From patchwork Mon Jun 15 04:00:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11603755 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 69B286A2 for ; Mon, 15 Jun 2020 04:00:08 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id CE840207BC for ; Mon, 15 Jun 2020 04:00:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE840207BC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-18962-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 5723 invoked by uid 550); 15 Jun 2020 04:00:06 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 5639 invoked from network); 15 Jun 2020 03:59:55 -0000 From: Jason Yan To: , , , CC: , Jason Yan , Kees Cook Subject: [PATCH] ACPI: Eliminate usage of uninitialized_var() macro Date: Mon, 15 Jun 2020 12:00:47 +0800 Message-ID: <20200615040047.3535543-1-yanaijie@huawei.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected This is an effort to eliminate the uninitialized_var() macro[1]. The use of this macro is the wrong solution because it forces off ANY analysis by the compiler for a given variable. It even masks "unused variable" warnings. Quoted from Linus[2]: "It's a horrible thing to use, in that it adds extra cruft to the source code, and then shuts up a compiler warning (even the _reliable_ warnings from gcc)." The gcc option "-Wmaybe-uninitialized" has been disabled and this change will not produce any warnnings even with "make W=1". [1] https://github.com/KSPP/linux/issues/81 [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Cc: Kees Cook Signed-off-by: Jason Yan --- drivers/acpi/acpi_pad.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index e7dc0133f817..6cc4c92d9ff9 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index) cpumask_var_t tmp; int cpu; unsigned long min_weight = -1; - unsigned long uninitialized_var(preferred_cpu); + unsigned long preferred_cpu; if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) return;