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 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  32
  33 asmlinkage int
  34 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  35                 unsigned long r2, unsigned long r3, unsigned long r4,
  36                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
  37 {
  38         return do_sigaltstack(uss, uoss, regs->spu);
  39 }
  40
  41
  42 /*
  43  * Do a signal return; undo the signal stack.
  44  */
  45
  46 struct rt_sigframe
  47 {
  48         int sig;
  49         struct siginfo __user *pinfo;
  50         void __user *puc;
  51         struct siginfo info;
  52         struct ucontext uc;
  53 //      struct _fpstate fpstate;
  54 };
  55
  56 static int
  57 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  58                    int *r0_p)
  59 {
  60         unsigned int err = 0;
  61
  62         /* Always make any pending restarted system calls return -EINTR */
  63         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  64
  65 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
  66         COPY(r4);
  67         COPY(r5);
  68         COPY(r6);
  69         COPY(pt_regs);
  70         /* COPY(r0); Skip r0 */
  71         COPY(r1);
  72         COPY(r2);
  73         COPY(r3);
  74         COPY(r7);
  75         COPY(r8);
  76         COPY(r9);
  77         COPY(r10);
  78         COPY(r11);
  79         COPY(r12);
  80         COPY(acc0h);
  81         COPY(acc0l);
  82         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
  83         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
  84         COPY(psw);
  85         COPY(bpc);
  86         COPY(bbpsw);
  87         COPY(bbpc);
  88         COPY(spu);
  89         COPY(fp);
  90         COPY(lr);
  91         COPY(spi);
  92 #undef COPY
  93
  94         regs->syscall_nr = -1;  /* disable syscall checks */
  95         err |= __get_user(*r0_p, &sc->sc_r0);
  96
  97         return err;
  98 }
  99
 100 asmlinkage int
 101 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 102                  unsigned long r2, unsigned long r3, unsigned long r4,
 103                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
 104 {
 105         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 106         sigset_t set;
 107         int result;
 108
 109         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 110                 goto badframe;
 111         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 112                 goto badframe;
 113
 114         sigdelsetmask(&set, ~_BLOCKABLE);
 115         spin_lock_irq(&current->sighand->siglock);
 116         current->blocked = set;
 117         recalc_sigpending();
 118         spin_unlock_irq(&current->sighand->siglock);
 119
 120         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
 121                 goto badframe;
 122
 123         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 124                 goto badframe;
 125
 126         return result;
 127
 128 badframe:
 129         force_sig(SIGSEGV, current);
 130         return 0;
 131 }
 132
 133 /*
 134  * Set up a signal frame.
 135  */
 136
 137 static int
 138 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 139                  unsigned long mask)
 140 {
 141         int err = 0;
 142
 143 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 144         COPY(r4);
 145         COPY(r5);
 146         COPY(r6);
 147         COPY(pt_regs);
 148         COPY(r0);
 149         COPY(r1);
 150         COPY(r2);
 151         COPY(r3);
 152         COPY(r7);
 153         COPY(r8);
 154         COPY(r9);
 155         COPY(r10);
 156         COPY(r11);
 157         COPY(r12);
 158         COPY(acc0h);
 159         COPY(acc0l);
 160         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
 161         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
 162         COPY(psw);
 163         COPY(bpc);
 164         COPY(bbpsw);
 165         COPY(bbpc);
 166         COPY(spu);
 167         COPY(fp);
 168         COPY(lr);
 169         COPY(spi);
 170 #undef COPY
 171
 172         err |= __put_user(mask, &sc->oldmask);
 173
 174         return err;
 175 }
 176
 177 /*
 178  * Determine which stack to use..
 179  */
 180 static inline void __user *
 181 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 182 {
 183         /* This is the X/Open sanctioned signal stack switching.  */
 184         if (ka->sa.sa_flags & SA_ONSTACK) {
 185                 if (sas_ss_flags(sp) == 0)
 186                         sp = current->sas_ss_sp + current->sas_ss_size;
 187         }
 188
 189         return (void __user *)((sp - frame_size) & -8ul);
 190 }
 191
 192 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 193                            sigset_t *set, struct pt_regs *regs)
 194 {
 195         struct rt_sigframe __user *frame;
 196         int err = 0;
 197         int signal;
 198
 199         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 200
 201         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 202                 goto give_sigsegv;
 203
 204         signal = current_thread_info()->exec_domain
 205                 && current_thread_info()->exec_domain->signal_invmap
 206                 && sig < 32
 207                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 208                 : sig;
 209
 210         err |= __put_user(signal, &frame->sig);
 211         if (err)
 212                 goto give_sigsegv;
 213
 214         err |= __put_user(&frame->info, &frame->pinfo);
 215         err |= __put_user(&frame->uc, &frame->puc);
 216         err |= copy_siginfo_to_user(&frame->info, info);
 217         if (err)
 218                 goto give_sigsegv;
 219
 220         /* Create the ucontext.  */
 221         err |= __put_user(0, &frame->uc.uc_flags);
 222         err |= __put_user(0, &frame->uc.uc_link);
 223         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 224         err |= __put_user(sas_ss_flags(regs->spu),
 225                           &frame->uc.uc_stack.ss_flags);
 226         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 227         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 228         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 229         if (err)
