Example #1
0
static void
handle_signal(unsigned long sig, struct k_sigaction *ka,
              siginfo_t *info, sigset_t *oldset,
              struct pt_regs * regs, int syscall)
{
    struct thread_info *thread = current_thread_info();
    struct task_struct *tsk = current;
    int usig = sig;
    int ret;

    /*
     * If we were from a system call, check for system call restarting...
     */
    if (syscall) {
        switch (regs->r5) {
        case -ERESTART_RESTARTBLOCK:
        case -ERESTARTNOHAND:
            regs->r5 = -EINTR;
            break;
        case -ERESTARTSYS:
            if (!(ka->sa.sa_flags & SA_RESTART)) {
                regs->r5 = -EINTR;
                break;
            }
        /* fallthrough */
        case -ERESTARTNOINTR:
            restart_syscall(regs);
        }
    }

    /*
     * translate the signal
     */
    if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
        usig = thread->exec_domain->signal_invmap[usig];

    /*
     * Set up the stack frame
     */
    if (ka->sa.sa_flags & SA_SIGINFO)
        ret = setup_rt_frame(usig, ka, info, oldset, regs);
    else
        ret = setup_frame(usig, ka, oldset, regs);

    if (ret != 0) {
        force_sigsegv(sig, tsk);
        return;
    }

    /*
     * Block the signal if we were successful.
     */
    spin_lock_irq(&tsk->sighand->siglock);
    sigorsets(&tsk->blocked, &tsk->blocked,
              &ka->sa.sa_mask);
    if (!(ka->sa.sa_flags & SA_NODEFER))
        sigaddset(&tsk->blocked, sig);
    recalc_sigpending();
    spin_unlock_irq(&tsk->sighand->siglock);
}
Example #2
0
static ssize_t ifalias_store(struct device *dev, struct device_attribute *attr,
			     const char *buf, size_t len)
{
	struct net_device *netdev = to_net_dev(dev);
	struct net *net = dev_net(netdev);
	size_t count = len;
	ssize_t ret = 0;

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	/* ignore trailing newline */
	if (len >  0 && buf[len - 1] == '\n')
		--count;

	if (!rtnl_trylock())
		return restart_syscall();

	if (dev_isalive(netdev)) {
		ret = dev_set_alias(netdev, buf, count);
		if (ret < 0)
			goto err;
		ret = len;
		netdev_state_change(netdev);
	}
err:
	rtnl_unlock();

	return ret;
}
Example #3
0
static ssize_t brport_store(struct kobject *kobj,
			    struct attribute *attr,
			    const char *buf, size_t count)
{
	struct brport_attribute *brport_attr = to_brport_attr(attr);
	struct net_bridge_port *p = to_brport(kobj);
	ssize_t ret = -EINVAL;
	char *endp;
	unsigned long val;

	if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	val = simple_strtoul(buf, &endp, 0);
	if (endp != buf) {
		if (!rtnl_trylock())
			return restart_syscall();
		if (p->dev && p->br && brport_attr->store) {
			spin_lock_bh(&p->br->lock);
			ret = brport_attr->store(p, val);
			spin_unlock_bh(&p->br->lock);
			if (!ret) {
				br_ifinfo_notify(RTM_NEWLINK, p);
				ret = count;
			}
		}
		rtnl_unlock();
	}
	return ret;
}
Example #4
0
static ssize_t phys_switch_id_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	ssize_t ret = -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	if (dev_isalive(netdev)) {
		struct switchdev_attr attr = {
			.orig_dev = netdev,
			.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
			.flags = SWITCHDEV_F_NO_RECURSE,
		};

		ret = switchdev_port_attr_get(netdev, &attr);
		if (!ret)
			ret = sprintf(buf, "%*phN\n", attr.u.ppid.id_len,
				      attr.u.ppid.id);
	}
	rtnl_unlock();

	return ret;
}
Example #5
0
static ssize_t duplex_show(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	int ret = -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	if (netif_running(netdev)) {
		struct ethtool_link_ksettings cmd;

		if (!__ethtool_get_link_ksettings(netdev, &cmd)) {
			const char *duplex;

