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fusd/kfusd/kfusd.c
Godzil 70f58ed6dc Update 2018 -> 2019
2019-07-24 15:57:48 +01:00

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/*
*
* Copyright (c) 2003 The Regents of the University of California. All
* rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/*
* FUSD: the Framework for User-Space Devices
*
* Linux Kernel Module
*
* Jeremy Elson <jelson@circlemud.org>
* Copyright (c) 2001, Sensoria Corporation
* Copyright (c) 2002-2003, Regents of the University of California
* Copyright (c) 2007 Monty and Xiph.Org
* Copyright (c) 2009-2019 Manoel Trapier <godzil@godzil.net>
*
*/
/*
* Note on debugging messages: Unexpected errors (i.e., indicators of
* bugs in this kernel module) should always contain '!'. Expected
* conditions, even if exceptional (e.g., the device-driver-provider
* disappears while a file is waiting for a return from a system call)
* must NOT contain '!'.
*/
#ifndef __KERNEL__
#define __KERNEL__
#endif
#ifdef MODVERSIONS
#include <linux/modversions.h>
#endif
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/poll.h>
#include <linux/version.h>
#include <linux/major.h>
#include <linux/uio.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/highmem.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#include <linux/sched/signal.h>
#endif
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <asm/ioctl.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#define STATIC
#ifndef GIT_DESCRIBE
#define GIT_DESCRIBE "unknownversion-dirty"
#endif
/* Define this if you want to emit debug messages (adds ~8K) */
//#define CONFIG_FUSD_DEBUG
/* Default debug level for FUSD messages. Has no effect unless
* CONFIG_FUSD_DEBUG is defined. */
#ifndef CONFIG_FUSD_DEBUGLEVEL
#define CONFIG_FUSD_DEBUGLEVEL 4
#endif
/* Define this to check for memory leaks */
/*#define CONFIG_FUSD_MEMDEBUG*/
/* Define this to use the faster wake_up_interruptible_sync instead of
* the normal wake_up_interruptible. Note: you can't do this unless
* you're bulding fusd as part of the kernel (not a module); or you've
* patched kernel/ksyms.s to add __wake_up_sync in addition to
* __wake_up. */
/* #define CONFIG_FUSD_USE_WAKEUPSYNC */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 13)
#define CLASS class_simple
#define class_create class_simple_create
#define class_destroy class_simple_destroy
#define CLASS_DEVICE_CREATE(a, b, c, d, e) class_simple_device_add(a, c, d, e)
#define CLASS_DEVICE_DESTROY(a, b) class_simple_device_remove(b)
#else /* < 2.6.13 */
#define CLASS class
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 15)
#define CLASS_DEVICE_CREATE(a, b, c, d, e) class_device_create(a, c, d, e)
#elif LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 30)
#define CLASS_DEVICE_CREATE(a, b, c, d, e) device_create(a, b, c, d, e)
#else
#define CLASS_DEVICE_CREATE(a, b, c, d, e) device_create(a, b, c, d, e)
#endif /* < 2.6.15 */
#endif /* < 2.6.13 */
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 30)
#define CLASS_DEVICE_DESTROY(a, b) device_destroy(a, b)
#else
#define CLASS_DEVICE_DESTROY(a, b) device_destroy(a, b)
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
#define GET_USER_PAGES(t,m,s,n,w,f,p,v) get_user_pages_remote(t,m,s,n,(w?FOLL_WRITE:0)|(f?FOLL_FORCE:0),p,v, NULL)
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
#define GET_USER_PAGES(t,m,s,n,w,f,p,v) get_user_pages_remote(t,m,s,n,w,f,p,v)
#else
#define GET_USER_PAGES(t, m, s, n, w, f, p, v) get_user_pages(t,m,s,n,w,f,p,v)
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
#define FULL_NAME_HASH(h, a, b) full_name_hash(h, a, b)
#else
#define FULL_NAME_HASH(h, a, b) full_name_hash(a, b)
#endif
/**************************************************************************/
#include "fusd.h"
#include "fusd_msg.h"
#include "kfusd.h"
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 13)
#error "***FUSD doesn't work before Linux Kernel v2.6.13"
#endif
STATIC struct cdev *fusd_control_cdev;
STATIC struct cdev *fusd_status_cdev;
STATIC dev_t control_id;
STATIC dev_t status_id;
static struct CLASS *fusd_class;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
static struct class_device *fusd_control_device;
static struct class_device *fusd_status_device;
#else
static struct device *fusd_control_device;
static struct device *fusd_status_device;
#endif
/* version number incremented for each registered device */
STATIC int last_version = 1;
/* version number incremented for each transaction to userspace */
STATIC int last_transid = 1;
/* wait queue that is awakened when new devices are registered */
STATIC DECLARE_WAIT_QUEUE_HEAD (new_device_wait);
/* the list of valid devices, and sem to protect it */
LIST_HEAD (fusd_devlist_head);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 33)
DECLARE_MUTEX (fusd_devlist_sem);
#else
DEFINE_SEMAPHORE (fusd_devlist_sem);
#endif
//#ifdef MODULE_LICENSE
MODULE_AUTHOR ("Jeremy Elson <jelson@acm.org> (c)2001");
MODULE_AUTHOR ("Manoel Trapier <godzil@godzil.net> (c)2009-2019");
MODULE_VERSION(GIT_DESCRIBE);
MODULE_LICENSE ("GPL");
//#endif
/***************************Debugging Support*****************************/
#ifdef CONFIG_FUSD_DEBUG
STATIC int fusd_debug_level = CONFIG_FUSD_DEBUGLEVEL;
module_param (fusd_debug_level, int, S_IRUGO);
# define BUFSIZE 1000 /* kernel's kmalloc pool has a 1012-sized bucket */
static int debug_throttle = 0; /* emit a maximum number of debug
messages, else it's possible to take
out the machine accidentally if a
daemon disappears with open files */
STATIC void rdebug_real(char *fmt, ...)
{
va_list ap;
int len;
char *message;
if (debug_throttle > 100) return;
debug_throttle++;
/* I'm kmallocing since you don't really want 1k on the stack. I've
* had stack overflow problems before; the kernel stack is quite
* small... */
if ((message = KMALLOC(BUFSIZE, GFP_KERNEL)) == NULL)
return;
va_start(ap, fmt);
len = vsnprintf(message, BUFSIZE - 1, fmt, ap);
va_end(ap);
if (len >= BUFSIZE) {
printk("WARNING: POSSIBLE KERNEL CORRUPTION; MESSAGE TOO LONG\n");
} else {
printk("fusd: %.975s\n", message); /* note msgs are truncated at
* ~1000 chars to fit inside the 1024 printk
* limit imposed by the kernel */
}
KFREE(message);
}
#endif /* CONFIG_FUSD_DEBUG */
/******************** Memory Debugging ************************************/
#ifdef CONFIG_FUSD_MEMDEBUG
#define MAX_MEM_DEBUG 10000
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,30)
DECLARE_MUTEX (fusd_memdebug_sem);
#else
DEFINE_SEMAPHORE (fusd_memdebug_sem);
#endif
typedef struct
{
void *ptr;
int line;
int size;
} mem_debug_t;
mem_debug_t *mem_debug;
STATIC int fusd_mem_init (void)
{
int i;
mem_debug = kmalloc(sizeof (mem_debug_t ) * MAX_MEM_DEBUG, GFP_KERNEL);
if ( mem_debug == NULL )
{
RDEBUG(2, "argh - memdebug malloc failed!");
return -ENOMEM;
}
/* initialize */
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
mem_debug[i].ptr = NULL;
RDEBUG(2, "FUSD memory debugger activated");
return 0;
}
STATIC void fusd_mem_cleanup (void)
{
int i;
int count = 0;
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
if ( mem_debug[i].ptr != NULL )
{
RDEBUG(0, "memdebug: failed to free memory allocated at line %d (%d b)",
mem_debug[i].line, mem_debug[i].size);
count++;
}
if ( !count )
RDEBUG(2, "congratulations - memory debugger is happy!");
kfree(mem_debug);
}
STATIC void fusd_mem_add (void *ptr, int line, int size)
{
int i;
if ( ptr == NULL )
return;
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
{
if ( mem_debug[i].ptr == NULL )
{
mem_debug[i].ptr = ptr;
mem_debug[i].line = line;
mem_debug[i].size = size;
return;
}
}
RDEBUG(1, "WARNING - memdebug out of space!!!!");
}
STATIC void fusd_mem_del (void *ptr)
{
int i;
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
{
if ( mem_debug[i].ptr == ptr )
{
mem_debug[i].ptr = NULL;
return;
}
}
RDEBUG(2, "WARNING - memdebug is confused!!!!");
}
STATIC void *fusd_kmalloc (size_t size, int type, int line)
{
void *ptr = kmalloc(size, type);
down(&fusd_memdebug_sem);
fusd_mem_add(ptr, line, size);
up(&fusd_memdebug_sem);
return ptr;
}
STATIC void fusd_kfree (void *ptr)
{
down(&fusd_memdebug_sem);
fusd_mem_del(ptr);
kfree(ptr);
up(&fusd_memdebug_sem);
}
STATIC void *fusd_vmalloc (size_t size, int line)
{
void *ptr = vmalloc(size);
down(&fusd_memdebug_sem);
fusd_mem_add(ptr, line, size);
up(&fusd_memdebug_sem);
return ptr;
}
STATIC void fusd_vfree (void *ptr)
{
down(&fusd_memdebug_sem);
fusd_mem_del(ptr);
vfree(ptr);
up(&fusd_memdebug_sem);
}
#endif /* CONFIG_FUSD_MEMDEBUG */
/********************* FUSD Device List ***************************/
/*************************************************************************/
/************** STATE MANAGEMENT AND BOOKKEEPING UTILITIES ***************/
/*************************************************************************/
STATIC inline void init_fusd_msg(fusd_msg_t *fusd_msg)
{
if (fusd_msg == NULL)
return;
memset(fusd_msg, 0, sizeof(fusd_msg_t));
fusd_msg->magic = FUSD_MSG_MAGIC;
fusd_msg->cmd = FUSD_FOPS_CALL; /* typical, but can be overwritten */
}
/*
* free a fusd_msg, and NULL out the pointer that points to that fusd_msg.
*/
STATIC inline void free_fusd_msg(fusd_msg_t **fusd_msg)
{
if (fusd_msg == NULL || *fusd_msg == NULL)
return;
if ((*fusd_msg)->data != NULL) {
VFREE((*fusd_msg)->data);
(*fusd_msg)->data = NULL;
}
RDEBUG(1, "Freeing fusd_msg [%p] then set to NULL", fusd_msg);
KFREE(*fusd_msg);
*fusd_msg = NULL;
}
/* adjust the size of the 'files' array attached to the device to
* better match the number of files. In all cases, size must be at
* least MIN_ARRAY_SIZE. Subject to that constraint: if
* num_files==array_size, the size is doubled; if
* num_files<array_size/4, the size is halved. Array is kept as is if
* the malloc fails. Returns a pointer to the new file struct or NULL
* if there isn't one. */
STATIC fusd_file_t **fusd_dev_adjsize(fusd_dev_t *fusd_dev)
{
fusd_file_t **old_array;
int old_size;
old_array = fusd_dev->files;
old_size = fusd_dev->array_size;
/* compute the new size of the array */
if (fusd_dev->array_size > 4 * fusd_dev->num_files)
fusd_dev->array_size /= 2;
else if (fusd_dev->array_size == fusd_dev->num_files)
fusd_dev->array_size *= 2;
/* respect the minimums and maximums (policy) */
if (fusd_dev->array_size < MIN_FILEARRAY_SIZE)
fusd_dev->array_size = MIN_FILEARRAY_SIZE;
if (fusd_dev->array_size > MAX_FILEARRAY_SIZE)
fusd_dev->array_size = MAX_FILEARRAY_SIZE;
/* make sure it's sane */
if (fusd_dev->array_size < fusd_dev->num_files) {
RDEBUG(0, "fusd_dev_adjsize is royally screwed up!!!!!");
return fusd_dev->files;
}
/* create a new array. if successful, copy the contents of the old
* one. if not, revert back to the old. */
fusd_dev->files = KMALLOC(fusd_dev->array_size * sizeof(fusd_file_t * ),
GFP_KERNEL);
if (fusd_dev->files == NULL) {
RDEBUG(1, "malloc failed in fusd_dev_adjsize!");
fusd_dev->files = old_array;
fusd_dev->array_size = old_size;
} else {
RDEBUG(10, "/dev/%s now has space for %d files (had %d)", NAME(fusd_dev),
fusd_dev->array_size, old_size);
memset(fusd_dev->files, 0, fusd_dev->array_size * sizeof(fusd_file_t * ));
memcpy(fusd_dev->files, old_array,
fusd_dev->num_files * sizeof(fusd_file_t * ));
KFREE(old_array);
}
return fusd_dev->files;
}
/*
* DEVICE LOCK MUST BE HELD TO CALL THIS FUNCTION
*
* This function frees a device IF there is nothing left that is
* referencing it.
