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