			switch (cmd.base.duplex) {
			case DUPLEX_HALF:
				duplex = "half";
				break;
			case DUPLEX_FULL:
				duplex = "full";
				break;
			default:
				duplex = "unknown";
				break;
			}
			ret = sprintf(buf, "%s\n", duplex);
		}
	}
	rtnl_unlock();
	return ret;
}
Example #6
0
/* use same locking and permission rules as SIF* ioctl's */
static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t len,
			    int (*set)(struct net_device *, unsigned long))
{
	struct net_device *netdev = to_net_dev(dev);
	struct net *net = dev_net(netdev);
	unsigned long new;
	int ret = -EINVAL;

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	ret = kstrtoul(buf, 0, &new);
	if (ret)
		goto err;

	if (!rtnl_trylock())
		return restart_syscall();

	if (dev_isalive(netdev)) {
		ret = (*set)(netdev, new);
		if (ret == 0)
			ret = len;
	}
	rtnl_unlock();
 err:
	return ret;
}
Example #7
0
/*
 * Common code for storing bridge parameters.
 */
static ssize_t store_bridge_parm(struct device *d,
				 const char *buf, size_t len,
				 int (*set)(struct net_bridge *, unsigned long))
{
	struct net_bridge *br = to_bridge(d);
	char *endp;
	unsigned long val;
	int err;

	if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	val = simple_strtoul(buf, &endp, 0);
	if (endp == buf)
		return -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	err = (*set)(br, val);
	if (!err)
		netdev_state_change(br->dev);
	rtnl_unlock();

	return err ? err : len;
}
Example #8
0
	~CPtrace() {
		restart_syscall();

		if (ptrace(PTRACE_SETREGS, m_pid, 0, &m_regs_bak) < 0) {
			perror("setregs");
		}

		if (ptrace(PTRACE_DETACH, m_pid, NULL, NULL) < 0) {
			perror("detach");
		}
	}
Example #9
0
static ssize_t ifalias_show(struct device *dev,
			    struct device_attribute *attr, char *buf)
{
	const struct net_device *netdev = to_net_dev(dev);
	ssize_t ret = 0;

	if (!rtnl_trylock())
		return restart_syscall();
	if (netdev->ifalias)
		ret = sprintf(buf, "%s\n", netdev->ifalias);
	rtnl_unlock();
	return ret;
}
Example #10
0
/**
 * bond_opt_tryset_rtnl - try to acquire rtnl and call __bond_opt_set
 * @bond: target bond device
 * @option: option to set
 * @buf: value to set it to
 *
 * This function tries to acquire RTNL without blocking and if successful
 * calls __bond_opt_set. It is mainly used for sysfs option manipulation.
 */
int bond_opt_tryset_rtnl(struct bonding *bond, unsigned int option, char *buf)
{
	struct bond_opt_value optval;
	int ret;

	if (!rtnl_trylock())
		return restart_syscall();
	bond_opt_initstr(&optval, buf);
	ret = __bond_opt_set_notify(bond, option, &optval);
	rtnl_unlock();

	return ret;
}
int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
{
	if (!rtnl_trylock())
		return restart_syscall();

	if (br->vlan_enabled == val)
		goto unlock;

	br->vlan_enabled = val;

unlock:
	rtnl_unlock();
	return 0;
}
Example #12
0
static ssize_t speed_show(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	int ret = -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	if (netif_running(netdev)) {
		struct ethtool_link_ksettings cmd;

		if (!__ethtool_get_link_ksettings(netdev, &cmd))
			ret = sprintf(buf, fmt_dec, cmd.base.speed);
	}
	rtnl_unlock();
	return ret;
}
Example #13
0
static ssize_t raw_ip_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
{
	struct usbnet *dev = netdev_priv(to_net_dev(d));
	struct qmi_wwan_state *info = (void *)&dev->data;
	bool enable;
	int ret;

	if (strtobool(buf, &enable))
		return -EINVAL;

	/* no change? */
	if (enable == (info->flags & QMI_WWAN_FLAG_RAWIP))
		return len;

	if (!rtnl_trylock())
		return restart_syscall();