*
* Specifically, we do not free the device if:
* - The driver is still active (i.e. device is not a zombie)
* - There are still files with the device open
* - There is an open in progress, i.e. a client has verified that
* this is a valid device and is getting ready to add itself as an
* open file.
*
* If the device is safe to free, it is removed from the valid list
* (in verysafe mode only) and freed.
*
* Returns: 1 if the device was freed
* 0 if the device still exists (and can be unlocked) */
STATIC int maybe_free_fusd_dev(fusd_dev_t *fusd_dev)
{
fusd_msgC_t *ptr, *next;
down(&fusd_devlist_sem);
/* DON'T free the device under conditions listed above */
if (!fusd_dev->zombie || fusd_dev->num_files || fusd_dev->open_in_progress) {
up(&fusd_devlist_sem);
return 0;
}
/* OK - bombs away! This fusd_dev_t is on its way out the door! */
RDEBUG(8, "freeing state associated with /dev/%s", NAME(fusd_dev));
/* delete it off the list of valid devices, and unlock */
list_del(&fusd_dev->devlist);
up(&fusd_devlist_sem);
/* free any outgoing messages that the device might have waiting */
for (ptr = fusd_dev->msg_head; ptr != NULL; ptr = next) {
next = ptr->next;
FREE_FUSD_MSGC(ptr);
}
/* free the device's dev name */
if (fusd_dev->dev_name != NULL) {
KFREE(fusd_dev->dev_name);
fusd_dev->dev_name = NULL;
}
/* free the device's class name */
if (fusd_dev->class_name != NULL) {
KFREE(fusd_dev->class_name);
fusd_dev->class_name = NULL;
}
/* free the device's name */
if (fusd_dev->name != NULL) {
KFREE(fusd_dev->name);
fusd_dev->name = NULL;
}
/* free the array used to store pointers to fusd_file_t's */
if (fusd_dev->files != NULL) {
KFREE(fusd_dev->files);
fusd_dev->files = NULL;
}
/* clear the structure and free it! */
memset(fusd_dev, 0, sizeof(fusd_dev_t));
KFREE(fusd_dev);
/* notify fusd_status readers that there has been a change in the
* list of registered devices */
atomic_inc_and_ret(&last_version);
wake_up_interruptible(&new_device_wait);
//MOD_DEC_USE_COUNT;
return 1;
}
/*
*
* DO NOT CALL THIS FUNCTION UNLESS THE DEVICE IS ALREADY LOCKED
*
* zombify_device: called when the driver disappears. Indicates that
* the driver is no longer available to service requests. If there
* are no outstanding system calls waiting for the fusd_dev state, the
* device state itself is freed.
*
*/
STATIC void zombify_dev(fusd_dev_t *fusd_dev)
{
int i;
if (fusd_dev->zombie) {
RDEBUG(1, "zombify_device called on a zombie!!");
return;
}
fusd_dev->zombie = 1;
RDEBUG(3, "/dev/%s turning into a zombie (%d open files)", NAME(fusd_dev),
fusd_dev->num_files);
/* If there are files holding this device open, wake them up. */
for (i = 0; i < fusd_dev->num_files; i++) {
wake_up_interruptible(&fusd_dev->files[i]->file_wait);
wake_up_interruptible(&fusd_dev->files[i]->poll_wait);
}
}
/* utility function to find the index of a fusd_file in a fusd_dev.
* returns index if found, -1 if not found. ASSUMES WE HAVE A VALID
* fusd_dev. fusd_file may be NULL if we are searching for an empty
* slot. */
STATIC int find_fusd_file(fusd_dev_t *fusd_dev, fusd_file_t *fusd_file)
{
int i, num_files = fusd_dev->num_files;
fusd_file_t **files = fusd_dev->files;
for (i = 0; i < num_files; i++)
if (files[i] == fusd_file)
return i;
return -1;
}
/*
* DEVICE LOCK MUST BE HELD BEFORE THIS IS CALLED
*
* Returns 1 if the device was also freed. 0 if only the file was
* freed. If the device is freed, then do not try to unlock it!
* (Callers: Check the return value before unlocking!)
*/
STATIC int free_fusd_file(fusd_dev_t *fusd_dev, fusd_file_t *fusd_file)
{
int i;
struct list_head *tmp, *it;
/* find the index of the file in the device's file-list... */
if ((i = find_fusd_file(fusd_dev, fusd_file)) < 0)
panic("corrupted fusd_dev: releasing a file that we think is closed");
/* ...and remove it (by putting the last entry into its place) */
fusd_dev->files[i] = fusd_dev->files[--(fusd_dev->num_files)];
/* there might be an incoming message waiting for a restarted system
* call. free it -- after possibly forging a close (see
* fusd_forge_close). */
list_for_each_safe(it, tmp, &fusd_file->transactions)
{
struct fusd_transaction *transaction = list_entry(it,
struct fusd_transaction, list);
if (transaction->msg_in) {
if (transaction->msg_in->subcmd == FUSD_OPEN && transaction->msg_in->parm.fops_msg.retval == 0)
fusd_forge_close(transaction->msg_in, fusd_dev);
free_fusd_msg(&transaction->msg_in);
}
KFREE(transaction);
}
/* free state associated with this file */
memset(fusd_file, 0, sizeof(fusd_file_t));
KFREE(fusd_file);
/* reduce the size of the file array if necessary */
if (fusd_dev->array_size > MIN_FILEARRAY_SIZE &&
fusd_dev->array_size > 4 * fusd_dev->num_files)
fusd_dev_adjsize(fusd_dev);
/* renumber the array */
for (i = 0; i < fusd_dev->num_files; i++)
fusd_dev->files[i]->index = i;
/* try to free the device -- this may have been its last file */
return maybe_free_fusd_dev(fusd_dev);
}
/****************************************************************************/
/********************** CLIENT CALLBACK FUNCTIONS ***************************/
/****************************************************************************/
/* todo
* fusd_restart_check: Called from the beginning of most system calls
* to see if we are restarting a system call.
*
* In the common case -- that this is NOT a restarted syscall -- we
* return 0.
*
* In the much less common case, we return ERESTARTSYS, and expect the
* caller to jump right to its fusd_fops_call() call.
*
* In the even LESS (hopefully very rare) case when one PID had an
* interrupted syscall, but a different PID is the next to do a system
* call on that file descriptor -- well, we lose. Clear state of that
* old syscall out and continue as usual.
*/
STATIC struct fusd_transaction *fusd_find_incomplete_transaction(fusd_file_t *fusd_file, int subcmd)
{
struct fusd_transaction *transaction = fusd_find_transaction_by_pid(fusd_file, current->pid);
if (transaction == NULL)
return NULL;
if (transaction->subcmd != subcmd) {
RDEBUG(2, "Incomplete transaction %ld thrown out, was expecting subcmd %d but received %d",
transaction->transid, transaction->subcmd, subcmd);
fusd_cleanup_transaction(fusd_file, transaction);
return NULL;
}
RDEBUG(4, "pid %d restarting system call with transid %ld", current->pid,
transaction->transid);
return transaction;
}
STATIC int send_to_dev(fusd_dev_t *fusd_dev, fusd_msg_t *fusd_msg, int locked)
{
fusd_msgC_t *fusd_msgC;
/* allocate a container for the message */
if ((fusd_msgC = KMALLOC(sizeof(fusd_msgC_t), GFP_KERNEL)) == NULL)
return -ENOMEM;
memset(fusd_msgC, 0, sizeof(fusd_msgC_t));
memcpy(&fusd_msgC->fusd_msg, fusd_msg, sizeof(fusd_msg_t));
if (!locked)
LOCK_FUSD_DEV(fusd_dev);
/* put the message in the device's outgoing queue. */
if (fusd_dev->msg_head == NULL) {
fusd_dev->msg_head = fusd_dev->msg_tail = fusd_msgC;
} else {
fusd_dev->msg_tail->next = fusd_msgC;
fusd_dev->msg_tail = fusd_msgC;
}
if (!locked)
UNLOCK_FUSD_DEV(fusd_dev);
/* wake up the driver, which now has a message waiting in its queue */
WAKE_UP_INTERRUPTIBLE_SYNC(&fusd_dev->dev_wait);
return 0;
zombie_dev:
KFREE(fusd_msgC);
return -EPIPE;
}
/*
* special case: if the driver sent back a successful "open", but
* there is no file that is actually open, we forge a "close" so that
* the driver can maintain balanced open/close pairs. We put calls to
* this in fusd_fops_reply, when the reply first comes in; and,
* free_fusd_file, when we throw away a reply that had been
* pending for a restart.
*/
STATIC void fusd_forge_close(fusd_msg_t *msg, fusd_dev_t *fusd_dev)
{
RDEBUG(2, "/dev/%s tried to complete an open for transid %ld, "
"forging a close", NAME(fusd_dev), msg->parm.fops_msg.transid);
msg->cmd = FUSD_FOPS_CALL_DROPREPLY;
msg->subcmd = FUSD_CLOSE;
msg->parm.fops_msg.transid = atomic_inc_and_ret(&last_transid);
send_to_dev(fusd_dev, msg, 1);
}
/*
* fusd_fops_call_send: send a fusd_msg into userspace.
