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   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/suspend.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 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 113         COPY(acc0h);
 114         COPY(acc0l);
 115         COPY(acc1h);
 116         COPY(acc1l);
 117 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 118         COPY(acch);
 119         COPY(accl);
 120         COPY(dummy_acc1h);
 121         COPY(dummy_acc1l);
 122 #else
 123 #error unknown isa configuration
 124 #endif
 125         COPY(psw);
 126         COPY(bpc);
 127         COPY(bbpsw);
 128         COPY(bbpc);
 129         COPY(spu);
 130         COPY(fp);
 131         COPY(lr);
 132         COPY(spi);
 133 #undef COPY
 134
 135         regs->syscall_nr = -1;  /* disable syscall checks */
 136         err |= __get_user(*r0_p, &sc->sc_r0);
 137
 138         return err;
 139 }
 140
 141 asmlinkage int
 142 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 143                  unsigned long r2, unsigned long r3, unsigned long r4,
 144                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
 145 {
 146         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 147         sigset_t set;
 148         int result;
 149
 150         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 151                 goto badframe;
 152         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 153                 goto badframe;
 154
 155         sigdelsetmask(&set, ~_BLOCKABLE);
 156         spin_lock_irq(&current->sighand->siglock);
 157         current->blocked = set;
 158         recalc_sigpending();
 159         spin_unlock_irq(&current->sighand->siglock);
 160
 161         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 162                 goto badframe;
 163
 164         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 165                 goto badframe;
 166
 167         return result;
 168
 169 badframe:
 170         force_sig(SIGSEGV, current);
 171         return 0;
 172 }
 173
 174 /*
 175  * Set up a signal frame.
 176  */
 177
 178 static int
 179 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 180                  unsigned long mask)
 181 {
 182         int err = 0;
 183
 184 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 185         COPY(r4);
 186         COPY(r5);
 187         COPY(r6);
 188         COPY(pt_regs);
 189         COPY(r0);
 190         COPY(r1);
 191         COPY(r2);
 192         COPY(r3);
 193         COPY(r7);
 194         COPY(r8);
 195         COPY(r9);
 196         COPY(r10);
 197         COPY(r11);
 198         COPY(r12);
 199 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 200         COPY(acc0h);
 201         COPY(acc0l);
 202         COPY(acc1h);
 203         COPY(acc1l);
 204 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 205         COPY(acch);
 206         COPY(accl);
 207         COPY(dummy_acc1h);
 208         COPY(dummy_acc1l);
 209 #else
 210 #error unknown isa configuration
 211 #endif
 212         COPY(psw);
 213         COPY(bpc);
 214         COPY(bbpsw);
 215         COPY(bbpc);
 216         COPY(spu);
 217         COPY(fp);
 218         COPY(lr);
 219         COPY(spi);
 220 #undef COPY
 221
 222         err |= __put_user(mask, &sc->oldmask);
 223
 224         return err;
 225 }
 226
 227 /*
 228  * Determine which stack to use..
 229  */
 230 static inline void __user *
 231 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 232 {
 233         /* This is the X/Open sanctioned signal stack switching.  */
 234         if (ka->sa.sa_flags & SA_ONSTACK) {
 235                 if (sas_ss_flags(sp) == 0)
 236                         sp = current->sas_ss_sp + current->sas_ss_size;
 237         }
 238
 239         return (void __user *)((sp - frame_size) & -8ul);
 240 }
 241
 242 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 243                            sigset_t *set, struct pt_regs *regs)
 244 {
 245         struct rt_sigframe __user *frame;
 246         int err = 0;
 247         int signal;
 248
 249         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 250
 251         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 252                 goto give_sigsegv;
 253
 254         signal = current_thread_info()->exec_domain
 255                 && current_thread_info()->exec_domain->signal_invmap
 256                 && sig < 32
 257                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 258                 : sig;
 259
 260         err |= __put_user(signal, &frame->sig);
 261         if (err)
 262                 goto give_sigsegv;
 263
 264         err |= __put_user(&frame->info, &frame->pinfo);
 265         err |= __put_user(&frame->uc, &frame->puc);
 266         err |= copy_siginfo_to_user(&frame->info, info);
 267         if (err)
 268                 goto give_sigsegv;
 269
 270         /* Create the ucontext.  */
 271         err |= __put_user(0, &frame->uc.uc_flags);
 272         err |= __put_user(0, &frame->uc.uc_link);
 273         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 274         err |= __put_user(sas_ss_flags(regs->spu),
 275                           &frame->uc.uc_stack.ss_flags);
 276         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 277         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 278         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 279         if (err)
 280                 goto give_sigsegv;
 281
 282         /* Set up to return from userspace.  */
 283         regs->lr = (unsigned long)ka->sa.sa_restorer;
 284
 285         /* Set up registers for signal handler */
