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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C120C433F5 for ; Wed, 6 Oct 2021 15:22:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 33F1A60FDA for ; Wed, 6 Oct 2021 15:22:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 33F1A60FDA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ysQrDHgjT8ZaoML5+nxU3cli9P9lhClApAG9pugWGXk=; b=N0CzeKbku7bwom n+3PyHBuzNEJ0ltlWe4foolX9LaiEhpNWV+j8wfvkZIyr59r7xGOMPTsw+oMr4nBsY68/YFwaWnjJ JLu+I8hoOvC0jK0SB+0z84guEQ9FznFUQ6w2ZfSpWI8oRHKgvT3zH6iqPZLe3rv1fTRtERMZ3LWSB ePWogAyZ0HbWDVk8APuZUrUSHjB30/DeIlKfkaCgSzfA2P03ecKDOxjNgoOISgAMSDMLxEOQ8/I26 FADMSHsqqMJJqT9/lxgD5TYIeUvYob2BhTcBOe10IBxwCB2/vYyWO+TW2iqMGI5TJV27DkPWOrjJ9 bSmCT1itM4XlJafUJU3Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mY8jN-00EmLi-9d; Wed, 06 Oct 2021 15:21:17 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mY8jJ-00EmKt-3B for linux-arm-kernel@lists.infradead.org; Wed, 06 Oct 2021 15:21:14 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 629E660F6D for ; Wed, 6 Oct 2021 15:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633533672; bh=P0j0bicIxZxAtp9gk4Sw1jObCfrF8GW9Hl39IhZJUVg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=CBmkowyJG7NP/0ckV2EquAnBOk50xYdpuISMbxo/pfq/6sMvg8pqtgVnmExV1sgbb EgRDAyRQXVsuFdS3qKhnVTe8VzWcawLH7hnAasIMKcHNGVIrP27+qkEAZqNfo6HGIF k3EvLYpTACF9ujVHd1jYzK+4lGW694fz+aVADJDLplOTNTR/+31zNb+cudRLyeuEHv y9Kc2NkpFGTQu9mK0m1IXFMQ4nzxiiKznoZCrGsbthFPIwmdbAuMaj8XXp7X9Cy3w5 fcBuviSrmVOqPGpwwHkCVuh17G/oQtANm8WoUuejzI0xwMRGQAxnOfsURVHnjwv4kK 81SDDBGIa5NYw== Received: by mail-oi1-f179.google.com with SMTP id 24so4580663oix.0 for ; Wed, 06 Oct 2021 08:21:12 -0700 (PDT) X-Gm-Message-State: AOAM530ukdVSFc7d41A0jWUUaFtrhbSyiOPzsvmbJpROGr5OKJYkbgoQ 5mCdnKdnPSLx5VdEYVZJy05Yu6PfcTTXzvRbolw= X-Google-Smtp-Source: ABdhPJzrX/mVYjm773OOhksi4qMXl9y42mgAUXK1yMrKgj6zghfSBEQRRv/V9WqyGuD9qHNB+0Rm8miOXwa3I0nS/fk= X-Received: by 2002:a05:6808:1148:: with SMTP id u8mr7741813oiu.33.1633533671706; Wed, 06 Oct 2021 08:21:11 -0700 (PDT) MIME-Version: 1.0 References: <20211005071542.3127341-1-ardb@kernel.org> <20211005071542.3127341-10-ardb@kernel.org> In-Reply-To: From: Ard Biesheuvel Date: Wed, 6 Oct 2021 17:21:00 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 9/9] ARM: run softirqs on the per-CPU IRQ stack To: Arnd Bergmann Cc: Linux ARM , Russell King - ARM Linux , Kees Cook , Keith Packard , Linus Walleij X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211006_082113_180666_8CB265FE X-CRM114-Status: GOOD ( 18.43 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 5 Oct 2021 at 14:23, Arnd Bergmann wrote: > > On Tue, Oct 5, 2021 at 9:15 AM Ard Biesheuvel wrote: > > > > Now that we have enabled IRQ stacks, any softIRQs that are handled over > > the back of a hard IRQ will run from the IRQ stack as well. However, any > > synchronous softirq processing that happens when re-enabling softIRQs > > from task context will still execute on that task's stack. > > > > So let's wire up the existing infrastructure to run these softIRQs from > > the IRQ stack as well. > > > > Signed-off-by: Ard Biesheuvel > > The change looks reasonable, but maybe try to explain why it is > a good idea to do this. > > Reviewed-by: Arnd Bergmann Sure. I will add something along the lines of """ Since any call to local_bh_enable() at any level in the task's call stack may trigger a softIRQ processing run, which could potentially cause a task stack overflow if the combined stack footprints exceed the stack's size, let's run these synchronous invocations of do_softirq() on the IRQ stack as well. """ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel