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