[mirror_ubuntu-artful-kernel.git] / kernel / gcov / gcc_3_4.c

/*
 *  This code provides functions to handle gcc's profiling data format
 *  introduced with gcc 3.4. Future versions of gcc may change the gcov
 *  format (as happened before), so all format-specific information needs
 *  to be kept modular and easily exchangeable.
 *
 *  This file is based on gcc-internal definitions. Functions and data
 *  structures are defined to be compatible with gcc counterparts.
 *  For a better understanding, refer to gcc source: gcc/gcov-io.h.
 *
 *    Copyright IBM Corp. 2009
 *    Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
 *
 *    Uses gcc-internal data definitions.
 */

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include "gcov.h"

#define GCOV_COUNTERS		5

static struct gcov_info *gcov_info_head;

/**
 * struct gcov_fn_info - profiling meta data per function
 * @ident: object file-unique function identifier
 * @checksum: function checksum
 * @n_ctrs: number of values per counter type belonging to this function
 *
 * This data is generated by gcc during compilation and doesn't change
 * at run-time.
 */
struct gcov_fn_info {
	unsigned int ident;
	unsigned int checksum;
	unsigned int n_ctrs[0];
};

/**
 * struct gcov_ctr_info - profiling data per counter type
 * @num: number of counter values for this type
 * @values: array of counter values for this type
 * @merge: merge function for counter values of this type (unused)
 *
 * This data is generated by gcc during compilation and doesn't change
 * at run-time with the exception of the values array.
 */
struct gcov_ctr_info {
	unsigned int	num;
	gcov_type	*values;
	void		(*merge)(gcov_type *, unsigned int);
};

/**
 * struct gcov_info - profiling data per object file
 * @version: gcov version magic indicating the gcc version used for compilation
 * @next: list head for a singly-linked list
 * @stamp: time stamp
 * @filename: name of the associated gcov data file
 * @n_functions: number of instrumented functions
 * @functions: function data
 * @ctr_mask: mask specifying which counter types are active
 * @counts: counter data per counter type
 *
 * This data is generated by gcc during compilation and doesn't change
 * at run-time with the exception of the next pointer.
 */
struct gcov_info {
	unsigned int			version;
	struct gcov_info		*next;
	unsigned int			stamp;
	const char			*filename;
	unsigned int			n_functions;
	const struct gcov_fn_info	*functions;
	unsigned int			ctr_mask;
	struct gcov_ctr_info		counts[0];
};

/**
 * gcov_info_filename - return info filename
 * @info: profiling data set
 */
const char *gcov_info_filename(struct gcov_info *info)
{
	return info->filename;
}

/**
 * gcov_info_version - return info version
 * @info: profiling data set
 */
unsigned int gcov_info_version(struct gcov_info *info)
{
	return info->version;
}

/**
 * gcov_info_next - return next profiling data set
 * @info: profiling data set
 *
 * Returns next gcov_info following @info or first gcov_info in the chain if
 * @info is %NULL.
 */
struct gcov_info *gcov_info_next(struct gcov_info *info)
{
	if (!info)
		return gcov_info_head;

	return info->next;
}

/**
 * gcov_info_link - link/add profiling data set to the list
 * @info: profiling data set
 */
void gcov_info_link(struct gcov_info *info)
{
	info->next = gcov_info_head;
	gcov_info_head = info;
}

/**
 * gcov_info_unlink - unlink/remove profiling data set from the list
 * @prev: previous profiling data set
 * @info: profiling data set
 */
void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
{
	if (prev)
		prev->next = info->next;
	else
		gcov_info_head = info->next;
}

/* Symbolic links to be created for each profiling data file. */
const struct gcov_link gcov_link[] = {
	{ OBJ_TREE, "gcno" },	/* Link to .gcno file in $(objtree). */
	{ 0, NULL},
};

/*
 * Determine whether a counter is active. Based on gcc magic. Doesn't change
 * at run-time.
 */
static int counter_active(struct gcov_info *info, unsigned int type)
{
	return (1 << type) & info->ctr_mask;
}