 286         regs->spu = (unsigned long)frame;
 287         regs->r0 = signal;      /* Arg for signal handler */
 288         regs->r1 = (unsigned long)&frame->info;
 289         regs->r2 = (unsigned long)&frame->uc;
 290         regs->bpc = (unsigned long)ka->sa.sa_handler;
 291
 292         set_fs(USER_DS);
 293
 294 #if DEBUG_SIG
 295         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 296                 current->comm, current->pid, frame, regs->pc);
 297 #endif
 298
 299         return;
 300
 301 give_sigsegv:
 302         force_sigsegv(sig, current);
 303 }
 304
 305 /*
 306  * OK, we're invoking a handler
 307  */
 308
 309 static void
 310 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 311               sigset_t *oldset, struct pt_regs *regs)
 312 {
 313         unsigned short inst;
 314
 315         /* Are we from a system call? */
 316         if (regs->syscall_nr >= 0) {
 317                 /* If so, check system call restarting.. */
 318                 switch (regs->r0) {
 319                         case -ERESTART_RESTARTBLOCK:
 320                         case -ERESTARTNOHAND:
 321                                 regs->r0 = -EINTR;
 322                                 break;
 323
 324                         case -ERESTARTSYS:
 325                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 326                                         regs->r0 = -EINTR;
 327                                         break;
 328                                 }
 329                         /* fallthrough */
 330                         case -ERESTARTNOINTR:
 331                                 regs->r0 = regs->orig_r0;
 332                                 inst = *(unsigned short *)(regs->bpc - 2);
 333                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 334                                         regs->bpc -= 2;
 335                                 else
 336                                         regs->bpc -= 4;
 337                 }
 338         }
 339
 340         /* Set up the stack frame */
 341         setup_rt_frame(sig, ka, info, oldset, regs);
 342
 343         spin_lock_irq(&current->sighand->siglock);
 344         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 345         if (!(ka->sa.sa_flags & SA_NODEFER))
 346                 sigaddset(&current->blocked,sig);
 347         recalc_sigpending();
 348         spin_unlock_irq(&current->sighand->siglock);
 349 }
 350
 351 /*
 352  * Note that 'init' is a special process: it doesn't get signals it doesn't
 353  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 354  * mistake.
 355  */
 356 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 357 {
 358         siginfo_t info;
 359         int signr;
 360         struct k_sigaction ka;
 361         unsigned short inst;
 362
 363         /*
 364          * We want the common case to go fast, which
 365          * is why we may in certain cases get here from
 366          * kernel mode. Just return without doing anything
 367          * if so.
 368          */
 369         if (!user_mode(regs))
 370                 return 1;
 371
 372         if (try_to_freeze())
 373                 goto no_signal;
 374
 375         if (!oldset)
 376                 oldset = &current->blocked;
 377
 378         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 379         if (signr > 0) {
 380                 /* Reenable any watchpoints before delivering the
 381                  * signal to user space. The processor register will
 382                  * have been cleared if the watchpoint triggered
 383                  * inside the kernel.
 384                  */
 385
 386                 /* Whee!  Actually deliver the signal.  */
 387                 handle_signal(signr, &ka, &info, oldset, regs);
 388                 return 1;
 389         }
 390
 391  no_signal:
 392         /* Did we come from a system call? */
 393         if (regs->syscall_nr >= 0) {
 394                 /* Restart the system call - no handlers present */
 395                 if (regs->r0 == -ERESTARTNOHAND ||
 396                     regs->r0 == -ERESTARTSYS ||
 397                     regs->r0 == -ERESTARTNOINTR) {
 398                         regs->r0 = regs->orig_r0;
 399                         inst = *(unsigned short *)(regs->bpc - 2);
 400                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 401                                 regs->bpc -= 2;
 402                         else
 403                                 regs->bpc -= 4;
 404                 }
 405                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
 406                         regs->r0 = regs->orig_r0;
 407                         regs->r7 = __NR_restart_syscall;
 408                         inst = *(unsigned short *)(regs->bpc - 2);
 409                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 410                                 regs->bpc -= 2;
 411                         else
 412                                 regs->bpc -= 4;
 413                 }
 414         }
 415         return 0;
 416 }
 417
 418 /*
 419  * notification of userspace execution resumption
 420  * - triggered by current->work.notify_resume
 421  */
 422 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 423                       __u32 thread_info_flags)
 424 {
 425         /* Pending single-step? */
 426         if (thread_info_flags & _TIF_SINGLESTEP)
 427                 clear_thread_flag(TIF_SINGLESTEP);
 428
 429         /* deal with pending signal delivery */
 430         if (thread_info_flags & _TIF_SIGPENDING)
 431                 do_signal(regs,oldset);
 432
 433         clear_thread_flag(TIF_IRET);
 434 }