From nobody Sat Sep 27 20:23:25 2025 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 F1BCAC32774 for ; Tue, 23 Aug 2022 10:17:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353664AbiHWKP1 (ORCPT ); Tue, 23 Aug 2022 06:15:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352825AbiHWKGV (ORCPT ); Tue, 23 Aug 2022 06:06:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D69D4319; Tue, 23 Aug 2022 01:53:14 -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 6779E6150F; Tue, 23 Aug 2022 08:53:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68C99C433C1; Tue, 23 Aug 2022 08:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661244793; bh=JJQsM5JWENzuqdyo+/3XXUqAE06ZPzjerTGhvXhu4zE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FzewZks/I2xr6oI7vB/N/h7vl5+nBNFIMYzRDFDolsSvZ0vDtP3xzTjzwejQ4O359 +nFBQX375SvKGs0+iMn5bVz7jrEhpkjIbEr16XU366I8ZgD+GLiC0BLI0GDNRy/nK5 tYrzeuXcDk8o62bvZGKfrCKKUogEYOImDxY0Z/9M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ingo Molnar , Andrew Morton , Tzvetomir Stoyanov , Tom Zanussi , "Masami Hiramatsu (Google)" , "Steven Rostedt (Google)" Subject: [PATCH 5.15 153/244] tracing/eprobes: Fix reading of string fields Date: Tue, 23 Aug 2022 10:25:12 +0200 Message-Id: <20220823080104.290604565@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080059.091088642@linuxfoundation.org> References: <20220823080059.091088642@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Steven Rostedt (Google) commit f04dec93466a0481763f3b56cdadf8076e28bfbf upstream. Currently when an event probe (eprobe) hooks to a string field, it does not display it as a string, but instead as a number. This makes the field rather useless. Handle the different kinds of strings, dynamic, static, relational/dynamic etc. Now when a string field is used, the ":string" type can be used to display it: echo "e:sw sched/sched_switch comm=3D$next_comm:string" > dynamic_events Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_eprobe.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -320,6 +320,24 @@ static unsigned long get_event_field(str =20 addr =3D rec + field->offset; =20 + if (is_string_field(field)) { + switch (field->filter_type) { + case FILTER_DYN_STRING: + val =3D (unsigned long)(rec + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_STATIC_STRING: + val =3D (unsigned long)addr; + break; + case FILTER_PTR_STRING: + val =3D (unsigned long)(*(char *)addr); + break; + default: + WARN_ON_ONCE(1); + return 0; + } + return val; + } + switch (field->size) { case 1: if (field->is_signed)