forked from Minki/linux
a782a7e46b
We can spare the irq_desc lookup in the interrupt entry code if we store the descriptor pointer in the vector array instead the interrupt number. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/20150802203609.717724106@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
/*
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* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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*
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* This file contains the lowest level x86_64-specific interrupt
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* entry and irq statistics code. All the remaining irq logic is
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* done by the generic kernel/irq/ code and in the
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* x86_64-specific irq controller code. (e.g. i8259.c and
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* io_apic.c.)
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*/
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#include <linux/kernel_stat.h>
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#include <linux/interrupt.h>
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#include <linux/seq_file.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/ftrace.h>
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#include <linux/uaccess.h>
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#include <linux/smp.h>
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#include <asm/io_apic.h>
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#include <asm/idle.h>
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#include <asm/apic.h>
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int sysctl_panic_on_stackoverflow;
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/*
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* Probabilistic stack overflow check:
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*
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* Only check the stack in process context, because everything else
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* runs on the big interrupt stacks. Checking reliably is too expensive,
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* so we just check from interrupts.
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*/
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static inline void stack_overflow_check(struct pt_regs *regs)
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{
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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#define STACK_TOP_MARGIN 128
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struct orig_ist *oist;
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u64 irq_stack_top, irq_stack_bottom;
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u64 estack_top, estack_bottom;
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u64 curbase = (u64)task_stack_page(current);
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if (user_mode(regs))
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return;
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if (regs->sp >= curbase + sizeof(struct thread_info) +
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sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
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regs->sp <= curbase + THREAD_SIZE)
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return;
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irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
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STACK_TOP_MARGIN;
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irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
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if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
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return;
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oist = this_cpu_ptr(&orig_ist);
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estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
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estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
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if (regs->sp >= estack_top && regs->sp <= estack_bottom)
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return;
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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",
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current->comm, curbase, regs->sp,
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irq_stack_top, irq_stack_bottom,
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estack_top, estack_bottom);
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if (sysctl_panic_on_stackoverflow)
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panic("low stack detected by irq handler - check messages\n");
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#endif
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}
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bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
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{
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stack_overflow_check(regs);
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if (unlikely(IS_ERR_OR_NULL(desc)))
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return false;
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generic_handle_irq_desc(irq_desc_get_irq(desc), desc);
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return true;
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}
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