debug.c

该文件是rt_linux

/*
 *  arch/s390/kernel/debug.c
 *   S/390 debug facility
 *
 *    Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
 *                             IBM Corporation
 *    Author(s): Michael Holzheu ([e-mail]),
 *               Holger Smolinski ([e-mail])
 *
 *    Bugreports to: <[e-mail]>
 */

#include <linux/config.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/version.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>

#include <linux/module.h>

#include <asm/debug.h>

#define MIN(a,b) (((a)<(b))?(a):(b))
#define DEBUG_PROLOG_ENTRY -1

/* typedefs */

typedef struct file_private_info {
	loff_t offset;			/* offset of last read in file */
	int    act_area;                /* number of last formated area */
	int    act_entry;               /* last formated entry (offset */
                                        /* relative to beginning of last */
                                        /* formated area) */ 
	size_t act_entry_offset;        /* up to this offset we copied */
					/* in last read the last formated */
					/* entry to userland */
	char   temp_buf[2048];		/* buffer for output */
	debug_info_t *debug_info_org;   /* original debug information */
	debug_info_t *debug_info_snap;	/* snapshot of debug information */
	struct debug_view *view;	/* used view of debug info */
} file_private_info_t;

typedef struct
{
	char *string;
	/* 
	 * This assumes that all args are converted into longs 
	 * on L/390 this is the case for all types of parameter 
	 * except of floats, and long long (32 bit) 
         *
         */
	long args[0];
} debug_sprintf_entry;


extern void tod_to_timeval(uint64_t todval, struct timeval *xtime);

/* internal function prototyes */

static int debug_init(void);
static ssize_t debug_output(struct file *file, char *user_buf,
			    size_t user_len, loff_t * offset);
static ssize_t debug_input(struct file *file, const char *user_buf,
			   size_t user_len, loff_t * offset);
static int debug_open(struct inode *inode, struct file *file);
static int debug_close(struct inode *inode, struct file *file);
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);
static void debug_delete_proc_dir_entry(struct proc_dir_entry *root,
					struct proc_dir_entry *entry);
static debug_info_t*  debug_info_create(char *name, int page_order, int nr_areas, int buf_size);
static void debug_info_get(debug_info_t *);
static void debug_info_put(debug_info_t *);
static int debug_prolog_level_fn(debug_info_t * id,
				 struct debug_view *view, char *out_buf);
static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
				struct file *file, const char *user_buf,
				size_t user_buf_size, loff_t * offset);
static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
                                struct file *file, const char *user_buf,
                                size_t user_buf_size, loff_t * offset);
static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
                                char *out_buf, const char *in_buf);
static int debug_raw_format_fn(debug_info_t * id,
				 struct debug_view *view, char *out_buf,
				 const char *in_buf);
static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
                         int area, debug_entry_t * entry, char *out_buf);

static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
				   char *out_buf, debug_sprintf_entry *curr_event);

/* globals */

struct debug_view debug_raw_view = {
	"raw",
	NULL,
	&debug_raw_header_fn,
	&debug_raw_format_fn,
	NULL,
	NULL
};

struct debug_view debug_hex_ascii_view = {
	"hex_ascii",
	NULL,
	&debug_dflt_header_fn,
	&debug_hex_ascii_format_fn,
	NULL,
	NULL
};

struct debug_view debug_level_view = {
	"level",
	&debug_prolog_level_fn,
	NULL,
	NULL,
	&debug_input_level_fn,
	NULL
};

struct debug_view debug_flush_view = {
        "flush",
        NULL,
        NULL,
        NULL,
        &debug_input_flush_fn,
        NULL
};

struct debug_view debug_sprintf_view = {
	"sprintf",
	NULL,
	&debug_dflt_header_fn,
	(debug_format_proc_t*)&debug_sprintf_format_fn,
	NULL,
	NULL
};


unsigned int debug_feature_version = __DEBUG_FEATURE_VERSION;

