On 29/05/2023 10:45, guoren@xxxxxxxxxx wrote:
From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
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 <jszhang@xxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
Cc: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
arch/riscv/Kconfig | 7 ++++++
arch/riscv/include/asm/irq_stack.h | 32 +++++++++++++++++++++++++
arch/riscv/include/asm/thread_info.h | 2 ++
arch/riscv/kernel/irq.c | 33 ++++++++++++++++++++++++++
arch/riscv/kernel/traps.c | 35 ++++++++++++++++++++++++++--
5 files changed, 107 insertions(+), 2 deletions(-)
create mode 100644 arch/riscv/include/asm/irq_stack.h
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index fa256f2e23c1..44b4c9690f94 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -588,6 +588,13 @@ config FPU
If you don't know what to do here, say Y.
+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"
menu "Kernel features"
diff --git a/arch/riscv/include/asm/irq_stack.h b/arch/riscv/include/asm/irq_stack.h
new file mode 100644
index 000000000000..b0dcee9a3fa2
--- /dev/null
+++ b/arch/riscv/include/asm/irq_stack.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_RISCV_IRQ_STACK_H
+#define _ASM_RISCV_IRQ_STACK_H
+
+#include <linux/bug.h>
+#include <linux/gfp.h>
+#include <linux/kconfig.h>
+#include <linux/vmalloc.h>
+#include <linux/pgtable.h>
+#include <asm/thread_info.h>
+
+DECLARE_PER_CPU(ulong *, irq_stack_ptr);
+
+#ifdef CONFIG_VMAP_STACK
+/*
+ * 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));
Hi Guo,
Since this function is already guarded with #ifdef CONFIG_VMAP_STACK, I
guess this BUILD_BUG_ON() is unnecessary).
Clément
