// SPDX-License-Identifier: GPL-2.0
|
/*
|
* This code provides functions to handle gcc's profiling data format
|
* introduced with gcc 4.7.
|
*
|
* This file is based heavily on gcc_3_4.c file.
|
*
|
* For a better understanding, refer to gcc source:
|
* gcc/gcov-io.h
|
* libgcc/libgcov.c
|
*
|
* 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"
|
|
#if (__GNUC__ >= 10)
|
#define GCOV_COUNTERS 8
|
#elif (__GNUC__ >= 7)
|
#define GCOV_COUNTERS 9
|
#elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
|
#define GCOV_COUNTERS 10
|
#elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9
|
#define GCOV_COUNTERS 9
|
#else
|
#define GCOV_COUNTERS 8
|
#endif
|
|
#define GCOV_TAG_FUNCTION_LENGTH 3
|
|
/* Since GCC 12.1 sizes are in BYTES and not in WORDS (4B). */
|
#if (__GNUC__ >= 12)
|
#define GCOV_UNIT_SIZE 4
|
#else
|
#define GCOV_UNIT_SIZE 1
|
#endif
|
|
static struct gcov_info *gcov_info_head;
|
|
/**
|
* struct gcov_ctr_info - information about counters for a single function
|
* @num: number of counter values for this type
|
* @values: array of counter values for this type
|
*
|
* 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;
|
};
|
|
/**
|
* struct gcov_fn_info - profiling meta data per function
|
* @key: comdat key
|
* @ident: unique ident of function
|
* @lineno_checksum: function lineo_checksum
|
* @cfg_checksum: function cfg checksum
|
* @ctrs: instrumented counters
|
*
|
* This data is generated by gcc during compilation and doesn't change
|
* at run-time.
|
*
|
* Information about a single function. This uses the trailing array
|
* idiom. The number of counters is determined from the merge pointer
|
* array in gcov_info. The key is used to detect which of a set of
|
* comdat functions was selected -- it points to the gcov_info object
|
* of the object file containing the selected comdat function.
|
*/
|
struct gcov_fn_info {
|
const struct gcov_info *key;
|
unsigned int ident;
|
unsigned int lineno_checksum;
|
unsigned int cfg_checksum;
|
struct gcov_ctr_info ctrs[];
|
};
|
|
/**
|
* 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: uniquifying time stamp
|
* @filename: name of the associated gcov data file
|
* @merge: merge functions (null for unused counter type)
|
* @n_functions: number of instrumented functions
|
* @functions: pointer to pointers to function information
|
*
|
* 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;
|
void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int);
|
unsigned int n_functions;
|
struct gcov_fn_info **functions;
|
};
|
|
/**
|
* 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;
|
}
|
|
/**
|
* gcov_info_within_module - check if a profiling data set belongs to a module
|
* @info: profiling data set
|
* @mod: module
|
*
|
* Returns true if profiling data belongs module, false otherwise.
|
*/
|
bool gcov_info_within_module(struct gcov_info *info, struct module *mod)
|
{
|
return within_module((unsigned long)info, mod);
|
}
|
|
/* 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. Doesn't change at run-time.
