linux_dsm_epyc7002/include/linux/uio_driver.h
Xiubo Li 543af5861f uio: change to use the mutex lock instead of the spin lock
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>
2018-07-07 16:57:35 +02:00

144 lines
4.1 KiB
C

/*
* include/linux/uio_driver.h
*
* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
* Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
*
* Userspace IO driver.
*
* Licensed under the GPLv2 only.
*/
#ifndef _UIO_DRIVER_H_
#define _UIO_DRIVER_H_
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
struct module;
struct uio_map;
/**
* struct uio_mem - description of a UIO memory region
* @name: name of the memory region for identification
* @addr: address of the device's memory rounded to page
* size (phys_addr is used since addr can be
* logical, virtual, or physical & phys_addr_t
* should always be large enough to handle any of
* the address types)
* @offs: offset of device memory within the page
* @size: size of IO (multiple of page size)
* @memtype: type of memory addr points to
* @internal_addr: ioremap-ped version of addr, for driver internal use
* @map: for use by the UIO core only.
*/
struct uio_mem {
const char *name;
phys_addr_t addr;
unsigned long offs;
resource_size_t size;
int memtype;
void __iomem *internal_addr;
struct uio_map *map;
};
#define MAX_UIO_MAPS 5
struct uio_portio;
/**
* struct uio_port - description of a UIO port region
* @name: name of the port region for identification
* @start: start of port region
* @size: size of port region
* @porttype: type of port (see UIO_PORT_* below)
* @portio: for use by the UIO core only.
*/
struct uio_port {
const char *name;
unsigned long start;
unsigned long size;
int porttype;
struct uio_portio *portio;
};
#define MAX_UIO_PORT_REGIONS 5
struct uio_device {
struct module *owner;
struct device dev;
int minor;
atomic_t event;
struct fasync_struct *async_queue;
wait_queue_head_t wait;
struct uio_info *info;
struct mutex info_lock;
struct kobject *map_dir;
struct kobject *portio_dir;
};
/**
* struct uio_info - UIO device capabilities
* @uio_dev: the UIO device this info belongs to
* @name: device name
* @version: device driver version
* @mem: list of mappable memory regions, size==0 for end of list
* @port: list of port regions, size==0 for end of list
* @irq: interrupt number or UIO_IRQ_CUSTOM
* @irq_flags: flags for request_irq()
* @priv: optional private data
* @handler: the device's irq handler
* @mmap: mmap operation for this uio device
* @open: open operation for this uio device
* @release: release operation for this uio device
* @irqcontrol: disable/enable irqs when 0/1 is written to /dev/uioX
*/
struct uio_info {
struct uio_device *uio_dev;
const char *name;
const char *version;
struct uio_mem mem[MAX_UIO_MAPS];
struct uio_port port[MAX_UIO_PORT_REGIONS];
long irq;
unsigned long irq_flags;
void *priv;
irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
int (*open)(struct uio_info *info, struct inode *inode);
int (*release)(struct uio_info *info, struct inode *inode);
int (*irqcontrol)(struct uio_info *info, s32 irq_on);
};
extern int __must_check
__uio_register_device(struct module *owner,
struct device *parent,
struct uio_info *info);
/* use a define to avoid include chaining to get THIS_MODULE */
#define uio_register_device(parent, info) \
__uio_register_device(THIS_MODULE, parent, info)
extern void uio_unregister_device(struct uio_info *info);
extern void uio_event_notify(struct uio_info *info);
/* defines for uio_info->irq */
#define UIO_IRQ_CUSTOM -1
#define UIO_IRQ_NONE 0
/* defines for uio_mem->memtype */
#define UIO_MEM_NONE 0
#define UIO_MEM_PHYS 1
#define UIO_MEM_LOGICAL 2
#define UIO_MEM_VIRTUAL 3
/* defines for uio_port->porttype */
#define UIO_PORT_NONE 0
#define UIO_PORT_X86 1
#define UIO_PORT_GPIO 2
#define UIO_PORT_OTHER 3
#endif /* _LINUX_UIO_DRIVER_H_ */