	/* we don't want to modify a running netdev */
	if (netif_running(dev->net)) {
		netdev_err(dev->net, "Cannot change a running device\n");
		ret = -EBUSY;
		goto err;
	}

	/* let other drivers deny the change */
	ret = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev->net);
	ret = notifier_to_errno(ret);
	if (ret) {
		netdev_err(dev->net, "Type change was refused\n");
		goto err;
	}

	if (enable)
		info->flags |= QMI_WWAN_FLAG_RAWIP;
	else
		info->flags &= ~QMI_WWAN_FLAG_RAWIP;
	qmi_wwan_netdev_setup(dev->net);
	call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev->net);
	ret = len;
err:
	rtnl_unlock();
	return ret;
}
Example #14
0
static ssize_t phys_port_name_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	ssize_t ret = -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	if (dev_isalive(netdev)) {
		char name[IFNAMSIZ];

		ret = dev_get_phys_port_name(netdev, name, sizeof(name));
		if (!ret)
			ret = sprintf(buf, "%s\n", name);
	}
	rtnl_unlock();

	return ret;
}
Example #15
0
static ssize_t phys_switch_id_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	ssize_t ret = -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	if (dev_isalive(netdev)) {
		struct netdev_phys_item_id ppid = { };

		ret = dev_get_port_parent_id(netdev, &ppid, false);
		if (!ret)
			ret = sprintf(buf, "%*phN\n", ppid.id_len, ppid.id);
	}
	rtnl_unlock();

	return ret;
}
Example #16
0
static ssize_t group_addr_store(struct device *d,
				struct device_attribute *attr,
				const char *buf, size_t len)
{
	struct net_bridge *br = to_bridge(d);
	u8 new_addr[6];
	int i;

	if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	if (sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
		   &new_addr[0], &new_addr[1], &new_addr[2],
		   &new_addr[3], &new_addr[4], &new_addr[5]) != 6)
		return -EINVAL;

	if (!is_link_local_ether_addr(new_addr))
		return -EINVAL;

	if (new_addr[5] == 1 ||		/* 802.3x Pause address */
	    new_addr[5] == 2 ||		/* 802.3ad Slow protocols */
	    new_addr[5] == 3)		/* 802.1X PAE address */
		return -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();

	spin_lock_bh(&br->lock);
	for (i = 0; i < 6; i++)
		br->group_addr[i] = new_addr[i];
	spin_unlock_bh(&br->lock);

	br->group_addr_set = true;
	br_recalculate_fwd_mask(br);
	netdev_state_change(br->dev);

	rtnl_unlock();

	return len;
}
Example #17
0
static ssize_t stp_state_store(struct device *d,
			       struct device_attribute *attr, const char *buf,
			       size_t len)
{
	struct net_bridge *br = to_bridge(d);
	char *endp;
	unsigned long val;

	if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	val = simple_strtoul(buf, &endp, 0);
	if (endp == buf)
		return -EINVAL;

	if (!rtnl_trylock())
		return restart_syscall();
	br_stp_set_enabled(br, val);
	rtnl_unlock();

	return len;
}
Example #18
0
/*
 * 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.
 */
asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
{
	struct k_sigaction *ka;
	siginfo_t info;
	int single_stepping;

	/*
	 * 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 0;

	if (!oldset)
		oldset = &current->blocked;

	single_stepping = ptrace_cancel_bpt(current);

	for (;;) {
		unsigned long signr;

		spin_lock_irq (&current->sigmask_lock);
		signr = dequeue_signal(&current->blocked, &info);
		spin_unlock_irq (&current->sigmask_lock);

		if (!signr)
			break;

		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
			/* Let the debugger run.  */
			current->exit_code = signr;
			current->state = TASK_STOPPED;
			notify_parent(current, SIGCHLD);
			schedule();
			single_stepping |= ptrace_cancel_bpt(current);

			/* We're back.  Did the debugger cancel the sig?  */
			if (!(signr = current->exit_code))
				continue;
			current->exit_code = 0;

			/* The debugger continued.  Ignore SIGSTOP.  */
			if (signr == SIGSTOP)
				continue;

