release/src-rt-6.x/linux/linux-2.6/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 saveset, 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, ~_BLOCKABLE);
  48
  49         spin_lock_irq(&current->sighand->siglock);
  50         saveset = current->blocked;
  51         current->blocked = newset;
  52         recalc_sigpending();
  53         spin_unlock_irq(&current->sighand->siglock);
  54
  55         regs->r0 = -EINTR;
  56         while (1) {
  57                 current->state = TASK_INTERRUPTIBLE;
  58                 schedule();
  59                 if (do_signal(regs, &saveset))
  60                         return regs->r0;
  61         }
  62 }
  63
  64 asmlinkage int
  65 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  66                 unsigned long r2, unsigned long r3, unsigned long r4,
  67                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
  68 {
  69         return do_sigaltstack(uss, uoss, regs->spu);
  70 }
  71
  72
  73 /*
  74  * Do a signal return; undo the signal stack.
  75  */
  76
  77 struct rt_sigframe
  78 {
  79         int sig;
  80         struct siginfo __user *pinfo;
  81         void __user *puc;
  82         struct siginfo info;
  83         struct ucontext uc;
  84 //      struct _fpstate fpstate;
  85 };
  86
  87 static int
  88 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  89                    int *r0_p)
  90 {
  91         unsigned int err = 0;
  92
  93         /* Always make any pending restarted system calls return -EINTR */
  94         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  95
  96 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
  97         COPY(r4);
  98         COPY(r5);
  99         COPY(r6);
 100         COPY(pt_regs);
 101         /* COPY(r0); Skip r0 */
 102         COPY(r1);
 103         COPY(r2);
 104         COPY(r3);
 105         COPY(r7);
 106         COPY(r8);
 107         COPY(r9);
 108         COPY(r10);
 109         COPY(r11);
 110         COPY(r12);
 111         COPY(acc0h);
 112         COPY(acc0l);
 113         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 114         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 115         COPY(psw);
 116         COPY(bpc);
 117         COPY(bbpsw);
 118         COPY(bbpc);
 119         COPY(spu);
 120         COPY(fp);
 121         COPY(lr);
 122         COPY(spi);
 123 #undef COPY
 124
 125         regs->syscall_nr = -1;  /* disable syscall checks */
 126         err |= __get_user(*r0_p, &sc->sc_r0);
 127
 128         return err;
 129 }
 130
 131 asmlinkage int
 132 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 133                  unsigned long r2, unsigned long r3, unsigned long r4,
 134                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
 135 {
 136         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 137         sigset_t set;
 138         int result;
 139
 140         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 141                 goto badframe;
 142         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 143                 goto badframe;
 144
 145         sigdelsetmask(&set, ~_BLOCKABLE);
 146         spin_lock_irq(&current->sighand->siglock);
 147         current->blocked = set;
 148         recalc_sigpending();
 149         spin_unlock_irq(&current->sighand->siglock);
 150
 151         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 152                 goto badframe;
 153
 154         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 155                 goto badframe;
 156
 157         return result;
 158
 159 badframe:
 160         force_sig(SIGSEGV, current);
 161         return 0;
 162 }
 163
 164 /*
 165  * Set up a signal frame.
 166  */
 167
 168 static int
 169 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 170                  unsigned long mask)
 171 {
 172         int err = 0;
 173
 174 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 175         COPY(r4);
 176         COPY(r5);
 177         COPY(r6);
 178         COPY(pt_regs);
 179         COPY(r0);
 180         COPY(r1);
 181         COPY(r2);
 182         COPY(r3);
 183         COPY(r7);
 184         COPY(r8);
 185         COPY(r9);
 186         COPY(r10);
 187         COPY(r11);
 188         COPY(r12);
 189         COPY(acc0h);
 190         COPY(acc0l);
 191         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 192         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 193         COPY(psw);
 194         COPY(bpc);
 195         COPY(bbpsw);
 196         COPY(bbpc);
 197         COPY(spu);
 198         COPY(fp);
 199         COPY(lr);
 200         COPY(spi);
 201 #undef COPY
 202
 203         err |= __put_user(mask, &sc->oldmask);
 204
 205         return err;
 206 }
 207
 208 /*
 209  * Determine which stack to use..
