From nobody Wed Apr 8 11:43:13 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F47EC25B08 for ; Sun, 21 Aug 2022 00:08:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236210AbiHUAIw (ORCPT ); Sat, 20 Aug 2022 20:08:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233847AbiHUAIe (ORCPT ); Sat, 20 Aug 2022 20:08:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF92DDFA4; Sat, 20 Aug 2022 17:08:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 46C0E60C5A; Sun, 21 Aug 2022 00:08:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8B5EC433B5; Sun, 21 Aug 2022 00:08:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1oPYWD-005Dmd-1s; Sat, 20 Aug 2022 20:08:45 -0400 Message-ID: <20220821000845.407218228@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 20 Aug 2022 20:07:43 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org Subject: [for-linus][PATCH 06/10] tracing/eprobes: Do not hardcode $comm as a string References: <20220821000737.328590235@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" The variable $comm is hard coded as a string, which is true for both kprobes and uprobes, but for event probes (eprobes) it is a field name. In most cases the "comm" field would be a string, but there's no guarantee of that fact. Do not assume that comm is a string. Not to mention, it currently forces comm fields to fault, as string processing for event probes is currently broken. Cc: stable@vger.kernel.org Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_probe.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dec657af363c..4daabbb8b772 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -622,9 +622,10 @@ static int traceprobe_parse_probe_arg_body(const char = *argv, ssize_t *size, =20 /* * Since $comm and immediate string can not be dereferenced, - * we can find those by strcmp. + * we can find those by strcmp. But ignore for eprobes. */ - if (strcmp(arg, "$comm") =3D=3D 0 || strncmp(arg, "\\\"", 2) =3D=3D 0) { + if (!(flags & TPARG_FL_TPOINT) && + (strcmp(arg, "$comm") =3D=3D 0 || strncmp(arg, "\\\"", 2) =3D=3D 0)) { /* The type of $comm must be "string", and not an array. */ if (parg->count || (t && strcmp(t, "string"))) goto out; --=20 2.35.1