Current File : //usr/share/systemtap/runtime/transport/debugfs.c
/* -*- linux-c -*-
*
* debugfs functions
* Copyright (C) 2009 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#include <linux/debugfs.h>
#include "transport.h"
#include "../uidgid_compatibility.h"
/* Defines the number of buffers allocated in control.c (which #includes
this file) for the _stp_pool_q. This is the number of .cmd messages
the module can store before they have to be read by stapio.
40 is somewhat arbitrary, 8 pre-allocated messages, 32 dynamic. */
#define STP_DEFAULT_BUFFERS 40
/* Always returns zero, we just push all messages on the _stp_ctl_ready_q. */
inline static int _stp_ctl_write_fs(int type, void *data, unsigned len)
{
return 0;
}
static struct dentry *_stp_cmd_file = NULL;
static int _stp_register_ctl_channel_fs(void)
{
struct dentry *module_dir = _stp_get_module_dir();
if (module_dir == NULL) {
errk("no module directory found.\n");
return -1;
}
/* create [debugfs]/systemtap/module_name/.cmd */
_stp_cmd_file = debugfs_create_file(".cmd", 0600, module_dir,
NULL, &_stp_ctl_fops_cmd);
if (_stp_cmd_file == NULL) {
errk("Error creating systemtap debugfs entries.\n");
return -1;
}
else if (IS_ERR(_stp_cmd_file)) {
_stp_cmd_file = NULL;
errk("Error creating systemtap debugfs entries: %ld\n",
-PTR_ERR(_stp_cmd_file));
return -1;
}
_stp_cmd_file->d_inode->i_uid = KUIDT_INIT(_stp_uid);
_stp_cmd_file->d_inode->i_gid = KGIDT_INIT(_stp_gid);
return 0;
}
static void _stp_unregister_ctl_channel_fs(void)
{
if (_stp_cmd_file)
debugfs_remove(_stp_cmd_file);
}
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