linux/kernel/gcov/gcc_4_7.c
Johannes Berg 1391efa952 gcov: use kvmalloc()
Using vmalloc() in gcov is really quite wasteful, many of the objects
allocated are really small (e.g.  I've seen 24 bytes.) Use kvmalloc() to
automatically pick the better of kmalloc() or vmalloc() depending on the
size.

[johannes.berg@intel.com: fix clang-11+ build]
  Link: https://lkml.kernel.org/r/20210412214210.6e1ecca9cdc5.I24459763acf0591d5e6b31c7e3a59890d802f79c@changeid

Link: https://lkml.kernel.org/r/20210315235453.799e7a9d627d.I741d0db096c6f312910f7f1bcdfde0fda20801a4@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:32 -07:00

418 lines
10 KiB
C

// 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/mm.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
#else
#define GCOV_COUNTERS 9
#endif
#define GCOV_TAG_FUNCTION_LENGTH 3
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
* @dst: profiling data set to which data is added
* @src: profiling data set which is added
*
* Adds profiling counts of @src to @dst.
*/
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 = kvmalloc(cv_size, GFP_KERNEL);
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++)
kvfree(ci_ptr->values);
kfree(info->functions[fi_idx]);
}
free_info:
kfree(info->functions);
kfree(info->filename);
kfree(info);
}
/**
* 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.
*/
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);
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);
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);
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;
}