debug.c

底层驱动开发

		return NULL;

	numargs=debug_count_numargs(string);

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
	va_start(ap,string);
	curr_event->string=string;
	for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
		curr_event->args[idx]=va_arg(ap,long);
	va_end(ap);
	debug_finish_entry(id, active, level, 1);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * debug_init:
 * - is called exactly once to initialize the debug feature
 */

static int
__init debug_init(void)
{
	int rc = 0;

	s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table, 1);
	down(&debug_lock);
	debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
	printk(KERN_INFO "debug: Initialization complete\n");
	initialized = 1;
	up(&debug_lock);

	return rc;
}

/*
 * debug_register_view:
 */

int
debug_register_view(debug_info_t * id, struct debug_view *view)
{
	int rc = 0;
	int i;
	unsigned long flags;
	mode_t mode = S_IFREG;
	struct dentry *pde;

	if (!id)
		goto out;
	if (view->prolog_proc || view->format_proc || view->header_proc)
		mode |= S_IRUSR;
	if (view->input_proc)
		mode |= S_IWUSR;
	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
				id , &debug_file_ops);
	if (!pde){
		printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
			" Cannot register view %s/%s\n", id->name,view->name);
		rc = -1;
		goto out;
	}
	spin_lock_irqsave(&id->lock, flags);
	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
		if (!id->views[i])
			break;
	}
	if (i == DEBUG_MAX_VIEWS) {
		printk(KERN_WARNING "debug: cannot register view %s/%s\n",
			id->name,view->name);
		printk(KERN_WARNING 
			"debug: maximum number of views reached (%i)!\n", i);
		debugfs_remove(pde);
		rc = -1;
	} else {
		id->views[i] = view;
		id->debugfs_entries[i] = pde;
	}
	spin_unlock_irqrestore(&id->lock, flags);
out:
	return rc;
}

/*
 * debug_unregister_view:
 */

int
debug_unregister_view(debug_info_t * id, struct debug_view *view)
{
	int rc = 0;
	int i;
	unsigned long flags;

	if (!id)
		goto out;
	spin_lock_irqsave(&id->lock, flags);
	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
		if (id->views[i] == view)
			break;
	}
	if (i == DEBUG_MAX_VIEWS)
		rc = -1;
	else {
		debugfs_remove(id->debugfs_entries[i]);
		id->views[i] = NULL;
		rc = 0;
	}
	spin_unlock_irqrestore(&id->lock, flags);
out:
	return rc;
}

static inline char *
debug_get_user_string(const char __user *user_buf, size_t user_len)
{
	char* buffer;

	buffer = kmalloc(user_len + 1, GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);
	if (copy_from_user(buffer, user_buf, user_len) != 0) {
		kfree(buffer);
		return ERR_PTR(-EFAULT);
	}
	/* got the string, now strip linefeed. */
	if (buffer[user_len - 1] == '\n')
		buffer[user_len - 1] = 0;
	else
		buffer[user_len] = 0;
        return buffer;
}

static inline int
debug_get_uint(char *buf)
{
	int rc;

	for(; isspace(*buf); buf++);
	rc = simple_strtoul(buf, &buf, 10);
	if(*buf){
		printk("debug: no integer specified!\n");
		rc = -EINVAL;
	}
	return rc;
}

/*
 * functions for debug-views
 ***********************************
*/

/*
 * prints out actual debug level
 */

static int
debug_prolog_pages_fn(debug_info_t * id,
				 struct debug_view *view, char *out_buf)
{
	return sprintf(out_buf, "%i\n", id->pages_per_area);
}

/*
 * reads new size (number of pages per debug area)
 */

static int
debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
			struct file *file, const char __user *user_buf,
			size_t user_len, loff_t * offset)
{
	char *str;
	int rc,new_pages;

	if (user_len > 0x10000)
                user_len = 0x10000;
	if (*offset != 0){
		rc = -EPIPE;
		goto out;
	}
	str = debug_get_user_string(user_buf,user_len);
	if(IS_ERR(str)){
		rc = PTR_ERR(str);
		goto out;
	}
	new_pages = debug_get_uint(str);
	if(new_pages < 0){
		rc = -EINVAL;
		goto free_str;
	}
	rc = debug_set_size(id,id->nr_areas, new_pages);
	if(rc != 0){
		rc = -EINVAL;
		goto free_str;
	}
	rc = user_len;
free_str:
	kfree(str);
out:
	*offset += user_len;
	return rc;		/* number of input characters */
}

