From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 81B2A330D4C for ; Sat, 30 May 2026 00:00:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780099205; cv=none; b=E9GHofg9y/dICFa+9lSaFF+ZMlOCV0QB7PHcteZpaXgPA7XOKfdCCQNNplMlfNh1jyFLLRri67K7+wrgpLhsGA5J4qYuOGEWHGNaizPNyJcKfvO9cGvhy3xVN1IwfBgMVntu89T+k6FgFmNHzGjpoiVEhoG51A8hgftYeFrvf3U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780099205; c=relaxed/simple; bh=1rPIFPNC1B/eNQ0FrJ53quiwOvorrOn2OagZSjjE+jM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=ej7k6ZSYKmRhLryvIToiZOCBkhlbBtorvQjz7LzyGgD6bwLL987MYjWjff6v3TodfKF/QI/zYvPMjHQJdu6QRzKsHcyU0LSaS9KJwwKAHu2rOcy2qUThnTHCdClH9jdirU1kHaxUZiuNl5tbab7gL7UgpddGe4y2a7/La+qOGrk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AjAyokTe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AjAyokTe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63B491F0089D; Sat, 30 May 2026 00:00:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780099204; bh=mLzlMTZL1EhYOfs566k/d5qHrckzkqW2i4ea3o5O3qc=; h=Date:From:To:Cc:Subject:References; b=AjAyokTeXKV9PlOud3rJohTAb5EBsqwEydk1HLaIaJOMV8l49T2bmmQztz6g5i8Fy cRDJR1xdyZtgwk24ximI5jz0hQQtPGbirCWyFnDIvytX0UB8gDyKKM2gl6Z/A9Pq1g gQM7K8S76aOjkIabLPi/F5svn6lqFQQfuCDeovE3FvO7FAnNtoLOuD7xxnMCjflC1o dsSrcnHAXQl1Q5MqS2UCjantTgfM6iSeJn3OEkc0LP7oV3rpWzu00odX+ahI+Eh7mY PVtCb5UNJy0KfxuvIgewF4TVGuO+CL2cmSwL2mPMQ4PTayd1dJR4KqXtSZpG2dB/LU CHMkQK1izcCAg== Received: from rostedt by gandalf with local (Exim 4.99.2) (envelope-from ) id 1wT788-0000000AgDc-2PhG; Fri, 29 May 2026 20:00:44 -0400 Message-ID: <20260530000044.431608744@kernel.org> User-Agent: quilt/0.69 Date: Fri, 29 May 2026 20:00:32 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Rik van Riel Subject: [for-next][PATCH 3/3] perf/ftrace: Fix WARNING in __unregister_ftrace_function References: <20260530000029.648858285@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Rik van Riel perf_ftrace_function_unregister() unconditionally calls unregister_ftrace_function() without checking whether the ftrace_ops was ever successfully registered. This triggers a WARN_ON in __unregister_ftrace_function() when the ops doesn't have FTRACE_OPS_FL_ENABLED set. This can happen during perf_event_alloc() error cleanup when perf_trace_destroy() is called via __free_event() on an event whose ftrace_ops registration failed or was already torn down by perf_try_init_event()'s err_destroy path. The call path is: perf_event_alloc() error cleanup -> __free_event() -> event->destroy() [tp_perf_event_destroy] -> perf_trace_destroy() -> perf_trace_event_close() -> TRACE_REG_PERF_CLOSE -> perf_ftrace_function_unregister() -> unregister_ftrace_function() -> __unregister_ftrace_function() -> WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)) Fix this by checking FTRACE_OPS_FL_ENABLED before attempting to unregister. If the ops is not enabled, just free the filter and return success. Link: https://patch.msgid.link/20260527111301.2d0d8256@fangorn Signed-off-by: Rik van Riel Signed-off-by: Steven Rostedt --- kernel/trace/trace_event_perf.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index a6bb7577e8c5..5b272856e5ab 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -497,7 +497,17 @@ static int perf_ftrace_function_register(struct perf_event *event) static int perf_ftrace_function_unregister(struct perf_event *event) { struct ftrace_ops *ops = &event->ftrace_ops; - int ret = unregister_ftrace_function(ops); + int ret = 0; + + /* + * Perf will call this unconditionally even if the ops is not + * enabled. The unregister_ftrace_function() will warn if called + * when not enabled. Just bypass the unregistering if ops isn't + * enabled here. + */ + if (ops->flags & FTRACE_OPS_FL_ENABLED) + ret = unregister_ftrace_function(ops); + ftrace_free_filter(ops); return ret; } -- 2.53.0