dwarves/lib/ctracer_relay.c
Arnaldo Carvalho de Melo b4d6de9b6f [LICENSE]: Add COPYING file and add missing license info on some files
Thanks to Otavio Salvador for bringing up this issue.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2007-12-17 14:15:42 -02:00

102 lines
2.4 KiB
C

/*
Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
This program is free software; you can redistribute it and/or modify it
under the terms of version 2 of the GNU General Public License as
published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/percpu.h>
#include <linux/relay.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/module.h>
#include "ctracer_relay.h"
static struct rchan *ctracer__rchan;
static int ctracer__subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
void *prev_subbuf,
size_t prev_padding)
{
static int warned;
if (!relay_buf_full(buf))
return 1;
if (!warned) {
warned = 1;
printk("relay_buf_full!\n");
}
return 0;
}
static struct dentry *ctracer__create_buf_file_callback(const char *filename,
struct dentry *parent,
int mode,
struct rchan_buf *buf,
int *is_global)
{
return debugfs_create_file(filename, mode, parent, buf,
&relay_file_operations);
}
static int ctracer__remove_buf_file_callback(struct dentry *dentry)
{
debugfs_remove(dentry);
return 0;
}
static struct rchan_callbacks ctracer__relay_callbacks = {
.subbuf_start = ctracer__subbuf_start_callback,
.create_buf_file = ctracer__create_buf_file_callback,
.remove_buf_file = ctracer__remove_buf_file_callback,
};
extern void ctracer__class_state(const void *from, void *to);
void ctracer__method_hook(const unsigned long long now,
const int probe_type,
const unsigned long long function_id,
const void *object, const int state_len)
{
if (object != NULL) {
void *t = relay_reserve(ctracer__rchan,
sizeof(struct trace_entry) + state_len);
if (t != NULL) {
struct trace_entry *entry = t;
entry->nsec = now;
entry->probe_type = probe_type;
entry->object = object;
entry->function_id = function_id;
ctracer__class_state(object, t + sizeof(*entry));
}
}
}
EXPORT_SYMBOL_GPL(ctracer__method_hook);
static int __init ctracer__relay_init(void)
{
ctracer__rchan = relay_open("ctracer", NULL, 512 * 1024, 64,
&ctracer__relay_callbacks, NULL);
if (ctracer__rchan == NULL) {
pr_info("ctracer: couldn't create the relay\n");
return -1;
}
return 0;
}
module_init(ctracer__relay_init);
static void __exit ctracer__relay_exit(void)
{
relay_close(ctracer__rchan);
}
module_exit(ctracer__relay_exit);
MODULE_LICENSE("GPL");