/* static globals */

static debug_info_t *debug_area_first = NULL;
static debug_info_t *debug_area_last = NULL;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,3,98))
static struct semaphore debug_lock = MUTEX;
#else
DECLARE_MUTEX(debug_lock);
#endif

static int initialized = 0;

static struct file_operations debug_file_ops = {
	read:    debug_output,
	write:   debug_input,	
	open:    debug_open,
	release: debug_close,
};

static struct inode_operations debug_inode_ops = {
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,3,98))
	default_file_ops: &debug_file_ops,	/* file ops */
#endif
};


static struct proc_dir_entry *debug_proc_root_entry;

/* functions */

/*
 * debug_info_alloc
 * - alloc new debug-info
 */

static debug_info_t*  debug_info_alloc(char *name, int page_order,
                                        int nr_areas, int buf_size)
{
	debug_info_t* rc;
	int i;

	/* alloc everything */

	rc = (debug_info_t*) kmalloc(sizeof(debug_info_t), GFP_ATOMIC);
	if(!rc)
		goto fail_malloc_rc;
	rc->active_entry = (int*)kmalloc(nr_areas * sizeof(int), GFP_ATOMIC);
	if(!rc->active_entry)
		goto fail_malloc_active_entry;
	memset(rc->active_entry, 0, nr_areas * sizeof(int));
	rc->areas = (debug_entry_t **) kmalloc(nr_areas *
						sizeof(debug_entry_t *),
						GFP_ATOMIC);
	if (!rc->areas)
		goto fail_malloc_areas;
	for (i = 0; i < nr_areas; i++) {
		rc->areas[i] = (debug_entry_t *) __get_free_pages(GFP_ATOMIC,
								page_order);
		if (!rc->areas[i]) {
			for (i--; i >= 0; i--) {
				free_pages((unsigned long) rc->areas[i],
						page_order);
			}
			goto fail_malloc_areas2;
		} else {
			memset(rc->areas[i], 0, PAGE_SIZE << page_order);
		}
	}

	/* initialize members */

	spin_lock_init(&rc->lock);
	rc->page_order  = page_order;
	rc->nr_areas    = nr_areas;
	rc->active_area = 0;
	rc->level       = DEBUG_DEFAULT_LEVEL;
	rc->buf_size    = buf_size;
	rc->entry_size  = sizeof(debug_entry_t) + buf_size;
	strncpy(rc->name, name, MIN(strlen(name), (DEBUG_MAX_PROCF_LEN - 1)));
	rc->name[MIN(strlen(name), (DEBUG_MAX_PROCF_LEN - 1))] = 0;
	memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
#ifdef CONFIG_PROC_FS
	memset(rc->proc_entries, 0 ,DEBUG_MAX_VIEWS *
		sizeof(struct proc_dir_entry*));
#endif /* CONFIG_PROC_FS */
	atomic_set(&(rc->ref_count), 0);

	return rc;

fail_malloc_areas2:
	kfree(rc->areas);
fail_malloc_areas:
	kfree(rc->active_entry);
fail_malloc_active_entry:
	kfree(rc);
fail_malloc_rc:
	return NULL;
}

/*
 * debug_info_free
 * - free memory debug-info
 */

static void debug_info_free(debug_info_t* db_info){
	int i;
	for (i = 0; i < db_info->nr_areas; i++) {
		free_pages((unsigned long) db_info->areas[i],
		db_info->page_order);
	}
	kfree(db_info->areas);
	kfree(db_info->active_entry);
	kfree(db_info);
}

/*
 * debug_info_create
 * - create new debug-info
 */

static debug_info_t*  debug_info_create(char *name, int page_order, 
                                        int nr_areas, int buf_size)
{
	debug_info_t* rc;

        rc = debug_info_alloc(name, page_order, nr_areas, buf_size);
        if(!rc) 
		goto out;


	/* create proc rood directory */

        rc->proc_root_entry =
            debug_create_proc_dir_entry(debug_proc_root_entry, rc->name,
                                        S_IFDIR | S_IRUGO | S_IXUGO |
                                        S_IWUSR | S_IWGRP, NULL, NULL);

