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Message-Id: <1377247176-13537-3-git-send-email-fhrbata@redhat.com>
Date: Fri, 23 Aug 2013 10:39:34 +0200
From: Frantisek Hrbata <fhrbata@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: jstancek@...hat.com, keescook@...omium.org,
peter.oberparleiter@...ibm.com, rusty@...tcorp.com.au,
linux-arch@...r.kernel.org, arnd@...db.de, mgahagan@...hat.com,
agospoda@...hat.com
Subject: [RFC PATCH 2/4] gcov: add support for gcc 4.7 gcov format
The gcov in-memory format changed in gcc 4.7. The biggest change, which
requires this special implementation, is that gcov_info no longer contains
array of counters for each counter type for all functions and gcov_fn_info is
not used for mapping of function's counters to these arrays(offset). Now each
gcov_fn_info contans it's counters, which makes things a little bit easier.
This is heavily based on the previous gcc_3_4.c implementation.
Signed-off-by: Frantisek Hrbata <fhrbata@...hat.com>
---
kernel/gcov/base.c | 6 +
kernel/gcov/gcc_4_7.c | 612 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 618 insertions(+)
create mode 100644 kernel/gcov/gcc_4_7.c
diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c
index 912576a..f45b75b 100644
--- a/kernel/gcov/base.c
+++ b/kernel/gcov/base.c
@@ -79,6 +79,12 @@ void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
}
EXPORT_SYMBOL(__gcov_merge_delta);
+void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
+{
+ /* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_ior);
+
/**
* gcov_enable_events - enable event reporting through gcov_event()
*
diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
new file mode 100644
index 0000000..31bee00
--- /dev/null
+++ b/kernel/gcov/gcc_4_7.c
@@ -0,0 +1,612 @@
+/*
+ * This code provides functions to handle gcc's profiling data format
+ * introduced with gcc 4.7.
+ *
+ * This file is based heavily on gcc_3_4.c file.
+ *
+ * For a better understanding, refer to gcc source:
+ * gcc/gcov-io.h
+ * libgcc/libgcov.c
+ *
+ * Uses gcc-internal data definitions.
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/seq_file.h>
+#include "gcov.h"
+
+#define GCOV_COUNTERS 8
+#define GCOV_TAG_FUNCTION_LENGTH 3
+
+static struct gcov_info *gcov_info_head;
+
+/**
+ * struct gcov_ctr_info - information about counters for a single function
+ * @num: number of counter values for this type
+ * @values: array of counter values for this type
+ *
+ * This data is generated by gcc during compilation and doesn't change
+ * at run-time with the exception of the values array.
+ */
+struct gcov_ctr_info {
+ unsigned int num;
+ gcov_type *values;
+};
+
+/**
+ * struct gcov_fn_info - profiling meta data per function
+ * @key: comdat key
+ * @ident: unique ident of function
+ * @lineno_checksum: function lineo_checksum
+ * @cfg_checksum: function cfg checksum
+ * @ctrs: instrumented counters
+ *
+ * This data is generated by gcc during compilation and doesn't change
+ * at run-time.
+ *
+ * Information about a single function. This uses the trailing array
+ * idiom. The number of counters is determined from the merge pointer
+ * array in gcov_info. The key is used to detect which of a set of
+ * comdat functions was selected -- it points to the gcov_info object
+ * of the object file containing the selected comdat function.
+ */
+struct gcov_fn_info {
+ const struct gcov_info *key;
+ unsigned int ident;
+ unsigned int lineno_checksum;
+ unsigned int cfg_checksum;
+ struct gcov_ctr_info ctrs[0];
+};
+
+/**
+ * struct gcov_info - profiling data per object file
+ * @version: gcov version magic indicating the gcc version used for compilation
+ * @next: list head for a singly-linked list
+ * @stamp: uniquifying time stamp
+ * @filename: name of the associated gcov data file
+ * @merge: merge functions (null for unused counter type)
+ * @n_functions: number of instrumented functions
+ * @functions: pointer to pointers to function information
+ *
+ * This data is generated by gcc during compilation and doesn't change
+ * at run-time with the exception of the next pointer.
