[PATCH v2 10/10] gcov: Remove old GCC 3.4 support

Will Deacon
2020-01-23T15:34:21Z

The kernel requires at least GCC 4.8 in order to build, and so there is
no need to cater for the pre-4.7 gcov format.

Remove the obsolete code.

Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
kernel/gcov/Kconfig | 24 --
kernel/gcov/Makefile | 3 +-
kernel/gcov/gcc_3_4.c | 573 ------------------------------------------
3 files changed, 1 insertion(+), 599 deletions(-)
delete mode 100644 kernel/gcov/gcc_3_4.c

diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 060e8e726755..8df7fad82df8 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -51,28 +51,4 @@ config GCOV_PROFILE_ALL
larger and run slower. Also be sure to exclude files from profiling
which are not linked to the kernel image to prevent linker errors.

-choice
- prompt "Specify GCOV format"
- depends on GCOV_KERNEL
- depends on CC_IS_GCC
- ---help---
- The gcov format is usually determined by the GCC version, and the
- default is chosen according to your GCC version. However, there are
- exceptions where format changes are integrated in lower-version GCCs.
- In such a case, change this option to adjust the format used in the
- kernel accordingly.
-
-config GCOV_FORMAT_3_4
- bool "GCC 3.4 format"
- depends on GCC_VERSION < 40700
- ---help---
- Select this option to use the format defined by GCC 3.4.
-
-config GCOV_FORMAT_4_7
- bool "GCC 4.7 format"
- ---help---
- Select this option to use the format defined by GCC 4.7.
-
-endchoice
-
endmenu
diff --git a/kernel/gcov/Makefile b/kernel/gcov/Makefile
index d66a74b0f100..16f8ecc7d882 100644
--- a/kernel/gcov/Makefile
+++ b/kernel/gcov/Makefile
@@ -2,6 +2,5 @@
ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"'

