561 lines
13 KiB
C
561 lines
13 KiB
C
/*
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* This code provides functions to handle gcc's profiling data format
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* introduced with gcc 4.7.
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*
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* This file is based heavily on gcc_3_4.c file.
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*
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* For a better understanding, refer to gcc source:
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* gcc/gcov-io.h
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* libgcc/libgcov.c
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*
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* Uses gcc-internal data definitions.
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*/
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/seq_file.h>
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#include <linux/vmalloc.h>
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#include "gcov.h"
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#define GCOV_COUNTERS 8
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#define GCOV_TAG_FUNCTION_LENGTH 3
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static struct gcov_info *gcov_info_head;
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/**
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* struct gcov_ctr_info - information about counters for a single function
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* @num: number of counter values for this type
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* @values: array of counter values for this type
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*
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* This data is generated by gcc during compilation and doesn't change
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* at run-time with the exception of the values array.
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*/
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struct gcov_ctr_info {
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unsigned int num;
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gcov_type *values;
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};
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/**
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* struct gcov_fn_info - profiling meta data per function
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* @key: comdat key
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* @ident: unique ident of function
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* @lineno_checksum: function lineo_checksum
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* @cfg_checksum: function cfg checksum
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* @ctrs: instrumented counters
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*
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* This data is generated by gcc during compilation and doesn't change
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* at run-time.
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*
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* Information about a single function. This uses the trailing array
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* idiom. The number of counters is determined from the merge pointer
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* array in gcov_info. The key is used to detect which of a set of
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* comdat functions was selected -- it points to the gcov_info object
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* of the object file containing the selected comdat function.
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*/
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struct gcov_fn_info {
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const struct gcov_info *key;
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unsigned int ident;
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unsigned int lineno_checksum;
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unsigned int cfg_checksum;
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struct gcov_ctr_info ctrs[0];
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};
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/**
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* struct gcov_info - profiling data per object file
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* @version: gcov version magic indicating the gcc version used for compilation
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* @next: list head for a singly-linked list
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* @stamp: uniquifying time stamp
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* @filename: name of the associated gcov data file
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* @merge: merge functions (null for unused counter type)
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* @n_functions: number of instrumented functions
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* @functions: pointer to pointers to function information
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*
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* This data is generated by gcc during compilation and doesn't change
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* at run-time with the exception of the next pointer.
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*/
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struct gcov_info {
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unsigned int version;
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struct gcov_info *next;
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unsigned int stamp;
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const char *filename;
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void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int);
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unsigned int n_functions;
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struct gcov_fn_info **functions;
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};
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/**
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* gcov_info_filename - return info filename
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* @info: profiling data set
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*/
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const char *gcov_info_filename(struct gcov_info *info)
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{
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return info->filename;
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}
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/**
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* gcov_info_version - return info version
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* @info: profiling data set
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*/
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unsigned int gcov_info_version(struct gcov_info *info)
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{
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return info->version;
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}
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/**
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* gcov_info_next - return next profiling data set
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* @info: profiling data set
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*
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* Returns next gcov_info following @info or first gcov_info in the chain if
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* @info is %NULL.
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*/
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struct gcov_info *gcov_info_next(struct gcov_info *info)
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{
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if (!info)
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return gcov_info_head;
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return info->next;
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}
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/**
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* gcov_info_link - link/add profiling data set to the list
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* @info: profiling data set
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*/
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void gcov_info_link(struct gcov_info *info)
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{
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info->next = gcov_info_head;
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gcov_info_head = info;
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}
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/**
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* gcov_info_unlink - unlink/remove profiling data set from the list
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* @prev: previous profiling data set
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* @info: profiling data set
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*/
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void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
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{
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if (prev)
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prev->next = info->next;
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else
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gcov_info_head = info->next;
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}
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/* Symbolic links to be created for each profiling data file. */
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const struct gcov_link gcov_link[] = {
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{ OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */
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{ 0, NULL},
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};
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/*
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* Determine whether a counter is active. Doesn't change at run-time.
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*/
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static int counter_active(struct gcov_info *info, unsigned int type)
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{
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return info->merge[type] ? 1 : 0;
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}
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/* Determine number of active counters. Based on gcc magic. */
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static unsigned int num_counter_active(struct gcov_info *info)
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{
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unsigned int i;
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unsigned int result = 0;
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for (i = 0; i < GCOV_COUNTERS; i++) {
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if (counter_active(info, i))
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result++;
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}
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return result;
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}
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/**
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* gcov_info_reset - reset profiling data to zero
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* @info: profiling data set
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*/
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void gcov_info_reset(struct gcov_info *info)
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{
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struct gcov_ctr_info *ci_ptr;
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unsigned int fi_idx;
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unsigned int ct_idx;
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for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
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ci_ptr = info->functions[fi_idx]->ctrs;
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for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
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if (!counter_active(info, ct_idx))
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continue;
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memset(ci_ptr->values, 0,
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sizeof(gcov_type) * ci_ptr->num);
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ci_ptr++;
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}
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}
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}
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/**
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* gcov_info_is_compatible - check if profiling data can be added
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* @info1: first profiling data set
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* @info2: second profiling data set
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*
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* Returns non-zero if profiling data can be added, zero otherwise.
