debug.c

linux-2.4.29操作系统的源码

{
	size_t count = 0;
	size_t entry_offset, size = 0;
	int rc;
	file_private_info_t *p_info;

	p_info = ((file_private_info_t *) file->private_data);
	if (*offset != p_info->offset) 
		return -EPIPE;
	if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
		return 0;

	entry_offset = p_info->act_entry_offset;

	while(count < len){
		size = debug_format_entry(p_info);
		size = MIN((len - count), (size - entry_offset));

		if(size){
			if (copy_to_user(user_buf + count, 
					p_info->temp_buf + entry_offset, size))
				return -EFAULT;
		}
		count += size;
		entry_offset = 0;
		if(count != len)
			if(debug_next_entry(p_info)) 
				goto out;
	}
out:
	p_info->offset           += count;
	p_info->act_entry_offset = size;
	*offset = p_info->offset;
	return count;
}

/*
 * debug_input:
 * - called for user write()
 * - calls input function of view
 */

static ssize_t debug_input(struct file *file,
			   const char *user_buf, size_t length,
			   loff_t *offset)
{
	int rc = 0;
	file_private_info_t *p_info;

	down(&debug_lock);
	p_info = ((file_private_info_t *) file->private_data);
	if (p_info->view->input_proc)
		rc = p_info->view->input_proc(p_info->debug_info_org,
					      p_info->view, file, user_buf,
					      length, offset);
	else
		rc = -EPERM;
	up(&debug_lock);
	return rc;		/* number of input characters */
}

/*
 * debug_open:
 * - called for user open()
 * - copies formated output to private_data area of the file
 *   handle
 */

static int debug_open(struct inode *inode, struct file *file)
{
	int i = 0, rc = 0;
	file_private_info_t *p_info;
	debug_info_t *debug_info, *debug_info_snapshot;

#ifdef DEBUG
	printk("debug_open\n");
#endif
	MOD_INC_USE_COUNT;
	down(&debug_lock);

	/* find debug log and view */

	debug_info = debug_area_first;
	while(debug_info != NULL){
		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
			if (debug_info->views[i] == NULL)
				continue;
			else if (debug_info->proc_entries[i]->low_ino ==
				 file->f_dentry->d_inode->i_ino) {
				goto found;	/* found view ! */
			}
		}
		debug_info = debug_info->next;
	}
	/* no entry found */
	rc = -EINVAL;
	goto out;

      found:

	/* make snapshot of current debug areas to get it consistent */

	debug_info_snapshot = debug_info_copy(debug_info);

	if(!debug_info_snapshot){
#ifdef DEBUG
		printk(KERN_ERR "debug_open: debug_info_copy failed (out of mem)\n");
#endif
		rc = -ENOMEM;
		goto out;
	}

	if ((file->private_data =
	     kmalloc(sizeof(file_private_info_t), GFP_ATOMIC)) == 0) {
#ifdef DEBUG
		printk(KERN_ERR "debug_open: kmalloc failed\n");
#endif
		debug_info_free(debug_info_snapshot);	
		rc = -ENOMEM;
		goto out;
	}
	p_info = (file_private_info_t *) file->private_data;
	p_info->offset = 0;
	p_info->debug_info_snap = debug_info_snapshot;
	p_info->debug_info_org  = debug_info;
	p_info->view = debug_info->views[i];
	p_info->act_area = 0;
	p_info->act_entry = DEBUG_PROLOG_ENTRY;
	p_info->act_entry_offset = 0;

	debug_info_get(debug_info);

      out:
	up(&debug_lock);
	if (rc != 0)
		MOD_DEC_USE_COUNT;
	return rc;
}

/*
 * debug_close:
 * - called for user close()
 * - deletes  private_data area of the file handle
 */

static int debug_close(struct inode *inode, struct file *file)
{
	file_private_info_t *p_info;
#ifdef DEBUG
	printk("debug_close\n");
#endif
	p_info = (file_private_info_t *) file->private_data;
	debug_info_free(p_info->debug_info_snap);
	debug_info_put(p_info->debug_info_org);
	kfree(file->private_data);
	MOD_DEC_USE_COUNT;
	return 0;		/* success */
}

/*
 * debug_create_proc_dir_entry:
 * - initializes proc-dir-entry and registers it
 */

static struct proc_dir_entry *debug_create_proc_dir_entry
    (struct proc_dir_entry *root, const char *name, mode_t mode,
     struct inode_operations *iops, struct file_operations *fops) 
{
	struct proc_dir_entry *rc = NULL;

#ifdef CONFIG_PROC_FS
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,3,98))
	const char *fn = name;
	int len;
	len = strlen(fn);

	rc = (struct proc_dir_entry *) kmalloc(sizeof(struct proc_dir_entry)
					       + len + 1, GFP_ATOMIC);
	if (!rc)
		goto out;

	memset(rc, 0, sizeof(struct proc_dir_entry));
	memcpy(((char *) rc) + sizeof(*rc), fn, len + 1);
	rc->name = ((char *) rc) + sizeof(*rc);
	rc->namelen = len;
	rc->low_ino = 0, rc->mode = mode;
	rc->nlink = 1;
	rc->uid = 0;
	rc->gid = 0;
	rc->size = 0;
	rc->get_info = NULL;
	rc->ops = iops;

	proc_register(root, rc);
#else
	rc = create_proc_entry(name, mode, root);
	if (!rc)
		goto out;
	if (fops)
		rc->proc_fops = fops;
#endif

      out:
#endif /* CONFIG_PROC_FS */
	return rc;
}


/*
 * delete_proc_dir_entry:
 */

static void debug_delete_proc_dir_entry
    (struct proc_dir_entry *root, struct proc_dir_entry *proc_entry) 
{