			/* Update the siginfo structure.  Is this good? */
			if (signr != info.si_signo) {
				info.si_signo = signr;
				info.si_errno = 0;
				info.si_code = SI_USER;
				info.si_pid = current->p_pptr->pid;
				info.si_uid = current->p_pptr->uid;
			}

			/* If the (new) signal is now blocked, requeue it.  */
			if (sigismember(&current->blocked, signr)) {
				send_sig_info(signr, &info, current);
				continue;
			}
		}

		ka = &current->sig->action[signr-1];
		if (ka->sa.sa_handler == SIG_IGN) {
			if (signr != SIGCHLD)
				continue;
			/* Check for SIGCHLD: it's special.  */
			while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
				/* nothing */;
			continue;
		}

		if (ka->sa.sa_handler == SIG_DFL) {
			int exit_code = signr;

			/* Init gets no signals it doesn't want.  */
			if (current->pid == 1)
				continue;

			switch (signr) {
			case SIGCONT: case SIGCHLD: case SIGWINCH: case SIGURG:
				continue;

			case SIGTSTP: case SIGTTIN: case SIGTTOU:
				if (is_orphaned_pgrp(current->pgrp))
					continue;
				/* FALLTHRU */

			case SIGSTOP: {
				struct signal_struct *sig;
				current->state = TASK_STOPPED;
				current->exit_code = signr;
				sig = current->p_pptr->sig;
				if (sig && !(sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
					notify_parent(current, SIGCHLD);
				schedule();
				single_stepping |= ptrace_cancel_bpt(current);
				continue;
			}

			case SIGQUIT: case SIGILL: case SIGTRAP:
			case SIGABRT: case SIGFPE: case SIGSEGV:
			case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:
				if (do_coredump(signr, regs))
					exit_code |= 0x80;
				/* FALLTHRU */

			default:
				sig_exit(signr, exit_code, &info);
				/* NOTREACHED */
			}
		}

		/* Are we from a system call? */
		if (syscall) {
			switch (regs->ARM_r0) {
			case -ERESTARTNOHAND:
				regs->ARM_r0 = -EINTR;
				break;

			case -ERESTARTSYS:
				if (!(ka->sa.sa_flags & SA_RESTART)) {
					regs->ARM_r0 = -EINTR;
					break;
				}
				/* fallthrough */
			case -ERESTARTNOINTR:
				restart_syscall(regs);
				break;


			}
		}
		/* Whee!  Actually deliver the signal.  */
		handle_signal(signr, ka, &info, oldset, regs);
		if (single_stepping)
		    	ptrace_set_bpt(current);
		return 1;
	}

	if (syscall &&
	    (regs->ARM_r0 == -ERESTARTNOHAND ||
	     regs->ARM_r0 == -ERESTARTSYS ||
	     regs->ARM_r0 == -ERESTARTNOINTR)) {
		restart_syscall(regs);
	}

	if (single_stepping)
		ptrace_set_bpt(current);
	return 0;
}
Example #19
0
static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
{
    struct k_sigaction ka;
    siginfo_t info;
    int signr;

    /*
     * 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 0;

    if (try_to_freeze())
        goto no_signal;

    /*
     *FIXME: I don't know how to trace TriMedia executable.
     */
#if 0
    if (current->ptrace & PT_SINGLESTEP)
        ptrace_cancel_bpt(current);
#endif

    signr = get_signal_to_deliver(&info, &ka, regs, NULL);
    if (signr > 0) {
        handle_signal(signr, &ka, &info, oldset, regs, syscall);
        /*
         *FIXME: I don't know how to trace TriMedia executable.
         */
#if 0
        if (current->ptrace & PT_SINGLESTEP)
            ptrace_set_bpt(current);
#endif
        return 1;
    }

no_signal:
    /*
     * No signal to deliver to the process - restart the syscall.
     */
    if (syscall) {
        if (regs->r5 == -ERESTART_RESTARTBLOCK) {
            regs->r5=__NR_restart_syscall;
            regs->dpc=regs->spc;
        }
        if (regs->r5 == -ERESTARTNOHAND ||
                regs->r5 == -ERESTARTSYS ||
                regs->r5 == -ERESTARTNOINTR) {
            restart_syscall(regs);
        }
    }

