From patchwork Fri Aug 26 09:51:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12955812 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7EA66ECAAA3 for ; Fri, 26 Aug 2022 09:58:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WXP8Cg4S0mKdjYJwzk5A6XFXFKuYVXE7T252WNBEgAc=; b=RNHC77WDIOQepY faOohfPRCgAT1/4gZASLzUDjXY4OaPzSlOEamjUb/FPubXP2/07kHVsBEEbxWvquqxnJQZx5J7X8Y nAGJl9/UFva4/XwWC0+oGfYiv31YVGAQquKXvBXZMA87aLFk4TBRiARlhu2JTNt6uT2dSw6bLDz62 fRoyFfGDz9frUmbd2QV8p8kP/7kCBKTqZyGL4KBbsPXYa8iKdvdFKtD1j9dxp+DbpZTjzQHHg8HD7 RMLNSZXzr+/qLO1EUGWDu9AmtirAG1cUzYpwFU6wrxC3nDjSy8PLNWsjm7zbgN9crzKwtW39HV7Rd ywpfqjlm4aT8qb+jSWww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oRW5G-0014aU-WB; Fri, 26 Aug 2022 09:57:03 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oRW58-0014RG-TH for linux-arm-kernel@lists.infradead.org; Fri, 26 Aug 2022 09:56:56 +0000 Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MDZsC1TxyzkWhK; Fri, 26 Aug 2022 17:53:19 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 26 Aug 2022 17:56:20 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 26 Aug 2022 17:56:20 +0800 From: Zhen Lei To: Catalin Marinas , Will Deacon , Mark Rutland , Russell King , , , CC: Zhen Lei Subject: [PATCH v2 1/2] arm64/traps: Replace this_cpu_* with raw_cpu_* in panic_bad_stack() Date: Fri, 26 Aug 2022 17:51:11 +0800 Message-ID: <20220826095112.289-2-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20220826095112.289-1-thunder.leizhen@huawei.com> References: <20220826095112.289-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220826_025655_164742_ED2FE9FD X-CRM114-Status: GOOD ( 11.25 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The hardware automatically disable the IRQ interrupt before jumping to the interrupt or exception vector. Therefore, the preempt_disable() operation in this_cpu_read() after macro expansion is unnecessary for exception handler. Use raw_cpu_* instead of this_cpu_* can reduce a few lines of assembly code. To be honest, the fewer unnecessary operations in exception handler, the better. Signed-off-by: Zhen Lei --- arch/arm64/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index b7fed33981f7b76..e6b6f4650e3d895 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -871,8 +871,8 @@ DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack) void panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far) { unsigned long tsk_stk = (unsigned long)current->stack; - unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr); - unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack); + unsigned long irq_stk = (unsigned long)raw_cpu_read(irq_stack_ptr); + unsigned long ovf_stk = (unsigned long)raw_cpu_ptr(overflow_stack); console_verbose(); pr_emerg("Insufficient stack space to handle exception!");