From nobody Sat Feb 7 16:00:07 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 B8B73EB64DD for ; Tue, 4 Jul 2023 14:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231414AbjGDOIR (ORCPT ); Tue, 4 Jul 2023 10:08:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231415AbjGDOIM (ORCPT ); Tue, 4 Jul 2023 10:08:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD90511D; Tue, 4 Jul 2023 07:08:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5B08F6114F; Tue, 4 Jul 2023 14:08:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B05FC433C7; Tue, 4 Jul 2023 14:08:08 +0000 (UTC) Date: Tue, 4 Jul 2023 10:08:07 -0400 From: Steven Rostedt To: LKML , Linux trace kernel Cc: Masami Hiramatsu , Mark Rutland , Azeem Shaikh , Kees Cook Subject: [PATCH] tracing/boot: Test strscpy() against less than zero for error Message-ID: <20230704100807.707d1605@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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)" Instead of checking for -E2BIG, it is better to just check for less than zero of strscpy() for error. Testing for -E2BIG is not very robust, and the calling code does not really care about the error code, just that there was an error. One of the updates to convert strlcpy() to strscpy() had a v2 version that changed the test from testing against -E2BIG to less than zero, but I took the v1 version that still tested for -E2BIG. Link: https://lore.kernel.org/linux-trace-kernel/20230615180420.400769-1-az= eemshaikh38@gmail.com/ Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) --- kernel/trace/trace_boot.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 5fe525f1b8cc..7ccc7a8e155b 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -31,7 +31,7 @@ trace_boot_set_instance_options(struct trace_array *tr, s= truct xbc_node *node) =20 /* Common ftrace options */ xbc_node_for_each_array_value(node, "options", anode, p) { - if (strscpy(buf, p, ARRAY_SIZE(buf)) =3D=3D -E2BIG) { + if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) { pr_err("String is too long: %s\n", p); continue; } @@ -87,7 +87,7 @@ trace_boot_enable_events(struct trace_array *tr, struct x= bc_node *node) const char *p; =20 xbc_node_for_each_array_value(node, "events", anode, p) { - if (strscpy(buf, p, ARRAY_SIZE(buf)) =3D=3D -E2BIG) { + if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) { pr_err("String is too long: %s\n", p); continue; } @@ -486,7 +486,7 @@ trace_boot_init_one_event(struct trace_array *tr, struc= t xbc_node *gnode, =20 p =3D xbc_node_find_value(enode, "filter", NULL); if (p && *p !=3D '\0') { - if (strscpy(buf, p, ARRAY_SIZE(buf)) =3D=3D -E2BIG) + if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) pr_err("filter string is too long: %s\n", p); else if (apply_event_filter(file, buf) < 0) pr_err("Failed to apply filter: %s\n", buf); @@ -494,7 +494,7 @@ trace_boot_init_one_event(struct trace_array *tr, struc= t xbc_node *gnode, =20 if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) { xbc_node_for_each_array_value(enode, "actions", anode, p) { - if (strscpy(buf, p, ARRAY_SIZE(buf)) =3D=3D -E2BIG) + if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) pr_err("action string is too long: %s\n", p); else if (trigger_process_regex(file, buf) < 0) pr_err("Failed to apply an action: %s\n", p); --=20 2.39.2