	/* append new element to linked list */

        if(debug_area_first == NULL){
                /* first element in list */
                debug_area_first = rc;
                rc->prev = NULL;
        }
        else{
                /* append element to end of list */
                debug_area_last->next = rc;
                rc->prev = debug_area_last;
        }
        debug_area_last = rc;
        rc->next = NULL;

	debug_info_get(rc);
out:
	return rc;
}

/*
 * debug_info_copy
 * - copy debug-info
 */

static debug_info_t* debug_info_copy(debug_info_t* in)
{
        int i;
        debug_info_t* rc;
        rc = debug_info_alloc(in->name, in->page_order, 
                                in->nr_areas, in->buf_size);
        if(!rc)
                goto out;

        for(i = 0; i < in->nr_areas; i++){
                memcpy(rc->areas[i],in->areas[i], PAGE_SIZE << in->page_order);
        }
out:
        return rc;
}

/*
 * debug_info_get
 * - increments reference count for debug-info
 */

static void debug_info_get(debug_info_t * db_info)
{
	if (db_info)
		atomic_inc(&db_info->ref_count);
}

/*
 * debug_info_put:
 * - decreases reference count for debug-info and frees it if necessary
 */

static void debug_info_put(debug_info_t *db_info)
{
	int i;

	if (!db_info)
		return;
	if (atomic_dec_and_test(&db_info->ref_count)) {
#ifdef DEBUG
		printk(KERN_INFO "debug: freeing debug area %p (%s)\n",
		       db_info, db_info->name);
#endif
		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
			if (db_info->views[i] != NULL)
				debug_delete_proc_dir_entry
				    (db_info->proc_root_entry,
				     db_info->proc_entries[i]);
		}
		debug_delete_proc_dir_entry(debug_proc_root_entry,
					    db_info->proc_root_entry);
		if(db_info == debug_area_first)
			debug_area_first = db_info->next;
		if(db_info == debug_area_last)
			debug_area_last = db_info->prev;
		if(db_info->prev) db_info->prev->next = db_info->next;
		if(db_info->next) db_info->next->prev = db_info->prev;
		debug_info_free(db_info);
	}
}

/*
 * debug_format_entry:
 * - format one debug entry and return size of formated data
 */

static int debug_format_entry(file_private_info_t *p_info)
{
	debug_info_t *id_org    = p_info->debug_info_org;
	debug_info_t *id_snap   = p_info->debug_info_snap;
	struct debug_view *view = p_info->view;
	debug_entry_t *act_entry;
	size_t len = 0;
	if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
		/* print prolog */
        	if (view->prolog_proc)
                	len += view->prolog_proc(id_org, view,p_info->temp_buf);
		goto out;
	}

	act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area] +
					p_info->act_entry);
                        
	if (act_entry->id.stck == 0LL)
			goto out;  /* empty entry */
	if (view->header_proc)
		len += view->header_proc(id_org, view, p_info->act_area, 
					act_entry, p_info->temp_buf + len);
	if (view->format_proc)
		len += view->format_proc(id_org, view, p_info->temp_buf + len,
						DEBUG_DATA(act_entry));
      out:
        return len;
}

/*
 * debug_next_entry:
 * - goto next entry in p_info
 */

extern inline int debug_next_entry(file_private_info_t *p_info)
{
	debug_info_t *id = p_info->debug_info_snap;
	if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
		p_info->act_entry = 0;
		goto out;
	}
	if ((p_info->act_entry += id->entry_size)
		> ((PAGE_SIZE << (id->page_order)) 
		- id->entry_size)){

		/* next area */
		p_info->act_entry = 0;
        	p_info->act_area++;
        	if(p_info->act_area >= id->nr_areas)
			return 1;
	}
out:
	return 0;	
}

/*
 * debug_output:
 * - called for user read()
 * - copies formated debug entries to the user buffer
 */