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/config.h>
  14 #include <linux/sched.h>
  15 #include <linux/mm.h>
  16 #include <linux/smp.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/kernel.h>
  19 #include <linux/signal.h>
  20 #include <linux/errno.h>
  21 #include <linux/wait.h>
  22 #include <linux/unistd.h>
  23 #include <linux/stddef.h>
  24 #include <linux/personality.h>
  25 #include <linux/suspend.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/ucontext.h>
  28 #include <asm/uaccess.h>
  29
  30 #define DEBUG_SIG 0
  31
  32 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  33
  34 int do_signal(struct pt_regs *, sigset_t *);
  35
  36 asmlinkage int
  37 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
  38                   unsigned long r2, unsigned long r3, unsigned long r4,
  39                   unsigned long r5, unsigned long r6, struct pt_regs *regs)
  40 {
  41         sigset_t saveset, newset;
  42
  43         /* XXX: Don't preclude handling different sized sigset_t's.  */
  44         if (sigsetsize != sizeof(sigset_t))
  45                 return -EINVAL;
  46
  47         if (copy_from_user(&newset, unewset, sizeof(newset)))
  48                 return -EFAULT;
  49         sigdelsetmask(&newset, ~_BLOCKABLE);
  50
  51         spin_lock_irq(&current->sighand->siglock);
  52         saveset = current->blocked;
  53         current->blocked = newset;
  54         recalc_sigpending();
  55         spin_unlock_irq(&current->sighand->siglock);
  56
  57         regs->r0 = -EINTR;
  58         while (1) {
  59                 current->state = TASK_INTERRUPTIBLE;
  60                 schedule();
  61                 if (do_signal(regs, &saveset))
  62                         return regs->r0;
  63         }
  64 }
  65
  66 asmlinkage int
  67 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  68                 unsigned long r2, unsigned long r3, unsigned long r4,
  69                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
  70 {
  71         return do_sigaltstack(uss, uoss, regs->spu);
  72 }
  73
  74
  75 /*
  76  * Do a signal return; undo the signal stack.
  77  */
  78
  79 struct rt_sigframe
  80 {
  81         int sig;
  82         struct siginfo *pinfo;
  83         void *puc;
  84         struct siginfo info;
  85         struct ucontext uc;
  86 //      struct _fpstate fpstate;
  87 };
  88
  89 static int
  90 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  91                    int *r0_p)
  92 {
  93         unsigned int err = 0;
  94
  95         /* Always make any pending restarted system calls return -EINTR */
  96         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  97
  98 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
  99         COPY(r4);
 100         COPY(r5);
 101         COPY(r6);
 102         COPY(pt_regs);
 103         /* COPY(r0); Skip r0 */
 104         COPY(r1);
 105         COPY(r2);
 106         COPY(r3);
 107         COPY(r7);
 108         COPY(r8);
 109         COPY(r9);
 110         COPY(r10);
 111         COPY(r11);
 112         COPY(r12);
 113 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 114         COPY(acc0h);
 115         COPY(acc0l);
 116         COPY(acc1h);
 117         COPY(acc1l);
 118 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 119         COPY(acch);
 120         COPY(accl);
 121         COPY(dummy_acc1h);
 122         COPY(dummy_acc1l);
 123 #else
 124 #error unknown isa configuration
 125 #endif
 126         COPY(psw);
 127         COPY(bpc);
 128         COPY(bbpsw);
 129         COPY(bbpc);
 130         COPY(spu);
 131         COPY(fp);
 132         COPY(lr);
 133         COPY(spi);
 134 #undef COPY
 135
 136         regs->syscall_nr = -1;  /* disable syscall checks */
 137         err |= __get_user(*r0_p, &sc->sc_r0);
 138
 139         return err;
 140 }
 141
 142 asmlinkage int
 143 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 144                  unsigned long r2, unsigned long r3, unsigned long r4,
 145                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
 146 {
 147         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 148         sigset_t set;
 149         int result;
 150
 151         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 152                 goto badframe;
 153         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 154                 goto badframe;
 155
 156         sigdelsetmask(&set, ~_BLOCKABLE);
 157         spin_lock_irq(&current->sighand->siglock);
 158         current->blocked = set;
 159         recalc_sigpending();
 160         spin_unlock_irq(&current->sighand->siglock);
 161
 162         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 163                 goto badframe;
 164
 165         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 166                 goto badframe;
 167
 168         return result;
 169
 170 badframe:
 171         force_sig(SIGSEGV, current);
 172         return 0;
 173 }
 174
 175 /*
 176  * Set up a signal frame.
