From nobody Sun Feb 8 11:45:51 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 9478FEB64D7 for ; Wed, 14 Jun 2023 01:30:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230456AbjFNBap (ORCPT ); Tue, 13 Jun 2023 21:30:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232925AbjFNBai (ORCPT ); Tue, 13 Jun 2023 21:30:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9D2A1727; Tue, 13 Jun 2023 18:30:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6CB75638BD; Wed, 14 Jun 2023 01:30:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EE05C433C0; Wed, 14 Jun 2023 01:30:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686706227; bh=azzWoVCj3Bccwg8Kywl22aCyL/uPe8mZErp3ZfcZjno=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GsZ2ixvW1iFZ4XPLl767dRd6H3gGLs7hjL7T0Jj7qfH+6hOZXrFzkci3A0qRDvvpg I+E1WoX01vbgM43oqA6nWdcY6tqCWkkBTCyopRlxNy7vW9tleuqg3UKkpKNFKwAFCz VbmCnwfQuXDf1QdmF6wJFQCXowOxQj8fhfrOBogwrTIJWrtaqepKUnmdFwwwbaimEE XL7ZNdMA75gZOIki475U/VwE00wQrG9F8sbzGYaNxUlk+nyoMjFDi94L67KLHCtBRV o8Mz3Q7CtN6k+e3BusfhZZUuj3+wUhKbHEqBlCMHiWosOMbN6MryEFUtwf+f80hg6t yYZsBhYASZhxQ== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, bjorn@kernel.org, cleger@rivosinc.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: [PATCH -next V13 1/3] riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Date: Tue, 13 Jun 2023 21:30:16 -0400 Message-Id: <20230614013018.2168426-2-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20230614013018.2168426-1-guoren@kernel.org> References: <20230614013018.2168426-1-guoren@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guo Ren Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by arch_alloc_vmap_stack. Tested-by: Jisheng Zhang Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Cl=C3=A9ment L=C3=A9ger --- arch/riscv/Kconfig | 7 ++++++ arch/riscv/include/asm/irq_stack.h | 30 ++++++++++++++++++++++++ arch/riscv/include/asm/thread_info.h | 2 ++ arch/riscv/kernel/irq.c | 33 ++++++++++++++++++++++++++ arch/riscv/kernel/traps.c | 35 ++++++++++++++++++++++++++-- 5 files changed, 105 insertions(+), 2 deletions(-) create mode 100644 arch/riscv/include/asm/irq_stack.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index a3d54cd14fca..a8368fe7be14 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -590,6 +590,13 @@ 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. + endmenu # "Platform type" =20 menu "Kernel features" diff --git a/arch/riscv/include/asm/irq_stack.h b/arch/riscv/include/asm/ir= q_stack.h new file mode 100644 index 000000000000..e4042d297580 --- /dev/null +++ b/arch/riscv/include/asm/irq_stack.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_RISCV_IRQ_STACK_H +#define _ASM_RISCV_IRQ_STACK_H + +#include +#include +#include +#include +#include +#include + +DECLARE_PER_CPU(ulong *, irq_stack_ptr); + +#ifdef CONFIG_VMAP_STACK +/* + * 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; + + p =3D __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node, + __builtin_return_address(0)); + return kasan_reset_tag(p); +} +#endif /* CONFIG_VMAP_STACK */ + +#endif /* _ASM_RISCV_IRQ_STACK_H */ diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/= thread_info.h index 97e6f65ec176..2f32875276b0 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/kernel/irq.c b/arch/riscv/kernel/irq.c index eb9a68a539e6..a1dcf8e43b3c 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -28,6 +28,38 @@ struct fwnode_handle *riscv_get_intc_hwnode(void) } EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode); =20 +#ifdef CONFIG_IRQ_STACKS +#include + +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 */ + int arch_show_interrupts(struct seq_file *p, int prec) { show_ipi_stats(p, prec); @@ -36,6 +68,7 @@ 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."); diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 05ffdcd1424e..5158961ea977 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -27,6 +27,7 @@ #include #include #include +#include =20 int show_unhandled_signals =3D 1; =20 @@ -327,16 +328,46 @@ asmlinkage __visible noinstr void do_page_fault(struc= t pt_regs *regs) } #endif =20 -asmlinkage __visible noinstr void do_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_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