From mboxrd@z Thu Jan 1 00:00:00 1970 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 F2CABC54EBD for ; Mon, 9 Jan 2023 14:59:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231319AbjAIO7W (ORCPT ); Mon, 9 Jan 2023 09:59:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234795AbjAIO7S (ORCPT ); Mon, 9 Jan 2023 09:59:18 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E88AA17068; Mon, 9 Jan 2023 06:59:17 -0800 (PST) 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 70E3161165; Mon, 9 Jan 2023 14:59:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3939C433D2; Mon, 9 Jan 2023 14:59:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673276356; bh=WSuuqqqC0VC3G+Vlaj/ghfDY3b0eTRSPadxQXC50zlw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=I1b2s5nMSnLEEL88uWjemd2TSZy/f9oNaEt8W2BhUyDbWJuNm2iRcJYpcyPbS8TUo BY7tqUzCcfCp/AsAbhkA37dxGq4hZtjES27t07dqyu/mcqidkOLKpZqlD30JjDYGYk +PcObFtb2K1+3j9ZDhUuo6WLB+egCARAcliFrvsEyVk3q6R31A8P/lRbJaDujaHyqx QsdkI5LcLzdog3NNSdywtbKuFPnDym+M0UvGWoHFMyLVprvHESrnuzeMhwUHYXeQZl 0CUq/uG5EEwAGSWPeoIGjEHcZIlPINDJ5/79tHPeUhLdQtNdUiIMAEwDGOD+Eo2FBF Bh6Luq/ZPfhOg== Date: Mon, 9 Jan 2023 23:59:13 +0900 From: Masami Hiramatsu (Google) To: Quanfa Fu Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf Message-Id: <20230109235913.8ac99d54cff8b7c3fc5dcfa4@kernel.org> In-Reply-To: <20230109040625.3259642-1-quanfafu@gmail.com> References: <20230109040625.3259642-1-quanfafu@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Mon, 9 Jan 2023 12:06:25 +0800 Quanfa Fu wrote: > No need to check for negative return value from snprintf() as the > code does not return negative values. > Thanks for simplifying, this looks good to me. Acked-by: Masami Hiramatsu (Google) > Signed-off-by: Quanfa Fu > > ----- > V2 -> V3: continue to use snprintf > V1 -> V2: memory allc uses kzalloc and replace snprintf with memcpy > --- > kernel/trace/trace_eprobe.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c > index 352b65e2b910..594ac1d086aa 100644 > --- a/kernel/trace/trace_eprobe.c > +++ b/kernel/trace/trace_eprobe.c > @@ -923,17 +923,13 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch > > p = ep->filter_str; > for (i = 0; i < argc; i++) { > - ret = snprintf(p, len, "%s ", argv[i]); > - if (ret < 0) > - goto error; > - if (ret > len) { > - ret = -E2BIG; > - goto error; > - } > + if (i) > + ret = snprintf(p, len, " %s", argv[i]); > + else > + ret = snprintf(p, len, "%s", argv[i]); > p += ret; > len -= ret; > } > - p[-1] = '\0'; > > /* > * Ensure the filter string can be parsed correctly. Note, this > -- > 2.31.1 > -- Masami Hiramatsu (Google)