/* Determine number of active counters. Based on gcc magic. */
static unsigned int num_counter_active(struct gcov_info *info)
{
	unsigned int i;
	unsigned int result = 0;

	for (i = 0; i < GCOV_COUNTERS; i++) {
		if (counter_active(info, i))
			result++;
	}
	return result;
}

/**
 * gcov_info_reset - reset profiling data to zero
 * @info: profiling data set
 */
void gcov_info_reset(struct gcov_info *info)
{
	unsigned int active = num_counter_active(info);
	unsigned int i;

	for (i = 0; i < active; i++) {
		memset(info->counts[i].values, 0,
		       info->counts[i].num * sizeof(gcov_type));
	}
}

/**
 * gcov_info_is_compatible - check if profiling data can be added
 * @info1: first profiling data set
 * @info2: second profiling data set
 *
 * Returns non-zero if profiling data can be added, zero otherwise.
 */
int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
{
	return (info1->stamp == info2->stamp);
}

/**
 * gcov_info_add - add up profiling data
 * @dest: profiling data set to which data is added
 * @source: profiling data set which is added
 *
 * Adds profiling counts of @source to @dest.
 */
void gcov_info_add(struct gcov_info *dest, struct gcov_info *source)
{
	unsigned int i;
	unsigned int j;

	for (i = 0; i < num_counter_active(dest); i++) {
		for (j = 0; j < dest->counts[i].num; j++) {
			dest->counts[i].values[j] +=
				source->counts[i].values[j];
		}
	}
}

/* Get size of function info entry. Based on gcc magic. */
static size_t get_fn_size(struct gcov_info *info)
{
	size_t size;

	size = sizeof(struct gcov_fn_info) + num_counter_active(info) *
	       sizeof(unsigned int);
	if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int))
		size = ALIGN(size, __alignof__(struct gcov_fn_info));
	return size;
}

/* Get address of function info entry. Based on gcc magic. */
static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn)
{
	return (struct gcov_fn_info *)
		((char *) info->functions + fn * get_fn_size(info));
}

/**
 * gcov_info_dup - duplicate profiling data set
 * @info: profiling data set to duplicate
 *
 * Return newly allocated duplicate on success, %NULL on error.
 */
struct gcov_info *gcov_info_dup(struct gcov_info *info)
{
	struct gcov_info *dup;
	unsigned int i;
	unsigned int active;

	/* Duplicate gcov_info. */
	active = num_counter_active(info);
	dup = kzalloc(sizeof(struct gcov_info) +
		      sizeof(struct gcov_ctr_info) * active, GFP_KERNEL);
	if (!dup)
		return NULL;
	dup->version		= info->version;
	dup->stamp		= info->stamp;
	dup->n_functions	= info->n_functions;
	dup->ctr_mask		= info->ctr_mask;
	/* Duplicate filename. */
	dup->filename		= kstrdup(info->filename, GFP_KERNEL);
	if (!dup->filename)
		goto err_free;
	/* Duplicate table of functions. */
	dup->functions = kmemdup(info->functions, info->n_functions *
				 get_fn_size(info), GFP_KERNEL);
	if (!dup->functions)
		goto err_free;
	/* Duplicate counter arrays. */
	for (i = 0; i < active ; i++) {
		struct gcov_ctr_info *ctr = &info->counts[i];
		size_t size = ctr->num * sizeof(gcov_type);

		dup->counts[i].num = ctr->num;
		dup->counts[i].merge = ctr->merge;
		dup->counts[i].values = vmalloc(size);
		if (!dup->counts[i].values)
			goto err_free;
		memcpy(dup->counts[i].values, ctr->values, size);
	}
	return dup;

err_free:
	gcov_info_free(dup);
	return NULL;
}

/**
 * gcov_info_free - release memory for profiling data set duplicate
 * @info: profiling data set duplicate to free
 */
void gcov_info_free(struct gcov_info *info)
{
	unsigned int active = num_counter_active(info);
	unsigned int i;

	for (i = 0; i < active ; i++)
		vfree(info->counts[i].values);
	kfree(info->functions);
	kfree(info->filename);
	kfree(info);
}