 230                 goto give_sigsegv;
 231
 232         /* Set up to return from userspace.  */
 233         regs->lr = (unsigned long)ka->sa.sa_restorer;
 234
 235         /* Set up registers for signal handler */
 236         regs->spu = (unsigned long)frame;
 237         regs->r0 = signal;      /* Arg for signal handler */
 238         regs->r1 = (unsigned long)&frame->info;
 239         regs->r2 = (unsigned long)&frame->uc;
 240         regs->bpc = (unsigned long)ka->sa.sa_handler;
 241
 242         set_fs(USER_DS);
 243
 244 #if DEBUG_SIG
 245         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 246                 current->comm, current->pid, frame, regs->pc);
 247 #endif
 248
 249         return 0;
 250
 251 give_sigsegv:
 252         force_sigsegv(sig, current);
 253         return -EFAULT;
 254 }
 255
 256 static int prev_insn(struct pt_regs *regs)
 257 {
 258         u16 inst;
 259         if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
 260                 return -EFAULT;
 261         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 262                 regs->bpc -= 2;
 263         else
 264                 regs->bpc -= 4;
 265         regs->syscall_nr = -1;
 266         return 0;
 267 }
 268
 269 /*
 270  * OK, we're invoking a handler
 271  */
 272
 273 static int
 274 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 275               sigset_t *oldset, struct pt_regs *regs)
 276 {
 277         /* Are we from a system call? */
 278         if (regs->syscall_nr >= 0) {
 279                 /* If so, check system call restarting.. */
 280                 switch (regs->r0) {
 281                         case -ERESTART_RESTARTBLOCK:
 282                         case -ERESTARTNOHAND:
 283                                 regs->r0 = -EINTR;
 284                                 break;
 285
 286                         case -ERESTARTSYS:
 287                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 288                                         regs->r0 = -EINTR;
 289                                         break;
 290                                 }
 291                         /* fallthrough */
 292                         case -ERESTARTNOINTR:
 293                                 regs->r0 = regs->orig_r0;
 294                                 if (prev_insn(regs) < 0)
 295                                         return -EFAULT;
 296                 }
 297         }
 298
 299         /* Set up the stack frame */
 300         if (setup_rt_frame(sig, ka, info, oldset, regs))
 301                 return -EFAULT;
 302
 303         spin_lock_irq(&current->sighand->siglock);
 304         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 305         if (!(ka->sa.sa_flags & SA_NODEFER))
 306                 sigaddset(&current->blocked,sig);
 307         recalc_sigpending();
 308         spin_unlock_irq(&current->sighand->siglock);
 309         return 0;
 310 }
 311
 312 /*
 313  * Note that 'init' is a special process: it doesn't get signals it doesn't
 314  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 315  * mistake.
 316  */
 317 static void do_signal(struct pt_regs *regs)
 318 {
 319         siginfo_t info;
 320         int signr;
 321         struct k_sigaction ka;
 322         sigset_t *oldset;
 323
 324         /*
 325          * We want the common case to go fast, which
 326          * is why we may in certain cases get here from
 327          * kernel mode. Just return without doing anything
 328          * if so.
 329          */
 330         if (!user_mode(regs))
 331                 return;
 332
 333         if (try_to_freeze())
 334                 goto no_signal;
 335
 336         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 337                 oldset = &current->saved_sigmask;
 338         else
 339                 oldset = &current->blocked;
 340
 341         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 342         if (signr > 0) {
 343                 /* Re-enable any watchpoints before delivering the
 344                  * signal to user space. The processor register will
 345                  * have been cleared if the watchpoint triggered
 346                  * inside the kernel.
 347                  */
 348
 349                 /* Whee!  Actually deliver the signal.  */
 350                 if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
 351                         clear_thread_flag(TIF_RESTORE_SIGMASK);
 352
 353                 return;
 354         }
 355
 356  no_signal:
 357         /* Did we come from a system call? */
 358         if (regs->syscall_nr >= 0) {
 359                 /* Restart the system call - no handlers present */
 360                 if (regs->r0 == -ERESTARTNOHAND ||
 361                     regs->r0 == -ERESTARTSYS ||
 362                     regs->r0 == -ERESTARTNOINTR) {
 363                         regs->r0 = regs->orig_r0;
 364                         prev_insn(regs);
 365                 } else if (regs->r0 == -ERESTART_RESTARTBLOCK){
 366                         regs->r0 = regs->orig_r0;
 367                         regs->r7 = __NR_restart_syscall;
 368                         prev_insn(regs);
 369                 }
 370         }
 371         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 372                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 373                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 374         }
 375 }
 376
 377 /*
 378  * notification of userspace execution resumption
 379  * - triggered by current->work.notify_resume
 380  */
 381 void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
 382 {
 383         /* Pending single-step? */
 384         if (thread_info_flags & _TIF_SINGLESTEP)
 385                 clear_thread_flag(TIF_SINGLESTEP);
 386
 387         /* deal with pending signal delivery */
 388         if (thread_info_flags & _TIF_SIGPENDING)
 389                 do_signal(regs);
 390
 391         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 392                 clear_thread_flag(TIF_NOTIFY_RESUME);
 393                 tracehook_notify_resume(regs);
 394                 if (current->replacement_session_keyring)
 395                         key_replace_session_keyring();
 396         }
 397
 398         clear_thread_flag(TIF_IRET);
 399 }