linux/arch/m32r/kernel/signal.c
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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/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 <linux/tracehook.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
  33int do_signal(struct pt_regs *, sigset_t *);
  34
  35asmlinkage int
  36sys_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 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, sigmask(SIGKILL)|sigmask(SIGSTOP));
  49
  50        spin_lock_irq(&current->sighand->siglock);
  51        current->saved_sigmask = current->blocked;
  52        current->blocked = newset;
  53        recalc_sigpending();
  54        spin_unlock_irq(&current->sighand->siglock);
  55
  56        current->state = TASK_INTERRUPTIBLE;
  57        schedule();
  58        set_thread_flag(TIF_RESTORE_SIGMASK);
  59        return -ERESTARTNOHAND;
  60}
  61
  62asmlinkage int
  63sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  64                unsigned long r2, unsigned long r3, unsigned long r4,
  65                unsigned long r5, unsigned long r6, struct pt_regs *regs)
  66{
  67        return do_sigaltstack(uss, uoss, regs->spu);
  68}
  69
  70
  71/*
  72 * Do a signal return; undo the signal stack.
  73 */
  74
  75struct rt_sigframe
  76{
  77        int sig;
  78        struct siginfo __user *pinfo;
  79        void __user *puc;
  80        struct siginfo info;
  81        struct ucontext uc;
  82//      struct _fpstate fpstate;
  83};
  84
  85static int
  86restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  87                   int *r0_p)
  88{
  89        unsigned int err = 0;
  90
  91        /* Always make any pending restarted system calls return -EINTR */
  92        current_thread_info()->restart_block.fn = do_no_restart_syscall;
  93
  94#define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
  95        COPY(r4);
  96        COPY(r5);
  97        COPY(r6);
  98        COPY(pt_regs);
  99        /* COPY(r0); Skip r0 */
 100        COPY(r1);
 101        COPY(r2);
 102        COPY(r3);
 103        COPY(r7);
 104        COPY(r8);
 105        COPY(r9);
 106        COPY(r10);
 107        COPY(r11);
 108        COPY(r12);
 109        COPY(acc0h);
 110        COPY(acc0l);
 111        COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 112        COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 113        COPY(psw);
 114        COPY(bpc);
 115        COPY(bbpsw);
 116        COPY(bbpc);
 117        COPY(spu);
 118        COPY(fp);
 119        COPY(lr);
 120        COPY(spi);
 121#undef COPY
 122
 123        regs->syscall_nr = -1;  /* disable syscall checks */
 124        err |= __get_user(*r0_p, &sc->sc_r0);
 125
 126        return err;
 127}
 128
 129asmlinkage int
 130sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 131                 unsigned long r2, unsigned long r3, unsigned long r4,
 132                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
 133{
 134        struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 135        sigset_t set;
 136        int result;
 137
 138        if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 139                goto badframe;
 140        if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 141                goto badframe;
 142
 143        sigdelsetmask(&set, ~_BLOCKABLE);
 144        spin_lock_irq(&current->sighand->siglock);
 145        current->blocked = set;
 146        recalc_sigpending();
 147        spin_unlock_irq(&current->sighand->siglock);
 148
 149        if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 150                goto badframe;
 151
 152        if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 153                goto badframe;
 154
 155        return result;
 156
 157badframe:
 158        force_sig(SIGSEGV, current);
 159        return 0;
 160}
 161
 162/*
 163 * Set up a signal frame.
 164 */
 165
 166static int
 167setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 168                 unsigned long mask)
 169{
 170        int err = 0;
 171
 172#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 173        COPY(r4);
 174        COPY(r5);
 175        COPY(r6);
 176        COPY(pt_regs);
 177        COPY(r0);
 178        COPY(r1);
 179        COPY(r2);
 180        COPY(r3);
 181        COPY(r7);
 182        COPY(r8);
 183        COPY(r9);
 184        COPY(r10);
 185        COPY(r11);
 186        COPY(r12);
 187        COPY(acc0h);
 188        COPY(acc0l);
 189        COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 190        COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 191        COPY(psw);
 192        COPY(bpc);
 193        COPY(bbpsw);
 194        COPY(bbpc);
 195        COPY(spu);
 196        COPY(fp);
 197        COPY(lr);
 198        COPY(spi);
 199#undef COPY
 200
 201        err |= __put_user(mask, &sc->oldmask);
 202
 203        return err;
 204}
 205
 206/*
 207 * Determine which stack to use..