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*/
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int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
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{
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return (info1->stamp == info2->stamp);
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}
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/**
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* gcov_info_add - add up profiling data
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* @dest: profiling data set to which data is added
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* @source: profiling data set which is added
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*
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* Adds profiling counts of @source to @dest.
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*/
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void gcov_info_add(struct gcov_info *dst, struct gcov_info *src)
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{
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struct gcov_ctr_info *dci_ptr;
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struct gcov_ctr_info *sci_ptr;
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unsigned int fi_idx;
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unsigned int ct_idx;
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unsigned int val_idx;
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for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++) {
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dci_ptr = dst->functions[fi_idx]->ctrs;
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sci_ptr = src->functions[fi_idx]->ctrs;
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for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
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if (!counter_active(src, ct_idx))
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continue;
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for (val_idx = 0; val_idx < sci_ptr->num; val_idx++)
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dci_ptr->values[val_idx] +=
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sci_ptr->values[val_idx];
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dci_ptr++;
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sci_ptr++;
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}
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}
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}
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/**
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* gcov_info_dup - duplicate profiling data set
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* @info: profiling data set to duplicate
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*
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* Return newly allocated duplicate on success, %NULL on error.
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*/
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struct gcov_info *gcov_info_dup(struct gcov_info *info)
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{
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struct gcov_info *dup;
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struct gcov_ctr_info *dci_ptr; /* dst counter info */
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struct gcov_ctr_info *sci_ptr; /* src counter info */
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unsigned int active;
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unsigned int fi_idx; /* function info idx */
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unsigned int ct_idx; /* counter type idx */
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size_t fi_size; /* function info size */
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size_t cv_size; /* counter values size */
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dup = kmemdup(info, sizeof(*dup), GFP_KERNEL);
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if (!dup)
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return NULL;
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dup->next = NULL;
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dup->filename = NULL;
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dup->functions = NULL;
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dup->filename = kstrdup(info->filename, GFP_KERNEL);
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if (!dup->filename)
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goto err_free;
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dup->functions = kcalloc(info->n_functions,
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sizeof(struct gcov_fn_info *), GFP_KERNEL);
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if (!dup->functions)
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goto err_free;
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active = num_counter_active(info);
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fi_size = sizeof(struct gcov_fn_info);
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fi_size += sizeof(struct gcov_ctr_info) * active;
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for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
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dup->functions[fi_idx] = kzalloc(fi_size, GFP_KERNEL);
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if (!dup->functions[fi_idx])
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goto err_free;
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*(dup->functions[fi_idx]) = *(info->functions[fi_idx]);
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sci_ptr = info->functions[fi_idx]->ctrs;
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dci_ptr = dup->functions[fi_idx]->ctrs;
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for (ct_idx = 0; ct_idx < active; ct_idx++) {
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cv_size = sizeof(gcov_type) * sci_ptr->num;
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dci_ptr->values = vmalloc(cv_size);
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if (!dci_ptr->values)
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goto err_free;
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dci_ptr->num = sci_ptr->num;
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memcpy(dci_ptr->values, sci_ptr->values, cv_size);
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sci_ptr++;
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dci_ptr++;
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}
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}
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return dup;
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err_free:
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gcov_info_free(dup);
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return NULL;
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}
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/**
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* gcov_info_free - release memory for profiling data set duplicate
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* @info: profiling data set duplicate to free
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*/
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void gcov_info_free(struct gcov_info *info)
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{
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unsigned int active;
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unsigned int fi_idx;
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unsigned int ct_idx;
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struct gcov_ctr_info *ci_ptr;
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if (!info->functions)
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goto free_info;
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active = num_counter_active(info);
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for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
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if (!info->functions[fi_idx])
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continue;
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ci_ptr = info->functions[fi_idx]->ctrs;
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for (ct_idx = 0; ct_idx < active; ct_idx++, ci_ptr++)
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vfree(ci_ptr->values);
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kfree(info->functions[fi_idx]);
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}
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free_info:
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kfree(info->functions);
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kfree(info->filename);
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kfree(info);
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}
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#define ITER_STRIDE PAGE_SIZE
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/**
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* struct gcov_iterator - specifies current file position in logical records
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* @info: associated profiling data
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* @buffer: buffer containing file data
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* @size: size of buffer
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* @pos: current position in file
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*/
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struct gcov_iterator {
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struct gcov_info *info;
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void *buffer;
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size_t size;
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loff_t pos;
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};
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/**
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* store_gcov_u32 - store 32 bit number in gcov format to buffer
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* @buffer: target buffer or NULL
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* @off: offset into the buffer
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* @v: value to be stored
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*
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* Number format defined by gcc: numbers are recorded in the 32 bit
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* unsigned binary form of the endianness of the machine generating the
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* file. Returns the number of bytes stored. If @buffer is %NULL, doesn't
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* store anything.