/*
 * prints out actual debug level
 */

static int
debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
{
	int rc = 0;

	if(id->level == DEBUG_OFF_LEVEL) {
		rc = sprintf(out_buf,"-\n");
	}
	else {
		rc = sprintf(out_buf, "%i\n", id->level);
	}
	return rc;
}

/*
 * reads new debug level
 */

static int
debug_input_level_fn(debug_info_t * id, struct debug_view *view,
			struct file *file, const char __user *user_buf,
			size_t user_len, loff_t * offset)
{
	char *str;
	int rc,new_level;

	if (user_len > 0x10000)
                user_len = 0x10000;
	if (*offset != 0){
		rc = -EPIPE;
		goto out;
	}
	str = debug_get_user_string(user_buf,user_len);
	if(IS_ERR(str)){
		rc = PTR_ERR(str);
		goto out;
	}
	if(str[0] == '-'){
		debug_set_level(id, DEBUG_OFF_LEVEL);
		rc = user_len;
		goto free_str;
	} else {
		new_level = debug_get_uint(str);
	}
	if(new_level < 0) {
		printk(KERN_INFO "debug: level `%s` is not valid\n", str);
		rc = -EINVAL;
	} else {
		debug_set_level(id, new_level);
		rc = user_len;
	}
free_str:
	kfree(str);
out:
	*offset += user_len;
	return rc;		/* number of input characters */
}


/*
 * flushes debug areas
 */
 
void
debug_flush(debug_info_t* id, int area)
{
        unsigned long flags;
        int i,j;

        if(!id || !id->areas)
                return;
        spin_lock_irqsave(&id->lock,flags);
        if(area == DEBUG_FLUSH_ALL){
                id->active_area = 0;
                memset(id->active_entries, 0, id->nr_areas * sizeof(int));
                for (i = 0; i < id->nr_areas; i++) {
			id->active_pages[i] = 0;
			for(j = 0; j < id->pages_per_area; j++) {
                        	memset(id->areas[i][j], 0, PAGE_SIZE);
			}
		}
                printk(KERN_INFO "debug: %s: all areas flushed\n",id->name);
        } else if(area >= 0 && area < id->nr_areas) {
                id->active_entries[area] = 0;
		id->active_pages[area] = 0;
		for(i = 0; i < id->pages_per_area; i++) {
                	memset(id->areas[area][i],0,PAGE_SIZE);
		}
                printk(KERN_INFO "debug: %s: area %i has been flushed\n",
                        id->name, area);
        } else {
                printk(KERN_INFO
                      "debug: %s: area %i cannot be flushed (range: %i - %i)\n",
                        id->name, area, 0, id->nr_areas-1);
        }
        spin_unlock_irqrestore(&id->lock,flags);
}

/*
 * view function: flushes debug areas 
 */

static int
debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
			struct file *file, const char __user *user_buf,
			size_t user_len, loff_t * offset)
{
        char input_buf[1];
        int rc = user_len;

	if (user_len > 0x10000)
                user_len = 0x10000;
        if (*offset != 0){
		rc = -EPIPE;
                goto out;
	}
        if (copy_from_user(input_buf, user_buf, 1)){
                rc = -EFAULT;
                goto out;
        }
        if(input_buf[0] == '-') { 
                debug_flush(id, DEBUG_FLUSH_ALL);
                goto out;
        }
        if (isdigit(input_buf[0])) {
                int area = ((int) input_buf[0] - (int) '0');
                debug_flush(id, area);
                goto out;
        }

        printk(KERN_INFO "debug: area `%c` is not valid\n", input_buf[0]);

out:
        *offset += user_len;
        return rc;              /* number of input characters */
}