obj-y := base.o fs.o
-obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_base.o gcc_3_4.o
-obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_base.o gcc_4_7.o
+obj-$(CONFIG_CC_IS_GCC) += gcc_base.o gcc_4_7.o
obj-$(CONFIG_CC_IS_CLANG) += clang.o
diff --git a/kernel/gcov/gcc_3_4.c b/kernel/gcov/gcc_3_4.c
deleted file mode 100644
index 801ee4b0b969..000000000000
--- a/kernel/gcov/gcc_3_4.c
+++ /dev/null
@@ -1,573 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This code provides functions to handle gcc's profiling data format
- * introduced with gcc 3.4. Future versions of gcc may change the gcov
- * format (as happened before), so all format-specific information needs
- * to be kept modular and easily exchangeable.
- *
- * This file is based on gcc-internal definitions. Functions and data
- * structures are defined to be compatible with gcc counterparts.
- * For a better understanding, refer to gcc source: gcc/gcov-io.h.
- *
- * Copyright IBM Corp. 2009
- * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
- *
- * Uses gcc-internal data definitions.
- */
-
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/seq_file.h>
-#include <linux/vmalloc.h>
-#include "gcov.h"
-
-#define GCOV_COUNTERS 5
-
-static struct gcov_info *gcov_info_head;
-
-/**
- * struct gcov_fn_info - profiling meta data per function
- * @ident: object file-unique function identifier
- * @checksum: function checksum
- * @n_ctrs: number of values per counter type belonging to this function
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time.
- */
-struct gcov_fn_info {
- unsigned int ident;
- unsigned int checksum;
- unsigned int n_ctrs[0];
-};
-
-/**
- * struct gcov_ctr_info - profiling data per counter type
- * @num: number of counter values for this type
- * @values: array of counter values for this type
- * @merge: merge function for counter values of this type (unused)
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time with the exception of the values array.
- */
-struct gcov_ctr_info {
- unsigned int num;
- gcov_type *values;
- void (*merge)(gcov_type *, unsigned int);
-};
-
-/**
- * struct gcov_info - profiling data per object file
- * @version: gcov version magic indicating the gcc version used for compilation
- * @next: list head for a singly-linked list
- * @stamp: time stamp
- * @filename: name of the associated gcov data file
- * @n_functions: number of instrumented functions
- * @functions: function data
- * @ctr_mask: mask specifying which counter types are active
- * @counts: counter data per counter type
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time with the exception of the next pointer.
- */
-struct gcov_info {
- unsigned int version;
- struct gcov_info *next;
- unsigned int stamp;
- const char *filename;
- unsigned int n_functions;
- const struct gcov_fn_info *functions;
- unsigned int ctr_mask;
- struct gcov_ctr_info counts[0];
-};
-
-/**
- * gcov_info_filename - return info filename
- * @info: profiling data set
- */
-const char *gcov_info_filename(struct gcov_info *info)
-{
- return info->filename;
-}
-
-/**
- * gcov_info_version - return info version
- * @info: profiling data set
- */
-unsigned int gcov_info_version(struct gcov_info *info)
-{
- return info->version;
-}
-
-/**
- * gcov_info_next - return next profiling data set
- * @info: profiling data set
- *
- * Returns next gcov_info following @info or first gcov_info in the chain if
- * @info is %NULL.
- */
-struct gcov_info *gcov_info_next(struct gcov_info *info)
-{
- if (!info)
- return gcov_info_head;
-
- return info->next;
-}
-
-/**
- * gcov_info_link - link/add profiling data set to the list
- * @info: profiling data set
- */
-void gcov_info_link(struct gcov_info *info)
-{
- info->next = gcov_info_head;
- gcov_info_head = info;
-}
-
-/**
- * gcov_info_unlink - unlink/remove profiling data set from the list
- * @prev: previous profiling data set
- * @info: profiling data set
- */
-void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
-{
- if (prev)
- prev->next = info->next;
- else
- gcov_info_head = info->next;
-}
-
-/**
- * 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. Based on gcc magic. Doesn't change
- * at run-time.
- */
-static int counter_active(struct gcov_info *info, unsigned int type)
-{
- return (1 << type) & info->ctr_mask;
-}
-
-/* Determine number of active counters. Based on gcc magic. */
-static unsigned int num_counter_active(struct gcov_info *info)
-{
- unsigned int i;
- unsigned int result = 0;
-
- for (i = 0; i < GCOV_COUNTERS; i++) {
- if (counter_active(info, i))
- result++;
- }
- return result;
-}
-
-/**
- * gcov_info_reset - reset profiling data to zero
- * @info: profiling data set
- */
-void gcov_info_reset(struct gcov_info *info)
-{
- unsigned int active = num_counter_active(info);
- unsigned int i;
-
- for (i = 0; i < active; i++) {
