/* * arch/v850/kernel/signal.c -- Signal handling * * Copyright (C) 2001,02,03 NEC Electronics Corporation * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org> * Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima * Copyright (C) 1991,1992 Linus Torvalds * * This file is subject to the terms and conditions of the GNU General * Public License. See the file COPYING in the main directory of this * archive for more details. * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * * This file was derived from the sh version, arch/sh/kernel/signal.c */ #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/personality.h> #include <linux/tty.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/thread_info.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, 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->gpr[GPR_RVAL] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(regs, &saveset)) return -EINTR; } } asmlinkage int sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, 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->gpr[GPR_RVAL] = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(regs, &saveset)) return -EINTR; } } asmlinkage int sys_sigaction(int sig, const struct old_sigaction *act, struct old_sigaction *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 *uss, stack_t *uoss, struct pt_regs *regs) { return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]); } /* * Do a signal return; undo the signal stack. */ struct sigframe { struct sigcontext sc; unsigned long extramask[_NSIG_WORDS-1]; unsigned long tramp[2]; /* signal trampoline */ }; struct rt_sigframe { struct siginfo info; struct ucontext uc; unsigned long tramp[2]; /* signal trampoline */ }; static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p) { unsigned int err = 0; #define COPY(x) err |= __get_user(regs->x, &sc->regs.x) COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); COPY(pc); COPY(psw); COPY(ctpc); COPY(ctpsw); COPY(ctbp); #undef COPY return err; } asmlinkage int sys_sigreturn(struct pt_regs *regs) { struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP]; sigset_t set; int rval; 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(regs, &frame->sc, &rval)) goto badframe; return rval; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP]; sigset_t set; stack_t st; int rval; 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(regs, &frame->uc.uc_mcontext, &rval)) 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->gpr[GPR_SP]); return rval; badframe: force_sig(SIGSEGV, current); return 0; } /* * Set up a signal frame. */ static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, unsigned long mask) { int err = 0; #define COPY(x) err |= __put_user(regs->x, &sc->regs.x) COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); COPY(pc); COPY(psw); COPY(ctpc); COPY(ctpsw); COPY(ctbp); #undef COPY err |= __put_user(mask, &sc->oldmask); return err; } /* * Determine which stack to use.. */ static inline void * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) { /* Default to using normal stack */ unsigned long sp = regs->gpr[GPR_SP]; if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) sp = current->sas_ss_sp + current->sas_ss_size; return (void *)((sp - frame_size) & -8UL); } static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) { struct sigframe *frame; int err = 0; int signal; frame = get_sigframe(ka, regs, 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->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; } else { /* Note, these encodings are _little endian_! */ /* addi __NR_sigreturn, r0, r12 */ err |= __put_user(0x6600 | (__NR_sigreturn << 16), frame->tramp + 0); /* trap 0 */ err |= __put_user(0x010007e0, frame->tramp + 1); regs->gpr[GPR_LP] = (unsigned long)frame->tramp; flush_cache_sigtramp (regs->gpr[GPR_LP]); } if (err) goto give_sigsegv; /* Set up registers for signal handler. */ regs->pc = (v850_reg_t) ka->sa.sa_handler; regs->gpr[GPR_SP] = (v850_reg_t)frame; /* Signal handler args: */ regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */ set_fs(USER_DS); #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n", current->comm, current->pid, frame, regs->pc, ); #endif 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 *frame; int err = 0; int signal; frame = get_sigframe(ka, regs, 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->gpr[GPR_SP]), &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->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; } else { /* Note, these encodings are _little endian_! */ /* addi __NR_sigreturn, r0, r12 */ err |= __put_user(0x6600 | (__NR_sigreturn << 16), frame->tramp + 0); /* trap 0 */ err |= __put_user(0x010007e0, frame->tramp + 1); regs->gpr[GPR_LP] = (unsigned long)frame->tramp; flush_cache_sigtramp (regs->gpr[GPR_LP]); } if (err) goto give_sigsegv; /* Set up registers for signal handler. */ regs->pc = (v850_reg_t) ka->sa.sa_handler; regs->gpr[GPR_SP] = (v850_reg_t)frame; /* Signal handler args: */ regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */ regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */ 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 return; give_sigsegv: force_sigsegv(sig, current); } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, sigset_t *oldset, struct pt_regs * regs) { /* Are we from a system call? */ if (PT_REGS_SYSCALL (regs)) { /* If so, check system call restarting.. */ switch (regs->gpr[GPR_RVAL]) { case -ERESTART_RESTARTBLOCK: current_thread_info()->restart_block.fn = do_no_restart_syscall; /* fall through */ case -ERESTARTNOHAND: regs->gpr[GPR_RVAL] = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->gpr[GPR_RVAL] = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->gpr[12] = PT_REGS_SYSCALL (regs); regs->pc -= 4; /* Size of `trap 0' insn. */ } PT_REGS_SET_SYSCALL (regs, 0); } /* 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); 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 (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ handle_signal(signr, &info, &ka, oldset, regs); return 1; } /* Did we come from a system call? */ if (PT_REGS_SYSCALL (regs)) { int rval = (int)regs->gpr[GPR_RVAL]; /* Restart the system call - no handlers present */ if (rval == -ERESTARTNOHAND || rval == -ERESTARTSYS || rval == -ERESTARTNOINTR) { regs->gpr[12] = PT_REGS_SYSCALL (regs); regs->pc -= 4; /* Size of `trap 0' insn. */ } else if (rval == -ERESTART_RESTARTBLOCK) { regs->gpr[12] = __NR_restart_syscall; regs->pc -= 4; /* Size of `trap 0' insn. */ } } return 0; }