/*
 * proc_tty.c -- handles /proc/tty
 *
 * Copyright 1997, Theodore Ts'o
 */

#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <linux/seq_file.h>
#include <linux/bitops.h>

/*
 * The /proc/tty directory inodes...
 */
static struct proc_dir_entry *proc_tty_driver;

/*
 * This is the handler for /proc/tty/drivers
 */
static void show_tty_range(struct seq_file *m, struct tty_driver *p,
	dev_t from, int num)
{
	seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
	seq_printf(m, "/dev/%-8s ", p->name);
	if (p->num > 1) {
		seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
			MINOR(from) + num - 1);
	} else {
		seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
	}
	switch (p->type) {
	case TTY_DRIVER_TYPE_SYSTEM:
		seq_puts(m, "system");
		if (p->subtype == SYSTEM_TYPE_TTY)
			seq_puts(m, ":/dev/tty");
		else if (p->subtype == SYSTEM_TYPE_SYSCONS)
			seq_puts(m, ":console");
		else if (p->subtype == SYSTEM_TYPE_CONSOLE)
			seq_puts(m, ":vtmaster");
		break;
	case TTY_DRIVER_TYPE_CONSOLE:
		seq_puts(m, "console");
		break;
	case TTY_DRIVER_TYPE_SERIAL:
		seq_puts(m, "serial");
		break;
	case TTY_DRIVER_TYPE_PTY:
		if (p->subtype == PTY_TYPE_MASTER)
			seq_puts(m, "pty:master");
		else if (p->subtype == PTY_TYPE_SLAVE)
			seq_puts(m, "pty:slave");
		else
			seq_puts(m, "pty");
		break;
	default:
		seq_printf(m, "type:%d.%d", p->type, p->subtype);
	}
	seq_putc(m, '\n');
}

static int show_tty_driver(struct seq_file *m, void *v)
{
	struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
	dev_t from = MKDEV(p->major, p->minor_start);
	dev_t to = from + p->num;

	if (&p->tty_drivers == tty_drivers.next) {
		/* pseudo-drivers first */
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
		seq_puts(m, "system:/dev/tty\n");
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
		seq_puts(m, "system:console\n");
#ifdef CONFIG_UNIX98_PTYS
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
		seq_puts(m, "system\n");
#endif
#ifdef CONFIG_VT
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
		seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
		seq_puts(m, "system:vtmaster\n");
#endif
	}

	while (MAJOR(from) < MAJOR(to)) {
		dev_t next = MKDEV(MAJOR(from)+1, 0);
		show_tty_range(m, p, from, next - from);
		from = next;
	}
	if (from != to)
		show_tty_range(m, p, from, to - from);
	return 0;
}

/* iterator */
static void *t_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&tty_mutex);
	return seq_list_start(&tty_drivers, *pos);
}

static void *t_next(struct seq_file *m, void *v, loff_t *pos)
{
	return seq_list_next(v, &tty_drivers, pos);
}

static void t_stop(struct seq_file *m, void *v)
{
	mutex_unlock(&tty_mutex);
}

static const struct seq_operations tty_drivers_op = {
	.start	= t_start,
	.next	= t_next,
	.stop	= t_stop,
	.show	= show_tty_driver
};

static int tty_drivers_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &tty_drivers_op);
}

static const struct file_operations proc_tty_drivers_operations = {
	.open		= tty_drivers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

/*
 * This function is called by tty_register_driver() to handle
 * registering the driver's /proc handler into /proc/tty/driver/<foo>
 */
void proc_tty_register_driver(struct tty_driver *driver)
{
	struct proc_dir_entry *ent;
		
	if (!driver->driver_name || driver->proc_entry ||
	    !driver->ops->proc_fops)
		return;

	ent = proc_create_data(driver->driver_name, 0, proc_tty_driver,
			       driver->ops->proc_fops, driver);
	driver->proc_entry = ent;
}

/*
 * This function is called by tty_unregister_driver()
 */
void proc_tty_unregister_driver(struct tty_driver *driver)
{
	struct proc_dir_entry *ent;

	ent = driver->proc_entry;
	if (!ent)
		return;
		
	remove_proc_entry(driver->driver_name, proc_tty_driver);
	
	driver->proc_entry = NULL;
}

/*
 * Called by proc_root_init() to initialize the /proc/tty subtree
 */
void __init proc_tty_init(void)
{
	if (!proc_mkdir("tty", NULL))
		return;
	proc_mkdir("tty/ldisc", NULL);	/* Preserved: it's userspace visible */
	/*
	 * /proc/tty/driver/serial reveals the exact character counts for
	 * serial links which is just too easy to abuse for inferring
	 * password lengths and inter-keystroke timings during password
	 * entry.
	 */
	proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
	proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
	proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
}
ss='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;</td><td class='right'>2017-02-03 17:10:28 +1100</td></tr>
<tr><th>committer</th><td>Michael Ellerman &lt;mpe@ellerman.id.au&gt;</td><td class='right'>2017-02-08 23:36:29 +1100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/generic/simple-card-utils.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>d7df2443cd5f67fc6ee7c05a88e4996e8177f91b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/soc/generic/simple-card-utils.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>098a7c0ca4fceb8a65cb1f693c9d71990388933d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/soc/generic/simple-card-utils.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>sound/soc/generic/simple-card-utils.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/generic/simple-card-utils.c?h=nds-private-remove&amp;id=a0615a16f7d0ceb5804d295203c302d496d8ee91'>a0615a16f7d0ceb5804d295203c302d496d8ee91</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/generic/simple-card-utils.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b&amp;id2=a0615a16f7d0ceb5804d295203c302d496d8ee91'>diff</a>)</td></tr></table>
<div class='commit-subject'>powerpc/mm: Fix spurrious segfaults on radix with autonuma</div><div class='commit-msg'>When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Acked-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>Diffstat</a> (limited to 'sound/soc/generic/simple-card-utils.c')</div><table summary='diffstat' class='diffstat'>