/*
 * Created by: Jason Wessel <jason.wessel@windriver.com>
 *
 * Copyright (c) 2010 Wind River Systems, Inc.  All Rights Reserved.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/module.h>
#include <linux/kdb.h>

/*
 * All kdb shell command call backs receive argc and argv, where
 * argv[0] is the command the end user typed
 */
static int kdb_hello_cmd(int argc, const char **argv)
{
	if (argc > 1)
		return KDB_ARGCOUNT;

	if (argc)
		kdb_printf("Hello %s.\n", argv[1]);
	else
		kdb_printf("Hello world!\n");

	return 0;
}


static int __init kdb_hello_cmd_init(void)
{
	/*
	 * Registration of a dynamically added kdb command is done with
	 * kdb_register() with the arguments being:
	 *   1: The name of the shell command
	 *   2: The function that processes the command
	 *   3: Description of the usage of any arguments
	 *   4: Descriptive text when you run help
	 *   5: Number of characters to complete the command
	 *      0 == type the whole command
	 *      1 == match both "g" and "go" for example
	 */
	kdb_register("hello", kdb_hello_cmd, "[string]",
		     "Say Hello World or Hello [string]", 0);
	return 0;
}

static void __exit kdb_hello_cmd_exit(void)
{
	kdb_unregister("hello");
}

module_init(kdb_hello_cmd_init);
module_exit(kdb_hello_cmd_exit);

MODULE_AUTHOR("WindRiver");
MODULE_DESCRIPTION("KDB example to add a hello command");
MODULE_LICENSE("GPL");
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/wimax?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>wimax</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='07cd12945551b63ecb1a349d50a6d69d1d6feb4a'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='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>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wimax?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>07cd12945551b63ecb1a349d50a6d69d1d6feb4a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/wimax?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>patch</a>)</td></tr>
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<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wimax?id=7ce7d89f48834cefece7804d38fc5d85382edf77'>7ce7d89f48834cefece7804d38fc5d85382edf77</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/wimax?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a&amp;id2=7ce7d89f48834cefece7804d38fc5d85382edf77'>diff</a>)</td></tr></table>
<div class='commit-subject'>cgroup: don't online subsystems before cgroup_name/path() are operational</div><div class='commit-msg'>While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out
cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems
before the new cgroup is associated with it kernfs_node.  This is fine
for cgroup proper but cgroup_name/path() depend on the associated
kernfs_node and if a subsystem makes the new cgroup_subsys_state
visible, which they're allowed to after onlining, it can lead to NULL
dereference.

The current code performs cgroup creation and subsystem onlining in
cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems
visible afterwards.  There's no reason to online the subsystems early
and we can simply drop cgroup_apply_control_enable() call from
cgroup_create() so that the subsystems are onlined and made visible at
the same time.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Konstantin Khlebnikov &lt;khlebnikov@yandex-team.ru&gt;
Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") 
Cc: stable@vger.kernel.org # v4.6+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>Diffstat</a> (limited to 'net/wimax')</div><table summary='diffstat' class='diffstat'>