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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
4 *
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
9 * io_apic.c.)
10 */
11
12#include <linux/kernel_stat.h>
13#include <linux/interrupt.h>
14#include <linux/seq_file.h>
Ashok Raj76e4f662005-06-25 14:55:00 -070015#include <linux/delay.h>
Frederic Weisbeckerbcbc4f22008-12-09 23:54:20 +010016#include <linux/ftrace.h>
Jaswinder Singh Rajput5f66b2a2009-01-04 16:25:19 +053017#include <linux/uaccess.h>
18#include <linux/smp.h>
Ingo Molnar68db0cf2017-02-08 18:51:37 +010019#include <linux/sched/task_stack.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/io_apic.h>
Brian Gerst3819cd42009-01-23 11:03:29 +090021#include <asm/apic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +090023int sysctl_panic_on_stackoverflow;
24
Eric Sandeen4961f102006-06-26 14:00:05 +020025/*
26 * Probabilistic stack overflow check:
27 *
28 * Only check the stack in process context, because everything else
29 * runs on the big interrupt stacks. Checking reliably is too expensive,
30 * so we just check from interrupts.
31 */
32static inline void stack_overflow_check(struct pt_regs *regs)
33{
Ingo Molnarf377fa12008-11-23 09:02:26 +010034#ifdef CONFIG_DEBUG_STACKOVERFLOW
Mitsuo Hayasakad2db6612011-12-07 17:29:10 +090035#define STACK_TOP_MARGIN 128
Mitsuo Hayasaka37fe6a42011-11-29 15:08:29 +090036 struct orig_ist *oist;
37 u64 irq_stack_top, irq_stack_bottom;
38 u64 estack_top, estack_bottom;
Roman Zippelc9f4f062007-05-09 02:35:16 -070039 u64 curbase = (u64)task_stack_page(current);
Eric Sandeen4961f102006-06-26 14:00:05 +020040
Andy Lutomirskif39b6f02015-03-18 18:33:33 -070041 if (user_mode(regs))
Mitsuo Hayasaka69682b62011-11-29 15:08:21 +090042 return;
43
Andy Lutomirski15f4eae2016-09-13 14:29:25 -070044 if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
Mitsuo Hayasaka467e6b72011-11-29 15:08:45 +090045 regs->sp <= curbase + THREAD_SIZE)
Mitsuo Hayasaka37fe6a42011-11-29 15:08:29 +090046 return;
Ingo Molnarf377fa12008-11-23 09:02:26 +010047
Christoph Lameter89cbc762014-08-17 12:30:40 -050048 irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
Mitsuo Hayasakad2db6612011-12-07 17:29:10 +090049 STACK_TOP_MARGIN;
Christoph Lameter89cbc762014-08-17 12:30:40 -050050 irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
Mitsuo Hayasaka37fe6a42011-11-29 15:08:29 +090051 if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
52 return;
53
Christoph Lameter89cbc762014-08-17 12:30:40 -050054 oist = this_cpu_ptr(&orig_ist);
Mitsuo Hayasakad2db6612011-12-07 17:29:10 +090055 estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
Mitsuo Hayasaka37fe6a42011-11-29 15:08:29 +090056 estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
57 if (regs->sp >= estack_top && regs->sp <= estack_bottom)
58 return;
59
Andy Lutomirski4f3789e72017-12-04 15:07:11 +010060 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,ip:%pF)\n",
Mitsuo Hayasaka37fe6a42011-11-29 15:08:29 +090061 current->comm, curbase, regs->sp,
62 irq_stack_top, irq_stack_bottom,
Andy Lutomirski4f3789e72017-12-04 15:07:11 +010063 estack_top, estack_bottom, (void *)regs->ip);
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +090064
65 if (sysctl_panic_on_stackoverflow)
66 panic("low stack detected by irq handler - check messages\n");
Eric Sandeen4961f102006-06-26 14:00:05 +020067#endif
Ingo Molnarf377fa12008-11-23 09:02:26 +010068}
Eric Sandeen4961f102006-06-26 14:00:05 +020069
Thomas Gleixnera782a7e2015-08-02 20:38:27 +000070bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
Jeremy Fitzhardinge9b2b76a2009-02-06 14:09:40 -080071{
Jeremy Fitzhardinge9b2b76a2009-02-06 14:09:40 -080072 stack_overflow_check(regs);
73
Geliang Tanga7e705a2015-10-01 10:55:29 +080074 if (IS_ERR_OR_NULL(desc))
Jeremy Fitzhardinge9b2b76a2009-02-06 14:09:40 -080075 return false;
76
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +020077 generic_handle_irq_desc(desc);
Jeremy Fitzhardinge9b2b76a2009-02-06 14:09:40 -080078 return true;
79}