![Andrew Vagin](/assets/img/avatar_default.png)
A few events are interesting not only for a current task. For example, sched_stat_* events are interesting for a task which wakes up. For this reason, it will be good if such events will be delivered to a target task too. Now a target task can be set by using __perf_task(). The original idea and a draft patch belongs to Peter Zijlstra. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Inspired-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arun Sharma <asharma@fb.com> Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
789 lines
18 KiB
C
789 lines
18 KiB
C
/*
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* uprobes-based tracing events
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Copyright (C) IBM Corporation, 2010-2012
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* Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
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*/
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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <linux/uprobes.h>
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#include <linux/namei.h>
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#include "trace_probe.h"
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#define UPROBE_EVENT_SYSTEM "uprobes"
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/*
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* uprobe event core functions
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*/
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struct trace_uprobe;
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struct uprobe_trace_consumer {
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struct uprobe_consumer cons;
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struct trace_uprobe *tu;
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};
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struct trace_uprobe {
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struct list_head list;
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struct ftrace_event_class class;
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struct ftrace_event_call call;
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struct uprobe_trace_consumer *consumer;
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struct inode *inode;
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char *filename;
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unsigned long offset;
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unsigned long nhit;
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unsigned int flags; /* For TP_FLAG_* */
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ssize_t size; /* trace entry size */
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unsigned int nr_args;
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struct probe_arg args[];
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};
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#define SIZEOF_TRACE_UPROBE(n) \
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(offsetof(struct trace_uprobe, args) + \
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(sizeof(struct probe_arg) * (n)))
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static int register_uprobe_event(struct trace_uprobe *tu);
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static void unregister_uprobe_event(struct trace_uprobe *tu);
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static DEFINE_MUTEX(uprobe_lock);
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static LIST_HEAD(uprobe_list);
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static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
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/*
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* Allocate new trace_uprobe and initialize it (including uprobes).
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*/
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static struct trace_uprobe *
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alloc_trace_uprobe(const char *group, const char *event, int nargs)
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{
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struct trace_uprobe *tu;
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if (!event || !is_good_name(event))
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return ERR_PTR(-EINVAL);
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if (!group || !is_good_name(group))
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return ERR_PTR(-EINVAL);
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tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
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if (!tu)
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return ERR_PTR(-ENOMEM);
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tu->call.class = &tu->class;
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tu->call.name = kstrdup(event, GFP_KERNEL);
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if (!tu->call.name)
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goto error;
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tu->class.system = kstrdup(group, GFP_KERNEL);
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if (!tu->class.system)
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goto error;
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INIT_LIST_HEAD(&tu->list);
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return tu;
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error:
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kfree(tu->call.name);
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kfree(tu);
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return ERR_PTR(-ENOMEM);
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}
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static void free_trace_uprobe(struct trace_uprobe *tu)
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{
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int i;
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for (i = 0; i < tu->nr_args; i++)
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traceprobe_free_probe_arg(&tu->args[i]);
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iput(tu->inode);
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kfree(tu->call.class->system);
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kfree(tu->call.name);
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kfree(tu->filename);
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kfree(tu);
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}
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static struct trace_uprobe *find_probe_event(const char *event, const char *group)
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{
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struct trace_uprobe *tu;
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list_for_each_entry(tu, &uprobe_list, list)
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if (strcmp(tu->call.name, event) == 0 &&
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strcmp(tu->call.class->system, group) == 0)
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return tu;
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return NULL;
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}
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/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
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static void unregister_trace_uprobe(struct trace_uprobe *tu)
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{
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list_del(&tu->list);
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unregister_uprobe_event(tu);
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free_trace_uprobe(tu);
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}
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/* Register a trace_uprobe and probe_event */
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static int register_trace_uprobe(struct trace_uprobe *tu)
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{
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struct trace_uprobe *old_tp;
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int ret;
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mutex_lock(&uprobe_lock);
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/* register as an event */
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old_tp = find_probe_event(tu->call.name, tu->call.class->system);
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if (old_tp)
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/* delete old event */
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unregister_trace_uprobe(old_tp);
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ret = register_uprobe_event(tu);
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if (ret) {
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pr_warning("Failed to register probe event(%d)\n", ret);
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goto end;
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}
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list_add_tail(&tu->list, &uprobe_list);
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end:
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mutex_unlock(&uprobe_lock);
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return ret;
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}
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/*
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* Argument syntax:
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* - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS]
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*
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* - Remove uprobe: -:[GRP/]EVENT
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*/
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static int create_trace_uprobe(int argc, char **argv)
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{
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struct trace_uprobe *tu;
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struct inode *inode;
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char *arg, *event, *group, *filename;
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char buf[MAX_EVENT_NAME_LEN];
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struct path path;
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unsigned long offset;
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bool is_delete;
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int i, ret;
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inode = NULL;
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ret = 0;
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is_delete = false;
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event = NULL;
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group = NULL;
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/* argc must be >= 1 */
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if (argv[0][0] == '-')
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is_delete = true;
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else if (argv[0][0] != 'p') {
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pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n");
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return -EINVAL;
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}
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if (argv[0][1] == ':') {
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event = &argv[0][2];
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arg = strchr(event, '/');
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if (arg) {
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group = event;
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event = arg + 1;
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event[-1] = '\0';
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if (strlen(group) == 0) {
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pr_info("Group name is not specified\n");
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return -EINVAL;
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}
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}
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if (strlen(event) == 0) {
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pr_info("Event name is not specified\n");
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return -EINVAL;
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}
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}
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if (!group)
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group = UPROBE_EVENT_SYSTEM;
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if (is_delete) {
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if (!event) {
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pr_info("Delete command needs an event name.\n");
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return -EINVAL;
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}
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mutex_lock(&uprobe_lock);
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tu = find_probe_event(event, group);
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if (!tu) {
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mutex_unlock(&uprobe_lock);
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pr_info("Event %s/%s doesn't exist.\n", group, event);
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return -ENOENT;
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}
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/* delete an event */
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unregister_trace_uprobe(tu);
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mutex_unlock(&uprobe_lock);
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return 0;
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}
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if (argc < 2) {
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pr_info("Probe point is not specified.\n");
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return -EINVAL;
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}
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if (isdigit(argv[1][0])) {
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pr_info("probe point must be have a filename.\n");
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return -EINVAL;
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}
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arg = strchr(argv[1], ':');
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if (!arg)
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goto fail_address_parse;
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*arg++ = '\0';
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filename = argv[1];
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ret = kern_path(filename, LOOKUP_FOLLOW, &path);
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if (ret)
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goto fail_address_parse;
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ret = strict_strtoul(arg, 0, &offset);
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if (ret)
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goto fail_address_parse;
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inode = igrab(path.dentry->d_inode);
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argc -= 2;
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argv += 2;
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/* setup a probe */
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if (!event) {
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char *tail = strrchr(filename, '/');
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char *ptr;
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ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL);
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if (!ptr) {
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ret = -ENOMEM;
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goto fail_address_parse;
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}
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tail = ptr;
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ptr = strpbrk(tail, ".-_");
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if (ptr)
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*ptr = '\0';
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snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
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event = buf;
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kfree(tail);
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}
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tu = alloc_trace_uprobe(group, event, argc);
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if (IS_ERR(tu)) {
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pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
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ret = PTR_ERR(tu);
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goto fail_address_parse;
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}
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tu->offset = offset;
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tu->inode = inode;
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tu->filename = kstrdup(filename, GFP_KERNEL);
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if (!tu->filename) {
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pr_info("Failed to allocate filename.\n");
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ret = -ENOMEM;
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goto error;
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}
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/* parse arguments */
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ret = 0;
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for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
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/* Increment count for freeing args in error case */
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tu->nr_args++;
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/* Parse argument name */
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arg = strchr(argv[i], '=');
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if (arg) {
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*arg++ = '\0';