- memset(info->counts[i].values, 0,
- info->counts[i].num * sizeof(gcov_type));
- }
-}
-
-/**
- * gcov_info_is_compatible - check if profiling data can be added
- * @info1: first profiling data set
- * @info2: second profiling data set
- *
- * Returns non-zero if profiling data can be added, zero otherwise.
- */
-int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
-{
- return (info1->stamp == info2->stamp);
-}
-
-/**
- * gcov_info_add - add up profiling data
- * @dest: profiling data set to which data is added
- * @source: profiling data set which is added
- *
- * Adds profiling counts of @source to @dest.
- */
-void gcov_info_add(struct gcov_info *dest, struct gcov_info *source)
-{
- unsigned int i;
- unsigned int j;
-
- for (i = 0; i < num_counter_active(dest); i++) {
- for (j = 0; j < dest->counts[i].num; j++) {
- dest->counts[i].values[j] +=
- source->counts[i].values[j];
- }
- }
-}
-
-/* Get size of function info entry. Based on gcc magic. */
-static size_t get_fn_size(struct gcov_info *info)
-{
- size_t size;
-
- size = sizeof(struct gcov_fn_info) + num_counter_active(info) *
- sizeof(unsigned int);
- if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int))
- size = ALIGN(size, __alignof__(struct gcov_fn_info));
- return size;
-}
-
-/* Get address of function info entry. Based on gcc magic. */
-static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn)
-{
- return (struct gcov_fn_info *)
- ((char *) info->functions + fn * get_fn_size(info));
-}
-
-/**
- * gcov_info_dup - duplicate profiling data set
- * @info: profiling data set to duplicate
- *
- * Return newly allocated duplicate on success, %NULL on error.
- */
-struct gcov_info *gcov_info_dup(struct gcov_info *info)
-{
- struct gcov_info *dup;
- unsigned int i;
- unsigned int active;
-
- /* Duplicate gcov_info. */
- active = num_counter_active(info);
- dup = kzalloc(struct_size(dup, counts, active), GFP_KERNEL);
- if (!dup)
- return NULL;
- dup->version = info->version;
- dup->stamp = info->stamp;
- dup->n_functions = info->n_functions;
- dup->ctr_mask = info->ctr_mask;
- /* Duplicate filename. */
- dup->filename = kstrdup(info->filename, GFP_KERNEL);
- if (!dup->filename)
- goto err_free;
- /* Duplicate table of functions. */
- dup->functions = kmemdup(info->functions, info->n_functions *
- get_fn_size(info), GFP_KERNEL);
- if (!dup->functions)
- goto err_free;
- /* Duplicate counter arrays. */
- for (i = 0; i < active ; i++) {
- struct gcov_ctr_info *ctr = &info->counts[i];
- size_t size = ctr->num * sizeof(gcov_type);
-
- dup->counts[i].num = ctr->num;
- dup->counts[i].merge = ctr->merge;
- dup->counts[i].values = vmalloc(size);
- if (!dup->counts[i].values)
- goto err_free;
- memcpy(dup->counts[i].values, ctr->values, size);
- }
- return dup;
-
-err_free:
- gcov_info_free(dup);
- return NULL;
-}
-
-/**
- * gcov_info_free - release memory for profiling data set duplicate
- * @info: profiling data set duplicate to free
- */
-void gcov_info_free(struct gcov_info *info)
-{
- unsigned int active = num_counter_active(info);
- unsigned int i;
-
- for (i = 0; i < active ; i++)
- vfree(info->counts[i].values);
- kfree(info->functions);
- kfree(info->filename);
- kfree(info);
-}
-
-/**
- * struct type_info - iterator helper array
- * @ctr_type: counter type
- * @offset: index of the first value of the current function for this type
- *
- * This array is needed to convert the in-memory data format into the in-file
- * data format:
- *
- * In-memory:
- * for each counter type
- * for each function
- * values
- *
- * In-file:
- * for each function
- * for each counter type
- * values
- *
- * See gcc source gcc/gcov-io.h for more information on data organization.
- */
-struct type_info {
- int ctr_type;
- unsigned int offset;
-};
-
-/**
- * struct gcov_iterator - specifies current file position in logical records
- * @info: associated profiling data
- * @record: record type
- * @function: function number
- * @type: counter type
- * @count: index into values array
- * @num_types: number of counter types
- * @type_info: helper array to get values-array offset for current function
- */
-struct gcov_iterator {
- struct gcov_info *info;
-
- int record;
- unsigned int function;
- unsigned int type;
- unsigned int count;
-
- int num_types;
- struct type_info type_info[0];
-};
-
-static struct gcov_fn_info *get_func(struct gcov_iterator *iter)
-{
- return get_fn_info(iter->info, iter->function);
-}
-
-static struct type_info *get_type(struct gcov_iterator *iter)
-{
- return &iter->type_info[iter->type];
-}
-
-/**
- * gcov_iter_new - allocate and initialize profiling data iterator
- * @info: profiling data set to be iterated
- *
- * Return file iterator on success, %NULL otherwise.
- */
-struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
-{
- struct gcov_iterator *iter;
-
