path: root/arch/s390/kernel/debug.c

/*
 *  arch/s390/kernel/debug.c
 *   S/390 debug facility
 *
 *    Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
 *                             IBM Corporation
 *    Author(s): Michael Holzheu (holzheu@de.ibm.com),
 *               Holger Smolinski (Holger.Smolinski@de.ibm.com)
 *
 *    Bugreports to: <Linux390@de.ibm.com>
 */

#define KMSG_COMPONENT "s390dbf"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/sysctl.h>
#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/debugfs.h>

#include <asm/debug.h>

#define DEBUG_PROLOG_ENTRY -1

#define ALL_AREAS 0 /* copy all debug areas */
#define NO_AREAS  1 /* copy no debug areas */

/* 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_page;                /* act page in given area */
	int    act_entry;               /* last formated entry (offset */
                                        /* relative to beginning of last */
                                        /* formated page) */
	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_t;


/* internal function prototyes */

static int debug_init(void);
static ssize_t debug_output(struct file *file, char __user *user_buf,
			size_t user_len, loff_t * offset);
static ssize_t debug_input(struct file *file, const char __user *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 debug_info_t *debug_info_create(const char *name, int pages_per_area,
			int nr_areas, int buf_size, mode_t mode);
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 *user_buf,
			size_t user_buf_size, loff_t * offset);
static int debug_prolog_pages_fn(debug_info_t * id,
			struct debug_view *view, char *out_buf);
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_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 *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_t *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
};

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

static struct debug_view debug_pages_view = {
	"pages",
	&debug_prolog_pages_fn,
	NULL,
	NULL,
	&debug_input_pages_fn,
	NULL
};

static 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
};

/* used by dump analysis tools to determine version of debug feature */
static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;

/* static globals */

static debug_info_t *debug_area_first = NULL;
static debug_info_t *debug_area_last = NULL;
static DEFINE_MUTEX(debug_mutex);

static int initialized;

static const struct file_operations debug_file_ops = {
	.owner   = THIS_MODULE,
	.read    = debug_output,
	.write   = debug_input,
	.open    = debug_open,
	.release = debug_close,
};

static struct dentry *debug_debugfs_root_entry;

/* functions */

/*
 * debug_areas_alloc
 * - Debug areas are implemented as a threedimensonal array:
 *   areas[areanumber][pagenumber][pageoffset]
 */

static debug_entry_t***
debug_areas_alloc(int pages_per_area, int nr_areas)
{
	debug_entry_t*** areas;
	int i,j;

	areas = kmalloc(nr_areas *
					sizeof(debug_entry_t**),
					GFP_KERNEL);
	if (!areas)
		goto fail_malloc_areas;
	for (i = 0; i < nr_areas; i++) {
		areas[i] = kmalloc(pages_per_area *
				sizeof(debug_entry_t*),GFP_KERNEL);
		if (!areas[i]) {
			goto fail_malloc_areas2;
		}
		for(j = 0; j < pages_per_area; j++) {
			areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
			if(!areas[i][j]) {
				for(j--; j >=0 ; j--) {
					kfree(areas[i][j]);
				}
				kfree(areas[i]);
				goto fail_malloc_areas2;
			}
		}
	}
	return areas;

fail_malloc_areas2:
	for(i--; i >= 0; i--){
		for(j=0; j < pages_per_area;j++){
			kfree(areas[i][j]);
		}
		kfree(areas[i]);
	}
	kfree(areas);
fail_malloc_areas:
	return NULL;

}


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

static debug_info_t*
debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
		 int buf_size, int level, int mode)
{
	debug_info_t* rc;

	/* alloc everything */

	rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
	if(!rc)
		goto fail_malloc_rc;
	rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
	if(!rc->active_entries)
		goto fail_malloc_active_entries;
	rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
	if(!rc->active_pages)
		goto fail_malloc_active_pages;
	if((mode == ALL_AREAS) && (pages_per_area != 0)){
		rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
		if(!rc->areas)
			goto fail_malloc_areas;
	} else {
		rc->areas = NULL;
	}

	/* initialize members */

	spin_lock_init(&rc->lock);
	rc->pages_per_area = pages_per_a