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