 208 */
 209static inline void __user *
 210get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 211{
 212        /* This is the X/Open sanctioned signal stack switching.  */
 213        if (ka->sa.sa_flags & SA_ONSTACK) {
 214                if (sas_ss_flags(sp) == 0)
 215                        sp = current->sas_ss_sp + current->sas_ss_size;
 216        }
 217
 218        return (void __user *)((sp - frame_size) & -8ul);
 219}
 220
 221static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 222                           sigset_t *set, struct pt_regs *regs)
 223{
 224        struct rt_sigframe __user *frame;
 225        int err = 0;
 226        int signal;
 227
 228        frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 229
 230        if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 231                goto give_sigsegv;
 232
 233        signal = current_thread_info()->exec_domain
 234                && current_thread_info()->exec_domain->signal_invmap
 235                && sig < 32
 236                ? current_thread_info()->exec_domain->signal_invmap[sig]
 237                : sig;
 238
 239        err |= __put_user(signal, &frame->sig);
 240        if (err)
 241                goto give_sigsegv;
 242
 243        err |= __put_user(&frame->info, &frame->pinfo);
 244        err |= __put_user(&frame->uc, &frame->puc);
 245        err |= copy_siginfo_to_user(&frame->info, info);
 246        if (err)
 247                goto give_sigsegv;
 248
 249        /* Create the ucontext.  */
 250        err |= __put_user(0, &frame->uc.uc_flags);
 251        err |= __put_user(0, &frame->uc.uc_link);
 252        err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 253        err |= __put_user(sas_ss_flags(regs->spu),
 254                          &frame->uc.uc_stack.ss_flags);
 255        err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 256        err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 257        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 258        if (err)
 259                goto give_sigsegv;
 260
 261        /* Set up to return from userspace.  */
 262        regs->lr = (unsigned long)ka->sa.sa_restorer;
 263
 264        /* Set up registers for signal handler */
 265        regs->spu = (unsigned long)frame;
 266        regs->r0 = signal;      /* Arg for signal handler */
 267        regs->r1 = (unsigned long)&frame->info;
 268        regs->r2 = (unsigned long)&frame->uc;
 269        regs->bpc = (unsigned long)ka->sa.sa_handler;
 270
 271        set_fs(USER_DS);
 272
 273#if DEBUG_SIG
 274        printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 275                current->comm, current->pid, frame, regs->pc);
 276#endif
 277
 278        return;
 279
 280give_sigsegv:
 281        force_sigsegv(sig, current);
 282}
 283
 284/*
 285 * OK, we're invoking a handler
 286 */
 287
 288static void
 289handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 290              sigset_t *oldset, struct pt_regs *regs)
 291{
 292        unsigned short inst;
 293
 294        /* Are we from a system call? */
 295        if (regs->syscall_nr >= 0) {
 296                /* If so, check system call restarting.. */
 297                switch (regs->r0) {
 298                        case -ERESTART_RESTARTBLOCK:
 299                        case -ERESTARTNOHAND:
 300                                regs->r0 = -EINTR;
 301                                break;
 302
 303                        case -ERESTARTSYS:
 304                                if (!(ka->sa.sa_flags & SA_RESTART)) {
 305                                        regs->r0 = -EINTR;
 306                                        break;
 307                                }
 308                        /* fallthrough */
 309                        case -ERESTARTNOINTR:
 310                                regs->r0 = regs->orig_r0;
 311                                inst = *(unsigned short *)(regs->bpc - 2);
 312                                if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 313                                        regs->bpc -= 2;
 314                                else
 315                                        regs->bpc -= 4;
 316                }
 317        }
 318
 319        /* Set up the stack frame */
 320        setup_rt_frame(sig, ka, info, oldset, regs);
 321
 322        spin_lock_irq(&current->sighand->siglock);
 323        sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 324        if (!(ka->sa.sa_flags & SA_NODEFER))
 325                sigaddset(&current->blocked,sig);
 326        recalc_sigpending();
 327        spin_unlock_irq(&current->sighand->siglock);
 328}
 329
 330/*
 331 * Note that 'init' is a special process: it doesn't get signals it doesn't
 332 * want to handle. Thus you cannot kill init even with a SIGKILL even by
 333 * mistake.
 334 */
 335int do_signal(struct pt_regs *regs, sigset_t *oldset)
 336{
 337        siginfo_t info;
 338        int signr;
 339        struct k_sigaction ka;
 340        unsigned short inst;
 341
 342        /*
 343         * We want the common case to go fast, which
 344         * is why we may in certain cases get here from
 345         * kernel mode. Just return without doing anything
 346         * if so.
 347         */
 348        if (!user_mode(regs))
 349                return 1;
 350
 351        if (try_to_freeze()) 
 352                goto no_signal;
 353
 354        if (!oldset)
 355                oldset = &current->blocked;
 356
 357        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 358        if (signr > 0) {
 359                /* Re-enable any watchpoints before delivering the
 360                 * signal to user space. The processor register will
 361                 * have been cleared if the watchpoint triggered
 362                 * inside the kernel.
 363                 */
 364
 365                /* Whee!  Actually deliver the signal.  */
 366                handle_signal(signr, &ka, &info, oldset, regs);
 367                return 1;
 368        }
 369
 370 no_signal:
 371        /* Did we come from a system call? */
 372        if (regs->syscall_nr >= 0) {
 373                /* Restart the system call - no handlers present */
 374                if (regs->r0 == -ERESTARTNOHAND ||
 375                    regs->r0 == -ERESTARTSYS ||
 376                    regs->r0 == -ERESTARTNOINTR) {
 377                        regs->r0 = regs->orig_r0;
 378                        inst = *(unsigned short *)(regs->bpc - 2);
 379                        if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 380                                regs->bpc -= 2;
 381                        else
 382                                regs->bpc -= 4;
 383                }
 384                if (regs->r0 == -ERESTART_RESTARTBLOCK){
 385                        regs->r0 = regs->orig_r0;
 386                        regs->r7 = __NR_restart_syscall;
 387                        inst = *(unsigned short *)(regs->bpc - 2);
 388                        if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 389                                regs->bpc -= 2;
 390                        else
 391                                regs->bpc -= 4;
 392                }
 393        }
 394        return 0;
 395}
 396
 397/*
 398 * notification of userspace execution resumption
 399 * - triggered by current->work.notify_resume
 400 */
 401void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 402                      __u32 thread_info_flags)
 403{
 404        /* Pending single-step? */
 405        if (thread_info_flags & _TIF_SINGLESTEP)
 406                clear_thread_flag(TIF_SINGLESTEP);
 407
 408        /* deal with pending signal delivery */
 409        if (thread_info_flags & _TIF_SIGPENDING)
 410                do_signal(regs,oldset);
 411
 412        if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 413                clear_thread_flag(TIF_NOTIFY_RESUME);
 414                tracehook_notify_resume(regs);
 415                if (current->replacement_session_keyring)
 416                        key_replace_session_keyring();
 417        }
 418
 419        clear_thread_flag(TIF_IRET);
 420}
 421
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