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*/
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static size_t store_gcov_u32(void *buffer, size_t off, u32 v)
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{
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u32 *data;
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if (buffer) {
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data = buffer + off;
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*data = v;
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}
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return sizeof(*data);
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}
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/**
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* store_gcov_u64 - store 64 bit number in gcov format to buffer
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* @buffer: target buffer or NULL
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* @off: offset into the buffer
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* @v: value to be stored
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*
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* Number format defined by gcc: numbers are recorded in the 32 bit
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* unsigned binary form of the endianness of the machine generating the
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* file. 64 bit numbers are stored as two 32 bit numbers, the low part
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* first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
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* anything.
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*/
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static size_t store_gcov_u64(void *buffer, size_t off, u64 v)
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{
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u32 *data;
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if (buffer) {
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data = buffer + off;
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data[0] = (v & 0xffffffffUL);
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data[1] = (v >> 32);
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}
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return sizeof(*data) * 2;
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}
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/**
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* convert_to_gcda - convert profiling data set to gcda file format
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* @buffer: the buffer to store file data or %NULL if no data should be stored
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* @info: profiling data set to be converted
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*
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* Returns the number of bytes that were/would have been stored into the buffer.
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*/
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static size_t convert_to_gcda(char *buffer, struct gcov_info *info)
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{
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struct gcov_fn_info *fi_ptr;
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struct gcov_ctr_info *ci_ptr;
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unsigned int fi_idx;
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unsigned int ct_idx;
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unsigned int cv_idx;
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size_t pos = 0;
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/* File header. */
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pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC);
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pos += store_gcov_u32(buffer, pos, info->version);
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pos += store_gcov_u32(buffer, pos, info->stamp);
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for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
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fi_ptr = info->functions[fi_idx];
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/* Function record. */
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pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
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pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION_LENGTH);
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pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
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pos += store_gcov_u32(buffer, pos, fi_ptr->lineno_checksum);
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pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
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ci_ptr = fi_ptr->ctrs;
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for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
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if (!counter_active(info, ct_idx))
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continue;
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/* Counter record. */
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pos += store_gcov_u32(buffer, pos,
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GCOV_TAG_FOR_COUNTER(ct_idx));
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pos += store_gcov_u32(buffer, pos, ci_ptr->num * 2);
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for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) {
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pos += store_gcov_u64(buffer, pos,
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ci_ptr->values[cv_idx]);
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}
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ci_ptr++;
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}
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}
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return pos;
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}
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/**
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* gcov_iter_new - allocate and initialize profiling data iterator
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* @info: profiling data set to be iterated
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*
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* Return file iterator on success, %NULL otherwise.
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*/
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struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
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{
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struct gcov_iterator *iter;
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iter = kzalloc(sizeof(struct gcov_iterator), GFP_KERNEL);
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if (!iter)
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goto err_free;
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iter->info = info;
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/* Dry-run to get the actual buffer size. */
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iter->size = convert_to_gcda(NULL, info);
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iter->buffer = vmalloc(iter->size);
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if (!iter->buffer)
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goto err_free;
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convert_to_gcda(iter->buffer, info);
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return iter;
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err_free:
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kfree(iter);
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return NULL;
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}
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/**
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* gcov_iter_get_info - return profiling data set for given file iterator
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* @iter: file iterator
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*/
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void gcov_iter_free(struct gcov_iterator *iter)
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{
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vfree(iter->buffer);
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kfree(iter);
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}
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/**
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* gcov_iter_get_info - return profiling data set for given file iterator
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* @iter: file iterator
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*/
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struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter)
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{
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return iter->info;
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}
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/**
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* gcov_iter_start - reset file iterator to starting position
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* @iter: file iterator
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*/
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void gcov_iter_start(struct gcov_iterator *iter)
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{
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iter->pos = 0;
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}
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/**
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* gcov_iter_next - advance file iterator to next logical record
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* @iter: file iterator
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*
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* Return zero if new position is valid, non-zero if iterator has reached end.
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*/
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int gcov_iter_next(struct gcov_iterator *iter)
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{
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if (iter->pos < iter->size)
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iter->pos += ITER_STRIDE;
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if (iter->pos >= iter->size)
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return -EINVAL;
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return 0;
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}
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/**
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* gcov_iter_write - write data for current pos to seq_file
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* @iter: file iterator
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* @seq: seq_file handle
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*
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* Return zero on success, non-zero otherwise.
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*/
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int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq)
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{
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size_t len;
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if (iter->pos >= iter->size)
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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;
|
|
}
|