    /*
     *FIXME: I don't know how to trace TriMedia executable.
     */
#if 0
    if (current->ptrace & PT_SINGLESTEP)
        ptrace_set_bpt(current);
#endif
    return 0;
}
Example #20
0
/*
 * 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.
 */
static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
{
    siginfo_t info;
    int signr;

    /*
     * 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 0;

    if (current->flags & PF_FREEZE) {
        refrigerator(0);
        goto no_signal;
    }

    if (current->ptrace & PT_SINGLESTEP)
        ptrace_cancel_bpt(current);

    signr = get_signal_to_deliver(&info, regs, NULL);
    if (signr > 0) {
        handle_signal(signr, &info, oldset, regs, syscall);
        if (current->ptrace & PT_SINGLESTEP)
            ptrace_set_bpt(current);
        return 1;
    }

no_signal:
    /*
     * No signal to deliver to the process - restart the syscall.
     */
    if (syscall) {
        if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
            if (thumb_mode(regs)) {
                regs->ARM_r7 = __NR_restart_syscall;
                regs->ARM_pc -= 2;
            } else {
                u32 __user *usp;

                regs->ARM_sp -= 12;
                usp = (u32 __user *)regs->ARM_sp;

                put_user(regs->ARM_pc, &usp[0]);
                /* swi __NR_restart_syscall */
                put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
                /* ldr	pc, [sp], #12 */
                put_user(0xe49df00c, &usp[2]);

                flush_icache_range((unsigned long)usp,
                                   (unsigned long)(usp + 3));

                regs->ARM_pc = regs->ARM_sp + 4;
            }
        }
        if (regs->ARM_r0 == -ERESTARTNOHAND ||
                regs->ARM_r0 == -ERESTARTSYS ||
                regs->ARM_r0 == -ERESTARTNOINTR) {
            restart_syscall(regs);
        }
    }
    if (current->ptrace & PT_SINGLESTEP)
        ptrace_set_bpt(current);
    return 0;
}
Example #21
0
/*
 * OK, we're invoking a handler
 */
static void
handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
              struct pt_regs * regs, int syscall)
{
    struct thread_info *thread = current_thread_info();
    struct task_struct *tsk = current;
    struct k_sigaction *ka = &tsk->sighand->action[sig-1];
    int usig = sig;
    int ret;

    /*
     * If we were from a system call, check for system call restarting...
     */
    if (syscall) {
        switch (regs->ARM_r0) {
        case -ERESTART_RESTARTBLOCK:
        case -ERESTARTNOHAND:
            regs->ARM_r0 = -EINTR;
            break;
        case -ERESTARTSYS:
            if (!(ka->sa.sa_flags & SA_RESTART)) {
                regs->ARM_r0 = -EINTR;
                break;
            }
        /* fallthrough */
        case -ERESTARTNOINTR:
            restart_syscall(regs);
        }
    }

    /*
     * translate the signal
     */
    if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
        usig = thread->exec_domain->signal_invmap[usig];

    /*
     * Set up the stack frame
     */
    if (ka->sa.sa_flags & SA_SIGINFO)
        ret = setup_rt_frame(usig, ka, info, oldset, regs);
    else
        ret = setup_frame(usig, ka, oldset, regs);

    /*
     * Check that the resulting registers are actually sane.
     */
    ret |= !valid_user_regs(regs);

    /*
     * Block the signal if we were unsuccessful.
     */
    if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) {
        spin_lock_irq(&tsk->sighand->siglock);
        sigorsets(&tsk->blocked, &tsk->blocked,
                  &ka->sa.sa_mask);
        sigaddset(&tsk->blocked, sig);
        recalc_sigpending();
        spin_unlock_irq(&tsk->sighand->siglock);
    }

    if (ret == 0) {
        if (ka->sa.sa_flags & SA_ONESHOT)
            ka->sa.sa_handler = SIG_DFL;
        return;
    }

    if (sig == SIGSEGV)
        ka->sa.sa_handler = SIG_DFL;
    force_sig(SIGSEGV, tsk);
}
Example #22
0
/*
 * 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.
 */
static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;

