/* * linux/arch/sh/kernel/signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima * */ #include <linux/sched.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/kernel.h> #include <linux/signal.h> #include <linux/errno.h> #include <linux/wait.h> #include <linux/ptrace.h> #include <linux/unistd.h> #include <linux/stddef.h> #include <linux/tty.h> #include <linux/personality.h> #include <linux/binfmts.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/cacheflush.h> #define DEBUG_SIG 0 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); /* * Atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int sys_sigsuspend(old_sigset_t mask, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { sigset_t saveset; mask &= _BLOCKABLE; spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs.regs[0] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(®s, &saveset)) return -EINTR; } } asmlinkage int sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, unsigned long r6, unsigned long r7, struct pt_regs regs) { sigset_t saveset, newset; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (copy_from_user(&newset, unewset, sizeof(newset))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs.regs[0] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(®s, &saveset)) return -EINTR; } } asmlinkage int sys_sigaction(int sig, const struct old_sigaction __user *act, struct old_sigaction __user *oact) { struct k_sigaction new_ka, old_ka; int ret; if (act) { old_sigset_t mask; if (!access_ok(VERIFY_READ, act, sizeof(*act)) || __get_user(new_ka.sa.sa_handler, &act->sa_handler) || __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) return -EFAULT; __get_user(new_ka.sa.sa_flags, &act->sa_flags); __get_user(mask, &act->sa_mask); siginitset(&new_ka.sa.sa_mask, mask); } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) return -EFAULT; __put_user(old_ka.sa.sa_flags, &oact->sa_flags); __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); } return ret; } asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r6, unsigned long r7, struct pt_regs regs) { return do_sigaltstack(uss, uoss, regs.regs[15]); } /* * Do a signal return; undo the signal stack. */ #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */ #define TRAP16 0xc310 /* Syscall w/no args (NR in R3) */ #define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */ struct sigframe { struct sigcontext sc; unsigned long extramask[_NSIG_WORDS-1]; u16 retcode[8]; }; struct rt_sigframe { struct siginfo info; struct ucontext uc; u16 retcode[8]; }; #ifdef CONFIG_SH_FPU static inline int restore_sigcontext_fpu(struct sigcontext __user *sc) { struct task_struct *tsk = current; if (!(cpu_data->flags & CPU_HAS_FPU)) return 0; set_used_math(); return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0], sizeof(long)*(16*2+2)); } static inline int save_sigcontext_fpu(struct sigcontext __user *sc, struct pt_regs *regs) { struct task_struct *tsk = current; if (!(cpu_data->flags & CPU_HAS_FPU)) return 0; if (!used_math()) { __put_user(0, &sc->sc_ownedfp); return 0; } __put_user(1, &sc->sc_ownedfp); /* This will cause a "finit" to be triggered by the next attempted FPU operation by the 'current' process. */ clear_used_math(); unlazy_fpu(tsk, regs); return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard, sizeof(long)*(16*2+2)); } #endif /* CONFIG_SH_FPU */ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p) { unsigned int err = 0; #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) COPY(regs[1]); COPY(regs[2]); COPY(regs[3]); COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]); COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]); COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY #ifdef CONFIG_SH_FPU if (cpu_data->flags & CPU_HAS_FPU) { int owned_fp; struct task_struct *tsk = current; regs->sr |= SR_FD; /* Release FPU */ clear_fpu(tsk, regs); clear_used_math(); __get_user (owned_fp, &sc->sc_ownedfp); if (owned_fp) err |= restore_sigcontext_fpu(sc); } #endif regs->tra = -1; /* disable syscall checks */ err |= __get_user(*r0_p, &sc->sc_regs[0]); return err; } asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { struct sigframe __user *frame = (struct sigframe __user *)regs.regs[15]; sigset_t set; int r0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 && __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(®s, &frame->sc, &r0)) goto badframe; return r0; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs.regs[15]; sigset_t set; stack_t st; int r0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(®s, &frame->uc.uc_mcontext, &r0)) goto badframe; if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) goto badframe; /* It is more difficult to avoid calling this function than to call it and ignore errors. */ do_sigaltstack(&st, NULL, regs.regs[15]); return r0; badframe: force_sig(SIGSEGV, current); return 0; } /* * Set up a signal frame. */ static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask) { int err = 0; #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]); COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]); COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]); COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY #ifdef CONFIG_SH_FPU err |= save_sigcontext_fpu(sc, regs); #endif /* non-iBCS2 extensions.. */ err |= __put_user(mask, &sc->oldmask); return err; } /* * Determine which stack to use.. */ static inline void __user * get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) { if (ka->sa.sa_flags & SA_ONSTACK) { if (sas_ss_flags(sp) == 0) sp = current->sas_ss_sp + current->sas_ss_size; } return (void __user *)((sp - frame_size) & -8ul); } static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) { struct sigframe __user *frame; int err = 0; int signal; frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; signal = current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); if (_NSIG_WORDS > 1) { err |= __copy_to_user(frame->extramask, &set->sig[1], sizeof(frame->extramask)); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->pr = (unsigned long) ka->sa.sa_restorer; } else { /* Generate return code (system call to sigreturn) */ err |= __put_user(MOVW(7), &frame->retcode[0]); err |= __put_user(TRAP16, &frame->retcode[1]); err |= __put_user(OR_R0_R0, &frame->retcode[2]); err |= __put_user(OR_R0_R0, &frame->retcode[3]); err |= __put_user(OR_R0_R0, &frame->retcode[4]); err |= __put_user(OR_R0_R0, &frame->retcode[5]); err |= __put_user(OR_R0_R0, &frame->retcode[6]); err |= __put_user((__NR_sigreturn), &frame->retcode[7]); regs->pr = (unsigned long) frame->retcode; } if (err) goto give_sigsegv; /* Set up registers for signal handler */ regs->regs[15] = (unsigned long) frame; regs->regs[4] = signal; /* Arg for signal handler */ regs->regs[5] = 0; regs->regs[6] = (unsigned long) &frame->sc; regs->pc = (unsigned long) ka->sa.sa_handler; set_fs(USER_DS); #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", current->comm, current->pid, frame, regs->pc, regs->pr); #endif flush_cache_sigtramp(regs->pr); if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode)) flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES); return; give_sigsegv: force_sigsegv(sig, current); } static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs *regs) { struct rt_sigframe __user *frame; int err = 0; int signal; frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; signal = current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; err |= copy_siginfo_to_user(&frame->info, info); /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->regs[15]), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->pr = (unsigned long) ka->sa.sa_restorer; } else { /* Generate return code (system call to rt_sigreturn) */ err |= __put_user(MOVW(7), &frame->retcode[0]); err |= __put_user(TRAP16, &frame->retcode[1]); err |= __put_user(OR_R0_R0, &frame->retcode[2]); err |= __put_user(OR_R0_R0, &frame->retcode[3]); err |= __put_user(OR_R0_R0, &frame->retcode[4]); err |= __put_user(OR_R0_R0, &frame->retcode[5]); err |= __put_user(OR_R0_R0, &frame->retcode[6]); err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]); regs->pr = (unsigned long) frame->retcode; } if (err) goto give_sigsegv; /* Set up registers for signal handler */ regs->regs[15] = (unsigned long) frame; regs->regs[4] = signal; /* Arg for signal handler */ regs->regs[5] = (unsigned long) &frame->info; regs->regs[6] = (unsigned long) &frame->uc; regs->pc = (unsigned long) ka->sa.sa_handler; set_fs(USER_DS); #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", current->comm, current->pid, frame, regs->pc, regs->pr); #endif flush_cache_sigtramp(regs->pr); if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode)) flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES); return; give_sigsegv: force_sigsegv(sig, current); } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) { /* Are we from a system call? */ if (regs->tra >= 0) { /* If so, check system call restarting.. */ switch (regs->regs[0]) { case -ERESTARTNOHAND: regs->regs[0] = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->regs[0] = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->pc -= 2; } } else { /* gUSA handling */ #ifdef CONFIG_PREEMPT unsigned long flags; local_irq_save(flags); #endif if (regs->regs[15] >= 0xc0000000) { int offset = (int)regs->regs[15]; /* Reset stack pointer: clear critical region mark */ regs->regs[15] = regs->regs[1]; if (regs->pc < regs->regs[0]) /* Go to rewind point #1 */ regs->pc = regs->regs[0] + offset - 2; } #ifdef CONFIG_PREEMPT local_irq_restore(flags); #endif } /* Set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) setup_rt_frame(sig, ka, info, oldset, regs); else setup_frame(sig, ka, oldset, regs); if (ka->sa.sa_flags & SA_ONESHOT) ka->sa.sa_handler = SIG_DFL; spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) sigaddset(¤t->blocked,sig); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } /* * Note that 'init' is a special process: it doesn't get signals it doesn't * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. * * Note that we go through the signals twice: once to check the signals that * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */ int do_signal(struct pt_regs *regs, sigset_t *oldset) { siginfo_t info; int signr; struct k_sigaction ka; /* * We want the common case to go fast, which * is why we may in certain cases get here from * kernel mode. Just return without doing anything * if so. */ if (!user_mode(regs)) return 1; if (try_to_freeze()) goto no_signal; if (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ handle_signal(signr, &ka, &info, oldset, regs); return 1; } no_signal: /* Did we come from a system call? */ if (regs->tra >= 0) { /* Restart the system call - no handlers present */ if (regs->regs[0] == -ERESTARTNOHAND || regs->regs[0] == -ERESTARTSYS || regs->regs[0] == -ERESTARTNOINTR || regs->regs[0] == -ERESTART_RESTARTBLOCK) { regs->pc -= 2; } } return 0; }