- iter = kzalloc(struct_size(iter, type_info, num_counter_active(info)),
- GFP_KERNEL);
- if (iter)
- iter->info = info;
-
- return iter;
-}
-
-/**
- * gcov_iter_free - release memory for iterator
- * @iter: file iterator to free
- */
-void gcov_iter_free(struct gcov_iterator *iter)
-{
- kfree(iter);
-}
-
-/**
- * gcov_iter_get_info - return profiling data set for given file iterator
- * @iter: file iterator
- */
-struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter)
-{
- return iter->info;
-}
-
-/**
- * gcov_iter_start - reset file iterator to starting position
- * @iter: file iterator
- */
-void gcov_iter_start(struct gcov_iterator *iter)
-{
- int i;
-
- iter->record = 0;
- iter->function = 0;
- iter->type = 0;
- iter->count = 0;
- iter->num_types = 0;
- for (i = 0; i < GCOV_COUNTERS; i++) {
- if (counter_active(iter->info, i)) {
- iter->type_info[iter->num_types].ctr_type = i;
- iter->type_info[iter->num_types++].offset = 0;
- }
- }
-}
-
-/* Mapping of logical record number to actual file content. */
-#define RECORD_FILE_MAGIC 0
-#define RECORD_GCOV_VERSION 1
-#define RECORD_TIME_STAMP 2
-#define RECORD_FUNCTION_TAG 3
-#define RECORD_FUNCTON_TAG_LEN 4
-#define RECORD_FUNCTION_IDENT 5
-#define RECORD_FUNCTION_CHECK 6
-#define RECORD_COUNT_TAG 7
-#define RECORD_COUNT_LEN 8
-#define RECORD_COUNT 9
-
-/**
- * gcov_iter_next - advance file iterator to next logical record
- * @iter: file iterator
- *
- * Return zero if new position is valid, non-zero if iterator has reached end.
- */
-int gcov_iter_next(struct gcov_iterator *iter)
-{
- switch (iter->record) {
- case RECORD_FILE_MAGIC:
- case RECORD_GCOV_VERSION:
- case RECORD_FUNCTION_TAG:
- case RECORD_FUNCTON_TAG_LEN:
- case RECORD_FUNCTION_IDENT:
- case RECORD_COUNT_TAG:
- /* Advance to next record */
- iter->record++;
- break;
- case RECORD_COUNT:
- /* Advance to next count */
- iter->count++;
- /* fall through */
- case RECORD_COUNT_LEN:
- if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
- iter->record = 9;
- break;
- }
- /* Advance to next counter type */
- get_type(iter)->offset += iter->count;
- iter->count = 0;
- iter->type++;
- /* fall through */
- case RECORD_FUNCTION_CHECK:
- if (iter->type < iter->num_types) {
- iter->record = 7;
- break;
- }
- /* Advance to next function */
- iter->type = 0;
- iter->function++;
- /* fall through */
- case RECORD_TIME_STAMP:
- if (iter->function < iter->info->n_functions)
- iter->record = 3;
- else
- iter->record = -1;
- break;
- }
- /* Check for EOF. */
- if (iter->record == -1)
- return -EINVAL;
- else
- return 0;
-}
-
-/**
- * seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file
- * @seq: seq_file handle
- * @v: value to be stored
- *
- * Number format defined by gcc: numbers are recorded in the 32 bit
- * unsigned binary form of the endianness of the machine generating the
- * file.
- */
-static int seq_write_gcov_u32(struct seq_file *seq, u32 v)
-{
- return seq_write(seq, &v, sizeof(v));
-}
-
-/**
- * seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file
- * @seq: seq_file handle
- * @v: value to be stored
- *
- * Number format defined by gcc: numbers are recorded in the 32 bit
- * unsigned binary form of the endianness of the machine generating the
- * file. 64 bit numbers are stored as two 32 bit numbers, the low part
- * first.
- */
-static int seq_write_gcov_u64(struct seq_file *seq, u64 v)
-{
- u32 data[2];
-
- data[0] = (v & 0xffffffffUL);
- data[1] = (v >> 32);
- return seq_write(seq, data, sizeof(data));
-}
-
-/**
- * gcov_iter_write - write data for current pos to seq_file
- * @iter: file iterator
- * @seq: seq_file handle
- *
- * Return zero on success, non-zero otherwise.
- */
-int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq)
-{
- int rc = -EINVAL;
-
- switch (iter->record) {
- case RECORD_FILE_MAGIC:
- rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
- break;
- case RECORD_GCOV_VERSION:
- rc = seq_write_gcov_u32(seq, iter->info->version);
- break;
- case RECORD_TIME_STAMP:
- rc = seq_write_gcov_u32(seq, iter->info->stamp);
- break;
- case RECORD_FUNCTION_TAG:
- rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION);
- break;
- case RECORD_FUNCTON_TAG_LEN:
- rc = seq_write_gcov_u32(seq, 2);
- break;
- case RECORD_FUNCTION_IDENT:
- rc = seq_write_gcov_u32(seq, get_func(iter)->ident);
- break;
- case RECORD_FUNCTION_CHECK:
- rc = seq_write_gcov_u32(seq, get_func(iter)->checksum);
- break;
- case RECORD_COUNT_TAG:
- rc = seq_write_gcov_u32(seq,
- GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type));
- break;
- case RECORD_COUNT_LEN:
- rc = seq_write_gcov_u32(seq,
- get_func(iter)->n_ctrs[iter->type] * 2);
- break;
- case RECORD_COUNT:
- rc = seq_write_gcov_u64(seq,
- iter->info->counts[iter->type].
- values[iter->count + get_type(iter)->offset]);
- break;
- }
- return rc;
-}
--
2.25.0.341.g760bfbb309-goog