*
* NOTE - we are already holding the lock on fusd_file_arg when this
* function is called, but NOT the lock on the fusd_dev
*/
STATIC int fusd_fops_call_send(fusd_file_t *fusd_file_arg,
fusd_msg_t *fusd_msg, struct fusd_transaction **transaction)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
/* I check this just in case, shouldn't be necessary. */
GET_FUSD_FILE_AND_DEV(fusd_file_arg, fusd_file, fusd_dev);
/* make sure message is sane */
if ((fusd_msg->data == NULL) != (fusd_msg->datalen == 0)) {
RDEBUG(2, "fusd_fops_call: data pointer and datalen mismatch");
return -EINVAL;
}
/* fill the rest of the structure */
fusd_msg->parm.fops_msg.pid = current->pid;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
fusd_msg->parm.fops_msg.uid = current_uid();
fusd_msg->parm.fops_msg.gid = current_gid();
#endif
fusd_msg->parm.fops_msg.flags = fusd_file->file->f_flags;
fusd_msg->parm.fops_msg.offset = fusd_file->file->f_pos;
fusd_msg->parm.fops_msg.device_info = fusd_dev->private_data;
fusd_msg->parm.fops_msg.private_info = fusd_file->private_data;
fusd_msg->parm.fops_msg.fusd_file = fusd_file;
fusd_msg->parm.fops_msg.transid = atomic_inc_and_ret(&last_transid);
/* set up certain state depending on if we expect a reply */
switch (fusd_msg->cmd) {
case FUSD_FOPS_CALL: /* common case */
fusd_msg->parm.fops_msg.hint = fusd_file->index;
break;
case FUSD_FOPS_CALL_DROPREPLY:
/* nothing needed */
break;
case FUSD_FOPS_NONBLOCK:
fusd_msg->parm.fops_msg.hint = fusd_file->index;
break;
default:
RDEBUG(0, "whoa - fusd_fops_call_send got msg with unknown cmd!");
break;
}
if (transaction != NULL) {
int retval;
retval = fusd_add_transaction(fusd_file, fusd_msg->parm.fops_msg.transid, fusd_msg->subcmd,
fusd_msg->parm.fops_msg.length, transaction);
if (retval < 0)
return retval;
}
/* now add the message to the device's outgoing queue! */
return send_to_dev(fusd_dev, fusd_msg, 0);
/* bizarre errors go straight here */
invalid_dev:
invalid_file:
RDEBUG(0, "fusd_fops_call: got invalid device or file!!!!");
return -EPIPE;
}
/*
* fusd_fops_call_wait: wait for a driver to reply to a message
*
* NOTE - we are already holding the lock on fusd_file_arg when this
* function is called, but NOT the lock on the fusd_dev
*/
STATIC int fusd_fops_call_wait(fusd_file_t *fusd_file_arg,
fusd_msg_t **fusd_msg_reply, struct fusd_transaction *transaction)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
int retval;
/* I check this just in case, shouldn't be necessary. */
GET_FUSD_FILE_AND_DEV(fusd_file_arg, fusd_file, fusd_dev);
/* initialize first to tell callers there is no reply (yet) */
if (fusd_msg_reply != NULL)
*fusd_msg_reply = NULL;
/*
* Now, lock the device, check for an incoming message, and sleep if
* there is not a message already waiting for us. Note that we are
* unrolling the interruptible_sleep_on, as in the kernel's
* fs/pipe.c, to avoid race conditions between checking for the
* sleep condition and sleeping.
*/
LOCK_FUSD_DEV(fusd_dev);
while (transaction->msg_in == NULL) {
DECLARE_WAITQUEUE(wait, current);
RDEBUG(10, "pid %d blocking on transid %ld", current->pid, transaction->transid);
current->state = TASK_INTERRUPTIBLE;
add_wait_queue(&fusd_file->file_wait, &wait);
UNLOCK_FUSD_DEV(fusd_dev);
UNLOCK_FUSD_FILE(fusd_file);
schedule();
remove_wait_queue(&fusd_file->file_wait, &wait);
current->state = TASK_RUNNING;
/*
* If we woke up due to a signal -- and not due to a reply message
* coming in -- then we are in some trouble. The driver is already
* processing the request and might have changed some state that is
* hard to roll back. So, we'll tell the process to restart the
* system call, and come back to this point when the system call is
* restarted. We need to remember the PID to avoid confusion in
* case there is another process holding this file descriptor that
* is also trying to make a call.
*/
if (signal_pending(current)) {
RDEBUG(5, "blocked pid %d got a signal; sending -ERESTARTSYS",
current->pid);
LOCK_FUSD_FILE(fusd_file);
return -ERESTARTSYS;
}
LOCK_FUSD_FILE(fusd_file);
/* re-lock the device, so we can do our msg_in check again */
LOCK_FUSD_DEV(fusd_dev);
}
UNLOCK_FUSD_DEV(fusd_dev);
/* ok - at this point we are awake due to a message received. */
if (transaction->msg_in->cmd != FUSD_FOPS_REPLY ||
transaction->msg_in->subcmd != transaction->subcmd ||
transaction->msg_in->parm.fops_msg.transid != transaction->transid ||
transaction->msg_in->parm.fops_msg.fusd_file != fusd_file) {
RDEBUG(2, "fusd_fops_call: invalid reply!");
goto invalid_reply;
}
/* copy metadata back from userspace */
fusd_file->file->f_flags = transaction->msg_in->parm.fops_msg.flags;
fusd_file->private_data = transaction->msg_in->parm.fops_msg.private_info;
/* note, changes to device_info are NO LONGER honored here */
/* if everything's okay, return the return value. if caller is
* willing to take responsibility for freeing the message itself, we
* return the message too. */
retval = transaction->msg_in->parm.fops_msg.retval;
if (fusd_msg_reply != NULL) {
/* NOW TRANSFERRING RESPONSIBILITY FOR FREEING THIS DATA TO THE CALLER */
*fusd_msg_reply = transaction->msg_in;
transaction->msg_in = NULL;
} else {
/* free the message ourselves */
free_fusd_msg(&transaction->msg_in);
}
/* success */
fusd_cleanup_transaction(fusd_file, transaction);
return retval;
invalid_reply:
fusd_cleanup_transaction(fusd_file, transaction);
return -EPIPE;
/* bizarre errors go straight here */
invalid_dev:
invalid_file:
RDEBUG(0, "fusd_fops_call: got invalid device or file!!!!");
return -EPIPE;
zombie_dev:
RDEBUG(2, "fusd_fops_call: %s zombified while waiting for reply",
NAME(fusd_dev));
return -EPIPE;
}
/* fusd client system call handlers should call this after they call
* fops_call, to destroy the message that was returned to them. */
STATIC void fusd_transaction_done(struct fusd_transaction *transaction)
{
transaction->transid = -1;
transaction->pid = 0;
}
/********* Functions for opening a FUSD device *******************/
/*
* The process of having a client open a FUSD device is surprisingly
* tricky -- perhaps the most complex piece of FUSD (or, a close
* second to poll_diffs). Race conditions are rampant here.
*
* The main problem is that there is a race between clients trying to
* open the FUSD device, and providers unregistering it (e.g., the
* driver dying). If the device-unregister callback starts, and is
* scheduled out after it locks the fusd device but before it
* unregisters the device with devfs, the open callback might be
* invoked in this interval. This means the client will down() on a
* semaphore that is about to be freed when the device is destroyed.
*
* The only way to fix this, as far as I can tell, is for device
* registration and unregistration to both share a global lock; the
* client checks its 'private_data' pointer to make sure it's on the
* list of valid devices. If so, it sets a flag (open_in_progress)
* which means "Don't free this device yet!". Then, it releases the
* global lock, grabs the device lock, and tries to add itself as a
* "file" to the device array. It is then safe to decrement
* open_in_progress, because being a member of the file array will
* guarantee that the device will zombify instead of being freed.
*
* Another gotcha: To avoid infinitely dining with philosophers, the
* global lock (fusd_devlist_sem) should always be acquired AFTER a
* fusd device is locked. The code path that frees devices acquires
* the device lock FIRST, so the code here must do the same.
*
* Because of the complexity of opening a file, I've broken it up into
* multiple sub-functions.
*/
/*
* fusd_dev_is_valid: If a fusd device is valid, returns 1, and will have
* set the "open_in_progress" flag on the device.
*/
int fusd_dev_is_valid(fusd_dev_t *fusd_dev)
{
struct list_head *tmp;
int dev_found = 0;
/* The first thing we must do is acquire the global lock on the
* device list, and make sure this device is valid; if so, mark it
* as being "in use". If we don't do this, there's a race: after we
* enter this function, the device may be unregistered. */
down(&fusd_devlist_sem);
list_for_each(tmp, &fusd_devlist_head)
{
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
if (d == fusd_dev && d->magic == FUSD_DEV_MAGIC && !ZOMBIE(d)) {
dev_found = 1;
break;
}
}
/* A device will not be deallocated when this counter is >0 */
if (dev_found)
fusd_dev->open_in_progress++;
up(&fusd_devlist_sem);
return dev_found;
}
int fusd_dev_add_file(struct file *file, fusd_dev_t *fusd_dev, fusd_file_t **fusd_file_ret)
{
fusd_file_t *fusd_file;
int i;
/* Make sure the device didn't become a zombie while we were waiting
* for the device lock */
if (ZOMBIE(fusd_dev))
return -ENOENT;
/* this shouldn't happen. maybe i'm insane, but i check anyway. */
for (i = 0; i < fusd_dev->num_files; i++)
if (fusd_dev->files[i]->file == file) {
RDEBUG(1, "warning: fusd_client_open got open for already-open file!?");
return -EIO;
}
/* You can't open your own file! Return -EDEADLOCK if someone tries to.
*
* XXX - TODO - FIXME - This should eventually be more general
* deadlock detection of arbitrary length cycles */
if (current->pid == fusd_dev->pid) {
RDEBUG(3, "pid %d tried to open its own device (/dev/%s)",
fusd_dev->pid, NAME(fusd_dev));
return -EDEADLOCK;
}
/* make more space in the file array if we need it */
if (fusd_dev->num_files == fusd_dev->array_size &&
fusd_dev->array_size < MAX_FILEARRAY_SIZE)
fusd_dev_adjsize(fusd_dev);
/* make sure we have room... adjsize may have failed */
if (fusd_dev->num_files >= fusd_dev->array_size) {
RDEBUG(1, "/dev/%s out of state space for open files!", NAME(fusd_dev));
return -ENOMEM;
}
/* create state for this file */
if ((fusd_file = KMALLOC(sizeof(fusd_file_t), GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory");
return -ENOMEM;
}
memset(fusd_file, 0, sizeof(fusd_file_t));
init_waitqueue_head(&fusd_file->file_wait);
init_waitqueue_head(&fusd_file->poll_wait);
INIT_LIST_HEAD(&fusd_file->transactions);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 30)
init_MUTEX(&fusd_file->file_sem);
init_MUTEX(&fusd_file->transactions_sem);
#else
sema_init(&fusd_file->file_sem, 1);
sema_init(&fusd_file->transactions_sem, 1);
#endif
fusd_file->last_poll_sent = -1;
fusd_file->magic = FUSD_FILE_MAGIC;
fusd_file->fusd_dev = fusd_dev;
fusd_file->fusd_dev_version = fusd_dev->version;
fusd_file->file = file;
/* add this file to the list of files managed by the device */
fusd_file->index = fusd_dev->num_files++;
fusd_dev->files[fusd_file->index] = fusd_file;
/* store the pointer to this file with the kernel */
file->private_data = fusd_file;
*fusd_file_ret = fusd_file;
/* success! */
return 0;
}
STATIC struct fusd_dev_t_s *find_user_device(int dev_id)
{
struct list_head *entry;
down(&fusd_devlist_sem);
list_for_each(entry, &fusd_devlist_head)
{
fusd_dev_t *d = list_entry(entry, fusd_dev_t, devlist);
if (d->dev_id == dev_id) {
up(&fusd_devlist_sem);
return d;
}
}
up(&fusd_devlist_sem);
return NULL;
}
/*
* A client has called open() has been called on a registered device.
* See comment higher up for detailed notes on this function.
*/
STATIC int fusd_client_open(struct inode *inode, struct file *file)
{
int retval;
int device_freed = 0;
fusd_dev_t *fusd_dev = find_user_device(inode->i_rdev);
fusd_file_t *fusd_file;
fusd_msg_t fusd_msg;
struct fusd_transaction *transaction;
/* If the device wasn't on our valid list, stop here. */
if (!fusd_dev_is_valid(fusd_dev))
return -ENOENT;
/* fusd_dev->open_in_progress now set */
/* Lock the fusd device. Note, when we finally do acquire the lock,
* the device might be a zombie (driver disappeared). */
RAWLOCK_FUSD_DEV(fusd_dev);
RDEBUG(3, "got an open for /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
/* Try to add ourselves to the device's file list. If retval==0, we
are now part of the file array. */
retval = fusd_dev_add_file(file, fusd_dev, &fusd_file);
/*
* It is now safe to unset the open_in_progress flag. Either:
* 1) We are part of the file array, so dev won't be freed, or;
* 2) Something failed, so we are returning a failure now and no
* longer need the device.