 210  */
 211 static inline void __user *
 212 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 213 {
 214         /* This is the X/Open sanctioned signal stack switching.  */
 215         if (ka->sa.sa_flags & SA_ONSTACK) {
 216                 if (sas_ss_flags(sp) == 0)
 217                         sp = current->sas_ss_sp + current->sas_ss_size;
 218         }
 219
 220         return (void __user *)((sp - frame_size) & -8ul);
 221 }
 222
 223 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 224                            sigset_t *set, struct pt_regs *regs)
 225 {
 226         struct rt_sigframe __user *frame;
 227         int err = 0;
 228         int signal;
 229
 230         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 231
 232         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 233                 goto give_sigsegv;
 234
 235         signal = current_thread_info()->exec_domain
 236                 && current_thread_info()->exec_domain->signal_invmap
 237                 && sig < 32
 238                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 239                 : sig;
 240
 241         err |= __put_user(signal, &frame->sig);
 242         if (err)
 243                 goto give_sigsegv;
 244
 245         err |= __put_user(&frame->info, &frame->pinfo);
 246         err |= __put_user(&frame->uc, &frame->puc);
 247         err |= copy_siginfo_to_user(&frame->info, info);
 248         if (err)
 249                 goto give_sigsegv;
 250
 251         /* Create the ucontext.  */
 252         err |= __put_user(0, &frame->uc.uc_flags);
 253         err |= __put_user(0, &frame->uc.uc_link);
 254         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 255         err |= __put_user(sas_ss_flags(regs->spu),
 256                           &frame->uc.uc_stack.ss_flags);
 257         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 258         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 259         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 260         if (err)
 261                 goto give_sigsegv;
 262
 263         /* Set up to return from userspace.  */
 264         regs->lr = (unsigned long)ka->sa.sa_restorer;
 265
 266         /* Set up registers for signal handler */
 267         regs->spu = (unsigned long)frame;
 268         regs->r0 = signal;      /* Arg for signal handler */
 269         regs->r1 = (unsigned long)&frame->info;
 270         regs->r2 = (unsigned long)&frame->uc;
 271         regs->bpc = (unsigned long)ka->sa.sa_handler;
 272
 273         set_fs(USER_DS);
 274
 275 #if DEBUG_SIG
 276         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 277                 current->comm, current->pid, frame, regs->pc);
 278 #endif
 279
 280         return;
 281
 282 give_sigsegv:
 283         force_sigsegv(sig, current);
 284 }
 285
 286 /*
 287  * OK, we're invoking a handler
 288  */
 289
 290 static void
 291 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 292               sigset_t *oldset, struct pt_regs *regs)
 293 {
 294         unsigned short inst;
 295
 296         /* Are we from a system call? */
 297         if (regs->syscall_nr >= 0) {
 298                 /* If so, check system call restarting.. */
 299                 switch (regs->r0) {
 300                         case -ERESTART_RESTARTBLOCK:
 301                         case -ERESTARTNOHAND:
 302                                 regs->r0 = -EINTR;
 303                                 break;
 304
 305                         case -ERESTARTSYS:
 306                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 307                                         regs->r0 = -EINTR;
 308                                         break;
 309                                 }
 310                         /* fallthrough */
 311                         case -ERESTARTNOINTR:
 312                                 regs->r0 = regs->orig_r0;
 313                                 inst = *(unsigned short *)(regs->bpc - 2);
 314                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 315                                         regs->bpc -= 2;
 316                                 else
 317                                         regs->bpc -= 4;
 318                 }
 319         }
 320
 321         /* Set up the stack frame */
 322         setup_rt_frame(sig, ka, info, oldset, regs);
 323
 324         spin_lock_irq(&current->sighand->siglock);
 325         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 326         if (!(ka->sa.sa_flags & SA_NODEFER))
 327                 sigaddset(&current->blocked,sig);
 328         recalc_sigpending();
 329         spin_unlock_irq(&current->sighand->siglock);
 330 }
 331
 332 /*
 333  * Note that 'init' is a special process: it doesn't get signals it doesn't
 334  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 335  * mistake.
 336  */
 337 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 338 {
 339         siginfo_t info;
 340         int signr;
 341         struct k_sigaction ka;
 342         unsigned short inst;
 343
 344         /*
 345          * We want the common case to go fast, which
 346          * is why we may in certain cases get here from
 347          * kernel mode. Just return without doing anything
 348          * if so.
 349          */
 350         if (!user_mode(regs))
 351                 return 1;
 352
 353         if (try_to_freeze())
 354                 goto no_signal;
 355
 356         if (!oldset)
 357                 oldset = &current->blocked;
 358
 359         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 360         if (signr > 0) {
 361                 /* Reenable any watchpoints before delivering the
 362                  * signal to user space. The processor register will
 363                  * have been cleared if the watchpoint triggered
 364                  * inside the kernel.
 365                  */
 366
 367                 /* Whee!  Actually deliver the signal.  */
 368                 handle_signal(signr, &ka, &info, oldset, regs);
 369                 return 1;
 370         }
 371
 372  no_signal:
 373         /* Did we come from a system call? */
 374         if (regs->syscall_nr >= 0) {
 375                 /* Restart the system call - no handlers present */
 376                 if (regs->r0 == -ERESTARTNOHAND ||
 377                     regs->r0 == -ERESTARTSYS ||
 378                     regs->r0 == -ERESTARTNOINTR) {
 379                         regs->r0 = regs->orig_r0;
 380                         inst = *(unsigned short *)(regs->bpc - 2);
 381                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 382                                 regs->bpc -= 2;
 383                         else
 384                                 regs->bpc -= 4;
 385                 }
 386                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
 387                         regs->r0 = regs->orig_r0;
 388                         regs->r7 = __NR_restart_syscall;
 389                         inst = *(unsigned short *)(regs->bpc - 2);
 390                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 391                                 regs->bpc -= 2;
 392                         else
 393                                 regs->bpc -= 4;
 394                 }
 395         }
 396         return 0;
 397 }
 398
 399 /*
 400  * notification of userspace execution resumption
 401  * - triggered by current->work.notify_resume
 402  */
 403 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 404                       __u32 thread_info_flags)
 405 {
 406         /* Pending single-step? */
 407         if (thread_info_flags & _TIF_SINGLESTEP)
 408                 clear_thread_flag(TIF_SINGLESTEP);
 409
 410         /* deal with pending signal delivery */
 411         if (thread_info_flags & _TIF_SIGPENDING)
 412                 do_signal(regs,oldset);
 413
 414         clear_thread_flag(TIF_IRET);
 415 }