+ */
+struct gcov_info {
+ unsigned int version;
+ struct gcov_info *next;
+ unsigned int stamp;
+ const char *filename;
+ void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int);
+ unsigned int n_functions;
+ const struct gcov_fn_info *const *functions;
+};
+
+/**
+ * gcov_info_filename - return info filename
+ * @info: profiling data set
+ */
+const char *gcov_info_filename(struct gcov_info *info)
+{
+ return info->filename;
+}
+
+/**
+ * gcov_info_version - return info version
+ * @info: profiling data set
+ */
+unsigned int gcov_info_version(struct gcov_info *info)
+{
+ return info->version;
+}
+
+/**
+ * gcov_info_next - return next profiling data set
+ * @info: profiling data set
+ *
+ * Returns next gcov_info following @info or first gcov_info in the chain if
+ * @info is %NULL.
+ */
+struct gcov_info *gcov_info_next(struct gcov_info *info)
+{
+ if (!info)
+ return gcov_info_head;
+
+ return info->next;
+}
+
+/**
+ * gcov_info_link - link/add profiling data set to the list
+ * @info: profiling data set
+ */
+void gcov_info_link(struct gcov_info *info)
+{
+ info->next = gcov_info_head;
+ gcov_info_head = info;
+}
+
+/**
+ * gcov_info_unlink - unlink/remove profiling data set from the list
+ * @prev: previous profiling data set
+ * @info: profiling data set
+ */
+void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
+{
+ if (prev)
+ prev->next = info->next;
+ else
+ gcov_info_head = info->next;
+}
+
+/* Symbolic links to be created for each profiling data file. */
+const struct gcov_link gcov_link[] = {
+ { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */
+ { 0, NULL},
+};
+
+/*
+ * Determine whether a counter is active. Doesn't change at run-time.
+ */
+static int counter_active(struct gcov_info *info, unsigned int type)
+{
+ return info->merge[type] ? 1 : 0;
+}
+
+/* Determine number of active counters. Based on gcc magic. */
+static unsigned int num_counter_active(struct gcov_info *info)
+{
+ unsigned int i;
+ unsigned int result = 0;
+
+ for (i = 0; i < GCOV_COUNTERS; i++) {
+ if (counter_active(info, i))
+ result++;
+ }
+ return result;
+}
+
+/**
+ * gcov_info_reset - reset profiling data to zero
+ * @info: profiling data set
+ */
+void gcov_info_reset(struct gcov_info *info)
+{
+ const struct gcov_ctr_info *ci_ptr;
+ unsigned int fi_idx;
+ unsigned int t_idx;
+
+ for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++)
+ {
+ ci_ptr = info->functions[fi_idx]->ctrs;
+
+ for (t_idx = 0; t_idx < GCOV_COUNTERS; t_idx++) {
+ if (!counter_active(info, t_idx))
+ continue;
+
+ memset(ci_ptr->values, 0,
+ sizeof(gcov_type) * ci_ptr->num);
+ ci_ptr++;
+ }
+ }
+}
+
+/**
+ * gcov_info_is_compatible - check if profiling data can be added
+ * @info1: first profiling data set
+ * @info2: second profiling data set
+ *
+ * Returns non-zero if profiling data can be added, zero otherwise.
+ */
+int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
+{
+ return (info1->stamp == info2->stamp);
+}
+
+/**
+ * gcov_info_add - add up profiling data
+ * @dest: profiling data set to which data is added
+ * @source: profiling data set which is added
+ *
+ * Adds profiling counts of @source to @dest.
+ */
+void gcov_info_add(struct gcov_info *dst, struct gcov_info *src)
+{
+ const struct gcov_ctr_info *dci_ptr;
+ const struct gcov_ctr_info *sci_ptr;
+ unsigned int fi_idx;
+ unsigned int t_idx;
+ unsigned int val_idx;
+
+ for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++)
+ {
+ dci_ptr = dst->functions[fi_idx]->ctrs;
+ sci_ptr = src->functions[fi_idx]->ctrs;
+
+ for (t_idx = 0; t_idx < GCOV_COUNTERS; t_idx++) {
+ if (!counter_active(src, t_idx))
+ continue;
+
+ for (val_idx = 0; val_idx < sci_ptr->num; val_idx++)
+ dci_ptr->values[val_idx] +=
+ sci_ptr->values[val_idx];
+
+ dci_ptr++;
+ sci_ptr++;
+ }
+ }
+}
+
+/**
+ * gcov_info_dup - duplicate profiling data set
+ * @info: profiling data set to duplicate
+ *
+ * Return newly allocated duplicate on success, %NULL on error.
