From mboxrd@z Thu Jan 1 00:00:00 1970 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 0B691261B77; Tue, 21 Oct 2025 00:52:13 +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=1761007935; cv=none; b=hrjL1uur/P6rLTFT6/nVDGoyjHQdb3hDe7ORvIlrFvKdN58amSC0ujiZck37mc1dylSGHndg9Ex6g3OeSK4JaUbtgyckFrZaUq7vbhHhyqqNtbTakLhiWmRg0NDWwTV0AxGpRJ09jIpa26Q98vYwbJEoTEooWPV5QO/UobHNyFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761007935; c=relaxed/simple; bh=pEZ5P2P/pcsHQBwGmSCZzSbB6LsFpFMiLNyesbHEmAw=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=gSkQZeCNL4/u+FiOGbOZJN6zBIrYP4JtzOWlWxKggV1hxV2aBz6Blr5wGzM4t+i71jIkqR+rypcn0w45qWSTNG90Kua/QONUxGnj/EUZXmN5JLTcx5XpSCis41d5d0TjXv5XgrFcmNlaRyFzppt/1IZ1ygaqidshFRkZndn428I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qUur1Vpl; 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="qUur1Vpl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B654C113D0; Tue, 21 Oct 2025 00:52:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761007933; bh=pEZ5P2P/pcsHQBwGmSCZzSbB6LsFpFMiLNyesbHEmAw=; h=Date:From:To:Cc:Subject:References:From; b=qUur1VplDrg7z/4hVtbuujHIxBdApqOgB4inITEZKlwGnLqBpTe5+/mRAXo42kv8k GC0mHUNf4e2bN18TddxT+Pc+QXhx6jTgEnzWVAYivYLkJPjsPCYN8okAuULbWSPsI9 lS9BDgGicym+xwiIMA+M39cu/O8O7DtqIz5wpBRHehkXQpTktqTANNeD6rqXIVr+My hG1pZzUKiAdIuk9Tspc5lwtrAs22upOJyvlpJDL0jb5RtX9kKJevtoNzJEoESalBvL t66A3aKax8WlxKYQSybj7B+77ST2Ji+KUSBAjChN6V8chmsrHa02W2qLk5ImO8LRPq M71hqSt8RGVKg== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1vB0c6-000000020Ap-1eU2; Mon, 20 Oct 2025 20:52:34 -0400 Message-ID: <20251021005234.245481539@kernel.org> User-Agent: quilt/0.68 Date: Mon, 20 Oct 2025 20:52:07 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@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: [PATCH v4 12/13] tracing: Check for printable characters when printing field dyn strings References: <20251021005155.705735078@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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. 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, struct trace_event_call *c int offset; int len; int ret; + int i; void *pos; + char *str; list_for_each_entry_reverse(field, head, link) { trace_seq_printf(&iter->seq, " %s=", 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 = (void *)iter->ent + offset; - trace_seq_printf(&iter->seq, "%.*s", len, (char *)pos); + str = (char *)iter->ent + offset; + /* Check if there's any non printable strings */ + for (i = 0; i < len; i++) { + if (str[i] && !(isascii(str[i]) && isprint(str[i]))) + break; + } + if (i < len) { + for (i = 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 = 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) -- 2.51.0