1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
5 * This file contains the lowest level x86_64-specific interrupt
6 * entry and irq statistics code. All the remaining irq logic is
7 * done by the generic kernel/irq/ code and in the
8 * x86_64-specific irq controller code. (e.g. i8259.c and
12 #include <linux/kernel_stat.h>
13 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/seq_file.h>
16 #include <linux/delay.h>
17 #include <linux/ftrace.h>
18 #include <linux/uaccess.h>
19 #include <linux/smp.h>
20 #include <linux/sched/task_stack.h>
21 #include <asm/io_apic.h>
24 int sysctl_panic_on_stackoverflow;
27 * Probabilistic stack overflow check:
29 * Regular device interrupts can enter on the following stacks:
35 * - Interrupt stack if a device driver reenables interrupts
36 * which should only happen in really old drivers.
40 * All other contexts are invalid.
42 static inline void stack_overflow_check(struct pt_regs *regs)
44 #ifdef CONFIG_DEBUG_STACKOVERFLOW
45 #define STACK_MARGIN 128
46 struct orig_ist *oist;
47 u64 irq_stack_top, irq_stack_bottom;
48 u64 estack_top, estack_bottom;
49 u64 curbase = (u64)task_stack_page(current);
54 if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_MARGIN &&
55 regs->sp <= curbase + THREAD_SIZE)
58 irq_stack_top = (u64)__this_cpu_read(irq_stack_ptr);
59 irq_stack_bottom = irq_stack_top - IRQ_STACK_SIZE + STACK_MARGIN;
60 if (regs->sp >= irq_stack_bottom && regs->sp <= irq_stack_top)
63 oist = this_cpu_ptr(&orig_ist);
64 estack_top = (u64)oist->ist[ESTACK_DB];
65 estack_bottom = estack_top - DEBUG_STKSZ + STACK_MARGIN;
66 if (regs->sp >= estack_bottom && regs->sp <= estack_top)
69 WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx, irq stack:%Lx-%Lx, exception stack: %Lx-%Lx, ip:%pF)\n",
70 current->comm, curbase, regs->sp,
71 irq_stack_bottom, irq_stack_top,
72 estack_bottom, estack_top, (void *)regs->ip);
74 if (sysctl_panic_on_stackoverflow)
75 panic("low stack detected by irq handler - check messages\n");
79 bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
81 stack_overflow_check(regs);
83 if (IS_ERR_OR_NULL(desc))
86 generic_handle_irq_desc(desc);