mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Tom Zanussi <tzanussi@gmail.com>
To: linux-kernel <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
	fweisbec@gmail.com
Subject: [PATCH] tracing/filters: disallow concurrent/multiple setting/enabling of filters
Date: Thu, 02 Apr 2009 01:29:30 -0500	[thread overview]
Message-ID: <1238653770.6655.62.camel@bookworm> (raw)

This patch disallows setting/enabling or multiple concurrent setting
and/or reading of event filters. 

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>

---
 kernel/trace/trace_events.c |   30 ++++++++++++++++++++++++++----
 1 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index be9299a..eb7ee65 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -481,7 +481,10 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 
 	trace_seq_init(s);
 
+	mutex_lock(&event_mutex);
 	filter_print_preds(call->preds, s);
+	mutex_unlock(&event_mutex);
+
 	r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
 	kfree(s);
@@ -514,20 +517,28 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		return err;
 	}
 
+	mutex_lock(&event_mutex);
 	if (pred->clear) {
 		filter_free_preds(call);
 		filter_free_pred(pred);
-		return cnt;
+		err = cnt;
+		goto out;
 	}
 
 	if (filter_add_pred(call, pred)) {
 		filter_free_pred(pred);
-		return -EINVAL;
+		err = -EINVAL;
+		goto out;
 	}
+	mutex_unlock(&event_mutex);
 
 	*ppos += cnt;
 
 	return cnt;
+
+out:
+	mutex_unlock(&event_mutex);
+	return err;
 }
 
 static ssize_t
@@ -547,7 +558,10 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 
 	trace_seq_init(s);
 
+	mutex_lock(&event_mutex);
 	filter_print_preds(system->preds, s);
+	mutex_unlock(&event_mutex);
+
 	r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
 	kfree(s);
@@ -580,21 +594,29 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		return err;
 	}
 
+	mutex_lock(&event_mutex);
 	if (pred->clear) {
 		filter_free_subsystem_preds(system);
 		filter_free_pred(pred);
-		return cnt;
+		err = cnt;
+		goto out;
 	}
 
 	if (filter_add_subsystem_pred(system, pred)) {
 		filter_free_subsystem_preds(system);
 		filter_free_pred(pred);
-		return -EINVAL;
+		err = -EINVAL;
+		goto out;
 	}
+	mutex_unlock(&event_mutex);
 
 	*ppos += cnt;
 
 	return cnt;
+
+out:
+	mutex_unlock(&event_mutex);
+	return err;
 }
 
 static const struct seq_operations show_event_seq_ops = {
-- 
1.5.6.3




                 reply	other threads:[~2009-04-02  6:29 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1238653770.6655.62.camel@bookworm \
    --to=tzanussi@gmail.com \
    --cc=fweisbec@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®