diff options
Diffstat (limited to 'arch/mn10300/kernel/signal.c')
| -rw-r--r-- | arch/mn10300/kernel/signal.c | 564 |
1 files changed, 564 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c new file mode 100644 index 000000000000..841ca9955a18 --- /dev/null +++ b/arch/mn10300/kernel/signal.c @@ -0,0 +1,564 @@ +/* MN10300 Signal handling + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#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/suspend.h> +#include <asm/cacheflush.h> +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/fpu.h> +#include "sigframe.h" + +#define DEBUG_SIG 0 + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +/* + * atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage long sys_sigsuspend(int history0, int history1, old_sigset_t mask) +{ + mask &= _BLOCKABLE; + spin_lock_irq(¤t->sighand->siglock); + current->saved_sigmask = current->blocked; + siginitset(¤t->blocked, mask); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + current->state = TASK_INTERRUPTIBLE; + schedule(); + set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; +} + +/* + * set signal action syscall + */ +asmlinkage long 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 (verify_area(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 (verify_area(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; +} + +/* + * set alternate signal stack syscall + */ +asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t *uoss) +{ + return do_sigaltstack(uss, uoss, __frame->sp); +} + +/* + * do a signal return; undo the signal stack. + */ +static int restore_sigcontext(struct pt_regs *regs, + struct sigcontext __user *sc, long *_d0) +{ + unsigned int err = 0; + + if (is_using_fpu(current)) + fpu_kill_state(current); + +#define COPY(x) err |= __get_user(regs->x, &sc->x) + COPY(d1); COPY(d2); COPY(d3); + COPY(a0); COPY(a1); COPY(a2); COPY(a3); + COPY(e0); COPY(e1); COPY(e2); COPY(e3); + COPY(e4); COPY(e5); COPY(e6); COPY(e7); + COPY(lar); COPY(lir); + COPY(mdr); COPY(mdrq); + COPY(mcvf); COPY(mcrl); COPY(mcrh); + COPY(sp); COPY(pc); +#undef COPY + + { + unsigned int tmpflags; +#ifndef CONFIG_MN10300_USING_JTAG +#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \ + EPSW_T | EPSW_nAR) +#else +#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \ + EPSW_nAR) +#endif + err |= __get_user(tmpflags, &sc->epsw); + regs->epsw = (regs->epsw & ~USER_EPSW) | + (tmpflags & USER_EPSW); + regs->orig_d0 = -1; /* disable syscall checks */ + } + + { + struct fpucontext *buf; + err |= __get_user(buf, &sc->fpucontext); + if (buf) { + if (verify_area(VERIFY_READ, buf, sizeof(*buf))) + goto badframe; + err |= fpu_restore_sigcontext(buf); + } + } + + err |= __get_user(*_d0, &sc->d0); + return err; + +badframe: + return 1; +} + +/* + * standard signal return syscall + */ +asmlinkage long sys_sigreturn(void) +{ + struct sigframe __user *frame = (struct sigframe __user *) __frame->sp; + sigset_t set; + long d0; + + if (verify_area(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + if (__get_user(set.sig[0], &frame->sc.oldmask)) + goto badframe; + + if (_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(__frame, &frame->sc, &d0)) + goto badframe; + + return d0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * realtime signal return syscall + */ +asmlinkage long sys_rt_sigreturn(void) +{ + struct rt_sigframe __user *frame = + (struct rt_sigframe __user *) __frame->sp; + sigset_t set; + unsigned long d0; + + if (verify_area(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(__frame, &frame->uc.uc_mcontext, &d0)) + goto badframe; + + if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT) + goto badframe; + + return d0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * store the userspace context into a signal frame + */ +static int setup_sigcontext(struct sigcontext __user *sc, + struct fpucontext *fpuctx, + struct pt_regs *regs, + unsigned long mask) +{ + int tmp, err = 0; + +#define COPY(x) err |= __put_user(regs->x, &sc->x) + COPY(d0); COPY(d1); COPY(d2); COPY(d3); + COPY(a0); COPY(a1); COPY(a2); COPY(a3); + COPY(e0); COPY(e1); COPY(e2); COPY(e3); + COPY(e4); COPY(e5); COPY(e6); COPY(e7); + COPY(lar); COPY(lir); + COPY(mdr); COPY(mdrq); + COPY(mcvf); COPY(mcrl); COPY(mcrh); + COPY(sp); COPY(epsw); COPY(pc); +#undef COPY + + tmp = fpu_setup_sigcontext(fpuctx); + if (tmp < 0) + err = 1; + else + err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext); + + /* 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, + struct pt_regs *regs, + size_t frame_size) +{ + unsigned long sp; + + /* default to using normal stack */ + sp = regs->sp; + + /* this is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (!on_sig_stack(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + } + + return (void __user *) ((sp - frame_size) & ~7UL); +} + +/* + * set up a normal signal frame + */ +static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, + struct pt_regs *regs) +{ + struct sigframe __user *frame; + int rsig; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + rsig = sig; + if (sig < 32 && + current_thread_info()->exec_domain && + current_thread_info()->exec_domain->signal_invmap) + rsig = current_thread_info()->exec_domain->signal_invmap[sig]; + + if (__put_user(rsig, &frame->sig) < 0 || + __put_user(&frame->sc, &frame->psc) < 0) + goto give_sigsegv; + + if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0])) + goto give_sigsegv; + + if (_NSIG_WORDS > 1) { + if (__copy_to_user(frame->extramask, &set->sig[1], + sizeof(frame->extramask))) + goto give_sigsegv; + } + + /* set up to return from userspace. If provided, use a stub already in + * userspace */ + if (ka->sa.sa_flags & SA_RESTORER) { + if (__put_user(ka->sa.sa_restorer, &frame->pretcode)) + goto give_sigsegv; + } else { + if (__put_user((void (*)(void))frame->retcode, + &frame->pretcode)) + goto give_sigsegv; + /* this is mov $,d0; syscall 0 */ + if (__put_user(0x2c, (char *)(frame->retcode + 0)) || + __put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) || + __put_user(0x00, (char *)(frame->retcode + 2)) || + __put_user(0xf0, (char *)(frame->retcode + 3)) || + __put_user(0xe0, (char *)(frame->retcode + 4))) + goto give_sigsegv; + flush_icache_range((unsigned long) frame->retcode, + (unsigned long) frame->retcode + 5); + } + + /* set up registers for signal handler */ + regs->sp = (unsigned long) frame; + regs->pc = (unsigned long) ka->sa.sa_handler; + regs->d0 = sig; + regs->d1 = (unsigned long) &frame->sc; + + set_fs(USER_DS); + + /* the tracer may want to single-step inside the handler */ + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + +#if DEBUG_SIG + printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", + sig, current->comm, current->pid, frame, regs->pc, + frame->pretcode); +#endif + + return 0; + +give_sigsegv: + force_sig(SIGSEGV, current); + return -EFAULT; +} + +/* + * set up a realtime signal frame + */ +static int 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 rsig; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + rsig = sig; + if (sig < 32 && + current_thread_info()->exec_domain && + current_thread_info()->exec_domain->signal_invmap) + rsig = current_thread_info()->exec_domain->signal_invmap[sig]; + + if (__put_user(rsig, &frame->sig) || + __put_user(&frame->info, &frame->pinfo) || + __put_user(&frame->uc, &frame->puc) || + copy_siginfo_to_user(&frame->info, info)) + goto give_sigsegv; + + /* create the ucontext. */ + if (__put_user(0, &frame->uc.uc_flags) || + __put_user(0, &frame->uc.uc_link) || + __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) || + __put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags) || + __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size) || + setup_sigcontext(&frame->uc.uc_mcontext, + &frame->fpuctx, regs, set->sig[0]) || + __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set))) + goto give_sigsegv; + + /* set up to return from userspace. If provided, use a stub already in + * userspace */ + if (ka->sa.sa_flags & SA_RESTORER) { + if (__put_user(ka->sa.sa_restorer, &frame->pretcode)) + goto give_sigsegv; + } else { + if (__put_user((void(*)(void))frame->retcode, + &frame->pretcode) || + /* This is mov $,d0; syscall 0 */ + __put_user(0x2c, (char *)(frame->retcode + 0)) || + __put_user(__NR_rt_sigreturn, + (char *)(frame->retcode + 1)) || + __put_user(0x00, (char *)(frame->retcode + 2)) || + __put_user(0xf0, (char *)(frame->retcode + 3)) || + __put_user(0xe0, (char *)(frame->retcode + 4))) + goto give_sigsegv; + + flush_icache_range((u_long) frame->retcode, + (u_long) frame->retcode + 5); + } + + /* Set up registers for signal handler */ + regs->sp = (unsigned long) frame; + regs->pc = (unsigned long) ka->sa.sa_handler; + regs->d0 = sig; + regs->d1 = (long) &frame->info; + + set_fs(USER_DS); + + /* the tracer may want to single-step inside the handler */ + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + +#if DEBUG_SIG + printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", + sig, current->comm, current->pid, frame, regs->pc, + frame->pretcode); +#endif + + return 0; + +give_sigsegv: + force_sig(SIGSEGV, current); + return -EFAULT; +} + +/* + * handle the actual delivery of a signal to userspace + */ +static int handle_signal(int sig, + siginfo_t *info, struct k_sigaction *ka, + sigset_t *oldset, struct pt_regs *regs) +{ + int ret; + + /* Are we from a system call? */ + if (regs->orig_d0 >= 0) { + /* If so, check system call restarting.. */ + switch (regs->d0) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + regs->d0 = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->d0 = -EINTR; + break; + } + + /* fallthrough */ + case -ERESTARTNOINTR: + regs->d0 = regs->orig_d0; + regs->pc -= 2; + } + } + + /* Set up the stack frame */ + if (ka->sa.sa_flags & SA_SIGINFO) + ret = setup_rt_frame(sig, ka, info, oldset, regs); + else + ret = setup_frame(sig, ka, oldset, regs); + + if (ret == 0) { + 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); + } + + return ret; +} + +/* + * handle a potential signal + */ +static void do_signal(struct pt_regs *regs) +{ + struct k_sigaction ka; + siginfo_t info; + sigset_t *oldset; + int signr; + + /* we want the common case to go fast, which is why we may in certain + * cases get here from kernel mode */ + if (!user_mode(regs)) + return; + + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + oldset = ¤t->saved_sigmask; + else + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { + /* a signal was successfully delivered; the saved + * sigmask will have been stored in the signal frame, + * and will be restored by sigreturn, so we can simply + * clear the TIF_RESTORE_SIGMASK flag */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + clear_thread_flag(TIF_RESTORE_SIGMASK); + } + + return; + } + + /* did we come from a system call? */ + if (regs->orig_d0 >= 0) { + /* restart the system call - no handlers present */ + switch (regs->d0) { + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + regs->d0 = regs->orig_d0; + regs->pc -= 2; + break; + + case -ERESTART_RESTARTBLOCK: + regs->d0 = __NR_restart_syscall; + regs->pc -= 2; + break; + } + } + + /* if there's no signal to deliver, we just put the saved sigmask + * back */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) { + clear_thread_flag(TIF_RESTORE_SIGMASK); + sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); + } +} + +/* + * notification of userspace execution resumption + * - triggered by current->work.notify_resume + */ +asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) +{ + /* Pending single-step? */ + if (thread_info_flags & _TIF_SINGLESTEP) { +#ifndef CONFIG_MN10300_USING_JTAG + regs->epsw |= EPSW_T; + clear_thread_flag(TIF_SINGLESTEP); +#else + BUG(); /* no h/w single-step if using JTAG unit */ +#endif + } + + /* deal with pending signal delivery */ + if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) + do_signal(regs); +} |
