linux-kernel - [tip:tracing/ftrace] ftrace: provide an id file for each event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 20 Mar 2009 10:19:27 GMT
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, paulus@...ba.org, hpa@...or.com,
	mingo@...hat.com, rostedt@...dmis.org, a.p.zijlstra@...llo.nl,
	tglx@...utronix.de, mingo@...e.hu
Subject: [tip:tracing/ftrace] ftrace: provide an id file for each event

Commit-ID:  23725aeeab10ba02bcf10ec49ad73146b54cb52f
Gitweb:     http://git.kernel.org/tip/23725aeeab10ba02bcf10ec49ad73146b54cb52f
Author:     Peter Zijlstra <a.p.zijlstra@...llo.nl>
AuthorDate: Thu, 19 Mar 2009 20:26:13 +0100
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Fri, 20 Mar 2009 10:17:05 +0100

ftrace: provide an id file for each event

Since not every event has a format file to read the id from,
expose it explicitly in a separate file.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Steven Rostedt <rostedt@...dmis.org>
LKML-Reference: <20090319194233.372534033@...llo.nl>
Signed-off-by: Ingo Molnar <mingo@...e.hu>


---
 kernel/trace/trace_events.c |   36 ++++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index c88227b..7763db8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -412,6 +412,29 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 	return r;
 }
 
+static ssize_t
+event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	struct ftrace_event_call *call = filp->private_data;
+	struct trace_seq *s;
+	int r;
+
+	if (*ppos)
+		return 0;
+
+	s = kmalloc(sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	trace_seq_init(s);
+	trace_seq_printf(s, "%d\n", call->id);
+
+	r = simple_read_from_buffer(ubuf, cnt, ppos,
+				    s->buffer, s->len);
+	kfree(s);
+	return r;
+}
+
 static const struct seq_operations show_event_seq_ops = {
 	.start = t_start,
 	.next = t_next,
@@ -452,6 +475,11 @@ static const struct file_operations ftrace_event_format_fops = {
 	.read = event_format_read,
 };
 
+static const struct file_operations ftrace_event_id_fops = {
+	.open = tracing_open_generic,
+	.read = event_id_read,
+};
+
 static struct dentry *event_trace_events_dir(void)
 {
 	static struct dentry *d_tracer;
@@ -550,6 +578,14 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
 				   "'%s/enable' entry\n", call->name);
 	}
 
+	if (call->id) {
+		entry = debugfs_create_file("id", 0444, call->dir, call,
+				&ftrace_event_id_fops);
+		if (!entry)
+			pr_warning("Could not create debugfs '%s/id' entry\n",
+					call->name);
+	}
+
 	/* A trace may not want to export its format */
 	if (!call->show_format)
 		return 0;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/