linux-stable/kernel/gcov/gcc_4_7.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

570 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* This code provides functions to handle gcc's profiling data format
* introduced with gcc 4.7.
*
* This file is based heavily on gcc_3_4.c file.
*
* For a better understanding, refer to gcc source:
* gcc/gcov-io.h
* libgcc/libgcov.c
*
* Uses gcc-internal data definitions.
*/
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include "gcov.h"
#if (__GNUC__ >= 7)
#define GCOV_COUNTERS 9
#elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
#define GCOV_COUNTERS 10
#elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9
#define GCOV_COUNTERS 9
#else
#define GCOV_COUNTERS 8
#endif
#define GCOV_TAG_FUNCTION_LENGTH 3
static struct gcov_info *gcov_info_head;
/**
* struct gcov_ctr_info - information about counters for a single function
* @num: number of counter values for this type
* @values: array of counter values for this type
*
* This data is generated by gcc during compilation and doesn't change
* at run-time with the exception of the values array.
*/
struct gcov_ctr_info {
unsigned int num;
gcov_type *values;
};
/**
* struct gcov_fn_info - profiling meta data per function
* @key: comdat key
* @ident: unique ident of function
* @lineno_checksum: function lineo_checksum
* @cfg_checksum: function cfg checksum
* @ctrs: instrumented counters
*
* This data is generated by gcc during compilation and doesn't change
* at run-time.
*
* Information about a single function. This uses the trailing array
* idiom. The number of counters is determined from the merge pointer
* array in gcov_info. The key is used to detect which of a set of
* comdat functions was selected -- it points to the gcov_info object
* of the object file containing the selected comdat function.
*/
struct gcov_fn_info {
const struct gcov_info *key;
unsigned int ident;
unsigned int lineno_checksum;
unsigned int cfg_checksum;
struct gcov_ctr_info ctrs[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;
struct gcov_fn_info **functions;
};
/**
* gcov_info_filename - return info filename
* @info: profiling data set
*/
const char *gcov_info_filename(struct gcov_info *info)
{
return info->filename;
}
/**
* gcov_info_version - return info version
* @info: profiling data set
*/
unsigned int gcov_info_version(struct gcov_info *info)
{
return info->version;
}
/**
* gcov_info_next - return next profiling data set
* @info: profiling data set
*
* Returns next gcov_info following @info or first gcov_info in the chain if
* @info is %NULL.
*/
struct gcov_info *gcov_info_next(struct gcov_info *info)
{
if (!info)
return gcov_info_head;
return info->next;
}
/**
* gcov_info_link - link/add profiling data set to the list
* @info: profiling data set
*/
void gcov_info_link(struct gcov_info *info)
{
info->next = gcov_info_head;
gcov_info_head = info;
}
/**
* gcov_info_unlink - unlink/remove profiling data set from the list
* @prev: previous profiling data set
* @info: profiling data set
*/
void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
{
if (prev)
prev->next = info->next;
else
gcov_info_head = info->next;
}
/* Symbolic links to be created for each profiling data file. */
const struct gcov_link gcov_link[] = {
{ OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */
{ 0, NULL},
};
/*
* Determine whether a counter is active. Doesn't change at run-time.
*/
static int counter_active(struct gcov_info *info, unsigned int type)
{
return info->merge[type] ? 1 : 0;
}
/* Determine number of active counters. Based on gcc magic. */
static unsigned int num_counter_active(struct gcov_info *info)
{
unsigned int i;
unsigned int result = 0;
for (i = 0; i < GCOV_COUNTERS; i++) {
if (counter_active(info, i))
result++;
}
return result;
}
/**
* gcov_info_reset - reset profiling data to zero
* @info: profiling data set
*/
void gcov_info_reset(struct gcov_info *info)
{
struct gcov_ctr_info *ci_ptr;
unsigned int fi_idx;
unsigned int ct_idx;
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
ci_ptr = info->functions[fi_idx]->ctrs;
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
if (!counter_active(info, ct_idx))
continue;
memset(ci_ptr->values, 0,
sizeof(gcov_type) * ci_ptr->num);
ci_ptr++;
}
}
}
/**
* gcov_info_is_compatible - check if profiling data can be added
* @info1: first profiling data set
* @info2: second profiling data set
*
* Returns non-zero if profiling data can be added, zero otherwise.
*/
int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
{
return (info1->stamp == info2->stamp);
}
/**
* gcov_info_add - add up profiling data
* @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)
{
struct gcov_ctr_info *dci_ptr;
struct gcov_ctr_info *sci_ptr;
unsigned int fi_idx;
unsigned int ct_idx;
unsigned int val_idx;
for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++) {
dci_ptr = dst->functions[fi_idx]->ctrs;
sci_ptr = src->functions[fi_idx]->ctrs;
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
if (!counter_active(src, ct_idx))
continue;
for (val_idx = 0; val_idx < sci_ptr->num; val_idx++)
dci_ptr->values[val_idx] +=
sci_ptr->values[val_idx];
dci_ptr++;
sci_ptr++;
}
}
}
/**
* gcov_info_dup - duplicate profiling data set
* @info: profiling data set to duplicate
*
* Return newly allocated duplicate on success, %NULL on error.
