543af5861f
We are hitting a regression with the following commit:
commit a93e7b3315
Author: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Date: Mon May 14 13:32:23 2018 +1200
uio: Prevent device destruction while fds are open
The problem is the addition of spin_lock_irqsave in uio_write. This
leads to hitting uio_write -> copy_from_user -> _copy_from_user ->
might_fault and the logs filling up with sleeping warnings.
I also noticed some uio drivers allocate memory, sleep, grab mutexes
from callouts like open() and release and uio is now doing
spin_lock_irqsave while calling them.
Reported-by: Mike Christie <mchristi@redhat.com>
CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
143 lines
4.1 KiB
C
143 lines
4.1 KiB
C
/*
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* include/linux/uio_driver.h
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*
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* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
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* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
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* Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
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* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
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*
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* Userspace IO driver.
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*
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* Licensed under the GPLv2 only.
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*/
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#ifndef _UIO_DRIVER_H_
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#define _UIO_DRIVER_H_
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/interrupt.h>
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struct module;
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struct uio_map;
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/**
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* struct uio_mem - description of a UIO memory region
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* @name: name of the memory region for identification
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* @addr: address of the device's memory rounded to page
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* size (phys_addr is used since addr can be
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* logical, virtual, or physical & phys_addr_t
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* should always be large enough to handle any of
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* the address types)
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* @offs: offset of device memory within the page
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* @size: size of IO (multiple of page size)
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* @memtype: type of memory addr points to
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* @internal_addr: ioremap-ped version of addr, for driver internal use
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* @map: for use by the UIO core only.
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*/
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struct uio_mem {
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const char *name;
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phys_addr_t addr;
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unsigned long offs;
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resource_size_t size;
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int memtype;
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void __iomem *internal_addr;
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struct uio_map *map;
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};
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#define MAX_UIO_MAPS 5
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struct uio_portio;
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/**
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* struct uio_port - description of a UIO port region
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* @name: name of the port region for identification
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* @start: start of port region
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* @size: size of port region
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* @porttype: type of port (see UIO_PORT_* below)
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* @portio: for use by the UIO core only.
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*/
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struct uio_port {
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const char *name;
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unsigned long start;
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unsigned long size;
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int porttype;
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struct uio_portio *portio;
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};
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#define MAX_UIO_PORT_REGIONS 5
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struct uio_device {
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struct module *owner;
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struct device dev;
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int minor;
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atomic_t event;
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struct fasync_struct *async_queue;
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wait_queue_head_t wait;
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struct uio_info *info;
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struct mutex info_lock;
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struct kobject *map_dir;
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struct kobject *portio_dir;
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};
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/**
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* struct uio_info - UIO device capabilities
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* @uio_dev: the UIO device this info belongs to
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* @name: device name
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* @version: device driver version
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* @mem: list of mappable memory regions, size==0 for end of list
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* @port: list of port regions, size==0 for end of list
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* @irq: interrupt number or UIO_IRQ_CUSTOM
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* @irq_flags: flags for request_irq()
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* @priv: optional private data
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* @handler: the device's irq handler
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* @mmap: mmap operation for this uio device
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* @open: open operation for this uio device
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* @release: release operation for this uio device
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* @irqcontrol: disable/enable irqs when 0/1 is written to /dev/uioX
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*/
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struct uio_info {
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struct uio_device *uio_dev;
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const char *name;
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const char *version;
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struct uio_mem mem[MAX_UIO_MAPS];
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struct uio_port port[MAX_UIO_PORT_REGIONS];
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long irq;
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unsigned long irq_flags;
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void *priv;
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irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
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int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
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int (*open)(struct uio_info *info, struct inode *inode);
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int (*release)(struct uio_info *info, struct inode *inode);
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int (*irqcontrol)(struct uio_info *info, s32 irq_on);
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};
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extern int __must_check
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__uio_register_device(struct module *owner,
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struct device *parent,
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struct uio_info *info);
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/* use a define to avoid include chaining to get THIS_MODULE */
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#define uio_register_device(parent, info) \
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__uio_register_device(THIS_MODULE, parent, info)
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extern void uio_unregister_device(struct uio_info *info);
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extern void uio_event_notify(struct uio_info *info);
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/* defines for uio_info->irq */
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#define UIO_IRQ_CUSTOM -1
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#define UIO_IRQ_NONE 0
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/* defines for uio_mem->memtype */
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#define UIO_MEM_NONE 0
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#define UIO_MEM_PHYS 1
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#define UIO_MEM_LOGICAL 2
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#define UIO_MEM_VIRTUAL 3
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/* defines for uio_port->porttype */
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#define UIO_PORT_NONE 0
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#define UIO_PORT_X86 1
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#define UIO_PORT_GPIO 2
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#define UIO_PORT_OTHER 3
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#endif /* _LINUX_UIO_DRIVER_H_ */
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