| /* |
| * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar |
| * |
| * This file contains the lowest level x86_64-specific interrupt |
| * entry and irq statistics code. All the remaining irq logic is |
| * done by the generic kernel/irq/ code and in the |
| * x86_64-specific irq controller code. (e.g. i8259.c and |
| * io_apic.c.) |
| */ |
| |
| #include <linux/kernel_stat.h> |
| #include <linux/interrupt.h> |
| #include <linux/seq_file.h> |
| #include <linux/module.h> |
| #include <linux/delay.h> |
| #include <linux/ftrace.h> |
| #include <linux/uaccess.h> |
| #include <linux/smp.h> |
| #include <asm/io_apic.h> |
| #include <asm/idle.h> |
| #include <asm/apic.h> |
| |
| int sysctl_panic_on_stackoverflow; |
| |
| /* |
| * Probabilistic stack overflow check: |
| * |
| * Only check the stack in process context, because everything else |
| * runs on the big interrupt stacks. Checking reliably is too expensive, |
| * so we just check from interrupts. |
| */ |
| static inline void stack_overflow_check(struct pt_regs *regs) |
| { |
| #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| #define STACK_TOP_MARGIN 128 |
| struct orig_ist *oist; |
| u64 irq_stack_top, irq_stack_bottom; |
| u64 estack_top, estack_bottom; |
| u64 curbase = (u64)task_stack_page(current); |
| |
| if (user_mode(regs)) |
| return; |
| |
| if (regs->sp >= curbase + sizeof(struct thread_info) + |
| sizeof(struct pt_regs) + STACK_TOP_MARGIN && |
| regs->sp <= curbase + THREAD_SIZE) |
| return; |
| |
| irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) + |
| STACK_TOP_MARGIN; |
| irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr); |
| if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom) |
| return; |
| |
| oist = this_cpu_ptr(&orig_ist); |
| estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN; |
| estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1]; |
| if (regs->sp >= estack_top && regs->sp <= estack_bottom) |
| return; |
| |
| WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n", |
| current->comm, curbase, regs->sp, |
| irq_stack_top, irq_stack_bottom, |
| estack_top, estack_bottom); |
| |
| if (sysctl_panic_on_stackoverflow) |
| panic("low stack detected by irq handler - check messages\n"); |
| #endif |
| } |
| |
| bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) |
| { |
| stack_overflow_check(regs); |
| |
| if (unlikely(IS_ERR_OR_NULL(desc))) |
| return false; |
| |
| generic_handle_irq_desc(irq_desc_get_irq(desc), desc); |
| return true; |
| } |