/**
 * struct type_info - iterator helper array
 * @ctr_type: counter type
 * @offset: index of the first value of the current function for this type
 *
 * This array is needed to convert the in-memory data format into the in-file
 * data format:
 *
 * In-memory:
 *   for each counter type
 *     for each function
 *       values
 *
 * In-file:
 *   for each function
 *     for each counter type
 *       values
 *
 * See gcc source gcc/gcov-io.h for more information on data organization.
 */
struct type_info {
	int ctr_type;
	unsigned int offset;
};

/**
 * struct gcov_iterator - specifies current file position in logical records
 * @info: associated profiling data
 * @record: record type
 * @function: function number
 * @type: counter type
 * @count: index into values array
 * @num_types: number of counter types
 * @type_info: helper array to get values-array offset for current function
 */
struct gcov_iterator {
	struct gcov_info *info;

	int record;
	unsigned int function;
	unsigned int type;
	unsigned int count;

	int num_types;
	struct type_info type_info[0];
};

static struct gcov_fn_info *get_func(struct gcov_iterator *iter)
{
	return get_fn_info(iter->info, iter->function);
}

static struct type_info *get_type(struct gcov_iterator *iter)
{
	return &iter->type_info[iter->type];
}

/**
 * gcov_iter_new - allocate and initialize profiling data iterator
 * @info: profiling data set to be iterated
 *
 * Return file iterator on success, %NULL otherwise.
 */
struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
{
	struct gcov_iterator *iter;

	iter = kzalloc(sizeof(struct gcov_iterator) +
		       num_counter_active(info) * sizeof(struct type_info),
		       GFP_KERNEL);
	if (iter)
		iter->info = info;

	return iter;
}

/**
 * gcov_iter_free - release memory for iterator
 * @iter: file iterator to free
 */
void gcov_iter_free(struct gcov_iterator *iter)
{
	kfree(iter);
}

/**
 * gcov_iter_get_info - return profiling data set for given file iterator
 * @iter: file iterator
 */
struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter)
{
	return iter->info;
}

/**
 * gcov_iter_start - reset file iterator to starting position
 * @iter: file iterator
 */
void gcov_iter_start(struct gcov_iterator *iter)
{
	int i;

	iter->record = 0;
	iter->function = 0;
	iter->type = 0;
	iter->count = 0;
	iter->num_types = 0;
	for (i = 0; i < GCOV_COUNTERS; i++) {
		if (counter_active(iter->info, i)) {
			iter->type_info[iter->num_types].ctr_type = i;
			iter->type_info[iter->num_types++].offset = 0;
		}
	}
}

/* Mapping of logical record number to actual file content. */
#define RECORD_FILE_MAGIC	0
#define RECORD_GCOV_VERSION	1
#define RECORD_TIME_STAMP	2
#define RECORD_FUNCTION_TAG	3
#define RECORD_FUNCTON_TAG_LEN	4
#define RECORD_FUNCTION_IDENT	5
#define RECORD_FUNCTION_CHECK	6
#define RECORD_COUNT_TAG	7
#define RECORD_COUNT_LEN	8
#define RECORD_COUNT		9

/**
 * gcov_iter_next - advance file iterator to next logical record
 * @iter: file iterator
 *
 * Return zero if new position is valid, non-zero if iterator has reached end.
 */
int gcov_iter_next(struct gcov_iterator *iter)
{
	switch (iter->record) {
	case RECORD_FILE_MAGIC:
	case RECORD_GCOV_VERSION:
	case RECORD_FUNCTION_TAG:
	case RECORD_FUNCTON_TAG_LEN:
	case RECORD_FUNCTION_IDENT:
	case RECORD_COUNT_TAG:
		/* Advance to next record */
		iter->record++;
		break;
	case RECORD_COUNT:
		/* Advance to next count */
		iter->count++;
		/* fall through */
	case RECORD_COUNT_LEN:
		if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
			iter->record = 9;
			break;
		}
		/* Advance to next counter type */
		get_type(iter)->offset += iter->count;
		iter->count = 0;
		iter->type++;
		/* fall through */
	case RECORD_FUNCTION_CHECK:
		if (iter->type < iter->num_types) {
			iter->record = 7;
			break;
		}
		/* Advance to next function */
		iter->type = 0;
		iter->function++;
		/* fall through */
	case RECORD_TIME_STAMP:
		if (iter->function < iter->info->n_functions)
			iter->record = 3;
		else
			iter->record = -1;
		break;
	}
	/* Check for EOF. */
	if (iter->record == -1)
		return -EINVAL;
	else
		return 0;
}

