[PATCH 1/2] modpost: reduce visibility of symbols and constify r/o arrays

From: Mathias Krause
Date: Mon Aug 25 2014 - 06:25:39 EST


Internally used symbols of modpost don't need to be externally visible;
make them static. Also constify the string arrays so they resist in the
r/o section instead of being runtime writable.

Those changes lead to a small size reduction as can be seen below:

text data bss dec hex filename
51381 2640 12416 66437 10385 scripts/mod/modpost.old
51765 2224 12416 66405 10365 scripts/mod/modpost.new

Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
---
...checkpatch warnings grossly ignored to comply to the coding style of
modpost.c

scripts/mod/modpost.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 091d90573b..c2ebdc788f 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -24,9 +24,9 @@
#include "../../include/linux/export.h"

/* Are we using CONFIG_MODVERSIONS? */
-int modversions = 0;
+static int modversions = 0;
/* Warn about undefined symbols? (do so if we have vmlinux) */
-int have_vmlinux = 0;
+static int have_vmlinux = 0;
/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
static int all_versions = 0;
/* If we are modposting external module set to 1 */
@@ -229,7 +229,7 @@ static struct symbol *find_symbol(const char *name)
return NULL;
}

-static struct {
+static const struct {
const char *str;
enum export export;
} export_list[] = {
@@ -805,7 +805,7 @@ static int match(const char *sym, const char * const pat[])
}

/* sections that we do not want to do full section mismatch check on */
-static const char *section_white_list[] =
+static const char *const section_white_list[] =
{
".comment*",
".debug*",
@@ -882,17 +882,18 @@ static void check_section(const char *modname, struct elf_info *elf,
#define MEM_EXIT_SECTIONS ".memexit.*"

/* init data sections */
-static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
+static const char *const init_data_sections[] =
+ { ALL_INIT_DATA_SECTIONS, NULL };

/* all init sections */
-static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
+static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };

/* All init and exit sections (code + data) */
-static const char *init_exit_sections[] =
+static const char *const init_exit_sections[] =
{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };

/* data section */
-static const char *data_sections[] = { DATA_SECTIONS, NULL };
+static const char *const data_sections[] = { DATA_SECTIONS, NULL };


/* symbols in .data that may refer to init/exit sections */
@@ -906,8 +907,8 @@ static const char *data_sections[] = { DATA_SECTIONS, NULL };
"*_probe_one", \
"*_console"

-static const char *head_sections[] = { ".head.text*", NULL };
-static const char *linker_symbols[] =
+static const char *const head_sections[] = { ".head.text*", NULL };
+static const char *const linker_symbols[] =
{ "__init_begin", "_sinittext", "_einittext", NULL };

enum mismatch {
@@ -929,7 +930,7 @@ struct sectioncheck {
const char *symbol_white_list[20];
};

-const struct sectioncheck sectioncheck[] = {
+static const struct sectioncheck sectioncheck[] = {
/* Do not reference init/exit code/data from
* normal code and data
*/
--
1.7.10.4

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