From nobody Sat Feb 7 21:14:46 2026 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 E24383358B2 for ; Wed, 29 Oct 2025 14:40:44 +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=1761748845; cv=none; b=uMp70CkEMrPZNvdt0hY8BKpmFSUJRtSjfVdY3CnvuHh/rCHXs+0fhpwiBszPZNrA6Aiq7aFWFuaj9bMGhHtXASUzZ8fU4S+MzOf8PCSXkRwdmgommMUFtgQkkfDGbVy23aQVUhpe2WtsC1YkvxU0OYMaSUZxJfPw5VIof1+YSWA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761748845; c=relaxed/simple; bh=lT04hyvXI3hRYRjGC/NWe2ZlZUcXJ5lKgvqe06P2w1Q=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=CNB77qB5Td715PhArdRiBI2+Zqbp7s2cO6sqryCtukt56qSJh1RnxCQASE4Urb8Ol9j7w7lbkEYvSQGlqBVCx2OC6yOq5m8Z3u+4mypn7KjOWeuXyZvDzBmDTT8aA5zXo7tq/bQRrv5C1XcRBD7Mh4+a4NBPl05J1iTvZeR5izU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n9us2OvS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="n9us2OvS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3158C116B1; Wed, 29 Oct 2025 14:40:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761748844; bh=lT04hyvXI3hRYRjGC/NWe2ZlZUcXJ5lKgvqe06P2w1Q=; h=Date:From:To:Cc:Subject:References:From; b=n9us2OvSrZx+atrtqSiiH86nSrJAvWh1HGodF1AvfBJSGSPWSj/BBRe2k6dzMetL+ tF5E3NBSLg7QN06wJ3SgwxgJ733JLJMt1rR8zMPVeRMkc+HF+lHZl9Us57DcGoLjxn g/2ue7+Phz1Oo1/NEdRmix8qXM8IwwiSLf9Z690wX7ftRishlQAWivHcDp8IxOPfuJ 5qRI1+qYmn3LpZmOeKpOQpFn1cQYgm/VZkOqx5Kad/vq2wyS2e/fxF55+6GRg+HR9T Zri/kp6y3u6eV6dT9tXUtRMAU0q3KRF4I7VQ9d6VAH7aBux041PJ+CGTeMiuzA4G/d TALd008CxWOqw== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1vE7Mb-000000052zh-2ZTU; Wed, 29 Oct 2025 10:41:25 -0400 Message-ID: <20251029144125.462405292@kernel.org> User-Agent: quilt/0.68 Date: Wed, 29 Oct 2025 10:40:53 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Peter Zijlstra , Namhyung Kim , Takaya Saeki , Tom Zanussi , Thomas Gleixner , Ian Rogers , Douglas Raillard , Arnaldo Carvalho de Melo , Jiri Olsa , Adrian Hunter , Ingo Molnar Subject: [for-next][PATCH 12/13] tracing: Check for printable characters when printing field dyn strings References: <20251029144041.475297995@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Steven Rostedt When the "fields" option is enabled, it prints each trace event field based on its type. But a dynamic array and a dynamic string can both have a "char *" type. Printing it as a string can cause escape characters to be printed and mess up the output of the trace. For dynamic strings, test if there are any non-printable characters, and if so, print both the string with the non printable characters as '.', and the print the hex value of the array. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Peter Zijlstra Cc: Namhyung Kim Cc: Takaya Saeki Cc: Tom Zanussi Cc: Thomas Gleixner Cc: Ian Rogers Cc: Douglas Raillard Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Adrian Hunter Cc: Ingo Molnar Link: https://lore.kernel.org/20251028231148.929243047@kernel.org Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_output.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 97db0b0ccf3e..718b255b6fd8 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -950,7 +950,9 @@ static void print_fields(struct trace_iterator *iter, s= truct trace_event_call *c int offset; int len; int ret; + int i; void *pos; + char *str; =20 list_for_each_entry_reverse(field, head, link) { trace_seq_printf(&iter->seq, " %s=3D", field->name); @@ -977,8 +979,29 @@ static void print_fields(struct trace_iterator *iter, = struct trace_event_call *c trace_seq_puts(&iter->seq, ""); break; } - pos =3D (void *)iter->ent + offset; - trace_seq_printf(&iter->seq, "%.*s", len, (char *)pos); + str =3D (char *)iter->ent + offset; + /* Check if there's any non printable strings */ + for (i =3D 0; i < len; i++) { + if (str[i] && !(isascii(str[i]) && isprint(str[i]))) + break; + } + if (i < len) { + for (i =3D 0; i < len; i++) { + if (isascii(str[i]) && isprint(str[i])) + trace_seq_putc(&iter->seq, str[i]); + else + trace_seq_putc(&iter->seq, '.'); + } + trace_seq_puts(&iter->seq, " ("); + for (i =3D 0; i < len; i++) { + if (i) + trace_seq_putc(&iter->seq, ':'); + trace_seq_printf(&iter->seq, "%02x", str[i]); + } + trace_seq_putc(&iter->seq, ')'); + } else { + trace_seq_printf(&iter->seq, "%.*s", len, str); + } break; case FILTER_PTR_STRING: if (!iter->fmt_size) --=20 2.51.0