From nobody Thu Sep 18 09:55:42 2025 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 09737C4708D for ; Thu, 8 Dec 2022 03:00:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230032AbiLHDAj (ORCPT ); Wed, 7 Dec 2022 22:00:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229998AbiLHDAC (ORCPT ); Wed, 7 Dec 2022 22:00:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 643988C69A; Wed, 7 Dec 2022 18:59:50 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 009B761D4E; Thu, 8 Dec 2022 02:59:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72467C43470; Thu, 8 Dec 2022 02:59:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670468389; bh=umRGPR1A2QmR7y4OP0ZFPkrv0cgKCxoX2M+AvQSNKwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=df3ii1Tr5RDQn2Jb+teQCjKX2HDaRnMvuoB04A0A6Vmi+rwUWualu9ZTNEMlRaEh+ UoDgm3LmrklqWnmccBAIYYkRtfJS7TCAUtkCPUYGbnt99ICZ/KOaFWgZSpzfySzYPX vUmZkw/IqvZL0Dq60XIU2XAE+ee3LjLUAvn0L7b7VJDMPQu8hIPl7uN/tkz11WPea9 hKXMP/4tvbetfj1G1O1By10oeXsfNTHp3s6tYFFdoQIZzWAZNIcCCx83T3TKW24g6U q5orWsBqxdOLSLbU4uqyWO6CmBhqKMjXuNKGuURDudj6HkCl3aQkHrlAZK+ldEYckz VnqqK4fU6Gxyg== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org, apatel@ventanamicro.com, atishp@atishpatra.org, palmer@dabbelt.com, paul.walmsley@sifive.com, mark.rutland@arm.com, zouyipeng@huawei.com, bigeasy@linutronix.de, David.Laight@aculab.com, chenzhongjin@huawei.com, greentime.hu@sifive.com, andy.chiu@sifive.com, ben@decadent.org.uk, bjorn@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: [PATCH -next V10 08/10] riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Date: Wed, 7 Dec 2022 21:58:14 -0500 Message-Id: <20221208025816.138712-9-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221208025816.138712-1-guoren@kernel.org> References: <20221208025816.138712-1-guoren@kernel.org> 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" From: Guo Ren Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by implementing arch_alloc_vmap_stack. Many architectures have supported HAVE_IRQ_EXIT_ON_IRQ_STACK, riscv should follow up. Tested-by: Jisheng Zhang Signed-off-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/Kconfig | 8 ++++ arch/riscv/include/asm/thread_info.h | 2 + arch/riscv/include/asm/vmap_stack.h | 28 ++++++++++++ arch/riscv/kernel/irq.c | 66 +++++++++++++++++++++++++++- 4 files changed, 102 insertions(+), 2 deletions(-) create mode 100644 arch/riscv/include/asm/vmap_stack.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 518e8523d41d..0a9d4bdc0338 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -446,6 +446,14 @@ config FPU =20 If you don't know what to do here, say Y. =20 +config IRQ_STACKS + bool "Independent irq stacks" if EXPERT + default y + select HAVE_IRQ_EXIT_ON_IRQ_STACK + help + Add independent irq stacks for percpu to prevent kernel stack overflows. + We may save some memory footprint by disabling IRQ_STACKS. + endmenu # "Platform type" =20 menu "Kernel features" diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/= thread_info.h index 7de4fb96f0b5..043da8ccc7e6 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -40,6 +40,8 @@ #define OVERFLOW_STACK_SIZE SZ_4K #define SHADOW_OVERFLOW_STACK_SIZE (1024) =20 +#define IRQ_STACK_SIZE THREAD_SIZE + #ifndef __ASSEMBLY__ =20 extern long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE / sizeof(long)]; diff --git a/arch/riscv/include/asm/vmap_stack.h b/arch/riscv/include/asm/v= map_stack.h new file mode 100644 index 000000000000..3fbf481abf4f --- /dev/null +++ b/arch/riscv/include/asm/vmap_stack.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copied from arch/arm64/include/asm/vmap_stack.h. +#ifndef _ASM_RISCV_VMAP_STACK_H +#define _ASM_RISCV_VMAP_STACK_H + +#include +#include +#include +#include +#include +#include + +/* + * To ensure that VMAP'd stack overflow detection works correctly, all VMA= P'd + * stacks need to have the same alignment. + */ +static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int = node) +{ + void *p; + + BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK)); + + p =3D __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node, + __builtin_return_address(0)); + return kasan_reset_tag(p); +} + +#endif /* _ASM_RISCV_VMAP_STACK_H */ diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index 24c2e1bd756a..5d77f692b198 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -10,6 +10,37 @@ #include #include #include +#include + +#ifdef CONFIG_IRQ_STACKS +static DEFINE_PER_CPU(ulong *, irq_stack_ptr); + +#ifdef CONFIG_VMAP_STACK +static void init_irq_stacks(void) +{ + int cpu; + ulong *p; + + for_each_possible_cpu(cpu) { + p =3D arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu)); + per_cpu(irq_stack_ptr, cpu) =3D p; + } +} +#else +/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned= . */ +DEFINE_PER_CPU_ALIGNED(ulong [IRQ_STACK_SIZE/sizeof(ulong)], irq_stack); + +static void init_irq_stacks(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + per_cpu(irq_stack_ptr, cpu) =3D per_cpu(irq_stack, cpu); +} +#endif /* CONFIG_VMAP_STACK */ +#else +static void init_irq_stacks(void) {} +#endif /* CONFIG_IRQ_STACKS */ =20 int arch_show_interrupts(struct seq_file *p, int prec) { @@ -19,21 +50,52 @@ int arch_show_interrupts(struct seq_file *p, int prec) =20 void __init init_IRQ(void) { + init_irq_stacks(); irqchip_init(); if (!handle_arch_irq) panic("No interrupt controller found."); } =20 -asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs) +static void noinstr handle_riscv_irq(struct pt_regs *regs) { struct pt_regs *old_regs; - irqentry_state_t state =3D irqentry_enter(regs); =20 irq_enter_rcu(); old_regs =3D set_irq_regs(regs); handle_arch_irq(regs); set_irq_regs(old_regs); irq_exit_rcu(); +} + +asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs) +{ + irqentry_state_t state =3D irqentry_enter(regs); +#ifdef CONFIG_IRQ_STACKS + if (on_thread_stack()) { + ulong *sp =3D per_cpu(irq_stack_ptr, smp_processor_id()) + + IRQ_STACK_SIZE/sizeof(ulong); + __asm__ __volatile( + "addi sp, sp, -"RISCV_SZPTR "\n" + REG_S" ra, (sp) \n" + "addi sp, sp, -"RISCV_SZPTR "\n" + REG_S" s0, (sp) \n" + "addi s0, sp, 2*"RISCV_SZPTR "\n" + "move sp, %[sp] \n" + "move a0, %[regs] \n" + "call handle_riscv_irq \n" + "addi sp, s0, -2*"RISCV_SZPTR"\n" + REG_L" s0, (sp) \n" + "addi sp, sp, "RISCV_SZPTR "\n" + REG_L" ra, (sp) \n" + "addi sp, sp, "RISCV_SZPTR "\n" + : + : [sp] "r" (sp), [regs] "r" (regs) + : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", + "t0", "t1", "t2", "t3", "t4", "t5", "t6", + "memory"); + } else +#endif + handle_riscv_irq(regs); =20 irqentry_exit(regs, state); } --=20 2.36.1