From patchwork Mon Oct 28 07:12:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13853109 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3703191F7F; Mon, 28 Oct 2024 07:12:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730099539; cv=none; b=tBiyVIn9AZIu0QbLM9ELwSMpKnYvr1gv0hNZ2w6WXm++XSyFLo+k4M1nivXnobxbrH+9iEqvLxueQOlJ7x9cCoifyALjOiLuqok/lZjOGhobfE8nyhEAMiS5EHIQ428S9gLkQCt7YKf7i6G5wu5E+qKDimJ4fn3UEpj5mLUys9s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730099539; c=relaxed/simple; bh=OZ76P+x20FJGM1mhnK21A4nkaPxTbLlBClKvkWtTMVg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=V1WIPk1PFtt5NdfLWt9gcpqyEIFM9/mQiNtYHfNeG45SjcqaWainGrCrRldx9G/1ZKGghRNkXx/QQ20oljL1RME8QH0OSd29Nc6Plk2bvpVrd+Fl2iy8W3i1uD3p02mgv2vyfTUc5dZt9M4LTP7AqkEKi79h2YLsc7GaBoL/FuQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6A53C4CEC7; Mon, 28 Oct 2024 07:12:19 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1t5Jw4-000000053F0-2HvF; Mon, 28 Oct 2024 03:13:08 -0400 Message-ID: <20241028071308.406073025@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 28 Oct 2024 03:12:33 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Thomas Gleixner , Peter Zijlstra Subject: [PATCH 5/5] ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash() References: <20241028071228.575900713@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt The ftrace_lock is taken for most of the ftrace_graph_set_hash() function throughout the end. Use guard to take the ftrace_lock to simplify the exit paths. Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ftrace.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c0fabd7da5b2..b4ef469f4fd2 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6816,12 +6816,10 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) func_g.len = strlen(func_g.search); - mutex_lock(&ftrace_lock); + guard(mutex)(&ftrace_lock); - if (unlikely(ftrace_disabled)) { - mutex_unlock(&ftrace_lock); + if (unlikely(ftrace_disabled)) return -ENODEV; - } do_for_each_ftrace_rec(pg, rec) { @@ -6837,7 +6835,7 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) if (entry) continue; if (add_hash_entry(hash, rec->ip) == NULL) - goto out; + return 0; } else { if (entry) { free_hash_entry(hash, entry); @@ -6846,13 +6844,8 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) } } } while_for_each_ftrace_rec(); -out: - mutex_unlock(&ftrace_lock); - if (fail) - return -EINVAL; - - return 0; + return fail ? -EINVAL : 0; } static ssize_t