* Note, open_in_progress must be protected by the global sem, not
* the device lock, due to the access of it in fusd_dev_is_valid().
*/
down(&fusd_devlist_sem);
fusd_dev->open_in_progress--;
up(&fusd_devlist_sem);
/* If adding ourselves to the device list failed, give up. Possibly
* free the device if it was a zombie and waiting for us to complete
* our open. */
if (retval < 0) {
if (!maybe_free_fusd_dev(fusd_dev))
UNLOCK_FUSD_DEV(fusd_dev);
return retval;
}
/* send message to userspace and get retval */
init_fusd_msg(&fusd_msg);
fusd_msg.subcmd = FUSD_OPEN;
/* send message to userspace and get the reply. Device can't be
* locked during that operation. */
UNLOCK_FUSD_DEV(fusd_dev);
retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction);
if (retval >= 0)
retval = fusd_fops_call_wait(fusd_file, NULL, transaction);
RAWLOCK_FUSD_DEV(fusd_dev);
/* If the device zombified (while we were waiting to reacquire the
* lock)... consider that a failure */
if (ZOMBIE(fusd_dev))
retval = -ENOENT;
/* if retval is negative, throw away state... the file open failed */
if (retval < 0) {
RDEBUG(3, "...open failed for /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
device_freed = free_fusd_file(fusd_dev, fusd_file);
}
/* Now unlock the device, if it still exists. (It may have been
* freed if the open failed, and we were the last outstanding
* request for it.) */
if (!device_freed)
UNLOCK_FUSD_DEV(fusd_dev);
return retval;
}
/* close() has been called on a registered device. like
* fusd_client_open, we must lock the entire device. */
STATIC int fusd_client_release(struct inode *inode, struct file *file)
{
int retval;
fusd_file_t *fusd_file;
fusd_dev_t *fusd_dev;
fusd_msg_t fusd_msg;
struct fusd_transaction *transaction;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
LOCK_FUSD_FILE(fusd_file);
RDEBUG(3, "got a close on /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
/* Tell the driver that the file closed, if it still exists. */
init_fusd_msg(&fusd_msg);
fusd_msg.subcmd = FUSD_CLOSE;
retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction);
RDEBUG(5, "fusd_client_release: send returned %d", retval);
if (retval >= 0)
retval = fusd_fops_call_wait(fusd_file, NULL, transaction);
RDEBUG(5, "fusd_client_release: call_wait %d", retval);
/* delete the file off the device's file-list, and free it. note
* that device may be a zombie right now and may be freed when we
* come back from free_fusd_file. we only release the lock if the
* device still exists. */
RAWLOCK_FUSD_DEV(fusd_dev);
if (!free_fusd_file(fusd_dev, fusd_file)) {
UNLOCK_FUSD_DEV(fusd_dev);
}
return retval;
invalid_dev:
invalid_file:
RDEBUG(1, "got a close on client file from pid %d, INVALID DEVICE!",
current->pid);
return -EPIPE;
}
STATIC ssize_t fusd_client_read(struct file *file, char *buf,
size_t count, loff_t *offset)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
struct fusd_transaction *transaction;
fusd_msg_t fusd_msg, *reply = NULL;
int retval = -EPIPE;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
if (ZOMBIE(fusd_dev))
goto zombie_dev;
LOCK_FUSD_FILE(fusd_file);
RDEBUG(3, "got a read on /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_READ);
if (transaction && transaction->size > count) {
RDEBUG(2,
"Incomplete I/O transaction %ld thrown out, as the transaction's size of %d bytes was greater than "
"the retry's size of %d bytes", transaction->transid, transaction->size, (int) count);
fusd_cleanup_transaction(fusd_file, transaction);
transaction = NULL;
}
if (transaction == NULL) {
/* make sure we aren't trying to read too big of a buffer */
if (count > MAX_RW_SIZE)
count = MAX_RW_SIZE;
/* send the message */
init_fusd_msg(&fusd_msg);
fusd_msg.subcmd = FUSD_READ;
fusd_msg.parm.fops_msg.length = count;
/* send message to userspace */
if ((retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction)) < 0)
goto done;
}
/* and wait for the reply */
/* todo: store and retrieve the transid from the interrupted messsage */
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
/* return immediately in case of error */
if (retval < 0 || reply == NULL)
goto done;
/* adjust the reval if the retval indicates a larger read than the
* data that was actually provided */
if (reply->datalen != retval) {
RDEBUG(1, "warning: /dev/%s driver (pid %d) claimed it returned %d bytes "
"on read but actually returned %d",
NAME(fusd_dev), fusd_dev->pid, retval, reply->datalen);
retval = reply->datalen;
}
/* adjust if the device driver gave us more data than the user asked for
* (bad! bad! why is the driver broken???) */
if (retval > count) {
RDEBUG(1, "warning: /dev/%s driver (pid %d) returned %d bytes on read but "
"the user only asked for %d",
NAME(fusd_dev), fusd_dev->pid, retval, (int) count);
retval = count;
}
/* copy the offset back from the message */
*offset = reply->parm.fops_msg.offset;
/* IFF return value indicates data present, copy it back */
if (retval > 0) {
if (copy_to_user(buf, reply->data, retval)) {
retval = -EFAULT;
goto done;
}
}
done:
/* clear the readable bit of our cached poll state */
fusd_file->cached_poll_state &= ~(FUSD_NOTIFY_INPUT);
free_fusd_msg(&reply);
UNLOCK_FUSD_FILE(fusd_file);
return retval;
invalid_file:
invalid_dev:
zombie_dev:
RDEBUG(3, "got a read on client file from pid %d, driver has disappeared",
current->pid);
return -EPIPE;
}
STATIC int fusd_add_transaction(fusd_file_t *fusd_file, int transid, int subcmd, int size,
struct fusd_transaction **out_transaction)
{
struct fusd_transaction *transaction = (struct fusd_transaction *) KMALLOC(sizeof(struct fusd_transaction),
GFP_KERNEL);
if (transaction == NULL)
return -ENOMEM;
transaction->msg_in = NULL;
transaction->transid = transid;
transaction->subcmd = subcmd;
transaction->pid = current->pid;
transaction->size = size;
down(&fusd_file->transactions_sem);
list_add_tail(&transaction->list, &fusd_file->transactions);
up(&fusd_file->transactions_sem);
if (out_transaction != NULL)
*out_transaction = transaction;
return 0;
}
STATIC void fusd_cleanup_transaction(fusd_file_t *fusd_file, struct fusd_transaction *transaction)
{
free_fusd_msg(&transaction->msg_in);
fusd_remove_transaction(fusd_file, transaction);
}
STATIC void fusd_remove_transaction(fusd_file_t *fusd_file, struct fusd_transaction *transaction)
{
down(&fusd_file->transactions_sem);
list_del(&transaction->list);
up(&fusd_file->transactions_sem);
KFREE(transaction);
}
STATIC struct fusd_transaction *fusd_find_transaction(fusd_file_t *fusd_file, int transid)
{
struct list_head *i;
down(&fusd_file->transactions_sem);
list_for_each(i, &fusd_file->transactions)
{
struct fusd_transaction *transaction = list_entry(i,
struct fusd_transaction, list);
if (transaction->transid == transid) {
up(&fusd_file->transactions_sem);
return transaction;
}
}
up(&fusd_file->transactions_sem);
return NULL;
}
STATIC struct fusd_transaction *fusd_find_transaction_by_pid(fusd_file_t *fusd_file, int pid)
{
struct list_head *i;
down(&fusd_file->transactions_sem);
list_for_each(i, &fusd_file->transactions)
{
struct fusd_transaction *transaction = list_entry(i,
struct fusd_transaction, list);
if (transaction->pid == pid) {
up(&fusd_file->transactions_sem);
return transaction;
}
}
up(&fusd_file->transactions_sem);
return NULL;
}
STATIC ssize_t fusd_client_write(struct file *file,
const char *buffer,
size_t length,
loff_t *offset)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
fusd_msg_t fusd_msg;
fusd_msg_t *reply = NULL;
int retval = -EPIPE;
struct fusd_transaction *transaction;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
if (ZOMBIE(fusd_dev))
goto zombie_dev;
LOCK_FUSD_FILE(fusd_file);
RDEBUG(3, "got a write on /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_WRITE);
if (transaction && transaction->size != length) {
RDEBUG(2,
"Incomplete I/O transaction %ld thrown out, as the transaction's size of %d bytes was not equal to "
"the retry's size of %d bytes", transaction->transid, transaction->size, (int) length);
fusd_cleanup_transaction(fusd_file, transaction);
transaction = NULL;
}
if (transaction == NULL) {
if (length < 0) {
RDEBUG(2, "fusd_client_write: got invalid length %d", (int) length);
retval = -EINVAL;
goto done;
}
if (length > MAX_RW_SIZE)
length = MAX_RW_SIZE;
init_fusd_msg(&fusd_msg);
/* sigh.. i guess zero length writes should be legal */
if (length > 0) {
if ((fusd_msg.data = VMALLOC(length)) == NULL) {
retval = -ENOMEM;
goto done;
}
if (copy_from_user(fusd_msg.data, buffer, length)) {
retval = -EFAULT;
goto done;
}
fusd_msg.datalen = length;
}
fusd_msg.subcmd = FUSD_WRITE;
fusd_msg.parm.fops_msg.length = length;
if ((retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction)) < 0)
goto done;
}
/* todo: fix transid on restart */
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
if (retval < 0 || reply == NULL)
goto done;
/* drivers should not write more bytes than they were asked to! */
if (retval > length) {
RDEBUG(1, "warning: /dev/%s driver (pid %d) returned %d bytes on write; "
"the user only wanted %d",
NAME(fusd_dev), fusd_dev->pid, retval, (int) length);
retval = length;
}
*offset = reply->parm.fops_msg.offset;
/* all done! */
done:
/* clear the writable bit of our cached poll state */
fusd_file->cached_poll_state &= ~(FUSD_NOTIFY_OUTPUT);
free_fusd_msg(&reply);
UNLOCK_FUSD_FILE(fusd_file);
return retval;
invalid_file:
invalid_dev:
zombie_dev:
RDEBUG(3, "got a write on client file from pid %d, driver has disappeared",
current->pid);
return -EPIPE;
}
#ifndef HAVE_UNLOCKED_IOCTL
STATIC int fusd_client_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
#else
STATIC long fusd_client_unlocked_ioctl (struct file *file,
