2 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
4 * This file contains the lowest level x86_64-specific interrupt
5 * entry and irq statistics code. All the remaining irq logic is
6 * done by the generic kernel/irq/ code and in the
7 * x86_64-specific irq controller code. (e.g. i8259.c and
11 #include <linux/kernel_stat.h>
12 #include <linux/interrupt.h>
13 #include <linux/seq_file.h>
14 #include <linux/module.h>
15 #include <linux/delay.h>
16 #include <linux/ftrace.h>
17 #include <linux/uaccess.h>
18 #include <linux/smp.h>
19 #include <asm/io_apic.h>
23 int sysctl_panic_on_stackoverflow;
26 * Probabilistic stack overflow check:
28 * Regular device interrupts can enter on the following stacks:
34 * - Interrupt stack if a device driver reenables interrupts
35 * which should only happen in really old drivers.
39 * All other contexts are invalid.
41 static inline void stack_overflow_check(struct pt_regs *regs)
43 #ifdef CONFIG_DEBUG_STACKOVERFLOW
44 #define STACK_TOP_MARGIN 128
45 struct orig_ist *oist;
46 u64 irq_stack_top, irq_stack_bottom;
47 u64 estack_top, estack_bottom;
48 u64 curbase = (u64)task_stack_page(current);
53 if (regs->sp >= curbase + sizeof(struct thread_info) +
54 sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
55 regs->sp <= curbase + THREAD_SIZE)
58 irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
60 irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
61 if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
64 oist = this_cpu_ptr(&orig_ist);
65 estack_bottom = (u64)oist->ist[DEBUG_STACK];
66 estack_top = estack_bottom - DEBUG_STKSZ + STACK_TOP_MARGIN;
67 if (regs->sp >= estack_top && regs->sp <= estack_bottom)
70 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",
71 current->comm, curbase, regs->sp,
72 irq_stack_top, irq_stack_bottom,
73 estack_top, estack_bottom);
75 if (sysctl_panic_on_stackoverflow)
76 panic("low stack detected by irq handler - check messages\n");
80 bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
82 stack_overflow_check(regs);
84 if (IS_ERR_OR_NULL(desc))
87 generic_handle_irq_desc(desc);