*/
struct gcov_info *gcov_info_dup(struct gcov_info *info)
{
struct gcov_info *dup;
struct gcov_ctr_info *dci_ptr; /* dst counter info */
struct gcov_ctr_info *sci_ptr; /* src counter info */
unsigned int active;
unsigned int fi_idx; /* function info idx */
unsigned int ct_idx; /* counter type idx */
size_t fi_size; /* function info size */
size_t cv_size; /* counter values size */
dup = kmemdup(info, sizeof(*dup), GFP_KERNEL);
if (!dup)
return NULL;
dup->next = NULL;
dup->filename = NULL;
dup->functions = NULL;
dup->filename = kstrdup(info->filename, GFP_KERNEL);
if (!dup->filename)
goto err_free;
dup->functions = kcalloc(info->n_functions,
sizeof(struct gcov_fn_info *), GFP_KERNEL);
if (!dup->functions)
goto err_free;
active = num_counter_active(info);
fi_size = sizeof(struct gcov_fn_info);
fi_size += sizeof(struct gcov_ctr_info) * active;
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
dup->functions[fi_idx] = kzalloc(fi_size, GFP_KERNEL);
if (!dup->functions[fi_idx])
goto err_free;
*(dup->functions[fi_idx]) = *(info->functions[fi_idx]);
sci_ptr = info->functions[fi_idx]->ctrs;
dci_ptr = dup->functions[fi_idx]->ctrs;
for (ct_idx = 0; ct_idx < active; ct_idx++) {
cv_size = sizeof(gcov_type) * sci_ptr->num;
dci_ptr->values = vmalloc(cv_size);
if (!dci_ptr->values)
goto err_free;
dci_ptr->num = sci_ptr->num;
memcpy(dci_ptr->values, sci_ptr->values, cv_size);
sci_ptr++;
dci_ptr++;
}
}
return dup;
err_free:
gcov_info_free(dup);
return NULL;
}
/**
* gcov_info_free - release memory for profiling data set duplicate
* @info: profiling data set duplicate to free
*/
void gcov_info_free(struct gcov_info *info)
{
unsigned int active;
unsigned int fi_idx;
unsigned int ct_idx;
struct gcov_ctr_info *ci_ptr;
if (!info->functions)
goto free_info;
active = num_counter_active(info);
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
if (!info->functions[fi_idx])
continue;
ci_ptr = info->functions[fi_idx]->ctrs;
for (ct_idx = 0; ct_idx < active; ct_idx++, ci_ptr++)
vfree(ci_ptr->values);
kfree(info->functions[fi_idx]);
}
free_info:
kfree(info->functions);
kfree(info->filename);
kfree(info);
}
#define ITER_STRIDE PAGE_SIZE
/**
* struct gcov_iterator - specifies current file position in logical records
* @info: associated profiling data
* @buffer: buffer containing file data
* @size: size of buffer
* @pos: current position in file
*/
struct gcov_iterator {
struct gcov_info *info;
void *buffer;
size_t size;
loff_t pos;
};
/**
* store_gcov_u32 - store 32 bit number in gcov format to buffer
* @buffer: target buffer or NULL
* @off: offset into the buffer
* @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. Returns the number of bytes stored. If @buffer is %NULL, doesn't
* store anything.
*/
static size_t store_gcov_u32(void *buffer, size_t off, u32 v)
{
u32 *data;
if (buffer) {
data = buffer + off;
*data = v;
}
return sizeof(*data);
}
/**
* store_gcov_u64 - store 64 bit number in gcov format to buffer
* @buffer: target buffer or NULL
* @off: offset into the buffer
* @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. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
* anything.
*/
static size_t store_gcov_u64(void *buffer, size_t off, u64 v)
{
u32 *data;
if (buffer) {
data = buffer + off;
data[0] = (v & 0xffffffffUL);
data[1] = (v >> 32);
}
return sizeof(*data) * 2;
}
/**
* convert_to_gcda - convert profiling data set to gcda file format
* @buffer: the buffer to store file data or %NULL if no data should be stored
* @info: profiling data set to be converted
*
* Returns the number of bytes that were/would have been stored into the buffer.
*/
static size_t convert_to_gcda(char *buffer, struct gcov_info *info)
{
struct gcov_fn_info *fi_ptr;
struct gcov_ctr_info *ci_ptr;
unsigned int fi_idx;
unsigned int ct_idx;
unsigned int cv_idx;
size_t pos = 0;
/* File header. */
pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC);
pos += store_gcov_u32(buffer, pos, info->version);
pos += store_gcov_u32(buffer, pos, info->stamp);
for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
fi_ptr = info->functions[fi_idx];
/* Function record. */
pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION_LENGTH);
pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
pos += store_gcov_u32(buffer, pos, fi_ptr->lineno_checksum);
pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
ci_ptr = fi_ptr->ctrs;
for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
if (!counter_active(info, ct_idx))
continue;
/* Counter record. */
pos += store_gcov_u32(buffer, pos,
GCOV_TAG_FOR_COUNTER(ct_idx));
pos += store_gcov_u32(buffer, pos, ci_ptr->num * 2);
for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) {
pos += store_gcov_u64(buffer, pos,
ci_ptr->values[cv_idx]);
}
ci_ptr++;
}
}
return pos;
}
/**
* 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), GFP_KERNEL);
if (!iter)
goto err_free;
iter->info = info;
/* Dry-run to get the actual buffer size. */
iter->size = convert_to_gcda(NULL, info);
iter->buffer = vmalloc(iter->size);
if (!iter->buffer)
goto err_free;
convert_to_gcda(iter->buffer, info);
return iter;
err_free:
kfree(iter);
return NULL;
}
/**
* gcov_iter_get_info - return profiling data set for given file iterator
* @iter: file iterator
*/
void gcov_iter_free(struct gcov_iterator *iter)
{
vfree(iter->buffer);
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)
{
iter->pos = 0;
}
/**
* 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)
{
if (iter->pos < iter->size)
iter->pos += ITER_STRIDE;
if (iter->pos >= iter->size)
return -EINVAL;
return 0;
}
/**
* 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)
{
size_t len;
if (iter->pos >= iter->size)
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;
}