unsigned int cmd, unsigned long arg)
#endif
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
fusd_msg_t fusd_msg, *reply = NULL;
int retval = -EPIPE, dir, length;
struct fusd_transaction *transaction;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
if (ZOMBIE(fusd_dev))
goto zombie_dev;
LOCK_FUSD_FILE(fusd_file);
RDEBUG(3, "got an ioctl on /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
dir = _IOC_DIR(cmd);
length = _IOC_SIZE(cmd);
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_IOCTL);
// todo: Check to make sure the transaction is for the same IOCTL
if (transaction == NULL) {
/* if we're trying to read or write, make sure length is sane */
if ((dir & (_IOC_WRITE | _IOC_READ)) &&
(length <= 0 || length > MAX_RW_SIZE)) {
RDEBUG(2, "client ioctl got crazy IOC_SIZE of %d", length);
retval = -EINVAL;
goto done;
}
/* fill the struct */
init_fusd_msg(&fusd_msg);
fusd_msg.subcmd = FUSD_IOCTL;
fusd_msg.parm.fops_msg.cmd = cmd;
fusd_msg.parm.fops_msg.arg.arg = arg;
/* get the data if user is trying to write to the driver */
if (dir & _IOC_WRITE) {
if ((fusd_msg.data = VMALLOC(length)) == NULL) {
RDEBUG(2, "can't vmalloc for client ioctl!");
retval = -ENOMEM;
goto done;
}
if (copy_from_user(fusd_msg.data, (void *) arg, length)) {
retval = -EFAULT;
goto done;
}
fusd_msg.datalen = length;
}
/* send request to the driver */
if ((retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction)) < 0)
goto done;
}
/* get the response */
/* todo: fix transid on restart */
if ((retval = fusd_fops_call_wait(fusd_file, &reply, transaction)) < 0 || reply == NULL)
goto done;
/* if user is trying to read from the driver, copy data back */
if (dir & _IOC_READ) {
if (reply->data == NULL || reply->datalen != length) {
RDEBUG(2, "client_ioctl read reply with screwy data (%d, %d)",
reply->datalen, length);
retval = -EIO;
goto done;
}
if (copy_to_user((void *) arg, reply->data, length)) {
retval = -EFAULT;
goto done;
}
}
/* all done! */
done:
free_fusd_msg(&reply);
UNLOCK_FUSD_FILE(fusd_file);
return retval;
invalid_file:
invalid_dev :
zombie_dev:
RDEBUG(3, "got an ioctl on client file from pid %d, driver has disappeared",
current->pid);
return -EPIPE;
}
static void fusd_client_mm_open(struct vm_area_struct *vma);
static void fusd_client_mm_close(struct vm_area_struct *vma);
/* int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf); */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
static int fusd_client_fault (struct vm_fault *vmf);
#elif LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 30)
static int fusd_client_fault (struct vm_area_struct *vma, struct vm_fault *vmf);
#else
static int fusd_client_fault(struct vm_area_struct *vma, struct vm_fault *vmf, int *type);
#endif
static struct vm_operations_struct fusd_remap_vm_ops = {
.open = fusd_client_mm_open,
.close = fusd_client_mm_close,
.fault = fusd_client_fault,
};
struct fusd_mmap_instance {
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
unsigned long addr;
unsigned long size;
atomic_t refcount;
};
static void fusd_client_mm_open(struct vm_area_struct *vma)
{
struct fusd_mmap_instance *mmap_instance = (struct fusd_mmap_instance *) vma->vm_private_data;
atomic_inc(&mmap_instance->refcount);
}
static void fusd_client_mm_close(struct vm_area_struct *vma)
{
struct fusd_mmap_instance *mmap_instance = (struct fusd_mmap_instance *) vma->vm_private_data;
if (atomic_dec_and_test(&mmap_instance->refcount)) {
KFREE(mmap_instance);
}
}
static int fusd_client_mmap(struct file *file, struct vm_area_struct *vma)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
struct fusd_transaction *transaction;
fusd_msg_t fusd_msg, *reply = NULL;
int retval = -EPIPE;
struct fusd_mmap_instance *mmap_instance;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
if (ZOMBIE(fusd_dev))
goto zombie_dev;
LOCK_FUSD_FILE(fusd_file);
RDEBUG(3, "got a mmap on /dev/%s (owned by pid %d) from pid %d",
NAME(fusd_dev), fusd_dev->pid, current->pid);
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_MMAP);
if (transaction == NULL) {
/* send the message */
init_fusd_msg(&fusd_msg);
fusd_msg.subcmd = FUSD_MMAP;
fusd_msg.parm.fops_msg.offset = vma->vm_pgoff << PAGE_SHIFT;
fusd_msg.parm.fops_msg.flags = vma->vm_flags;
fusd_msg.parm.fops_msg.length = vma->vm_end - vma->vm_start;
/* send message to userspace */
if ((retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction)) < 0)
goto done;
}
/* and wait for the reply */
/* todo: store and retrieve the transid from the interrupted message */
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
mmap_instance =
(struct fusd_mmap_instance *) KMALLOC(sizeof(struct fusd_mmap_instance), GFP_KERNEL);
// todo: free this thing at some point
mmap_instance->fusd_dev = fusd_dev;
mmap_instance->fusd_file = fusd_file;
mmap_instance->addr = reply->parm.fops_msg.arg.arg;
mmap_instance->size = reply->parm.fops_msg.length;
atomic_set(&mmap_instance->refcount, 0);
retval = reply->parm.fops_msg.retval;
vma->vm_private_data = mmap_instance;
vma->vm_ops = &fusd_remap_vm_ops;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 7, 0)
vma->vm_flags |= (VM_DONTEXPAND | VM_DONTDUMP);
#else
vma->vm_flags |= VM_RESERVED;
#endif
fusd_client_mm_open(vma);
done:
free_fusd_msg(&reply);
UNLOCK_FUSD_FILE(fusd_file);
return retval;
invalid_file:
invalid_dev:
zombie_dev:
RDEBUG(3, "got a mmap on client file from pid %d, driver has disappeared",
current->pid);
return -EPIPE;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
static int fusd_client_fault (struct vm_fault *vmf)
#elif LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 30)
static int fusd_client_fault (struct vm_area_struct *vma, struct vm_fault *vmf)
#else
static int fusd_client_fault(struct vm_area_struct *vma, struct vm_fault *vmf, int *type)
#endif
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
struct vm_area_struct *vma = vmf->vma;
#endif
struct fusd_mmap_instance *mmap_instance = (struct fusd_mmap_instance *) vma->vm_private_data;
unsigned long offset;
struct page *page = NULL;
int result;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
offset = ( (unsigned long) vmf->address - vma->vm_start ) + ( vma->vm_pgoff << PAGE_SHIFT );
#else
offset = ((unsigned long) vmf->virtual_address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
#endif
// todo: worry about size
if (offset > mmap_instance->size)
goto out;
down_read(&mmap_instance->fusd_dev->task->mm->mmap_sem);
result = GET_USER_PAGES(mmap_instance->fusd_dev->task, mmap_instance->fusd_dev->task->mm,
mmap_instance->addr + offset, 1, 1, 0, &page, NULL);
up_read(&mmap_instance->fusd_dev->task->mm->mmap_sem);
if (PageAnon(vmf->page)) {
RDEBUG(2,
"Cannot mmap anonymous pages. Be sure to allocate your shared buffer with MAP_SHARED | MAP_ANONYMOUS");
return VM_FAULT_SIGBUS;
}
if (result > 0) {
get_page(page);
vmf->page = page;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 30)
if ( type )
*type = VM_FAULT_MINOR;
#endif
}
out:
return 0;
}
/*
* The design of poll for clients is a bit subtle.
*
* We don't want the select() call itself to block, so we keep a cache
* of the most recently known state supplied by the driver. The cache
* is initialized to 0 (meaning: nothing readable/writable).
*
* When a poll comes in, we do a non-blocking (!) dispatch of a
* command telling the driver "This is the state we have cached, reply
* to this call when the state changes.", and then immediately return
* the cached state. We tell the kernel's select to sleep on our
* poll_wait wait queue.
*
* When the driver replies, we update our cached info and wake up the
* wait queue. Waking up the wait queue will most likely immediately
* effect a poll again, in which case we will reply whatever we just
* cached from the driver.
*
*/
STATIC unsigned int fusd_client_poll(struct file *file, poll_table *wait)
{
fusd_dev_t *fusd_dev;
fusd_file_t *fusd_file;
int kernel_bits = 0;
int send_poll = 0;
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
LOCK_FUSD_FILE(fusd_file);
LOCK_FUSD_DEV(fusd_dev);
RDEBUG(3, "got a select on /dev/%s (owned by pid %d) from pid %d, cps=%d",
NAME(fusd_dev), fusd_dev->pid, current->pid,
fusd_file->cached_poll_state);
poll_wait(file, &fusd_file->poll_wait, wait);
/*
* If our currently cached poll state is not the same as the
* most-recently-sent polldiff request, then, dispatch a new
* request. (We DO NOT wait for a reply, but just dispatch the
* request).
*
* Also, don't send a new polldiff if the most recent one resulted
* in an error.
*/
if (fusd_file->last_poll_sent != fusd_file->cached_poll_state &&
fusd_file->cached_poll_state >= 0) {
RDEBUG(3, "sending polldiff request because lps=%d, cps=%d",
fusd_file->last_poll_sent, fusd_file->cached_poll_state);
send_poll = 1;
fusd_file->last_poll_sent = fusd_file->cached_poll_state;
}
/* compute what to return for the state we had cached, converting to
* bits that have meaning to the kernel */
if (fusd_file->cached_poll_state > 0) {
if (fusd_file->cached_poll_state & FUSD_NOTIFY_INPUT)
kernel_bits |= POLLIN;
if (fusd_file->cached_poll_state & FUSD_NOTIFY_OUTPUT)
kernel_bits |= POLLOUT;
if (fusd_file->cached_poll_state & FUSD_NOTIFY_EXCEPT)
kernel_bits |= POLLPRI;
}
/* Now that we've committed to sending the poll, etc., it should be
* safe to unlock the device */
UNLOCK_FUSD_DEV(fusd_dev);
UNLOCK_FUSD_FILE(fusd_file);
if (send_poll) {
fusd_msg_t fusd_msg;
init_fusd_msg(&fusd_msg);
fusd_msg.cmd = FUSD_FOPS_NONBLOCK;
fusd_msg.subcmd = FUSD_POLL_DIFF;
fusd_msg.parm.fops_msg.cmd = fusd_file->cached_poll_state;
if (fusd_fops_call_send(fusd_file, &fusd_msg, NULL) < 0) {
/* If poll dispatched failed, set back to -1 so we try again.