 177  */
 178
 179 static int
 180 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 181                  unsigned long mask)
 182 {
 183         int err = 0;
 184
 185 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 186         COPY(r4);
 187         COPY(r5);
 188         COPY(r6);
 189         COPY(pt_regs);
 190         COPY(r0);
 191         COPY(r1);
 192         COPY(r2);
 193         COPY(r3);
 194         COPY(r7);
 195         COPY(r8);
 196         COPY(r9);
 197         COPY(r10);
 198         COPY(r11);
 199         COPY(r12);
 200 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 201         COPY(acc0h);
 202         COPY(acc0l);
 203         COPY(acc1h);
 204         COPY(acc1l);
 205 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 206         COPY(acch);
 207         COPY(accl);
 208         COPY(dummy_acc1h);
 209         COPY(dummy_acc1l);
 210 #else
 211 #error unknown isa configuration
 212 #endif
 213         COPY(psw);
 214         COPY(bpc);
 215         COPY(bbpsw);
 216         COPY(bbpc);
 217         COPY(spu);
 218         COPY(fp);
 219         COPY(lr);
 220         COPY(spi);
 221 #undef COPY
 222
 223         err |= __put_user(mask, &sc->oldmask);
 224
 225         return err;
 226 }
 227
 228 /*
 229  * Determine which stack to use..
 230  */
 231 static inline void __user *
 232 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 233 {
 234         /* This is the X/Open sanctioned signal stack switching.  */
 235         if (ka->sa.sa_flags & SA_ONSTACK) {
 236                 if (sas_ss_flags(sp) == 0)
 237                         sp = current->sas_ss_sp + current->sas_ss_size;
 238         }
 239
 240         return (void __user *)((sp - frame_size) & -8ul);
 241 }
 242
 243 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 244                            sigset_t *set, struct pt_regs *regs)
 245 {
 246         struct rt_sigframe __user *frame;
 247         int err = 0;
 248         int signal;
 249
 250         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 251
 252         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 253                 goto give_sigsegv;
 254
 255         signal = current_thread_info()->exec_domain
 256                 && current_thread_info()->exec_domain->signal_invmap
 257                 && sig < 32
 258                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 259                 : sig;
 260
 261         err |= __put_user(signal, &frame->sig);
 262         if (err)
 263                 goto give_sigsegv;
 264
 265         err |= __put_user(&frame->info, &frame->pinfo);
 266         err |= __put_user(&frame->uc, &frame->puc);
 267         err |= copy_siginfo_to_user(&frame->info, info);
 268         if (err)
 269                 goto give_sigsegv;
 270
 271         /* Create the ucontext.  */
 272         err |= __put_user(0, &frame->uc.uc_flags);
 273         err |= __put_user(0, &frame->uc.uc_link);
 274         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 275         err |= __put_user(sas_ss_flags(regs->spu),
 276                           &frame->uc.uc_stack.ss_flags);
 277         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 278         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 279         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 280         if (err)
 281                 goto give_sigsegv;
 282
 283         /* Set up to return from userspace.  */
 284         regs->lr = (unsigned long)ka->sa.sa_restorer;
 285
 286         /* Set up registers for signal handler */
 287         regs->spu = (unsigned long)frame;
 288         regs->r0 = signal;      /* Arg for signal handler */
 289         regs->r1 = (unsigned long)&frame->info;
 290         regs->r2 = (unsigned long)&frame->uc;
 291         regs->bpc = (unsigned long)ka->sa.sa_handler;
 292
 293         set_fs(USER_DS);
 294
 295 #if DEBUG_SIG
 296         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 297                 current->comm, current->pid, frame, regs->pc);
 298 #endif
 299
 300         return;
 301
 302 give_sigsegv:
 303         force_sigsegv(sig, current);
 304 }
 305
 306 /*
 307  * OK, we're invoking a handler
 308  */
 309
 310 static void
 311 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 312               sigset_t *oldset, struct pt_regs *regs)
 313 {
 314         unsigned short inst;
 315
 316         /* Are we from a system call? */
 317         if (regs->syscall_nr >= 0) {
 318                 /* If so, check system call restarting.. */
 319                 switch (regs->r0) {
 320                         case -ERESTART_RESTARTBLOCK:
 321                         case -ERESTARTNOHAND:
 322                                 regs->r0 = -EINTR;
 323                                 break;
 324
 325                         case -ERESTARTSYS:
 326                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 327                                         regs->r0 = -EINTR;
 328                                         break;
 329                                 }
 330                         /* fallthrough */
 331                         case -ERESTARTNOINTR:
 332                                 regs->r0 = regs->orig_r0;
 333                                 inst = *(unsigned short *)(regs->bpc - 2);
 334                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 335                                         regs->bpc -= 2;
 336                                 else
 337                                         regs->bpc -= 4;
 338                 }
 339         }
 340
 341         /* Set up the stack frame */
 342         setup_rt_frame(sig, ka, info, oldset, regs);
 343
 344         spin_lock_irq(&current->sighand->siglock);
 345         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 346         if (!(ka->sa.sa_flags & SA_NODEFER))
 347                 sigaddset(&current->blocked,sig);
 348         recalc_sigpending();
 349         spin_unlock_irq(&current->sighand->siglock);
 350 }
 351
 352 /*
 353  * Note that 'init' is a special process: it doesn't get signals it doesn't
 354  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 355  * mistake.
 356  */
 357 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 358 {
 359         siginfo_t info;
 360         int signr;
 361         struct k_sigaction ka;
 362         unsigned short inst;
 363
 364         /*
 365          * We want the common case to go fast, which
 366          * is why we may in certain cases get here from
 367          * kernel mode. Just return without doing anything
 368          * if so.
 369          */
 370         if (!user_mode(regs))
 371                 return 1;
 372
 373         if (try_to_freeze())
 374                 goto no_signal;
 375
 376         if (!oldset)
 377                 oldset = &current->blocked;
 378
 379         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 380         if (signr > 0) {
 381                 /* Reenable any watchpoints before delivering the
 382                  * signal to user space. The processor register will
 383                  * have been cleared if the watchpoint triggered
 384                  * inside the kernel.
 385                  */
 386
 387                 /* Whee!  Actually deliver the signal.  */
 388                 handle_signal(signr, &ka, &info, oldset, regs);
 389                 return 1;
 390         }
 391
 392  no_signal:
 393         /* Did we come from a system call? */
 394         if (regs->syscall_nr >= 0) {
 395                 /* Restart the system call - no handlers present */
 396                 if (regs->r0 == -ERESTARTNOHAND ||
 397                     regs->r0 == -ERESTARTSYS ||
 398                     regs->r0 == -ERESTARTNOINTR) {
 399                         regs->r0 = regs->orig_r0;
 400                         inst = *(unsigned short *)(regs->bpc - 2);
 401                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 402                                 regs->bpc -= 2;
 403                         else
 404                                 regs->bpc -= 4;
 405                 }
 406                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
 407                         regs->r0 = regs->orig_r0;
 408                         regs->r7 = __NR_restart_syscall;
 409                         inst = *(unsigned short *)(regs->bpc - 2);
 410                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 411                                 regs->bpc -= 2;
 412                         else
 413                                 regs->bpc -= 4;
 414                 }
 415         }
 416         return 0;
 417 }
 418
 419 /*
 420  * notification of userspace execution resumption
 421  * - triggered by current->work.notify_resume
 422  */
 423 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 424                       __u32 thread_info_flags)
 425 {
 426         /* Pending single-step? */
 427         if (thread_info_flags & _TIF_SINGLESTEP)
 428                 clear_thread_flag(TIF_SINGLESTEP);
 429
 430         /* deal with pending signal delivery */
 431         if (thread_info_flags & _TIF_SIGPENDING)
 432                 do_signal(regs,oldset);
 433
 434         clear_thread_flag(TIF_IRET);
 435 }