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tu->args[i].name = kstrdup(argv[i], GFP_KERNEL);
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} else {
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arg = argv[i];
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/* If argument name is omitted, set "argN" */
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snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
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tu->args[i].name = kstrdup(buf, GFP_KERNEL);
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}
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if (!tu->args[i].name) {
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pr_info("Failed to allocate argument[%d] name.\n", i);
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ret = -ENOMEM;
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goto error;
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}
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if (!is_good_name(tu->args[i].name)) {
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pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name);
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ret = -EINVAL;
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goto error;
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}
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if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) {
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pr_info("Argument[%d] name '%s' conflicts with "
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"another field.\n", i, argv[i]);
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ret = -EINVAL;
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goto error;
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}
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/* Parse fetch argument */
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ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false);
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if (ret) {
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pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
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goto error;
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}
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}
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ret = register_trace_uprobe(tu);
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if (ret)
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goto error;
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return 0;
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error:
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free_trace_uprobe(tu);
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return ret;
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fail_address_parse:
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if (inode)
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iput(inode);
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pr_info("Failed to parse address.\n");
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return ret;
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}
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static void cleanup_all_probes(void)
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{
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struct trace_uprobe *tu;
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mutex_lock(&uprobe_lock);
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while (!list_empty(&uprobe_list)) {
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tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
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unregister_trace_uprobe(tu);
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}
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mutex_unlock(&uprobe_lock);
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}
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/* Probes listing interfaces */
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static void *probes_seq_start(struct seq_file *m, loff_t *pos)
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{
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mutex_lock(&uprobe_lock);
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return seq_list_start(&uprobe_list, *pos);
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}
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static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
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{
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return seq_list_next(v, &uprobe_list, pos);
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}
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static void probes_seq_stop(struct seq_file *m, void *v)
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{
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mutex_unlock(&uprobe_lock);
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}
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static int probes_seq_show(struct seq_file *m, void *v)
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{
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struct trace_uprobe *tu = v;
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int i;
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seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name);
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seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
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for (i = 0; i < tu->nr_args; i++)
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seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm);
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seq_printf(m, "\n");
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return 0;
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}
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static const struct seq_operations probes_seq_op = {
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.start = probes_seq_start,
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.next = probes_seq_next,
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.stop = probes_seq_stop,
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.show = probes_seq_show
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};
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static int probes_open(struct inode *inode, struct file *file)
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{
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if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
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cleanup_all_probes();
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return seq_open(file, &probes_seq_op);
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}
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static ssize_t probes_write(struct file *file, const char __user *buffer,
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size_t count, loff_t *ppos)
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{
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return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
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}
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static const struct file_operations uprobe_events_ops = {
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.owner = THIS_MODULE,
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.open = probes_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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.write = probes_write,
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};
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/* Probes profiling interfaces */
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static int probes_profile_seq_show(struct seq_file *m, void *v)
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{
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struct trace_uprobe *tu = v;
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seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit);
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return 0;
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}
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static const struct seq_operations profile_seq_op = {
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.start = probes_seq_start,
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.next = probes_seq_next,
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.stop = probes_seq_stop,
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.show = probes_profile_seq_show
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};
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|
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static int profile_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &profile_seq_op);
|
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}
|
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|
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static const struct file_operations uprobe_profile_ops = {
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.owner = THIS_MODULE,
|
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.open = profile_open,
|