* Not a race (I think), since sending an *extra* polldiff never
* hurts anything. */
fusd_file->last_poll_sent = -1;
}
}
return kernel_bits;
zombie_dev:
/* might jump here from LOCK_FUSD_DEV */
UNLOCK_FUSD_FILE(fusd_file);
invalid_dev:
invalid_file:
RDEBUG(3, "got a select on client file from pid %d, driver has disappeared",
current->pid);
return POLLPRI;
}
#ifndef HAVE_UNLOCKED_IOCTL
STATIC struct file_operations fusd_client_fops = {
.owner = THIS_MODULE,
.open = fusd_client_open,
.release = fusd_client_release,
.read = fusd_client_read,
.write = fusd_client_write,
.ioctl = fusd_client_ioctl,
.poll = fusd_client_poll,
.mmap = fusd_client_mmap
};
#else
STATIC struct file_operations fusd_client_fops = {
.owner = THIS_MODULE,
.open = fusd_client_open,
.release = fusd_client_release,
.read = fusd_client_read,
.write = fusd_client_write,
.unlocked_ioctl = fusd_client_unlocked_ioctl,
.poll = fusd_client_poll,
.mmap = fusd_client_mmap
};
#endif
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
STATIC fusd_file_t *find_fusd_reply_file(fusd_dev_t *fusd_dev, fusd_msg_t *msg)
{
/* first, try the hint */
int i = msg->parm.fops_msg.hint;
if (i >= 0 &&
i < fusd_dev->num_files &&
fusd_dev->files[i] == msg->parm.fops_msg.fusd_file) {
RDEBUG(15, "find_fusd_reply_file: hint worked");
} else {
/* hint didn't work, fall back to a search of the whole array */
i = find_fusd_file(fusd_dev, msg->parm.fops_msg.fusd_file);
RDEBUG(15, "find_fusd_reply_file: hint failed");
}
/* we couldn't find anyone waiting for this message! */
if (i < 0) {
return NULL;
} else {
return fusd_dev->files[i];
}
}
/* Process an incoming reply to a message dispatched by
* fusd_fops_call. Called by fusd_write when a driver writes to
* /dev/fusd. */
STATIC int fusd_fops_reply(fusd_dev_t *fusd_dev, fusd_msg_t *msg)
{
fusd_file_t *fusd_file;
struct fusd_transaction *transaction;
/* figure out the index of the file we are replying to. usually
* very fast (uses a hint) */
if ((fusd_file = find_fusd_reply_file(fusd_dev, msg)) == NULL) {
RDEBUG(2, "fusd_fops_reply: got a reply on /dev/%s with no connection",
NAME(fusd_dev));
goto discard;
}
/* make sure this is not an old reply going to an old instance that's gone */
/* todo: kor fix this */
/*
if (fusd_file->fusd_dev_version != fusd_dev->version ||
msg->parm.fops_msg.transid != fusd_file->transid_outstanding) {
RDEBUG(2, "fusd_fops_reply: got an old message, discarding");
goto discard;
}*/
transaction = fusd_find_transaction(fusd_file, msg->parm.fops_msg.transid);
if (transaction == NULL) {
RDEBUG(2, "fusd_fops_reply: No transaction found with transid %ld", msg->parm.fops_msg.transid);
goto discard;
}
RDEBUG(10, "fusd_fops_reply: /dev/%s completed transid %ld (retval %d)",
NAME(fusd_dev), msg->parm.fops_msg.transid,
(int) msg->parm.fops_msg.retval);
transaction->msg_in = msg;
mb();
WAKE_UP_INTERRUPTIBLE_SYNC(&fusd_file->file_wait);
return 0;
discard:
if (msg->subcmd == FUSD_OPEN && msg->parm.fops_msg.retval == 0) {
fusd_forge_close(msg, fusd_dev);
return 0;
} else {
return -EPIPE;
}
}
/* special function to process responses to POLL_DIFF */
STATIC int fusd_polldiff_reply(fusd_dev_t *fusd_dev, fusd_msg_t *msg)
{
fusd_file_t *fusd_file;
/* figure out the index of the file we are replying to. usually
* very fast (uses a hint) */
if ((fusd_file = find_fusd_reply_file(fusd_dev, msg)) == NULL)
return -EPIPE;
/* record the poll state returned. convert all negative retvals to -1. */
if ((fusd_file->cached_poll_state = msg->parm.fops_msg.retval) < 0)
fusd_file->cached_poll_state = -1;
RDEBUG(3, "got updated poll state from /dev/%s driver: %d", NAME(fusd_dev),
fusd_file->cached_poll_state);
/* since the client has returned the polldiff we sent, set
* last_poll_sent to -1, so that we'll send a polldiff request on
* the next select. */
fusd_file->last_poll_sent = -1;
/* wake up select's queue so that a new polldiff is generated */
wake_up_interruptible(&fusd_file->poll_wait);
return 0;
}
STATIC int systest(struct super_block *sb, void *data)
{
return 1;
}
STATIC int fusd_register_device(fusd_dev_t *fusd_dev,
register_msg_t register_msg)
{
int error = 0;
struct list_head *tmp;
int dev_id;
/* make sure args are valid */
if (fusd_dev == NULL) {
RDEBUG(0, "fusd_register_device: bug in arguments!");
return -EINVAL;
}
register_msg.name[FUSD_MAX_NAME_LENGTH] = '\0';
/* make sure that there isn't already a device by this name */
down(&fusd_devlist_sem);
list_for_each(tmp, &fusd_devlist_head)
{
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
if (d && d->name && !d->zombie && !strcmp(d->name, register_msg.name)) {
error = -EEXIST;
break;
}
}
up(&fusd_devlist_sem);
if (error)
return error;
/* allocate memory for the name, and copy */
if ((fusd_dev->name = KMALLOC(strlen(register_msg.name) + 1, GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory");
return -ENOMEM;
}
strcpy(fusd_dev->name, register_msg.name);
/* allocate memory for the class name, and copy */
if ((fusd_dev->class_name = KMALLOC(strlen(register_msg.clazz) + 1, GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory");
return -ENOMEM;
}
strcpy(fusd_dev->class_name, register_msg.clazz);
/* allocate memory for the class name, and copy */
if ((fusd_dev->dev_name = KMALLOC(strlen(register_msg.devname) + 1, GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory");
return -ENOMEM;
}
strcpy(fusd_dev->dev_name, register_msg.devname);
dev_id = 0;
if ((error = alloc_chrdev_region(&dev_id, 0, 1, fusd_dev->name)) < 0) {
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", error);
goto register_failed;
}
fusd_dev->dev_id = dev_id;
fusd_dev->handle = cdev_alloc();
if (fusd_dev->handle == NULL) {
printk(KERN_ERR "cdev_alloc() failed\n");
error = -ENOMEM;
goto register_failed3;
}
fusd_dev->handle->owner = THIS_MODULE;
fusd_dev->handle->ops = &fusd_client_fops;
kobject_set_name(&fusd_dev->handle->kobj, fusd_dev->name);
if ((error = cdev_add(fusd_dev->handle, dev_id, 1)) < 0) {
printk(KERN_ERR "cdev_add failed status: %d\n", error);
kobject_put(&fusd_dev->handle->kobj);
goto register_failed3;
}
fusd_dev->device = CLASS_DEVICE_CREATE(fusd_class, NULL, fusd_dev->dev_id, NULL, fusd_dev->dev_name);
if (fusd_dev->device == NULL) {
error = PTR_ERR(fusd_dev->device);
printk(KERN_ERR "device_create failed status: %d\n", error);
goto register_failed5;
}
/* make sure the registration was successful */
if (fusd_dev->handle == 0) {
error = -EIO;
goto register_failed;
}
/* remember the user's private data so we can pass it back later */
fusd_dev->private_data = register_msg.device_info;
/* everything ok */
fusd_dev->version = atomic_inc_and_ret(&last_version);
RDEBUG(3, "pid %d registered /dev/%s v%ld", fusd_dev->pid, NAME(fusd_dev),
fusd_dev->version);
wake_up_interruptible(&new_device_wait);
return 0;
register_failed5:
fusd_dev->clazz = NULL;
cdev_del(fusd_dev->handle);
fusd_dev->handle = NULL;
register_failed3:
unregister_chrdev_region(dev_id, 1);
register_failed:
KFREE(fusd_dev->name);
fusd_dev->name = NULL;
return error;
}
/****************************************************************************/
/******************** CONTROL CHANNEL CALLBACK FUNCTIONS ********************/
/****************************************************************************/
/* open() called on /dev/fusd itself */
STATIC int fusd_open(struct inode *inode, struct file *file)
{
fusd_dev_t *fusd_dev = NULL;
fusd_file_t **file_array = NULL;
/* keep the module from being unloaded during initialization! */
//MOD_INC_USE_COUNT;
/* allocate memory for the device state */
if ((fusd_dev = KMALLOC(sizeof(fusd_dev_t), GFP_KERNEL)) == NULL)
goto dev_malloc_failed;
memset(fusd_dev, 0, sizeof(fusd_dev_t));
if ((file_array = fusd_dev_adjsize(fusd_dev)) == NULL)
goto file_malloc_failed;
init_waitqueue_head(&fusd_dev->dev_wait);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 30)
init_MUTEX(&fusd_dev->dev_sem);
#else
sema_init(&fusd_dev->dev_sem, 1);
#endif
fusd_dev->magic = FUSD_DEV_MAGIC;
fusd_dev->pid = current->pid;
fusd_dev->task = current;
file->private_data = fusd_dev;
/* add to the list of valid devices */
down(&fusd_devlist_sem);
list_add(&fusd_dev->devlist, &fusd_devlist_head);
up(&fusd_devlist_sem);
RDEBUG(3, "pid %d opened /dev/fusd", fusd_dev->pid);
return 0;
file_malloc_failed:
KFREE(fusd_dev);
dev_malloc_failed:
RDEBUG(1, "out of memory in fusd_open!");
//MOD_DEC_USE_COUNT;
return -ENOMEM;
}
/* close() called on /dev/fusd itself. destroy the device that
* was registered by it, if any. */
STATIC int fusd_release(struct inode *inode, struct file *file)
{
fusd_dev_t *fusd_dev;
GET_FUSD_DEV(file->private_data, fusd_dev);
LOCK_FUSD_DEV(fusd_dev);
if (fusd_dev->pid != current->pid) {
RDEBUG(2, "yikes!: when releasing device, pid mismatch");
}
RDEBUG(3, "pid %d closing /dev/fusd", current->pid);
#if 0
/* This delay is needed to exercise the openrace.c race condition,
* i.e. testing to make sure that our open_in_progress stuff works */
{
int target = jiffies + 10 * HZ;
RDEBUG(1, "starting to wait");
while ( jiffies < target )
schedule();
RDEBUG(1, "stopping wait");
}
#endif
if (fusd_dev->handle) {
CLASS_DEVICE_DESTROY(fusd_class, fusd_dev->dev_id);
if (fusd_dev->owns_class) {
class_destroy(fusd_dev->clazz);
}
cdev_del(fusd_dev->handle);
unregister_chrdev_region(fusd_dev->dev_id, 1);
}
/* mark the driver as being gone */
zombify_dev(fusd_dev);
/* ...and possibly free it. (Release lock if it hasn't been freed) */
if (!maybe_free_fusd_dev(fusd_dev))
UNLOCK_FUSD_DEV(fusd_dev);
/* notify fusd_status readers that there has been a change in the
* list of registered devices */
atomic_inc_and_ret(&last_version);
wake_up_interruptible(&new_device_wait);
return 0;
zombie_dev:
invalid_dev:
RDEBUG(1, "invalid device found in fusd_release!!");
return -ENODEV;
}
/*
* This function processes messages coming from userspace device drivers
* (i.e., writes to the /dev/fusd control channel.)