#ifdef CONFIG_PREEMPT_RT
	/*
	 * Fully-preemptible kernel does not need interrupts disabled:
	 */
	local_irq_enable();
	preempt_check_resched();
#endif

	/*
	 * 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 0;

	if (try_to_freeze())
		goto no_signal;

	single_step_clear(current);

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		handle_signal(signr, &ka, &info, oldset, regs, syscall);
		single_step_set(current);
		return 1;
	}

 no_signal:
	/*
	 * No signal to deliver to the process - restart the syscall.
	 */
	if (syscall) {
		if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
			if (thumb_mode(regs)) {
				regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
				regs->ARM_pc -= 2;
			} else {
#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
				regs->ARM_r7 = __NR_restart_syscall;
				regs->ARM_pc -= 4;
#else
				u32 __user *usp;
				u32 swival = __NR_restart_syscall;

				regs->ARM_sp -= 12;
				usp = (u32 __user *)regs->ARM_sp;

				/*
				 * Either we supports OABI only, or we have
				 * EABI with the OABI compat layer enabled.
				 * In the later case we don't know if user
				 * space is EABI or not, and if not we must
				 * not clobber r7.  Always using the OABI
				 * syscall solves that issue and works for
				 * all those cases.
				 */
				swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;

				put_user(regs->ARM_pc, &usp[0]);
				/* swi __NR_restart_syscall */
				put_user(0xef000000 | swival, &usp[1]);
				/* ldr	pc, [sp], #12 */
				put_user(0xe49df00c, &usp[2]);

				flush_icache_range((unsigned long)usp,
						   (unsigned long)(usp + 3));

				regs->ARM_pc = regs->ARM_sp + 4;
#endif
			}
		}
		if (regs->ARM_r0 == -ERESTARTNOHAND ||
		    regs->ARM_r0 == -ERESTARTSYS ||
		    regs->ARM_r0 == -ERESTARTNOINTR) {
			restart_syscall(regs);
		}
	}
	single_step_set(current);
	return 0;
}
Example #23
0
/*
 * 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.
 */
static void do_signal(struct pt_regs *regs, int syscall)
{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;
	sigset_t *oldset;

	/*
	 * 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;

	if (try_to_freeze())
		goto no_signal;

	single_step_clear(current);

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 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 */
			clear_thread_flag(TIF_RESTORE_SIGMASK);
		}
		single_step_set(current);
		return;
	}

 no_signal:
	/*
	 * No signal to deliver to the process - restart the syscall.
	 */
	if (syscall) {
		if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
			if (thumb_mode(regs)) {
				regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
				regs->ARM_pc -= 2;
			} else {
#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
				regs->ARM_r7 = __NR_restart_syscall;
				regs->ARM_pc -= 4;
#else
				u32 __user *usp;
				u32 swival = __NR_restart_syscall;

				regs->ARM_sp -= 12;
				usp = (u32 __user *)regs->ARM_sp;

				/*
				 * Either we support OABI only, or we have
				 * EABI with the OABI compat layer enabled.
				 * In the later case we don't know if user
				 * space is EABI or not, and if not we must
				 * not clobber r7.  Always using the OABI
				 * syscall solves that issue and works for
				 * all those cases.
				 */
				swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;

				put_user(regs->ARM_pc, &usp[0]);
				/* swi __NR_restart_syscall */
				put_user(0xef000000 | swival, &usp[1]);
				/* ldr	pc, [sp], #12 */
				put_user(0xe49df00c, &usp[2]);

				flush_icache_range((unsigned long)usp,
						   (unsigned long)(usp + 3));

				regs->ARM_pc = regs->ARM_sp + 4;
#endif
			}
		}
		if (regs->ARM_r0 == -ERESTARTNOHAND ||
		    regs->ARM_r0 == -ERESTARTSYS ||
		    regs->ARM_r0 == -ERESTARTNOINTR) {
			restart_syscall(regs);
		}
	}
	single_step_set(current);
 
        /* 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, &current->saved_sigmask, NULL);
        }
}