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