/**
 * seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file
 * @seq: seq_file handle
 * @v: value to be stored
 *
 * Number format defined by gcc: numbers are recorded in the 32 bit
 * unsigned binary form of the endianness of the machine generating the
 * file.
 */
static int seq_write_gcov_u32(struct seq_file *seq, u32 v)
{
	return seq_write(seq, &v, sizeof(v));
}

/**
 * seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file
 * @seq: seq_file handle
 * @v: value to be stored
 *
 * Number format defined by gcc: numbers are recorded in the 32 bit
 * unsigned binary form of the endianness of the machine generating the
 * file. 64 bit numbers are stored as two 32 bit numbers, the low part
 * first.
 */
static int seq_write_gcov_u64(struct seq_file *seq, u64 v)
{
	u32 data[2];

	data[0] = (v & 0xffffffffUL);
	data[1] = (v >> 32);
	return seq_write(seq, data, sizeof(data));
}

/**
 * gcov_iter_write - write data for current pos to seq_file
 * @iter: file iterator
 * @seq: seq_file handle
 *
 * Return zero on success, non-zero otherwise.
 */
int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq)
{
	int rc = -EINVAL;

	switch (iter->record) {
	case RECORD_FILE_MAGIC:
		rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
		break;
	case RECORD_GCOV_VERSION:
		rc = seq_write_gcov_u32(seq, iter->info->version);
		break;
	case RECORD_TIME_STAMP:
		rc = seq_write_gcov_u32(seq, iter->info->stamp);
		break;
	case RECORD_FUNCTION_TAG:
		rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION);
		break;
	case RECORD_FUNCTON_TAG_LEN:
		rc = seq_write_gcov_u32(seq, 2);
		break;
	case RECORD_FUNCTION_IDENT:
		rc = seq_write_gcov_u32(seq, get_func(iter)->ident);
		break;
	case RECORD_FUNCTION_CHECK:
		rc = seq_write_gcov_u32(seq, get_func(iter)->checksum);
		break;
	case RECORD_COUNT_TAG:
		rc = seq_write_gcov_u32(seq,
			GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type));
		break;
	case RECORD_COUNT_LEN:
		rc = seq_write_gcov_u32(seq,
				get_func(iter)->n_ctrs[iter->type] * 2);
		break;
	case RECORD_COUNT:
		rc = seq_write_gcov_u64(seq,
			iter->info->counts[iter->type].
				values[iter->count + get_type(iter)->offset]);
		break;
	}
	return rc;
}
Commit	Line	Data
2521f2c2 PO	1	/*
	2	* This code provides functions to handle gcc's profiling data format
	3	* introduced with gcc 3.4. Future versions of gcc may change the gcov
	4	* format (as happened before), so all format-specific information needs
	5	* to be kept modular and easily exchangeable.
	6	*
	7	* This file is based on gcc-internal definitions. Functions and data
	8	* structures are defined to be compatible with gcc counterparts.
	9	* For a better understanding, refer to gcc source: gcc/gcov-io.h.
	10	*
	11	* Copyright IBM Corp. 2009
	12	* Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
	13	*
	14	* Uses gcc-internal data definitions.
	15	*/
	16
	17	#include <linux/errno.h>
	18	#include <linux/slab.h>
	19	#include <linux/string.h>
	20	#include <linux/seq_file.h>
	21	#include <linux/vmalloc.h>
	22	#include "gcov.h"
	23
8cbce376 FH	24	#define GCOV_COUNTERS 5
	25
	26	static struct gcov_info *gcov_info_head;
	27
	28	/**
	29	* struct gcov_fn_info - profiling meta data per function
	30	* @ident: object file-unique function identifier
	31	* @checksum: function checksum
	32	* @n_ctrs: number of values per counter type belonging to this function
	33	*
	34	* This data is generated by gcc during compilation and doesn't change
	35	* at run-time.
	36	*/
	37	struct gcov_fn_info {
	38	unsigned int ident;
	39	unsigned int checksum;
	40	unsigned int n_ctrs[0];
	41	};
	42
	43	/**
