352                 goto no_signal;
 353
 354         if (!oldset)
 355                 oldset = &current->blocked;
 356
 357         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 358         if (signr > 0) {
 359                 /* Re-enable any watchpoints before delivering the
 360                  * signal to user space. The processor register will
 361                  * have been cleared if the watchpoint triggered
 362                  * inside the kernel.
 363                  */
 364
 365                 /* Whee!  Actually deliver the signal.  */
 366                 handle_signal(signr, &ka, &info, oldset, regs);
 367                 return 1;
 368         }
 369
 370  no_signal:
 371         /* Did we come from a system call? */
 372         if (regs->syscall_nr >= 0) {
 373                 /* Restart the system call - no handlers present */
 374                 if (regs->r0 == -ERESTARTNOHAND ||
 375                     regs->r0 == -ERESTARTSYS ||
 376                     regs->r0 == -ERESTARTNOINTR) {
 377                         regs->r0 = regs->orig_r0;
 378                         inst = *(unsigned short *)(regs->bpc - 2);
 379                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 380                                 regs->bpc -= 2;
 381                         else
 382                                 regs->bpc -= 4;
 383                 }
 384                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
 385                         regs->r0 = regs->orig_r0;
 386                         regs->r7 = __NR_restart_syscall;
 387                         inst = *(unsigned short *)(regs->bpc - 2);
 388                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 389                                 regs->bpc -= 2;
 390                         else
 391                                 regs->bpc -= 4;
 392                 }
 393         }
 394         return 0;
 395 }
 396
 397 /*
 398  * notification of userspace execution resumption
 399  * - triggered by current->work.notify_resume
 400  */
 401 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 402                       __u32 thread_info_flags)
 403 {
 404         /* Pending single-step? */
 405         if (thread_info_flags & _TIF_SINGLESTEP)
 406                 clear_thread_flag(TIF_SINGLESTEP);
 407
 408         /* deal with pending signal delivery */
 409         if (thread_info_flags & _TIF_SIGPENDING)
 410                 do_signal(regs,oldset);
 411
 412         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 413                 clear_thread_flag(TIF_NOTIFY_RESUME);
 414                 tracehook_notify_resume(regs);
 415                 if (current->replacement_session_keyring)
 416                         key_replace_session_keyring();
 417         }
 418
 419         clear_thread_flag(TIF_IRET);
 420 }