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.read = seq_read,
|
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.llseek = seq_lseek,
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.release = seq_release,
|
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};
|
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|
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/* uprobe handler */
|
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static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
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{
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struct uprobe_trace_entry_head *entry;
|
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struct ring_buffer_event *event;
|
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struct ring_buffer *buffer;
|
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u8 *data;
|
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int size, i, pc;
|
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unsigned long irq_flags;
|
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struct ftrace_event_call *call = &tu->call;
|
|
|
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tu->nhit++;
|
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|
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local_save_flags(irq_flags);
|
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pc = preempt_count();
|
|
|
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size = sizeof(*entry) + tu->size;
|
|
|
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event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
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size, irq_flags, pc);
|
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if (!event)
|
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return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
|
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data = (u8 *)&entry[1];
|
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for (i = 0; i < tu->nr_args; i++)
|
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call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
|
|
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if (!filter_current_check_discard(buffer, call, entry, event))
|
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trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
|
}
|
|
|
|
/* Event entry printers */
|
|
static enum print_line_t
|
|
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
|
|
{
|
|
struct uprobe_trace_entry_head *field;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_uprobe *tu;
|
|
u8 *data;
|
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int i;
|
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|
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field = (struct uprobe_trace_entry_head *)iter->ent;
|
|
tu = container_of(event, struct trace_uprobe, call.event);
|
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|
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if (!trace_seq_printf(s, "%s: (", tu->call.name))
|
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goto partial;
|
|
|
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if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
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goto partial;
|
|
|
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if (!trace_seq_puts(s, ")"))
|
|
goto partial;
|
|
|
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data = (u8 *)&field[1];
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
if (!tu->args[i].type->print(s, tu->args[i].name,
|
|
data + tu->args[i].offset, field))
|
|
goto partial;
|
|
}
|
|
|
|
if (trace_seq_puts(s, "\n"))
|
|
return TRACE_TYPE_HANDLED;
|
|
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static int probe_event_enable(struct trace_uprobe *tu, int flag)
|
|
{
|
|
struct uprobe_trace_consumer *utc;
|
|
int ret = 0;
|
|
|
|
if (!tu->inode || tu->consumer)
|
|
return -EINTR;
|
|
|
|
utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
|
|
if (!utc)
|
|
return -EINTR;
|
|
|
|
utc->cons.handler = uprobe_dispatcher;
|
|
utc->cons.filter = NULL;
|
|
ret = uprobe_register(tu->inode, tu->offset, &utc->cons);
|
|
if (ret) {
|
|
kfree(utc);
|
|
return ret;
|
|
}
|
|
|
|
tu->flags |= flag;
|
|
utc->tu = tu;
|
|
tu->consumer = utc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void probe_event_disable(struct trace_uprobe *tu, int flag)
|
|
{
|
|
if (!tu->inode || !tu->consumer)
|
|
return;
|
|
|
|
uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);
|
|
tu->flags &= ~flag;
|
|
kfree(tu->consumer);
|
|
tu->consumer = NULL;
|
|
}
|
|
|
|
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct uprobe_trace_entry_head field;
|
|
struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
ret = trace_define_field(event_call, tu->args[i].type->fmttype,
|
|
tu->args[i].name,
|
|
sizeof(field) + tu->args[i].offset,
|
|
tu->args[i].type->size,
|
|
tu->args[i].type->is_signed,
|
|
FILTER_OTHER);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len)
|
|
{
|
|
const char *fmt, *arg;
|
|
int i;
|
|
int pos = 0;
|
|
|
|
fmt = "(%lx)";
|
|
arg = "REC->" FIELD_STRING_IP;
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
|
|
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
|
|
tu->args[i].name, tu->args[i].type->fmt);
|
|
}
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
|
|
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
|
|
tu->args[i].name);
|
|
}
|
|
|
|
return pos; /* return the length of print_fmt */
|
|
}
|
|
#undef LEN_OR_ZERO
|
|
|
|
static int set_print_fmt(struct trace_uprobe *tu)
|
|
{
|
|
char *print_fmt;
|
|
int len;
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
len = __set_print_fmt(tu, NULL, 0);
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
|
if (!print_fmt)
|
|
return -ENOMEM;
|
|
|
|
/* Second: actually write the @print_fmt */
|
|
__set_print_fmt(tu, print_fmt, len + 1);
|
|
tu->call.print_fmt = print_fmt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
/* uprobe profile handler */
|
|
static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
|
{
|
|
struct ftrace_event_call *call = &tu->call;
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
u8 *data;
|
|
int size, __size, i;
|
|
int rctx;
|
|
|
|
__size = sizeof(*entry) + tu->size;
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
|
|
return;
|
|
|
|
preempt_disable();
|
|
|
|
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
|
|
if (!entry)
|
|
goto out;
|
|
|
|
entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
|
|
data = (u8 *)&entry[1];
|
|
for (i = 0; i < tu->nr_args; i++)
|
|
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
|
|
|
head = this_cpu_ptr(call->perf_events);
|
|
perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL);
|
|
|
|
out:
|
|
preempt_enable();
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
static
|
|
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
|
|
{
|
|
struct trace_uprobe *tu = (struct trace_uprobe *)event->data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return probe_event_enable(tu, TP_FLAG_TRACE);
|
|
|
|
case TRACE_REG_UNREGISTER:
|
|
probe_event_disable(tu, TP_FLAG_TRACE);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return probe_event_enable(tu, TP_FLAG_PROFILE);
|
|
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
probe_event_disable(tu, TP_FLAG_PROFILE);
|
|
return 0;
|
|
#endif
|
|
default:
|
|
return 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
|
|
{
|
|
struct uprobe_trace_consumer *utc;
|
|
struct trace_uprobe *tu;
|
|
|
|
utc = container_of(con, struct uprobe_trace_consumer, cons);
|
|
tu = utc->tu;
|
|
if (!tu || tu->consumer != utc)
|
|
return 0;
|
|
|
|
if (tu->flags & TP_FLAG_TRACE)
|
|
uprobe_trace_func(tu, regs);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->flags & TP_FLAG_PROFILE)
|
|
uprobe_perf_func(tu, regs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static struct trace_event_functions uprobe_funcs = {
|
|
.trace = print_uprobe_event
|
|
};
|
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
struct ftrace_event_call *call = &tu->call;
|
|
int ret;
|
|
|
|
/* Initialize ftrace_event_call */
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
call->event.funcs = &uprobe_funcs;
|
|
call->class->define_fields = uprobe_event_define_fields;
|
|
|
|
if (set_print_fmt(tu) < 0)
|
|
return -ENOMEM;
|
|
|
|
ret = register_ftrace_event(&call->event);
|
|
if (!ret) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
call->flags = 0;
|
|
call->class->reg = trace_uprobe_register;
|
|
call->data = tu;
|
|
ret = trace_add_event_call(call);
|
|
|
|
if (ret) {
|
|
pr_info("Failed to register uprobe event: %s\n", call->name);
|
|
kfree(call->print_fmt);
|
|
unregister_ftrace_event(&call->event);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void unregister_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
/* tu->event is unregistered in trace_remove_event_call() */
|
|
trace_remove_event_call(&tu->call);
|
|
kfree(tu->call.print_fmt);
|
|
tu->call.print_fmt = NULL;
|
|
}
|
|
|
|
/* Make a trace interface for controling probe points */
|
|
static __init int init_uprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
trace_create_file("uprobe_events", 0644, d_tracer,
|
|
NULL, &uprobe_events_ops);
|
|
/* Profile interface */
|
|
trace_create_file("uprobe_profile", 0444, d_tracer,
|
|
NULL, &uprobe_profile_ops);
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(init_uprobe_trace);
|