*/
STATIC ssize_t fusd_process_write(struct file *file,
const char *user_msg_buffer, size_t user_msg_len,
const char *user_data_buffer, size_t user_data_len)
{
fusd_dev_t *fusd_dev;
fusd_msg_t *msg = NULL;
int retval = 0;
int yield = 0;
GET_FUSD_DEV(file->private_data, fusd_dev);
LOCK_FUSD_DEV(fusd_dev);
/* get the header from userspace (first make sure there's enough data) */
if (user_msg_len != sizeof(fusd_msg_t)) {
RDEBUG(6, "control channel got bad write of %d bytes (wanted %d)",
(int) user_msg_len, (int) sizeof(fusd_msg_t));
retval = -EINVAL;
goto out_no_free;
}
if ((msg = KMALLOC(sizeof(fusd_msg_t), GFP_KERNEL)) == NULL) {
retval = -ENOMEM;
RDEBUG(1, "yikes! kernel can't allocate memory");
goto out;
}
memset(msg, 0, sizeof(fusd_msg_t));
if (copy_from_user(msg, user_msg_buffer, sizeof(fusd_msg_t))) {
retval = -EFAULT;
goto out;
}
msg->data = NULL; /* pointers from userspace have no meaning */
/* check the magic number before acting on the message at all */
if (msg->magic != FUSD_MSG_MAGIC) {
RDEBUG(2, "got invalid magic number on /dev/fusd write from pid %d",
current->pid);
retval = -EIO;
goto out;
}
/* now get data portion of the message */
if (user_data_len < 0 || user_data_len > MAX_RW_SIZE) {
RDEBUG(2, "fusd_process_write: got invalid length %d", (int) user_data_len);
retval = -EINVAL;
goto out;
}
if (msg->datalen != user_data_len) {
RDEBUG(2, "%s : msg->datalen(%d) != user_data_len(%d), sigh!", __func__,
msg->datalen, (int) user_data_len);
retval = -EINVAL;
goto out;
}
if (user_data_len > 0) {
if (user_data_buffer == NULL) {
RDEBUG(2, "msg->datalen and no data buffer, sigh!");
retval = -EINVAL;
goto out;
}
if ((msg->data = VMALLOC(user_data_len)) == NULL) {
retval = -ENOMEM;
RDEBUG(1, "yikes! kernel can't allocate memory");
goto out;
}
if (copy_from_user(msg->data, user_data_buffer, user_data_len)) {
retval = -EFAULT;
goto out;
}
}
/* before device registration, the only command allowed is 'register'. */
/*
if (!fusd_dev->handle && msg->cmd != FUSD_REGISTER_DEVICE) {
RDEBUG(2, "got a message other than 'register' on a new device!");
retval = -EINVAL;
goto out;
}
*/
/* now dispatch the command to the appropriate handler */
switch (msg->cmd) {
case FUSD_REGISTER_DEVICE:
retval = fusd_register_device(fusd_dev, msg->parm.register_msg);
goto out;
break;
case FUSD_FOPS_REPLY:
/* if reply is successful, DO NOT free the message */
if ((retval = fusd_fops_reply(fusd_dev, msg)) == 0) {
yield = 1;
goto out_no_free;
}
break;
case FUSD_FOPS_NONBLOCK_REPLY:
switch (msg->subcmd) {
case FUSD_POLL_DIFF:
retval = fusd_polldiff_reply(fusd_dev, msg);
break;
default:
RDEBUG(2, "fusd_fops_nonblock got unknown subcmd %d", msg->subcmd);
retval = -EINVAL;
}
break;
default:
RDEBUG(2, "warning: unknown message type of %d received!", msg->cmd);
retval = -EINVAL;
goto out;
break;
}
out:
if (msg && msg->data) {
VFREE(msg->data);
msg->data = NULL;
}
if (msg != NULL) {
KFREE(msg);
msg = NULL;
}
out_no_free:
/* the functions we call indicate success by returning 0. we
* convert that into a success indication by changing the retval to
* the length of the write. */
if (retval == 0)
retval = user_data_len + user_msg_len;
UNLOCK_FUSD_DEV(fusd_dev);
/* if we successfully completed someone's syscall, yield the
* processor to them immediately as a throughput optimization. we
* also hope that in the case of bulk data transfer, their next
* syscall will come in before we are scheduled again. */
if (yield) {
#ifdef SCHED_YIELD
current->policy |= SCHED_YIELD;
#endif
schedule();
}
return retval;
zombie_dev:
invalid_dev:
RDEBUG(1, "fusd_process_write: got invalid device!");
return -EPIPE;
}
STATIC ssize_t fusd_write(struct file *file,
const char *buffer,
size_t length,
loff_t *offset)
{
RDEBUG(1, "%s: [%p:%p:%lu:%p] [sl: %lu]!!", __func__, file, buffer, length, offset, sizeof(fusd_msg_t));
return fusd_process_write(file, buffer, length, NULL, 0);
}
#ifndef HAVE_UNLOCKED_IOCTL
STATIC ssize_t fusd_writev(struct file *file,
const struct iovec *iov,
unsigned long count,
loff_t *offset)
{
if (count != 2) {
RDEBUG(2, "fusd_writev: got illegal iov count of %ld", count);
return -EINVAL;
}
return fusd_process_write(file,
iov[0].iov_base, iov[0].iov_len,
iov[1].iov_base, iov[1].iov_len);
}
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 1, 0)
ssize_t fusd_write_iter (struct kiocb *iocb, struct iov_iter *iov)
{
unsigned long count = iov_iter_count(iov);
char *msg, *data;
size_t msg_len, data_len;
/*if ( count != 2 )
{
RDEBUG(2, "fusd_writev: got illegal iov count of %ld", count);
return -EINVAL;
}*/
msg = iov->iov->iov_base + iov->iov_offset;
msg_len = iov_iter_single_seg_count(iov);
iov_iter_advance(iov, msg_len);
data = iov->iov->iov_base + iov->iov_offset;
data_len = iov_iter_single_seg_count(iov);
return fusd_process_write(iocb->ki_filp,
msg, msg_len,
data, data_len);
}
#else
STATIC ssize_t fusd_aio_write (struct kiocb *iocb,
const struct iovec *iov,
unsigned long count,
loff_t offset)
{
if ( count != 2 )
{
RDEBUG(2, "fusd_writev: got illegal iov count of %ld", count);
return -EINVAL;
}
return fusd_process_write(iocb->ki_filp,
iov[0].iov_base, iov[0].iov_len,
iov[1].iov_base, iov[1].iov_len);
}
#endif
#ifndef HAVE_UNLOCKED_IOCTL
STATIC int fusd_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
#else
STATIC long fusd_unlocked_ioctl (struct file *file,
unsigned int cmd, unsigned long arg)
#endif
{
#ifdef CONFIG_FUSD_DEBUG
void __user
*argp = (void
__user *) arg;
#endif
#if 0
struct iovec iov;
if ( ( argp != NULL ) && ( cmd == 0xb16b00b5 ) )
{
RDEBUG(9, "%s: !!!!!!! ( o )( o ) !!!!!!!", __func__);
/* Act like writev... */
if (!copy_from_user(&iov, argp, sizeof (struct iovec) * 2))
{
return fusd_writev(file, &iov, 2, NULL);
}
else
{
return -EIO;
}
}
#endif
RDEBUG(2, "%s: got illegal ioctl #%08X# Or ARG is null [%p]", __func__, cmd, argp);
return -EINVAL;
}
/* fusd_read: a process is reading on /dev/fusd. return any messages
* waiting to go from kernel to userspace.
*
* Important note: there are 2 possible read modes;
* 1) header-read mode; just the fusd_msg structure is returned.
*
* 2) data-read mode; the data portion of a call (NOT including the
* fusd_msg structure) is returned.
*
* The protocol this function expects the user-space library to follow
* is:
* 1) Userspace library reads header.
* 2) If fusd_msg->datalen == 0, goto step 4.
* 3) Userspace library reads data.
* 4) Message gets dequeued by the kernel.
*
* In other words, userspace first reads the header. Then, if and
* only if the header you read indicates that data follows, userspace
* follows with a read for that data.
*
* For the header read, the length requested MUST be the exact length
* sizeof(fusd_msg_t). The corresponding data read must request
* exactly the number of bytes in the data portion of the message. NO
* OTHER READ LENGTHS ARE ALLOWED - ALL OTHER READ LENGTHS WILL GET AN
* -EINVAL. This is done as a basic safety measure to make sure we're
* talking to a userspace library that understands our protocol, and
* to detect framing errors.
*
* (note: normally you'd have to worry about reentrancy in a function
* like this because the process can block on the userspace access and
* another might try to read. usually we would copy the message into
* a temp location to make sure two processes don't get the same
* message. however in this very specialized case, we're okay,
* because each instance of /dev/fusd has a completely independent
* message queue.) */
/* do a "header" read: used by fusd_read */
STATIC int fusd_read_header(char *user_buffer, size_t user_length, fusd_msg_t *msg)
{
int len = sizeof(fusd_msg_t);
if (user_length != len) {
RDEBUG(4, "bad length of %d sent to /dev/fusd for peek", (int) user_length);
return -EINVAL;
}
if (copy_to_user(user_buffer, msg, len))
return -EFAULT;
return sizeof(fusd_msg_t);
}
/* do a "data" read: used by fusd_read */
STATIC int fusd_read_data(char *user_buffer, size_t user_length, fusd_msg_t *msg)
{
int len = msg->datalen;
if (len == 0 || msg->data == NULL) {
RDEBUG(1, "fusd_read_data: no data to send!");
return -EIO;
}
/* make sure the user is requesting exactly the right amount (as a
sanity check) */
if (user_length != len) {
RDEBUG(4, "bad read for %d bytes on /dev/fusd (need %d)", (int) user_length, len);
return -EINVAL;
}
/* now copy to userspace */
if (copy_to_user(user_buffer, msg->data, len))
return -EFAULT;
/* done! */
return len;
}
STATIC ssize_t fusd_read(struct file *file,
char *user_buffer, /* The buffer to fill with data */
size_t user_length, /* The length of the buffer */
loff_t *offset) /* Our offset in the file */
{
fusd_dev_t *fusd_dev;
fusd_msgC_t *msg_out;
int retval, dequeue = 0;
GET_FUSD_DEV(file->private_data, fusd_dev);
LOCK_FUSD_DEV(fusd_dev);
RDEBUG(15, "driver pid %d (/dev/%s) entering fusd_read", current->pid,
NAME(fusd_dev));
/* if no messages are waiting, either block or return EAGAIN */
while ((msg_out = fusd_dev->msg_head) == NULL) {
DECLARE_WAITQUEUE(wait, current);
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
goto out;
}
/*
* sleep, waiting for a message to arrive. we are unrolling
* interruptible_sleep_on to avoid a race between unlocking the
* device and sleeping (what if a message arrives in that
* interval?)
