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![Frantisek Hrbata](/assets/img/avatar_default.png)
Since also the gcov structures(gcov_info, gcov_fn_info, gcov_ctr_info) can change between gcc releases, as shown in gcc 4.7, they cannot be defined in a common header and need to be moved to a specific gcc implemention file. This also requires to make the gcov_info structure opaque for the common code and to introduce simple helpers for accessing data inside gcov_info. Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Gospodarek <agospoda@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
562 lines
14 KiB
C
562 lines
14 KiB
C
/*
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* This code provides functions to handle gcc's profiling data format
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* introduced with gcc 3.4. Future versions of gcc may change the gcov
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* format (as happened before), so all format-specific information needs
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* to be kept modular and easily exchangeable.
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*
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* This file is based on gcc-internal definitions. Functions and data
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* structures are defined to be compatible with gcc counterparts.
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* For a better understanding, refer to gcc source: gcc/gcov-io.h.
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*
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* Copyright IBM Corp. 2009
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* Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
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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 5
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static struct gcov_info *gcov_info_head;
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/**
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* struct gcov_fn_info - profiling meta data per function
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* @ident: object file-unique function identifier
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* @checksum: function checksum
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* @n_ctrs: number of values per counter type belonging to this function
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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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struct gcov_fn_info {
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unsigned int ident;
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unsigned int checksum;
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unsigned int n_ctrs[0];
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};
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/**
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* struct gcov_ctr_info - profiling data per counter type
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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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* @merge: merge function for counter values of this type (unused)
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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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void (*merge)(gcov_type *, unsigned int);
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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: time stamp
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* @filename: name of the associated gcov data file
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* @n_functions: number of instrumented functions
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* @functions: function data
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* @ctr_mask: mask specifying which counter types are active
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* @counts: counter data per counter 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 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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unsigned int n_functions;
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const struct gcov_fn_info *functions;
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unsigned int ctr_mask;
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struct gcov_ctr_info counts[0];
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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. Based on gcc magic. Doesn't change
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* 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 (1 << type) & info->ctr_mask;
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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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unsigned int active = num_counter_active(info);
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unsigned int i;
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for (i = 0; i < active; i++) {
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memset(info->counts[i].values, 0,
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info->counts[i].num * sizeof(gcov_type));
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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 *dest, struct gcov_info *source)
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{
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unsigned int i;
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unsigned int j;
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for (i = 0; i < num_counter_active(dest); i++) {
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for (j = 0; j < dest->counts[i].num; j++) {
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dest->counts[i].values[j] +=
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source->counts[i].values[j];
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}
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}
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}
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/* Get size of function info entry. Based on gcc magic. */
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static size_t get_fn_size(struct gcov_info *info)
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{
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size_t size;
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size = sizeof(struct gcov_fn_info) + num_counter_active(info) *
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sizeof(unsigned int);
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if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int))
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size = ALIGN(size, __alignof__(struct gcov_fn_info));
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return size;
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}
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/* Get address of function info entry. Based on gcc magic. */
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static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn)
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{
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return (struct gcov_fn_info *)
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((char *) info->functions + fn * get_fn_size(info));
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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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unsigned int i;
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unsigned int active;
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/* Duplicate gcov_info. */
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active = num_counter_active(info);
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dup = kzalloc(sizeof(struct gcov_info) +
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sizeof(struct gcov_ctr_info) * active, GFP_KERNEL);
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if (!dup)
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return NULL;
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dup->version = info->version;
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dup->stamp = info->stamp;
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dup->n_functions = info->n_functions;
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dup->ctr_mask = info->ctr_mask;
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/* Duplicate filename. */
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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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/* Duplicate table of functions. */
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dup->functions = kmemdup(info->functions, info->n_functions *
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get_fn_size(info), GFP_KERNEL);
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if (!dup->functions)
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goto err_free;
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/* Duplicate counter arrays. */
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for (i = 0; i < active ; i++) {
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struct gcov_ctr_info *ctr = &info->counts[i];
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size_t size = ctr->num * sizeof(gcov_type);
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dup->counts[i].num = ctr->num;
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dup->counts[i].merge = ctr->merge;
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dup->counts[i].values = vmalloc(size);
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if (!dup->counts[i].values)
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goto err_free;
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memcpy(dup->counts[i].values, ctr->values, size);
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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 = num_counter_active(info);
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unsigned int i;
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for (i = 0; i < active ; i++)
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vfree(info->counts[i].values);
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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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/**
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* struct type_info - iterator helper array
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* @ctr_type: counter type
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* @offset: index of the first value of the current function for this type
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*
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* This array is needed to convert the in-memory data format into the in-file
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* data format:
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*
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* In-memory:
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* for each counter type
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* for each function
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* values
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*
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* In-file:
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* for each function
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* for each counter type
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* values
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*
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* See gcc source gcc/gcov-io.h for more information on data organization.