#ifdef CONFIG_PROC_FS
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,3,98))
	proc_unregister(root, proc_entry->low_ino);
	kfree(proc_entry);
#else
	remove_proc_entry(proc_entry->name, root);
#endif
#endif /* CONFIG_PROC_FS */
}

/*
 * debug_register:
 * - creates and initializes debug area for the caller
 * - returns handle for debug area
 */

debug_info_t *debug_register
    (char *name, int page_order, int nr_areas, int buf_size) 
{
	debug_info_t *rc = NULL;

	MOD_INC_USE_COUNT;
	if (!initialized)
		debug_init();
	down(&debug_lock);

        /* create new debug_info */

	rc = debug_info_create(name, page_order, nr_areas, buf_size);
	if(!rc) 
		goto out;
	debug_register_view(rc, &debug_level_view);
        debug_register_view(rc, &debug_flush_view);
#ifdef DEBUG
	printk(KERN_INFO
	       "debug: reserved %d areas of %d pages for debugging %s\n",
	       nr_areas, 1 << page_order, rc->name);
#endif
      out:
        if (rc == NULL){
		printk(KERN_ERR "debug: debug_register failed for %s\n",name);
		MOD_DEC_USE_COUNT;
        }
	up(&debug_lock);
	return rc;
}

/*
 * debug_unregister:
 * - give back debug area
 */

void debug_unregister(debug_info_t * id)
{
	if (!id)
		goto out;
	down(&debug_lock);
#ifdef DEBUG
	printk(KERN_INFO "debug: unregistering %s\n", id->name);
#endif
	debug_info_put(id);
	up(&debug_lock);

	MOD_DEC_USE_COUNT;
      out:
	return;
}

/*
 * debug_set_level:
 * - set actual debug level
 */

void debug_set_level(debug_info_t* id, int new_level)
{
	unsigned long flags;
	if(!id)
		return;	
	spin_lock_irqsave(&id->lock,flags);
        if(new_level == DEBUG_OFF_LEVEL){
                id->level = DEBUG_OFF_LEVEL;
                printk(KERN_INFO "debug: %s: switched off\n",id->name);
        } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
                printk(KERN_INFO
                        "debug: %s: level %i is out of range (%i - %i)\n",
                        id->name, new_level, 0, DEBUG_MAX_LEVEL);
        } else {
                id->level = new_level;
#ifdef DEBUG
                printk(KERN_INFO 
			"debug: %s: new level %i\n",id->name,id->level);
#endif
        }
	spin_unlock_irqrestore(&id->lock,flags);
}


/*
 * proceed_active_entry:
 * - set active entry to next in the ring buffer
 */

extern inline void proceed_active_entry(debug_info_t * id)
{
	if ((id->active_entry[id->active_area] += id->entry_size)
	    > ((PAGE_SIZE << (id->page_order)) - id->entry_size))
		id->active_entry[id->active_area] = 0;
}

/*
 * proceed_active_area:
 * - set active area to next in the ring buffer
 */

extern inline void proceed_active_area(debug_info_t * id)
{
	id->active_area++;
	id->active_area = id->active_area % id->nr_areas;
}

/*
 * get_active_entry:
 */

extern inline debug_entry_t *get_active_entry(debug_info_t * id)
{
	return (debug_entry_t *) ((char *) id->areas[id->active_area] +
				  id->active_entry[id->active_area]);
}

/*
 * debug_common:
 * - set timestamp, caller address, cpu number etc.
 */

extern inline debug_entry_t *debug_common(debug_info_t * id, int level, 
                                    const void *buf, int len, int exception)
{
	unsigned long flags;
	debug_entry_t *active;

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	STCK(active->id.stck);
	active->id.fields.cpuid = smp_processor_id();
	active->caller = __builtin_return_address(0);
	active->id.fields.exception = exception;
	active->id.fields.level     = level;
	memset(DEBUG_DATA(active), 0, id->buf_size);
	memcpy(DEBUG_DATA(active), buf, MIN(len, id->buf_size));
	proceed_active_entry(id);
	if(exception)
		proceed_active_area(id);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * debug_event_common:
 * - write debug entry with given size
 */

debug_entry_t *debug_event_common(debug_info_t * id, int level, const void *buf,
			          int len)
{
	return debug_common(id, level, buf, len, 0);
}

/*
 * debug_exception_common:
 * - write debug entry with given size and switch to next debug area
 */

debug_entry_t *debug_exception_common(debug_info_t * id, int level, 
                                      const void *buf, int len)
{
	return debug_common(id, level, buf, len, 1);
}

/*
 * counts arguments in format string for sprintf view
 */

extern inline int debug_count_numargs(char *string)
{
	int numargs=0;

	while(*string) {
		if(*string++=='%')
			numargs++;
	}
	return(numargs);
}

/*
 * debug_sprintf_event:
 */

debug_entry_t *debug_sprintf_event(debug_info_t* id,
                                   int level,char *string,...)
{
	va_list   ap;
	int numargs,alloc_size,idx;
	debug_sprintf_entry *curr_event;
	debug_entry_t *retval = NULL;

	if((!id) || (level > id->level))
		return NULL;
	else {
		numargs=debug_count_numargs(string);
		alloc_size=offsetof(debug_sprintf_entry,args[numargs]);
		curr_event=alloca(alloc_size);

		if(curr_event){
			va_start(ap,string);
			curr_event->string=string;
			for(idx=0;idx<numargs;idx++)
				curr_event->args[idx]=va_arg(ap,long);
			retval=debug_common(id,level, curr_event,alloc_size,0);
			va_end(ap);
		}
		return retval;
	}
}