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 4995F6AB9 for ; Wed, 23 Mar 2022 23:07:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10843C340E8; Wed, 23 Mar 2022 23:07:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648076821; bh=GjfTSEjREVFETddnHTx3cT/Fhv/AEqbaNHY+hVV71Pc=; h=Date:To:From:In-Reply-To:Subject:From; b=mBpfeBqd8aUU3Frd340eKGpiVJQIlPHG+11jlF0Q43fY+5Wf+p9F/Nubpy8VTcUdj ui0Xch30KMol2sqDrsWpmmSwBeVtBZG2MjFcmXzOoe5rE9zKASBN/is4LKRI0g+XEl F9ZF8kIbFngbhxF0YvGCSp9JUJIgJlaEyQlYFQLI= Date: Wed, 23 Mar 2022 16:07:00 -0700 To: trix@redhat.com,ndesaulniers@google.com,natechancellor@gmail.com,bsingharora@gmail.com,lukas.bulwahn@gmail.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220323160453.65922ced539cbf445b191555@linux-foundation.org> Subject: [patch 34/41] taskstats: remove unneeded dead assignment Message-Id: <20220323230701.10843C340E8@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Lukas Bulwahn Subject: taskstats: remove unneeded dead assignment make clang-analyzer on x86_64 defconfig caught my attention with: kernel/taskstats.c:120:2: warning: Value stored to 'rc' is never read \ [clang-analyzer-deadcode.DeadStores] rc = 0; ^ Commit d94a041519f3 ("taskstats: free skb, avoid returns in send_cpu_listeners") made send_cpu_listeners() not return a value and hence, the rc variable remained only to be used within the loop where it is always assigned before read and it does not need any other initialisation. So, simply remove this unneeded dead initializing assignment. As compilers will detect this unneeded assignment and optimize this anyway, the resulting object code is identical before and after this change. No functional change. No change to object code. [akpm@linux-foundation.org: reduce scope of `rc'] Link: https://lkml.kernel.org/r/20220307093942.21310-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn Reviewed-by: Nick Desaulniers Cc: Balbir Singh Cc: Tom Rix Cc: Nathan Chancellor Signed-off-by: Andrew Morton --- kernel/taskstats.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/kernel/taskstats.c~taskstats-remove-unneeded-dead-assignment +++ a/kernel/taskstats.c @@ -113,13 +113,14 @@ static void send_cpu_listeners(struct sk struct listener *s, *tmp; struct sk_buff *skb_next, *skb_cur = skb; void *reply = genlmsg_data(genlhdr); - int rc, delcount = 0; + int delcount = 0; genlmsg_end(skb, reply); - rc = 0; down_read(&listeners->sem); list_for_each_entry(s, &listeners->list, list) { + int rc; + skb_next = NULL; if (!list_is_last(&s->list, &listeners->list)) { skb_next = skb_clone(skb_cur, GFP_KERNEL); _ 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 A934EC4332F for ; Wed, 23 Mar 2022 23:07:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345426AbiCWXIi (ORCPT ); Wed, 23 Mar 2022 19:08:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345436AbiCWXIf (ORCPT ); Wed, 23 Mar 2022 19:08:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A526190CEF for ; Wed, 23 Mar 2022 16:07:03 -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 ams.source.kernel.org (Postfix) with ESMTPS id 5563FB8214F for ; Wed, 23 Mar 2022 23:07:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10843C340E8; Wed, 23 Mar 2022 23:07:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648076821; bh=GjfTSEjREVFETddnHTx3cT/Fhv/AEqbaNHY+hVV71Pc=; h=Date:To:From:In-Reply-To:Subject:From; b=mBpfeBqd8aUU3Frd340eKGpiVJQIlPHG+11jlF0Q43fY+5Wf+p9F/Nubpy8VTcUdj ui0Xch30KMol2sqDrsWpmmSwBeVtBZG2MjFcmXzOoe5rE9zKASBN/is4LKRI0g+XEl F9ZF8kIbFngbhxF0YvGCSp9JUJIgJlaEyQlYFQLI= Date: Wed, 23 Mar 2022 16:07:00 -0700 To: trix@redhat.com, ndesaulniers@google.com, natechancellor@gmail.com, bsingharora@gmail.com, lukas.bulwahn@gmail.com, akpm@linux-foundation.org, patches@lists.linux.dev, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220323160453.65922ced539cbf445b191555@linux-foundation.org> Subject: [patch 34/41] taskstats: remove unneeded dead assignment Message-Id: <20220323230701.10843C340E8@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Lukas Bulwahn Subject: taskstats: remove unneeded dead assignment make clang-analyzer on x86_64 defconfig caught my attention with: kernel/taskstats.c:120:2: warning: Value stored to 'rc' is never read \ [clang-analyzer-deadcode.DeadStores] rc = 0; ^ Commit d94a041519f3 ("taskstats: free skb, avoid returns in send_cpu_listeners") made send_cpu_listeners() not return a value and hence, the rc variable remained only to be used within the loop where it is always assigned before read and it does not need any other initialisation. So, simply remove this unneeded dead initializing assignment. As compilers will detect this unneeded assignment and optimize this anyway, the resulting object code is identical before and after this change. No functional change. No change to object code. [akpm@linux-foundation.org: reduce scope of `rc'] Link: https://lkml.kernel.org/r/20220307093942.21310-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn Reviewed-by: Nick Desaulniers Cc: Balbir Singh Cc: Tom Rix Cc: Nathan Chancellor Signed-off-by: Andrew Morton --- kernel/taskstats.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/kernel/taskstats.c~taskstats-remove-unneeded-dead-assignment +++ a/kernel/taskstats.c @@ -113,13 +113,14 @@ static void send_cpu_listeners(struct sk struct listener *s, *tmp; struct sk_buff *skb_next, *skb_cur = skb; void *reply = genlmsg_data(genlhdr); - int rc, delcount = 0; + int delcount = 0; genlmsg_end(skb, reply); - rc = 0; down_read(&listeners->sem); list_for_each_entry(s, &listeners->list, list) { + int rc; + skb_next = NULL; if (!list_is_last(&s->list, &listeners->list)) { skb_next = skb_clone(skb_cur, GFP_KERNEL); _