ae891a1b93
devres uses the pointer value as key after it's freed, which is safe but triggers spurious use-after-free warnings on some static analysis tools. Rearrange code to avoid such warnings. Signed-off-by: Maxin B. John <maxin.john@gmail.com> Reviewed-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
95 lines
2.6 KiB
C
95 lines
2.6 KiB
C
#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <linux/gfp.h>
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/*
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* Device resource management aware IRQ request/free implementation.
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*/
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struct irq_devres {
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unsigned int irq;
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void *dev_id;
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};
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static void devm_irq_release(struct device *dev, void *res)
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{
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struct irq_devres *this = res;
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free_irq(this->irq, this->dev_id);
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}
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static int devm_irq_match(struct device *dev, void *res, void *data)
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{
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struct irq_devres *this = res, *match = data;
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return this->irq == match->irq && this->dev_id == match->dev_id;
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}
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/**
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* devm_request_threaded_irq - allocate an interrupt line for a managed device
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* @dev: device to request interrupt for
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* @irq: Interrupt line to allocate
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* @handler: Function to be called when the IRQ occurs
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* @thread_fn: function to be called in a threaded interrupt context. NULL
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* for devices which handle everything in @handler
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* @irqflags: Interrupt type flags
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* @devname: An ascii name for the claiming device
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* @dev_id: A cookie passed back to the handler function
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*
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* Except for the extra @dev argument, this function takes the
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* same arguments and performs the same function as
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* request_irq(). IRQs requested with this function will be
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* automatically freed on driver detach.
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*
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* If an IRQ allocated with this function needs to be freed
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* separately, devm_free_irq() must be used.
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*/
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int devm_request_threaded_irq(struct device *dev, unsigned int irq,
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irq_handler_t handler, irq_handler_t thread_fn,
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unsigned long irqflags, const char *devname,
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void *dev_id)
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{
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struct irq_devres *dr;
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int rc;
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dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
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GFP_KERNEL);
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if (!dr)
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return -ENOMEM;
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rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
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dev_id);
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if (rc) {
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devres_free(dr);
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return rc;
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}
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dr->irq = irq;
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dr->dev_id = dev_id;
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devres_add(dev, dr);
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return 0;
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}
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EXPORT_SYMBOL(devm_request_threaded_irq);
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/**
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* devm_free_irq - free an interrupt
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* @dev: device to free interrupt for
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* @irq: Interrupt line to free
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* @dev_id: Device identity to free
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*
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* Except for the extra @dev argument, this function takes the
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* same arguments and performs the same function as free_irq().
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* This function instead of free_irq() should be used to manually
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* free IRQs allocated with devm_request_irq().
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*/
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void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
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{
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struct irq_devres match_data = { irq, dev_id };
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WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
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&match_data));
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free_irq(irq, dev_id);
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}
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EXPORT_SYMBOL(devm_free_irq);
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