	44	* struct gcov_ctr_info - profiling data per counter type
	45	* @num: number of counter values for this type
	46	* @values: array of counter values for this type
	47	* @merge: merge function for counter values of this type (unused)
	48	*
	49	* This data is generated by gcc during compilation and doesn't change
	50	* at run-time with the exception of the values array.
	51	*/
	52	struct gcov_ctr_info {
	53	unsigned int num;
	54	gcov_type *values;
	55	void (merge)(gcov_type , unsigned int);
	56	};
	57
	58	/**
	59	* struct gcov_info - profiling data per object file
	60	* @version: gcov version magic indicating the gcc version used for compilation
	61	* @next: list head for a singly-linked list
	62	* @stamp: time stamp
	63	* @filename: name of the associated gcov data file
	64	* @n_functions: number of instrumented functions
	65	* @functions: function data
	66	* @ctr_mask: mask specifying which counter types are active
	67	* @counts: counter data per counter type
	68	*
	69	* This data is generated by gcc during compilation and doesn't change
	70	* at run-time with the exception of the next pointer.
	71	*/
	72	struct gcov_info {
	73	unsigned int version;
	74	struct gcov_info *next;
	75	unsigned int stamp;
	76	const char *filename;
	77	unsigned int n_functions;
	78	const struct gcov_fn_info *functions;
	79	unsigned int ctr_mask;
	80	struct gcov_ctr_info counts[0];
	81	};
	82
	83	/**
	84	* gcov_info_filename - return info filename
	85	* @info: profiling data set
	86	*/
	87	const char gcov_info_filename(struct gcov_info info)
88	{
89	return info->filename;
90	}
91
92	/**
93	* gcov_info_version - return info version
94	* @info: profiling data set
95	*/
96	unsigned int gcov_info_version(struct gcov_info *info)
97	{
98	return info->version;
99	}
100
101	/**
102	* gcov_info_next - return next profiling data set
103	* @info: profiling data set
104	*
105	* Returns next gcov_info following @info or first gcov_info in the chain if
106	* @info is %NULL.
107	*/
108	struct gcov_info gcov_info_next(struct gcov_info info)
109	{
110	if (!info)
111	return gcov_info_head;
112
113	return info->next;
114	}
115
116	/**
117	* gcov_info_link - link/add profiling data set to the list
118	* @info: profiling data set
119	*/
120	void gcov_info_link(struct gcov_info *info)
121	{
122	info->next = gcov_info_head;
123	gcov_info_head = info;
124	}
125
126	/**
127	* gcov_info_unlink - unlink/remove profiling data set from the list
128	* @prev: previous profiling data set
129	* @info: profiling data set
130	*/
131	void gcov_info_unlink(struct gcov_info prev, struct gcov_info info)
132	{
133	if (prev)
134	prev->next = info->next;
135	else
136	gcov_info_head = info->next;
137	}
138
2521f2c2 PO	139	/* Symbolic links to be created for each profiling data file. */
	140	const struct gcov_link gcov_link[] = {
	141	{ OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */
	142	{ 0, NULL},
	143	};
	144
	145	/*
	146	* Determine whether a counter is active. Based on gcc magic. Doesn't change
	147	* at run-time.
	148	*/
	149	static int counter_active(struct gcov_info *info, unsigned int type)
	150	{
	151	return (1 << type) & info->ctr_mask;
	152	}
	153
	154	/* Determine number of active counters. Based on gcc magic. */
	155	static unsigned int num_counter_active(struct gcov_info *info)
	156	{
	157	unsigned int i;
	158	unsigned int result = 0;
	159
	160	for (i = 0; i < GCOV_COUNTERS; i++) {
	161	if (counter_active(info, i))
	162	result++;
	163	}
	164	return result;
	165	}
	166
	167	/**
	168	* gcov_info_reset - reset profiling data to zero
	169	* @info: profiling data set
	170	*/
