linux/arch/x86/kernel/irq_64.c
Andy Lutomirski 15f4eae70d x86: Move thread_info into task_struct
Now that most of the thread_info users have been cleaned up,
this is straightforward.

Most of this code was written by Linus.

Originally-from: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a50eab40abeaec9cb9a9e3cbdeafd32190206654.1473801993.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-15 08:25:13 +02:00

79 lines
2.2 KiB
C

/*
* 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/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 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 (IS_ERR_OR_NULL(desc))
return false;
generic_handle_irq_desc(desc);
return true;
}