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*/
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struct type_info {
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int ctr_type;
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unsigned int offset;
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};
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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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* @record: record type
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* @function: function number
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* @type: counter type
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* @count: index into values array
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* @num_types: number of counter types
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* @type_info: helper array to get values-array offset for current function
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*/
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struct gcov_iterator {
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struct gcov_info *info;
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int record;
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unsigned int function;
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unsigned int type;
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unsigned int count;
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int num_types;
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struct type_info type_info[0];
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};
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static struct gcov_fn_info *get_func(struct gcov_iterator *iter)
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{
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return get_fn_info(iter->info, iter->function);
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}
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static struct type_info *get_type(struct gcov_iterator *iter)
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{
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return &iter->type_info[iter->type];
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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) +
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num_counter_active(info) * sizeof(struct type_info),
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GFP_KERNEL);
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if (iter)
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iter->info = info;
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return iter;
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}
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/**
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* gcov_iter_free - release memory for iterator
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* @iter: file iterator to free
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*/
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void gcov_iter_free(struct gcov_iterator *iter)
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{
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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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int i;
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iter->record = 0;
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iter->function = 0;
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iter->type = 0;
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iter->count = 0;
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iter->num_types = 0;
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for (i = 0; i < GCOV_COUNTERS; i++) {
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if (counter_active(iter->info, i)) {
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iter->type_info[iter->num_types].ctr_type = i;
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iter->type_info[iter->num_types++].offset = 0;
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}
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}
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}
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/* Mapping of logical record number to actual file content. */
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#define RECORD_FILE_MAGIC 0
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#define RECORD_GCOV_VERSION 1
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#define RECORD_TIME_STAMP 2
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#define RECORD_FUNCTION_TAG 3
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#define RECORD_FUNCTON_TAG_LEN 4
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#define RECORD_FUNCTION_IDENT 5
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#define RECORD_FUNCTION_CHECK 6
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#define RECORD_COUNT_TAG 7
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#define RECORD_COUNT_LEN 8
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#define RECORD_COUNT 9
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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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switch (iter->record) {
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case RECORD_FILE_MAGIC:
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case RECORD_GCOV_VERSION:
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case RECORD_FUNCTION_TAG:
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case RECORD_FUNCTON_TAG_LEN:
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case RECORD_FUNCTION_IDENT:
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case RECORD_COUNT_TAG:
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/* Advance to next record */
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iter->record++;
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break;
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case RECORD_COUNT:
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/* Advance to next count */
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iter->count++;
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/* fall through */
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case RECORD_COUNT_LEN:
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if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
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iter->record = 9;
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break;
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}
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/* Advance to next counter type */
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get_type(iter)->offset += iter->count;
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iter->count = 0;
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iter->type++;
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/* fall through */
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case RECORD_FUNCTION_CHECK:
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if (iter->type < iter->num_types) {
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iter->record = 7;
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break;
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}
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/* Advance to next function */
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iter->type = 0;
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iter->function++;
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/* fall through */
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case RECORD_TIME_STAMP:
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if (iter->function < iter->info->n_functions)
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iter->record = 3;
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else
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iter->record = -1;
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break;
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}
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/* Check for EOF. */
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if (iter->record == -1)
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return -EINVAL;
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else
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return 0;
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}
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/**
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* seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file
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* @seq: seq_file handle
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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.
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*/
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static int seq_write_gcov_u32(struct seq_file *seq, u32 v)
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{
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return seq_write(seq, &v, sizeof(v));
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}
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/**
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* seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file
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* @seq: seq_file handle
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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.
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*/
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static int seq_write_gcov_u64(struct seq_file *seq, u64 v)
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{
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u32 data[2];
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data[0] = (v & 0xffffffffUL);
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data[1] = (v >> 32);
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return seq_write(seq, data, sizeof(data));
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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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int rc = -EINVAL;
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switch (iter->record) {
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case RECORD_FILE_MAGIC:
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rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
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|
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;
|
|
}
|