From patchwork Sat Sep 3 16:38:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 12965013 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 BCFAFECAAD4 for ; Sat, 3 Sep 2022 16:38:45 +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=OwwM92d4VrCe2BWlZ5S5UAlAVOv6pXDktaIpPDnIxrg=; b=CvgjCmZR933tuv k8VwYghBHMLcu+0RjdSJ7Y/CqqXar+72Ra97xpsRCeO7TWcYHNiP73KoBbhtlOISGEEmrh9dljNx+ a9PLpsJSsm7qYzBhCX2X/B0hidbZZLUP5lrXrLZfI9nNuyF4kCCtHRoFRlrcuqEw7v4La4XXhA+qA pUw7SR9Jgg1xaHzl29lCKjDeZ2/L86NkKaHzjzqup2PA9p9L6xBVy+1JYfwJyMbsHJHbp3jkRpCAD TBPe/YZ8a3O66WHvszPTv3F126w5fB8ieLrAFJq94bMkVm3BSWlKTjU7UTUjlabz2Dr5xLDZAXZQ4 R7Rbk8/6ghLL7svD+DEg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oUWAE-00Djpw-MT; Sat, 03 Sep 2022 16:38:34 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oUWAB-00Djo4-SI for linux-riscv@lists.infradead.org; Sat, 03 Sep 2022 16:38:33 +0000 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 ams.source.kernel.org (Postfix) with ESMTPS id 82299B80B15; Sat, 3 Sep 2022 16:38:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBE90C433D6; Sat, 3 Sep 2022 16:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662223108; bh=r+/B4y7/2Ycs9FH3YAlRj9b9rkR7ki0cuEuVaBBj208=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qPovO0k6S6QfV4mX+kQwNVjRpeUbiim5XRq8Gucu4SVe55FY0LFgyXjLjOs4VpPAy DXSRjsMIQO6O+5O6hyPNfT9WEUpjuHQtMf7STEwARMAJYOb/efNWGE4XOyJCyErNbn b1BA7OlRjpJYsWl6woVLfFb9x0A4JqvoPYYICggcVviTW5e8ePSkW0+vPAxwhpZt6A g7AyB+FeFm0ueLdydHdGC+iQNS2eLaYkRQ0wd1g1eVU8K6VM6Can+VSdVWGAzpI8i+ W9NiEMOwf2zrSj/3eOWFFflQPhXojNg72TXHdsUDL5TA9T7eLewEeacrNGXwr9xiCP rVsBQyrBGTfUg== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: [PATCH 2/3] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Date: Sat, 3 Sep 2022 12:38:07 -0400 Message-Id: <20220903163808.1954131-3-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220903163808.1954131-1-guoren@kernel.org> References: <20220903163808.1954131-1-guoren@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220903_093832_222453_C15CDD78 X-CRM114-Status: GOOD ( 21.47 ) X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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. Signed-off-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/Kconfig | 8 +++++ arch/riscv/include/asm/irq.h | 2 ++ arch/riscv/include/asm/thread_info.h | 2 ++ arch/riscv/include/asm/vmap_stack.h | 28 ++++++++++++++++ arch/riscv/kernel/entry.S | 27 ++++++++++++++++ arch/riscv/kernel/irq.c | 48 ++++++++++++++++++++++++++-- 6 files changed, 113 insertions(+), 2 deletions(-) create mode 100644 arch/riscv/include/asm/vmap_stack.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index a07bb3b73b5b..a8a12b4ba1a9 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -433,6 +433,14 @@ config FPU If you don't know what to do here, say Y. +config IRQ_STACKS + bool "Independent irq stacks" + 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" menu "Kernel features" diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h index e4c435509983..4579777a49f7 100644 --- a/arch/riscv/include/asm/irq.h +++ b/arch/riscv/include/asm/irq.h @@ -13,5 +13,7 @@ #include extern void __init init_IRQ(void); +extern asmlinkage void call_on_stack(struct pt_regs *regs, ulong *sp, + void (*fn)(struct pt_regs *), ulong tmp); #endif /* _ASM_RISCV_IRQ_H */ 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) +#define IRQ_STACK_SIZE THREAD_SIZE + #ifndef __ASSEMBLY__ 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/vmap_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 VMAP'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 = __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/entry.S b/arch/riscv/kernel/entry.S index 5f49517cd3a2..551ce4c25698 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -332,6 +332,33 @@ ENTRY(ret_from_kernel_thread) tail syscall_exit_to_user_mode ENDPROC(ret_from_kernel_thread) +#ifdef CONFIG_IRQ_STACKS +ENTRY(call_on_stack) + /* Create a frame record to save our ra and fp */ + addi sp, sp, -RISCV_SZPTR + REG_S ra, (sp) + addi sp, sp, -RISCV_SZPTR + REG_S fp, (sp) + + /* Save sp in fp */ + move fp, sp + + /* Move to the new stack and call the function there */ + la a3, IRQ_STACK_SIZE + add sp, a1, a3 + jalr a2 + + /* + * Restore sp from prev fp, and fp, ra from the frame + */ + move sp, fp + REG_L fp, (sp) + addi sp, sp, RISCV_SZPTR + REG_L ra, (sp) + addi sp, sp, RISCV_SZPTR + ret +ENDPROC(call_on_stack) +#endif /* * Integer register context switch diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index 24c2e1bd756a..eec5c38100b6 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 +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 = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu)); + per_cpu(irq_stack_ptr, cpu) = 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) = 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) { @@ -19,21 +50,34 @@ int arch_show_interrupts(struct seq_file *p, int prec) void __init init_IRQ(void) { + init_irq_stacks(); irqchip_init(); if (!handle_arch_irq) panic("No interrupt controller found."); } -asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs) +asmlinkage void noinstr handle_riscv_irq(struct pt_regs *regs) { struct pt_regs *old_regs; - irqentry_state_t state = irqentry_enter(regs); irq_enter_rcu(); old_regs = 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 = irqentry_enter(regs); +#ifdef CONFIG_IRQ_STACKS + ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id()); + + if (on_thread_stack()) + call_on_stack(regs, sp, handle_riscv_irq, 0); + else +#endif + handle_riscv_irq(regs); irqentry_exit(regs, state); }