+ */
+struct gcov_info *gcov_info_dup(struct gcov_info *info)
+{
+ struct gcov_info *dup;
+ struct gcov_ctr_info *dci_ptr;
+ struct gcov_ctr_info *sci_ptr;
+ size_t size;
+ unsigned int active;
+ unsigned int fi_idx;
+ unsigned int t_idx;
+
+ dup = kmalloc(sizeof(struct gcov_info), GFP_KERNEL);
+ if (!dup)
+ return NULL;
+
+ *dup = *info;
+ dup->next = NULL;
+ dup->filename = NULL;
+ dup->functions = NULL;
+
+ dup->filename = kstrdup(info->filename, GFP_KERNEL);
+ if (!dup->filename)
+ goto err_free;
+
+ size = sizeof(void *) * info->n_functions;
+ dup->functions = kzalloc(size, GFP_KERNEL);
+ if (!dup->functions)
+ goto err_free;
+
+ active = num_counter_active(info);
+ size = sizeof(struct gcov_fn_info);
+ size += sizeof(struct gcov_ctr_info) * active;
+
+ for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
+ *(struct gcov_fn_info **)&dup->functions[fi_idx] =
+ kzalloc(size, GFP_KERNEL);
+ if (!dup->functions[fi_idx])
+ goto err_free;
+
+ *(struct gcov_fn_info *)&(*(dup->functions[fi_idx])) =
+ *(info->functions[fi_idx]);
+
+ sci_ptr = (struct gcov_ctr_info *)info->functions[fi_idx]->ctrs;
+ dci_ptr = (struct gcov_ctr_info *)dup->functions[fi_idx]->ctrs;
+
+ for (t_idx = 0; t_idx < GCOV_COUNTERS; t_idx++) {
+ if (!counter_active(info, t_idx))
+ continue;
+
+ dci_ptr->values = kmemdup(sci_ptr->values,
+ sizeof(gcov_type) * sci_ptr->num, GFP_KERNEL);
+
+ if (!dci_ptr->values)
+ goto err_free;
+
+ dci_ptr->num = sci_ptr->num;
+
+ sci_ptr++;
+ dci_ptr++;
+ }
+ }
+
+ return dup;
+err_free:
+ gcov_info_free(dup);
+ return NULL;
+}
+
+/**
+ * gcov_info_free - release memory for profiling data set duplicate
+ * @info: profiling data set duplicate to free
+ */
+void gcov_info_free(struct gcov_info *info)
+{
+ unsigned int active;
+ unsigned int fi_idx;
+ unsigned int t_idx;
+ const struct gcov_ctr_info *ci_ptr;
+
+ if (!info->functions)
+ goto free_info;
+
+ active = num_counter_active(info);
+
+ for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
+ if (!info->functions[fi_idx])
+ continue;
+
+ ci_ptr = info->functions[fi_idx]->ctrs;
+
+ for (t_idx = 0; t_idx < GCOV_COUNTERS; t_idx++) {
+ if (!counter_active(info, t_idx))
+ continue;
+
+ if (!ci_ptr->values)
+ continue;
+
+ kfree(ci_ptr->values);
+
+ ci_ptr++;
+ }
+
+ kfree(info->functions[fi_idx]);
+ }
+
+free_info:
+ kfree(info->functions);
+ kfree(info->filename);
+ kfree(info);
+}
+
+/**
+ * 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 current counter type
+ */
+struct gcov_iterator {
+ struct gcov_info *info;
+ int record;
+ unsigned int function;
+ unsigned int type;
+ unsigned int count;
+ int num_types;
+ int type_info[0];
+};
+
+static const struct gcov_fn_info *get_func(struct gcov_iterator *iter)
+{
+ return iter->info->functions[iter->function];
+}
+
+static const struct gcov_ctr_info *get_ctr(struct gcov_iterator *iter)
+{
+ return &get_func(iter)->ctrs[iter->type];
+}
+
+static gcov_type get_cnt_type(struct gcov_iterator *iter)
+{
+ return iter->type_info[iter->type];
+}
+
+static gcov_type get_cnt_val(struct gcov_iterator *iter)
+{
+ return get_ctr(iter)->values[iter->count];
+}
+
+/**
+ * gcov_iter_new - allocate and initialize profiling data iterator
+ * @info: profiling data set to be iterated
+ *
+ * Return file iterator on success, %NULL otherwise.