|
*/
|
static int counter_active(struct gcov_info *info, unsigned int type)
|
{
|
return info->merge[type] ? 1 : 0;
|
}
|
|
/* 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)
|
{
|
struct gcov_ctr_info *ci_ptr;
|
unsigned int fi_idx;
|
unsigned int ct_idx;
|
|
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
|
ci_ptr = info->functions[fi_idx]->ctrs;
|
|
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
|
if (!counter_active(info, ct_idx))
|
continue;
|
|
memset(ci_ptr->values, 0,
|
sizeof(gcov_type) * ci_ptr->num);
|
ci_ptr++;
|
}
|
}
|
}
|
|
/**
|
* 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 *dst, struct gcov_info *src)
|
{
|
struct gcov_ctr_info *dci_ptr;
|
struct gcov_ctr_info *sci_ptr;
|
unsigned int fi_idx;
|
unsigned int ct_idx;
|
unsigned int val_idx;
|
|
for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++) {
|
dci_ptr = dst->functions[fi_idx]->ctrs;
|
sci_ptr = src->functions[fi_idx]->ctrs;
|
|
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
|
if (!counter_active(src, ct_idx))
|
continue;
|
|
for (val_idx = 0; val_idx < sci_ptr->num; val_idx++)
|
dci_ptr->values[val_idx] +=
|
sci_ptr->values[val_idx];
|
|
dci_ptr++;
|
sci_ptr++;
|
}
|
}
|
}
|
|
/**
|
* 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;
|
struct gcov_ctr_info *dci_ptr; /* dst counter info */
|
struct gcov_ctr_info *sci_ptr; /* src counter info */
|
unsigned int active;
|
unsigned int fi_idx; /* function info idx */
|
unsigned int ct_idx; /* counter type idx */
|
size_t fi_size; /* function info size */
|
size_t cv_size; /* counter values size */
|
|
dup = kmemdup(info, sizeof(*dup), GFP_KERNEL);
|
if (!dup)
|
return NULL;
|
|
dup->next = NULL;
|
dup->filename = NULL;
|
dup->functions = NULL;
|
|
dup->filename = kstrdup(info->filename, GFP_KERNEL);
|
if (!dup->filename)
|
goto err_free;
|
|
dup->functions = kcalloc(info->n_functions,
|
sizeof(struct gcov_fn_info *), GFP_KERNEL);
|
if (!dup->functions)
|
goto err_free;
|
|
active = num_counter_active(info);
|
fi_size = sizeof(struct gcov_fn_info);
|
fi_size += sizeof(struct gcov_ctr_info) * active;
|
|
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
|
dup->functions[fi_idx] = kzalloc(fi_size, GFP_KERNEL);
|
if (!dup->functions[fi_idx])
|
goto err_free;
|
|
*(dup->functions[fi_idx]) = *(info->functions[fi_idx]);
|
|
sci_ptr = info->functions[fi_idx]->ctrs;
|
dci_ptr = dup->functions[fi_idx]->ctrs;
|
|
for (ct_idx = 0; ct_idx < active; ct_idx++) {
|
|
cv_size = sizeof(gcov_type) * sci_ptr->num;
|
|
dci_ptr->values = vmalloc(cv_size);
|
|
if (!dci_ptr->values)
|
goto err_free;
|
|
dci_ptr->num = sci_ptr->num;
|
memcpy(dci_ptr->values, sci_ptr->values, cv_size);
|
|
sci_ptr++;
|
dci_ptr++;
|
}
|
}
|
|
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;
|
unsigned int fi_idx;
|
unsigned int ct_idx;
|
struct gcov_ctr_info *ci_ptr;
|
|
if (!info->functions)
|
goto free_info;
|
|
active = num_counter_active(info);
|
|
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
|
if (!info->functions[fi_idx])
|
continue;
|
|
ci_ptr = info->functions[fi_idx]->ctrs;
|
|
for (ct_idx = 0; ct_idx < active; ct_idx++, ci_ptr++)
|
vfree(ci_ptr->values);
|
|
kfree(info->functions[fi_idx]);
|
}
|
|
free_info:
|
kfree(info->functions);
|
kfree(info->filename);
|
kfree(info);
|
}
|
|
#define ITER_STRIDE PAGE_SIZE
|
|
/**
|
* struct gcov_iterator - specifies current file position in logical records
|
* @info: associated profiling data
|
* @buffer: buffer containing file data
|
* @size: size of buffer
|
* @pos: current position in file
|
*/
|
struct gcov_iterator {
|
struct gcov_info *info;
|
void *buffer;
|
size_t size;
|
loff_t pos;
|
};
|
|
/**
|
* store_gcov_u32 - store 32 bit number in gcov format to buffer
|
* @buffer: target buffer or NULL
|
* @off: offset into the buffer
|
* @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. Returns the number of bytes stored. If @buffer is %NULL, doesn't
|
* store anything.