	171	void gcov_info_reset(struct gcov_info *info)
	172	{
	173	unsigned int active = num_counter_active(info);
	174	unsigned int i;
	175
	176	for (i = 0; i < active; i++) {
	177	memset(info->counts[i].values, 0,
	178	info->counts[i].num * sizeof(gcov_type));
	179	}
	180	}
	181
	182	/**
	183	* gcov_info_is_compatible - check if profiling data can be added
	184	* @info1: first profiling data set
	185	* @info2: second profiling data set
	186	*
	187	* Returns non-zero if profiling data can be added, zero otherwise.
	188	*/
	189	int gcov_info_is_compatible(struct gcov_info info1, struct gcov_info info2)
	190	{
	191	return (info1->stamp == info2->stamp);
	192	}
	193
	194	/**
	195	* gcov_info_add - add up profiling data
	196	* @dest: profiling data set to which data is added
	197	* @source: profiling data set which is added
	198	*
	199	* Adds profiling counts of @source to @dest.
	200	*/
	201	void gcov_info_add(struct gcov_info dest, struct gcov_info source)
	202	{
203	unsigned int i;
204	unsigned int j;
205
206	for (i = 0; i < num_counter_active(dest); i++) {
207	for (j = 0; j < dest->counts[i].num; j++) {
208	dest->counts[i].values[j] +=
209	source->counts[i].values[j];
210	}
211	}
212	}
213
214	/* Get size of function info entry. Based on gcc magic. */
215	static size_t get_fn_size(struct gcov_info *info)
216	{
217	size_t size;
218
219	size = sizeof(struct gcov_fn_info) + num_counter_active(info) *
220	sizeof(unsigned int);
221	if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int))
222	size = ALIGN(size, __alignof__(struct gcov_fn_info));
223	return size;
224	}
225
226	/* Get address of function info entry. Based on gcc magic. */
227	static struct gcov_fn_info get_fn_info(struct gcov_info info, unsigned int fn)
228	{
229	return (struct gcov_fn_info *)
230	((char ) info->functions + fn get_fn_size(info));
231	}
232
233	/**
234	* gcov_info_dup - duplicate profiling data set
235	* @info: profiling data set to duplicate
236	*
237	* Return newly allocated duplicate on success, %NULL on error.
238	*/
239	struct gcov_info gcov_info_dup(struct gcov_info info)
240	{
241	struct gcov_info *dup;
242	unsigned int i;
243	unsigned int active;
244
245	/* Duplicate gcov_info. */
246	active = num_counter_active(info);
247	dup = kzalloc(sizeof(struct gcov_info) +
248	sizeof(struct gcov_ctr_info) * active, GFP_KERNEL);
249	if (!dup)
250	return NULL;
251	dup->version = info->version;
252	dup->stamp = info->stamp;
253	dup->n_functions = info->n_functions;
254	dup->ctr_mask = info->ctr_mask;
255	/* Duplicate filename. */
256	dup->filename = kstrdup(info->filename, GFP_KERNEL);
257	if (!dup->filename)
258	goto err_free;
259	/* Duplicate table of functions. */
260	dup->functions = kmemdup(info->functions, info->n_functions *
261	get_fn_size(info), GFP_KERNEL);
262	if (!dup->functions)
263	goto err_free;
264	/* Duplicate counter arrays. */
265	for (i = 0; i < active ; i++) {
266	struct gcov_ctr_info *ctr = &info->counts[i];
267	size_t size = ctr->num * sizeof(gcov_type);
268
269	dup->counts[i].num = ctr->num;
270	dup->counts[i].merge = ctr->merge;
271	dup->counts[i].values = vmalloc(size);
272	if (!dup->counts[i].values)
273	goto err_free;
274	memcpy(dup->counts[i].values, ctr->values, size);
275	}
276	return dup;
277
278	err_free:
279	gcov_info_free(dup);
280	return NULL;
281	}
282
283	/**
284	* gcov_info_free - release memory for profiling data set duplicate
285	* @info: profiling data set duplicate to free
286	*/
287	void gcov_info_free(struct gcov_info *info)
288	{
289	unsigned int active = num_counter_active(info);
290	unsigned int i;
291
292	for (i = 0; i < active ; i++)
293	vfree(info->counts[i].values);
294	kfree(info->functions);
295	kfree(info->filename);
296	kfree(info);
297	}
298
299	/**
300	* struct type_info - iterator helper array
301	* @ctr_type: counter type
302	* @offset: index of the first value of the current function for this type
303	*
304	* This array is needed to convert the in-memory data format into the in-file
305	* data format:
306	*
307	* In-memory:
308	* for each counter type
309	* for each function
310	* values
311	*
312	* In-file:
313	* for each function
314	* for each counter type
315	* values
316	*
317	* See gcc source gcc/gcov-io.h for more information on data organization.
318	*/
319	struct type_info {
320	int ctr_type;
321	unsigned int offset;
322	};
323
324	/**
325	* struct gcov_iterator - specifies current file position in logical records
326	* @info: associated profiling data
327	* @record: record type
328	* @function: function number
329	* @type: counter type
330	* @count: index into values array
331	* @num_types: number of counter types
332	* @type_info: helper array to get values-array offset for current function
333	*/
334	struct gcov_iterator {
335	struct gcov_info *info;
336
337	int record;
338	unsigned int function;
339	unsigned int type;
340	unsigned int count;
341
342	int num_types;
343	struct type_info type_info[0];
344	};
345
346	static struct gcov_fn_info get_func(struct gcov_iterator iter)
347	{
348	return get_fn_info(iter->info, iter->function);
349	}
350
351	static struct type_info get_type(struct gcov_iterator iter)
352	{
353	return &iter->type_info[iter->type];
354	}
355
356	/**
357	* gcov_iter_new - allocate and initialize profiling data iterator
358	* @info: profiling data set to be iterated
359	*
360	* Return file iterator on success, %NULL otherwise.
361	*/
362	struct gcov_iterator gcov_iter_new(struct gcov_info info)
363	{
364	struct gcov_iterator *iter;
365
366	iter = kzalloc(sizeof(struct gcov_iterator) +
367	num_counter_active(info) * sizeof(struct type_info),
368	GFP_KERNEL);
369	if (iter)
370	iter->info = info;
371
372	return iter;
373	}
374
375	/**
376	* gcov_iter_free - release memory for iterator
377	* @iter: file iterator to free
378	*/
379	void gcov_iter_free(struct gcov_iterator *iter)
380	{
381	kfree(iter);
382	}
383
384	/**
385	* gcov_iter_get_info - return profiling data set for given file iterator
386	* @iter: file iterator
387	*/
388	struct gcov_info gcov_iter_get_info(struct gcov_iterator iter)
389	{
390	return iter->info;
391	}
392
393	/**
394	* gcov_iter_start - reset file iterator to starting position
395	* @iter: file iterator
396	*/
397	void gcov_iter_start(struct gcov_iterator *iter)
398	{
399	int i;
400
401	iter->record = 0;
402	iter->function = 0;
403	iter->type = 0;
404	iter->count = 0;
405	iter->num_types = 0;
406	for (i = 0; i < GCOV_COUNTERS; i++) {
407	if (counter_active(iter->info, i)) {
408	iter->type_info[iter->num_types].ctr_type = i;
409	iter->type_info[iter->num_types++].offset = 0;
410	}
411	}
412	}
413
414	/* Mapping of logical record number to actual file content. */
415	#define RECORD_FILE_MAGIC 0
416	#define RECORD_GCOV_VERSION 1
417	#define RECORD_TIME_STAMP 2
418	#define RECORD_FUNCTION_TAG 3
419	#define RECORD_FUNCTON_TAG_LEN 4
420	#define RECORD_FUNCTION_IDENT 5
421	#define RECORD_FUNCTION_CHECK 6
422	#define RECORD_COUNT_TAG 7
423	#define RECORD_COUNT_LEN 8
424	#define RECORD_COUNT 9
425
426	/**
427	* gcov_iter_next - advance file iterator to next logical record
428	* @iter: file iterator
429	*
430	* Return zero if new position is valid, non-zero if iterator has reached end.
431	*/
432	int gcov_iter_next(struct gcov_iterator *iter)
433	{
434	switch (iter->record) {
435	case RECORD_FILE_MAGIC:
436	case RECORD_GCOV_VERSION:
437	case RECORD_FUNCTION_TAG:
438	case RECORD_FUNCTON_TAG_LEN:
439	case RECORD_FUNCTION_IDENT:
440	case RECORD_COUNT_TAG:
441	/* Advance to next record */
442	iter->record++;
443	break;
444	case RECORD_COUNT:
445	/* Advance to next count */
446	iter->count++;
447	/* fall through */
448	case RECORD_COUNT_LEN:
449	if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
450	iter->record = 9;
451	break;
452	}
453	/* Advance to next counter type */
454	get_type(iter)->offset += iter->count;
455	iter->count = 0;
456	iter->type++;
457	/* fall through */
458	case RECORD_FUNCTION_CHECK:
459	if (iter->type < iter->num_types) {
460	iter->record = 7;
461	break;
462	}
463	/* Advance to next function */
464	iter->type = 0;
465	iter->function++;
466	/* fall through */
467	case RECORD_TIME_STAMP:
468	if (iter->function < iter->info->n_functions)
469	iter->record = 3;
470	else
471	iter->record = -1;
472	break;
473	}
474	/* Check for EOF. */
475	if (iter->record == -1)
476	return -EINVAL;
477	else
478	return 0;
479	}
480
481	/**
482	* seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file
483	* @seq: seq_file handle
484	* @v: value to be stored
485	*
486	* Number format defined by gcc: numbers are recorded in the 32 bit
487	* unsigned binary form of the endianness of the machine generating the
488	* file.
489	*/
490	static int seq_write_gcov_u32(struct seq_file *seq, u32 v)
491	{
492	return seq_write(seq, &v, sizeof(v));
493	}
494
495	/**
496	* seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file
497	* @seq: seq_file handle
498	* @v: value to be stored
499	*
500	* Number format defined by gcc: numbers are recorded in the 32 bit
501	* unsigned binary form of the endianness of the machine generating the
502	* file. 64 bit numbers are stored as two 32 bit numbers, the low part
503	* first.
504	*/
505	static int seq_write_gcov_u64(struct seq_file *seq, u64 v)
506	{
507	u32 data[2];
508
509	data[0] = (v & 0xffffffffUL);
510	data[1] = (v >> 32);
511	return seq_write(seq, data, sizeof(data));
512	}
513
514	/**
515	* gcov_iter_write - write data for current pos to seq_file
516	* @iter: file iterator
517	* @seq: seq_file handle
518	*
519	* Return zero on success, non-zero otherwise.
520	*/
521	int gcov_iter_write(struct gcov_iterator iter, struct seq_file seq)
522	{
523	int rc = -EINVAL;
524
525	switch (iter->record) {
526	case RECORD_FILE_MAGIC:
527	rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
528	break;
529	case RECORD_GCOV_VERSION:
530	rc = seq_write_gcov_u32(seq, iter->info->version);
531	break;
532	case RECORD_TIME_STAMP:
533	rc = seq_write_gcov_u32(seq, iter->info->stamp);
534	break;
535	case RECORD_FUNCTION_TAG:
536	rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION);
537	break;
538	case RECORD_FUNCTON_TAG_LEN:
539	rc = seq_write_gcov_u32(seq, 2);
540	break;
541	case RECORD_FUNCTION_IDENT:
542	rc = seq_write_gcov_u32(seq, get_func(iter)->ident);
543	break;
544	case RECORD_FUNCTION_CHECK:
545	rc = seq_write_gcov_u32(seq, get_func(iter)->checksum);
546	break;
547	case RECORD_COUNT_TAG:
548	rc = seq_write_gcov_u32(seq,
549	GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type));
550	break;
551	case RECORD_COUNT_LEN:
552	rc = seq_write_gcov_u32(seq,
553	get_func(iter)->n_ctrs[iter->type] * 2);
554	break;
555	case RECORD_COUNT:
556	rc = seq_write_gcov_u64(seq,
557	iter->info->counts[iter->type].
558	values[iter->count + get_type(iter)->offset]);
559	break;
560	}
561	return rc;
562	}