/*
 * prints debug header in raw format
 */

static int
debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
			int area, debug_entry_t * entry, char *out_buf)
{
        int rc;

	rc = sizeof(debug_entry_t);
	memcpy(out_buf,entry,sizeof(debug_entry_t));
        return rc;
}

/*
 * prints debug data in raw format
 */

static int
debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
			       char *out_buf, const char *in_buf)
{
	int rc;

	rc = id->buf_size;
	memcpy(out_buf, in_buf, id->buf_size);
	return rc;
}

/*
 * prints debug data in hex/ascii format
 */

static int
debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
	    		  char *out_buf, const char *in_buf)
{
	int i, rc = 0;

	for (i = 0; i < id->buf_size; i++) {
                rc += sprintf(out_buf + rc, "%02x ",
                              ((unsigned char *) in_buf)[i]);
        }
	rc += sprintf(out_buf + rc, "| ");
	for (i = 0; i < id->buf_size; i++) {
		unsigned char c = in_buf[i];
		if (!isprint(c))
			rc += sprintf(out_buf + rc, ".");
		else
			rc += sprintf(out_buf + rc, "%c", c);
	}
	rc += sprintf(out_buf + rc, "\n");
	return rc;
}

/*
 * prints header for debug entry
 */

int
debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
			 int area, debug_entry_t * entry, char *out_buf)
{
	struct timespec time_spec;
	unsigned long long time;
	char *except_str;
	unsigned long caller;
	int rc = 0;
	unsigned int level;

	level = entry->id.fields.level;
	time = entry->id.stck;
	/* adjust todclock to 1970 */
	time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
	tod_to_timeval(time, &time_spec);

	if (entry->id.fields.exception)
		except_str = "*";
	else
		except_str = "-";
	caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
	rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
		      area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
		      except_str, entry->id.fields.cpuid, (void *) caller);
	return rc;
}

/*
 * prints debug data sprintf-formated:
 * debug_sprinf_event/exception calls must be used together with this view
 */

#define DEBUG_SPRINTF_MAX_ARGS 10

static int
debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
                        char *out_buf, debug_sprintf_entry_t *curr_event)
{
	int num_longs, num_used_args = 0,i, rc = 0;
	int index[DEBUG_SPRINTF_MAX_ARGS];

	/* count of longs fit into one entry */
	num_longs = id->buf_size /  sizeof(long); 

	if(num_longs < 1)
		goto out; /* bufsize of entry too small */
	if(num_longs == 1) {
		/* no args, we use only the string */
		strcpy(out_buf, curr_event->string);
		rc = strlen(curr_event->string);
		goto out;
	}

	/* number of arguments used for sprintf (without the format string) */
	num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));

	memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));

	for(i = 0; i < num_used_args; i++)
		index[i] = i;

	rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
		curr_event->args[index[1]], curr_event->args[index[2]],
		curr_event->args[index[3]], curr_event->args[index[4]],
		curr_event->args[index[5]], curr_event->args[index[6]],
		curr_event->args[index[7]], curr_event->args[index[8]],
		curr_event->args[index[9]]);

out:

	return rc;
}

/*
 * clean up module
 */
void
__exit debug_exit(void)
{
	debugfs_remove(debug_debugfs_root_entry);
	unregister_sysctl_table(s390dbf_sysctl_header);
	return;
}

/*
 * module definitions
 */
postcore_initcall(debug_init);
module_exit(debug_exit);
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(debug_register);
EXPORT_SYMBOL(debug_unregister); 
EXPORT_SYMBOL(debug_set_level);
EXPORT_SYMBOL(debug_stop_all);
EXPORT_SYMBOL(debug_register_view);
EXPORT_SYMBOL(debug_unregister_view);
EXPORT_SYMBOL(debug_event_common);
EXPORT_SYMBOL(debug_exception_common);
EXPORT_SYMBOL(debug_hex_ascii_view);
EXPORT_SYMBOL(debug_raw_view);
EXPORT_SYMBOL(debug_dflt_header_fn);
EXPORT_SYMBOL(debug_sprintf_view);
EXPORT_SYMBOL(debug_sprintf_exception);
EXPORT_SYMBOL(debug_sprintf_event);