|
*/
|
static size_t store_gcov_u32(void *buffer, size_t off, u32 v)
|
{
|
u32 *data;
|
|
if (buffer) {
|
data = buffer + off;
|
*data = v;
|
}
|
|
return sizeof(*data);
|
}
|
|
/**
|
* store_gcov_u64 - store 64 bit number in gcov format to buffer
|
* @buffer: target buffer or NULL
|
* @off: offset into the buffer
|
* @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. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
|
* anything.
|
*/
|
static size_t store_gcov_u64(void *buffer, size_t off, u64 v)
|
{
|
u32 *data;
|
|
if (buffer) {
|
data = buffer + off;
|
|
data[0] = (v & 0xffffffffUL);
|
data[1] = (v >> 32);
|
}
|
|
return sizeof(*data) * 2;
|
}
|
|
/**
|
* convert_to_gcda - convert profiling data set to gcda file format
|
* @buffer: the buffer to store file data or %NULL if no data should be stored
|
* @info: profiling data set to be converted
|
*
|
* Returns the number of bytes that were/would have been stored into the buffer.
|
*/
|
static size_t convert_to_gcda(char *buffer, struct gcov_info *info)
|
{
|
struct gcov_fn_info *fi_ptr;
|
struct gcov_ctr_info *ci_ptr;
|
unsigned int fi_idx;
|
unsigned int ct_idx;
|
unsigned int cv_idx;
|
size_t pos = 0;
|
|
/* File header. */
|
pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC);
|
pos += store_gcov_u32(buffer, pos, info->version);
|
pos += store_gcov_u32(buffer, pos, info->stamp);
|
|
#if (__GNUC__ >= 12)
|
/* Use zero as checksum of the compilation unit. */
|
pos += store_gcov_u32(buffer, pos, 0);
|
#endif
|
|
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
|
fi_ptr = info->functions[fi_idx];
|
|
/* Function record. */
|
pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
|
pos += store_gcov_u32(buffer, pos,
|
GCOV_TAG_FUNCTION_LENGTH * GCOV_UNIT_SIZE);
|
pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
|
pos += store_gcov_u32(buffer, pos, fi_ptr->lineno_checksum);
|
pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
|
|
ci_ptr = fi_ptr->ctrs;
|
|
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
|
if (!counter_active(info, ct_idx))
|
continue;
|
|
/* Counter record. */
|
pos += store_gcov_u32(buffer, pos,
|
GCOV_TAG_FOR_COUNTER(ct_idx));
|
pos += store_gcov_u32(buffer, pos,
|
ci_ptr->num * 2 * GCOV_UNIT_SIZE);
|
|
for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) {
|
pos += store_gcov_u64(buffer, pos,
|
ci_ptr->values[cv_idx]);
|
}
|
|
ci_ptr++;
|
}
|
}
|
|
return pos;
|
}
|
|
/**
|
* 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), GFP_KERNEL);
|
if (!iter)
|
goto err_free;
|
|
iter->info = info;
|
/* Dry-run to get the actual buffer size. */
|
iter->size = convert_to_gcda(NULL, info);
|
iter->buffer = vmalloc(iter->size);
|
if (!iter->buffer)
|
goto err_free;
|
|
convert_to_gcda(iter->buffer, info);
|
|
return iter;
|
|
err_free:
|
kfree(iter);
|
return NULL;
|
}
|
|
|
/**
|
* gcov_iter_get_info - return profiling data set for given file iterator
|
* @iter: file iterator
|
*/
|
void gcov_iter_free(struct gcov_iterator *iter)
|
{
|
vfree(iter->buffer);
|
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)
|
{
|
iter->pos = 0;
|
}
|
|
/**
|
* 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)
|
{
|
if (iter->pos < iter->size)
|
iter->pos += ITER_STRIDE;
|
|
if (iter->pos >= iter->size)
|
return -EINVAL;
|
|
return 0;
|
}
|
|
/**
|
* 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)
|
{
|
size_t len;
|
|
if (iter->pos >= iter->size)
|
return -EINVAL;
|
|
len = ITER_STRIDE;
|
if (iter->pos + len > iter->size)
|
len = iter->size - iter->pos;
|
|
seq_write(seq, iter->buffer + iter->pos, len);
|
|
return 0;
|
}
|
