/*
* 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;
}
