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c36ba80ea0
This takes care of the following entry from Dan's list: kernel/irq/resend.c +73 check_irq_resend(17) warning: variable derefenced before check 'desc->chip' Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Eugene Teo <eteo@redhat.com> Cc: Julia Lawall <julia@diku.dk> LKML-Reference: <200908062146.03638.bzolnier@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
81 lines
2 KiB
C
81 lines
2 KiB
C
/*
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* linux/kernel/irq/resend.c
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*
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* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
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* Copyright (C) 2005-2006, Thomas Gleixner
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*
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* This file contains the IRQ-resend code
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*
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* If the interrupt is waiting to be processed, we try to re-run it.
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* We can't directly run it from here since the caller might be in an
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* interrupt-protected region. Not all irq controller chips can
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* retrigger interrupts at the hardware level, so in those cases
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* we allow the resending of IRQs via a tasklet.
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*/
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#include <linux/irq.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/interrupt.h>
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#include "internals.h"
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#ifdef CONFIG_HARDIRQS_SW_RESEND
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/* Bitmap to handle software resend of interrupts: */
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static DECLARE_BITMAP(irqs_resend, NR_IRQS);
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/*
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* Run software resends of IRQ's
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*/
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static void resend_irqs(unsigned long arg)
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{
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struct irq_desc *desc;
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int irq;
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while (!bitmap_empty(irqs_resend, nr_irqs)) {
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irq = find_first_bit(irqs_resend, nr_irqs);
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clear_bit(irq, irqs_resend);
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desc = irq_to_desc(irq);
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local_irq_disable();
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desc->handle_irq(irq, desc);
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local_irq_enable();
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}
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}
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/* Tasklet to handle resend: */
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static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
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#endif
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/*
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* IRQ resend
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*
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* Is called with interrupts disabled and desc->lock held.
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*/
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void check_irq_resend(struct irq_desc *desc, unsigned int irq)
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{
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unsigned int status = desc->status;
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/*
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* Make sure the interrupt is enabled, before resending it:
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*/
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desc->chip->enable(irq);
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/*
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* We do not resend level type interrupts. Level type
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* interrupts are resent by hardware when they are still
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* active.
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*/
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if ((status & (IRQ_LEVEL | IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
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desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
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if (!desc->chip->retrigger || !desc->chip->retrigger(irq)) {
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#ifdef CONFIG_HARDIRQS_SW_RESEND
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/* Set it pending and activate the softirq: */
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set_bit(irq, irqs_resend);
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tasklet_schedule(&resend_tasklet);
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#endif
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}
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}
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}
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