*/
current->state = TASK_INTERRUPTIBLE;
add_wait_queue(&fusd_dev->dev_wait, &wait);
UNLOCK_FUSD_DEV(fusd_dev);
schedule();
remove_wait_queue(&fusd_dev->dev_wait, &wait);
LOCK_FUSD_DEV(fusd_dev);
/* we're back awake! --see if a signal woke us up */
if (signal_pending(current)) {
retval = -ERESTARTSYS;
goto out;
}
}
/* is this a header read or data read? */
if (!msg_out->peeked) {
/* this is a header read (first read) */
retval = fusd_read_header(user_buffer, user_length, &msg_out->fusd_msg);
/* is there data? if so, make sure next read gets data. if not,
* make sure message is dequeued now.*/
if (msg_out->fusd_msg.datalen) {
msg_out->peeked = 1;
dequeue = 0;
} else {
dequeue = 1;
}
} else {
/* this is a data read (second read) */
retval = fusd_read_data(user_buffer, user_length, &msg_out->fusd_msg);
dequeue = 1; /* message should be dequeued */
}
/* if this message is done, take it out of the outgoing queue */
if (dequeue) {
if (fusd_dev->msg_tail == fusd_dev->msg_head)
fusd_dev->msg_tail = fusd_dev->msg_head = NULL;
else
fusd_dev->msg_head = msg_out->next;
FREE_FUSD_MSGC(msg_out);
}
out:
UNLOCK_FUSD_DEV(fusd_dev);
return retval;
zombie_dev:
invalid_dev:
RDEBUG(2, "got read on /dev/fusd for unknown device!");
return -EPIPE;
}
/* a poll on /dev/fusd itself (the control channel) */
STATIC unsigned int fusd_poll(struct file *file, poll_table *wait)
{
fusd_dev_t *fusd_dev;
GET_FUSD_DEV(file->private_data, fusd_dev);
poll_wait(file, &fusd_dev->dev_wait, wait);
if (fusd_dev->msg_head != NULL) {
return POLLIN | POLLRDNORM;
}
invalid_dev:
return 0;
}
#ifndef HAVE_UNLOCKED_IOCTL
STATIC struct file_operations fusd_fops = {
.owner = THIS_MODULE,
.open = fusd_open,
.read = fusd_read,
.write = fusd_write,
//writev: fusd_writev,
.ioctl = fusd_ioctl,
.release = fusd_release,
.poll = fusd_poll,
};
#else
STATIC struct file_operations fusd_fops = {
.owner = THIS_MODULE,
.open = fusd_open,
.read = fusd_read,
.write = fusd_write,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 1, 0)
.write_iter = fusd_write_iter,
#else
.aio_write = fusd_aio_write,
#endif
.unlocked_ioctl = fusd_unlocked_ioctl,
.release = fusd_release,
.poll = fusd_poll,
};
#endif
/*************************************************************************/
typedef struct fusd_status_state {
int binary_status;
int need_new_status;
char *curr_status;
int curr_status_len;
int last_version_seen;
} fusd_statcontext_t;
/* open() called on /dev/fusd/status */
STATIC int fusd_status_open(struct inode *inode, struct file *file)
{
int error = 0;
fusd_statcontext_t *fs;
//MOD_INC_USE_COUNT;
if ((fs = KMALLOC(sizeof(fusd_statcontext_t), GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory");
error = -ENOMEM;
goto out;
}
memset(fs, 0, sizeof(fusd_statcontext_t));
fs->need_new_status = 1;
file->private_data = (void *) fs;
out:
//if (error)
// MOD_DEC_USE_COUNT;
return error;
}
/* close on /dev/fusd_status */
STATIC int fusd_status_release(struct inode *inode, struct file *file)
{
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
if (fs) {
if (fs->curr_status)
KFREE(fs->curr_status);
KFREE(fs);
}
//MOD_DEC_USE_COUNT;
return 0;
}
/* ioctl() on /dev/fusd/status */
#ifndef HAVE_UNLOCKED_IOCTL
STATIC int fusd_status_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
#else
STATIC long fusd_status_unlocked_ioctl (struct file *file,
unsigned int cmd, unsigned long arg)
#endif
{
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
if (!fs)
return -EIO;
switch (cmd) {
case FUSD_STATUS_USE_BINARY:
fs->binary_status = 1;
return 0;
default:
return -EINVAL;
break;
}
}
/*
* maybe_expand_buffer: expand a buffer exponentially as it fills. We
* are given:
*
* - A reference to a pointer to a buffer (buf)
* - A reference to the buffer's current capacity (buf_size)
* - The current amount of buffer space used (len)
* - The amount of space we want to ensure is free in the buffer (space_needed)
*
* If there isn't at least space_needed difference between buf_size
* and len, the existing contents are moved into a larger buffer.
*/
STATIC int maybe_expand_buffer(char **buf, int *buf_size, int len,
int space_needed)
{
if (*buf_size - len < space_needed) {
char *old_buf = *buf;
*buf_size *= 2;
*buf = KMALLOC(*buf_size, GFP_KERNEL);
if (*buf != NULL)
memmove(*buf, old_buf, len);
KFREE(old_buf);
if (*buf == NULL) {
RDEBUG(1, "out of memory!");
return -1;
}
}
return 0;
}
/* Build a text buffer containing current fusd status. */
STATIC void fusd_status_build_text(fusd_statcontext_t *fs)
{
int buf_size = 512;
char *buf = KMALLOC(buf_size, GFP_KERNEL);
int len = 0, total_clients = 0, total_files = 0;
struct list_head *tmp;
if (buf == NULL) {
RDEBUG(1, "fusd_status_build: out of memory!");
return;
}
len += snprintf(buf + len, buf_size - len,
" PID Open Name\n"
"------ ---- -----------------\n");
down(&fusd_devlist_sem);
list_for_each(tmp, &fusd_devlist_head)
{
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
if (!d)
continue;
/* Possibly expand the buffer if we need more space */
if (maybe_expand_buffer(&buf, &buf_size, len, FUSD_MAX_NAME_LENGTH + 120) < 0)
goto out;
len += snprintf(buf + len, buf_size - len,
"%6d %4d %s%s\n", d->pid, d->num_files,
d->zombie ? "<zombie>" : "", NAME(d));
total_files++;
total_clients += d->num_files;
}
len += snprintf(buf + len, buf_size - len,
"\nFUSD %s - %d devices used by %d clients\n",
GIT_DESCRIBE,
total_files, total_clients);
out:
fs->last_version_seen = last_version;
up(&fusd_devlist_sem);
if (fs->curr_status)
KFREE(fs->curr_status);
fs->curr_status = buf;
fs->curr_status_len = len;
fs->need_new_status = 0;
}
/* Build the binary version of status */
STATIC void fusd_status_build_binary(fusd_statcontext_t *fs)
{
int buf_size = 512;
char *buf = KMALLOC(buf_size, GFP_KERNEL);
int len = 0, i = 0;
struct list_head *tmp;
fusd_status_t *s;
if (buf == NULL) {
RDEBUG(1, "out of memory!");
return;
}
down(&fusd_devlist_sem);
list_for_each(tmp, &fusd_devlist_head)
{
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
if (!d)
continue;
/* Possibly expand the buffer if we need more space */
if (maybe_expand_buffer(&buf, &buf_size, len, sizeof(fusd_status_t)) < 0)
goto out;
s = &((fusd_status_t *) buf)[i];
/* construct this status entry */
memset(s, 0, sizeof(fusd_status_t));
strncpy(s->name, NAME(d), FUSD_MAX_NAME_LENGTH);
s->zombie = d->zombie;
s->pid = d->pid;
s->num_open = d->num_files;
i++;
len += sizeof(fusd_status_t);
}
out:
fs->last_version_seen = last_version;
up(&fusd_devlist_sem);
if (fs->curr_status)
KFREE(fs->curr_status);
fs->curr_status = buf;
fs->curr_status_len = len;
fs->need_new_status = 0;
}
STATIC ssize_t fusd_status_read(struct file *file,
char *user_buffer, /* The buffer to fill with data */
size_t user_length, /* The length of the buffer */
loff_t *offset) /* Our offset in the file */
{
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
if (!fs)
return -EIO;
/* create a new status page, if we aren't in the middle of one */
if (fs->need_new_status) {
if (fs->binary_status)
fusd_status_build_binary(fs);
else
fusd_status_build_text(fs);
}
/* return EOF if we're at the end */
if (fs->curr_status == NULL || fs->curr_status_len == 0) {
fs->need_new_status = 1;
return 0;
}
/* return only as much data as we have */
if (fs->curr_status_len < user_length)
user_length = fs->curr_status_len;
if (copy_to_user(user_buffer, fs->curr_status, user_length))
return -EFAULT;
/* update fs, so we don't return the same data next time */
fs->curr_status_len -= user_length;
if (fs->curr_status_len)
memmove(fs->curr_status, fs->curr_status + user_length, fs->curr_status_len);
else {
KFREE(fs->curr_status);
fs->curr_status = NULL;
}
return user_length;
}
/* a poll on /dev/fusd itself (the control channel) */
STATIC unsigned int fusd_status_poll(struct file *file, poll_table *wait)
{
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
poll_wait(file, &new_device_wait, wait);
if (fs->last_version_seen < last_version)
return POLLIN | POLLRDNORM;
else
return 0;
}
#ifndef HAVE_UNLOCKED_IOCTL
STATIC struct file_operations fusd_status_fops = {
.owner = THIS_MODULE,
.open = fusd_status_open,
.ioctl = fusd_status_ioctl,
.read = fusd_status_read,
.release = fusd_status_release,
.poll = fusd_status_poll,
};
#else
STATIC struct file_operations fusd_status_fops = {
.owner = THIS_MODULE,
.open = fusd_status_open,
.unlocked_ioctl = fusd_status_unlocked_ioctl,
.read = fusd_status_read,
.release = fusd_status_release,
.poll = fusd_status_poll,
};
#endif
/*************************************************************************/
STATIC int init_fusd(void)
{
int retval;
#ifdef CONFIG_FUSD_MEMDEBUG
if ( ( retval = fusd_mem_init() ) < 0 )
return retval;
#endif
printk(KERN_INFO "fusd: starting - %s\n", GIT_DESCRIBE);
#ifdef CONFIG_FUSD_DEBUG
printk("fusd: debuglevel=%d\n", fusd_debug_level);
#endif
fusd_control_cdev = NULL;
fusd_status_cdev = NULL;
fusd_class = class_create(THIS_MODULE, "fusd");
if (IS_ERR(fusd_class)) {
retval = PTR_ERR(fusd_class);
printk(KERN_ERR "class_create failed status: %d\n", retval);
goto fail0;
}
control_id = 0;
if ((retval = alloc_chrdev_region(&control_id, 0, 1, FUSD_CONTROL_FILENAME)) < 0) {
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", retval);
goto fail1;
}
fusd_control_cdev = cdev_alloc();
if (fusd_control_cdev == NULL) {
printk(KERN_ERR "cdev-alloc failed\n");
retval = -ENOMEM;
goto fail3;
}
fusd_control_cdev->owner = THIS_MODULE;
fusd_control_cdev->ops = &fusd_fops;
kobject_set_name(&fusd_control_cdev->kobj, FUSD_CONTROL_FILENAME);
printk(KERN_ERR "cdev control id: %d\n", control_id);
if ((retval = cdev_add(fusd_control_cdev, control_id, 1)) < 0) {
printk(KERN_ERR "cdev_add failed status: %d\n", retval);
kobject_put(&fusd_control_cdev->kobj);
goto fail4;
}
fusd_control_device = CLASS_DEVICE_CREATE(fusd_class, NULL, control_id, NULL, "fusd!control");
if (fusd_control_device == NULL) {
retval = PTR_ERR(fusd_control_device);
printk("device_create failed status: %d\n", retval);
goto fail5;
}
status_id = 0;
if ((retval = alloc_chrdev_region(&status_id, 0, 1, FUSD_STATUS_FILENAME)) < 0) {
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", retval);
goto fail6;
}
fusd_status_cdev = cdev_alloc();
if (fusd_status_cdev == NULL) {
retval = -ENOMEM;
goto fail8;
}
fusd_status_cdev->owner = THIS_MODULE;
fusd_status_cdev->ops = &fusd_status_fops;
kobject_set_name(&fusd_status_cdev->kobj, FUSD_STATUS_FILENAME);
if ((retval = cdev_add(fusd_status_cdev, status_id, 1)) < 0) {
printk(KERN_ERR "cdev_add failed status: %d\n", retval);
kobject_put(&fusd_status_cdev->kobj);
goto fail9;
}
fusd_status_device = CLASS_DEVICE_CREATE(fusd_class, NULL, status_id, NULL, "fusd!status");
if (fusd_status_device == NULL) {
printk(KERN_ERR "device_create failed status: %d\n", retval);
retval = PTR_ERR(fusd_status_device);
goto fail10;
}
RDEBUG(1, "registration successful");
return 0;
fail10:
cdev_del(fusd_status_cdev);
fail9:
kfree(fusd_status_cdev);
fail8:
unregister_chrdev_region(status_id, 1);
fail6:
CLASS_DEVICE_DESTROY(fusd_class, control_id);
fail5:
cdev_del(fusd_control_cdev);
fail4:
kfree(fusd_control_cdev);
fail3:
unregister_chrdev_region(control_id, 1);
fail1:
class_destroy(fusd_class);
fail0:
return retval;
}
STATIC void cleanup_fusd(void)
{
RDEBUG(1, "cleaning up");
CLASS_DEVICE_DESTROY(fusd_class, status_id);
CLASS_DEVICE_DESTROY(fusd_class, control_id);
cdev_del(fusd_control_cdev);
cdev_del(fusd_status_cdev);
class_destroy(fusd_class);
#ifdef CONFIG_FUSD_MEMDEBUG
fusd_mem_cleanup();
#endif
}
module_init (init_fusd);
module_exit (cleanup_fusd);
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