From nobody Sun Apr 12 02:49:48 2026 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 EE17DC00140 for ; Tue, 2 Aug 2022 06:53:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233079AbiHBGxk (ORCPT ); Tue, 2 Aug 2022 02:53:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231932AbiHBGxg (ORCPT ); Tue, 2 Aug 2022 02:53:36 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43816491C8 for ; Mon, 1 Aug 2022 23:53:35 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id c19-20020a17090ae11300b001f2f94ed5c6so702296pjz.1 for ; Mon, 01 Aug 2022 23:53:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc; bh=uVFoLxQ6dMayohS3JHhDfe5iy+WrdfwvAxJQ06r4ODg=; b=xgH/Pm2Vq7i1xxAqCs0FiuBWEln7VQz8Mthw8a5mgC/b96Dpl/iGsVG5qf/IlnjGCx 3E8gpHm7laW2IZ2DSrKNi008izQaxPCz6pFvauX5MR5Hh5rgtgIUVQHhgooSpUjRLOIt NN0H9OwLhzBkSgFArjxFA5YKPVzTBVJXIep6q4+xmrm0HgXJgWuE6xFgqpfwhE5qBNzX rZrSbru+D8Ho2GNPHfscScz2RwhgIa0gbF5C+M3J/PT7tgpRdNhfK+9NYgvT/nGVXgxS 5z4ajg+2CDUDDrnQ/3U43uY+hN2UtNFdn0DkqF7YFj+VLGyfbYIcYnKC4Ice89pa1GE7 nWZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc; bh=uVFoLxQ6dMayohS3JHhDfe5iy+WrdfwvAxJQ06r4ODg=; b=Jx+HkRp/lZltYEmdXJO4wofsKDeyx6CTzYDI2EyVoUZkK45CIKraQC6qUBGlk/IUN+ 4WjWpejTyaqZ+smCLKtXjcSNJcHdU7y8n+NEJ/qN80dNeG4uZ4oNJbXR9+aBWQhxwXDd gyqcrTKOdgJCF7956ZS48NecWJStjbo3fjkRnhSOpjQTPVFDmxdd5LHsr5RZnX8Jwkzh 25ecmfT72rQWD6Pqxh1yPAv4+ASYF+ThVMCPjtfYm1GfgtSPiDmeSbz7RL17+3VBSFoJ fpb7+qO7ftg4jwH+yXC6cwMMmAj+VmaFL4yKskbwNfrLW+qTS/hvWVikXqbXiD5TUVGo Oriw== X-Gm-Message-State: ACgBeo269ymVP8KDim8Tgno2uBCQ9Do+qVZNrKwTkWgLhN7+HOqspvXo NleC/KnITVuffmHvVVoh0oGFow== X-Google-Smtp-Source: AA6agR49NL9qaHjMgzqU4n2JYSNt1BQhiTLN5q0K/x8eg2GJigMZYgcN0OEqv/0rRIO0OMkhEyZuMg== X-Received: by 2002:a17:903:248:b0:168:cf03:eefe with SMTP id j8-20020a170903024800b00168cf03eefemr19889308plh.124.1659423214750; Mon, 01 Aug 2022 23:53:34 -0700 (PDT) Received: from C02DW0BEMD6R.bytedance.net ([139.177.225.245]) by smtp.gmail.com with ESMTPSA id 18-20020a621912000000b0052ac5e304d0sm10198168pfz.179.2022.08.01.23.53.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Aug 2022 23:53:34 -0700 (PDT) From: Qi Zheng To: will@kernel.org, arnd@arndb.de, catalin.marinas@arm.com, mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Qi Zheng Subject: [PATCH v2] arm64: run softirqs on the per-CPU IRQ stack Date: Tue, 2 Aug 2022 14:53:25 +0800 Message-Id: <20220802065325.39740-1-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Currently arm64 supports per-CPU IRQ stack, but softirqs are still handled in the task context. 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 softirqs on the IRQ stack as well. Signed-off-by: Qi Zheng Reviewed-by: Arnd Bergmann Acked-by: Will Deacon Reported-by: kernel test robot --- v1: https://lore.kernel.org/lkml/20220708094950.41944-1-zhengqi.arch@byteda= nce.com/ RFC: https://lore.kernel.org/lkml/20220707110511.52129-1-zhengqi.arch@byted= ance.com/ Changelog in v1 -> v2: - temporarily discard [PATCH v1 2/2] to allow this patch to be merged first - rebase onto the v5.19 - collect Reviewed-by and Acked-by Changelog in RFC -> v1: - fix conflicts with commit f2c5092190f2 ("arch/*: Disable softirq stacks = on PREEMPT_RT.") arch/arm64/Kconfig | 1 + arch/arm64/kernel/irq.c | 13 +++++++++++++ 2 files changed, 14 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1652a9800ebe..90f1ab403724 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -226,6 +226,7 @@ config ARM64 select THREAD_INFO_IN_TASK select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD select TRACE_IRQFLAGS_SUPPORT + select HAVE_SOFTIRQ_ON_OWN_STACK help ARM 64-bit (AArch64) Linux support. =20 diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index bda49430c9ea..c36ad20a52f3 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -22,6 +22,7 @@ #include #include #include +#include =20 /* Only access this in an NMI enter/exit */ DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); @@ -71,6 +72,18 @@ static void init_irq_stacks(void) } #endif =20 +#ifndef CONFIG_PREEMPT_RT +static void ____do_softirq(struct pt_regs *regs) +{ + __do_softirq(); +} + +void do_softirq_own_stack(void) +{ + call_on_irq_stack(NULL, ____do_softirq); +} +#endif + static void default_handle_irq(struct pt_regs *regs) { panic("IRQ taken without a root IRQ handler\n"); --=20 2.20.1