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 CAB58376A19 for ; Tue, 11 Aug 2026 19:31:14 +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=1786476676; cv=none; b=ABxId4ETAic+Uyh/0/6C3oQykZpZ6l3KA53ZlYdlMbqY9Lb66EgQlH3kcBMqQnCLUMNnBI86Y2xAKiKRlzgGz3WwDYemee8PVpsgesGEHgeOlNJW0vFTYsMVQW1ELxs6HO8WDqpUoE4l4Q4iEtyJQGlai0ccSbz4AJb9cw/Vkn4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786476676; c=relaxed/simple; bh=BY4YQhpOUyAN7E4k3VLSop2UZQB9d4JCPDHrRkV3pIM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=JRnNwJAuV6q86RE/+Lu8qLKjXk2ae3RumNvTC8ruNO+xrf53hG4zQ9G3qTgKfs/MhVREs+3VeOw2XVtgXQtmg5+iZeJXFrpOTk+1yWYRtO/GFqC68P2KTAwytVAuIkfAKZscUMWCdoXjVI/FLIhJ6yXGSiUwKXB4kR4xR0fQyPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bBmQOu6B; 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="bBmQOu6B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B79A1F00A3E; Tue, 11 Aug 2026 19:31:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786476674; bh=Mv6gS3L+WboEA7tuyxu9Cgk6QK1Q0EXMZEbKR5kFXDw=; h=Date:From:To:Cc:Subject:References; b=bBmQOu6B9LciMKfdpUilF3mOY1ge143HC2r4FMobkjiGNhOZXnJRDDpns67Xju9fs GjX4Bd9U2x0A2mIyAxOelLKyyVTSOhlTDZKRyLQXMcALvgdVCcAD1hOS88msSzpW/o V20trUpUqbLIq09XjAVT2Q/AggxmpUZwDMKVm/ig7if/Pel9pEp26/bx8Q1/w8jX8a IQBUYYs4thIFai6DvtQ7tX/00jqQgfTRJKkah9zzVxInaxcKaBUIh3/rCYjReMRlfY 9Qq/7B6BAulOoEafZ+moD9SuuvF8CnJterUhuUUvUMUsmPkqDcUu8vNX9x6O5IuwDV kx9/dnEx91pvg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1wtsC6-00000002hZO-3YTU; Tue, 11 Aug 2026 15:31:26 -0400 Message-ID: <20260811193126.703949368@kernel.org> User-Agent: quilt/0.69 Date: Tue, 11 Aug 2026 15:31:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , David Carlier Subject: [for-next][PATCH 2/3] tracing: Report every TP_printk double dereference References: <20260811193100.764585233@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: David Carlier WARN_ONCE() splats once per call site, so only the first offending event registered is ever reported. The tree currently has six: ice_{rx,tx}_dim_template, two hfi1 txq events, mtu3_ep and edma_log_io. Whichever registers first hides the rest, and each has to be found again on the next boot. Add a pr_warn() next to the WARN_ONCE() so every offender is listed, the same way test_event_printk() already pairs WARN_ON_ONCE() with pr_warn() for unsafe %p* dereferences. The WARN_ONCE() stays so the condition still fails tests and panics under panic_on_warn. Link: https://patch.msgid.link/20260806215256.1680267-1-devnexen@gmail.com Suggested-by: Steven Rostedt Signed-off-by: David Carlier Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index a8590d2394e3..ce902482ec7c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -415,6 +415,8 @@ static void test_double_dereference(const char *str, int len, ptr += 5; for (; ptr < end; ptr++) { if (ptr[0] == '-' && ptr[1] == '>') { + pr_warn("TRACE EVENT ERROR: Event %s has double dereference in TP_printk: %.*s\n", + trace_event_name(call), len, str); WARN_ONCE(1, "Event %s has double dereference in TP_printk: %.*s\n", trace_event_name(call), len, str); return; -- 2.53.0