+ */
+struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
+{
+ struct gcov_iterator *iter;
+
+ iter = kzalloc(sizeof(struct gcov_iterator) +
+ num_counter_active(info) * sizeof(int), GFP_KERNEL);
+ if (iter)
+ iter->info = info;
+
+ return iter;
+}
+
+/**
+ * gcov_iter_get_info - return profiling data set for given file iterator
+ * @iter: file iterator
+ */
+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++] = i;
+ }
+}
+
+/* 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_FUNCTION_TAG_LEN 4
+#define RECORD_FUNCTION_IDENT 5
+#define RECORD_FUNCTION_LINENO_CHECK 6
+#define RECORD_FUNCTION_CFG_CHECK 7
+#define RECORD_COUNT_TAG 8
+#define RECORD_COUNT_LEN 9
+#define RECORD_COUNT 10
+
+/**
+ * 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_FUNCTION_TAG_LEN:
+ case RECORD_FUNCTION_IDENT:
+ case RECORD_FUNCTION_LINENO_CHECK:
+ case RECORD_COUNT_TAG:
+ /* Advance to next record */
+ iter->record++;
+ break;
+
+ case RECORD_COUNT:
+ iter->count++;
+ /* fall through */
+ case RECORD_COUNT_LEN:
+ if (iter->count < get_ctr(iter)->num) {
+ iter->record = RECORD_COUNT;
+ break;
+ }
+ iter->count = 0;
+ iter->type++;
+ /* fall through */
+ case RECORD_FUNCTION_CFG_CHECK:
+ if (iter->type < iter->num_types) {
+ iter->record = RECORD_COUNT_TAG;
+ break;
+ }
+ iter->type = 0;
+ iter->function++;
+ /* fall through */
+ case RECORD_TIME_STAMP:
+ if (iter->function < iter->info->n_functions)
+ iter->record = RECORD_FUNCTION_TAG;
+ 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)
+{
+ switch (iter->record) {
+ case RECORD_FILE_MAGIC:
+ seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
+ break;
+
+ case RECORD_GCOV_VERSION:
+ seq_write_gcov_u32(seq, iter->info->version);
+ break;
+
+ case RECORD_TIME_STAMP:
+ seq_write_gcov_u32(seq, iter->info->stamp);
+ break;
+
+ case RECORD_FUNCTION_TAG:
+ seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION);
+ break;
+
+ case RECORD_FUNCTION_TAG_LEN:
+ seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION_LENGTH);
+ break;
+
+ case RECORD_FUNCTION_IDENT:
+ seq_write_gcov_u32(seq, get_func(iter)->ident);
+ break;
+
+ case RECORD_FUNCTION_LINENO_CHECK:
+ seq_write_gcov_u32(seq, get_func(iter)->lineno_checksum);
+ break;
+
+ case RECORD_FUNCTION_CFG_CHECK:
+ seq_write_gcov_u32(seq, get_func(iter)->cfg_checksum);
+ break;
+
+ case RECORD_COUNT_TAG:
+ seq_write_gcov_u32(seq,
+ GCOV_TAG_FOR_COUNTER(get_cnt_type(iter)));
+ break;
+
+ case RECORD_COUNT_LEN:
+ seq_write_gcov_u32(seq, get_ctr(iter)->num * 2);
+ break;
+
+ case RECORD_COUNT:
+ seq_write_gcov_u64(seq, get_cnt_val(iter));
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
--
1.8.3.1
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