busybox/modutils/depmod.c
Denys Vlasenko cc70b6f8b6 depmod: simple memory optimization
function                                             old     new   delta
filename2modname                                      67      86     +19
parse_module                                         374     351     -23

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-01-24 22:30:30 +01:00

290 lines
7.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* depmod - generate modules.dep
* Copyright (c) 2008 Bernhard Reutner-Fischer
* Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
* Copyright (c) 2008 Vladimir Dronnikov
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//applet:IF_DEPMOD(APPLET(depmod, BB_DIR_SBIN, BB_SUID_DROP))
#include "libbb.h"
#include "modutils.h"
#include <sys/utsname.h> /* uname() */
/*
* Theory of operation:
* - iterate over all modules and record their full path
* - iterate over all modules looking for "depends=" entries
* for each depends, look through our list of full paths and emit if found
*/
typedef struct module_info {
struct module_info *next;
char *name, *modname;
llist_t *dependencies;
llist_t *aliases;
llist_t *symbols;
struct module_info *dnext, *dprev;
} module_info;
static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
void *data, int depth UNUSED_PARAM)
{
module_info **first = (module_info **) data;
char *image, *ptr;
module_info *info;
/* Arbitrary. Was sb->st_size, but that breaks .gz etc */
size_t len = (64*1024*1024 - 4096);
if (strrstr(fname, ".ko") == NULL)
return TRUE;
image = xmalloc_open_zipped_read_close(fname, &len);
info = xzalloc(sizeof(*info));
info->next = *first;
*first = info;
info->dnext = info->dprev = info;
info->name = xstrdup(fname + 2); /* skip "./" */
info->modname = filename2modname(
bb_get_last_path_component_nostrip(fname),
NULL
);
for (ptr = image; ptr < image + len - 10; ptr++) {
if (strncmp(ptr, "depends=", 8) == 0) {
char *u;
ptr += 8;
for (u = ptr; *u; u++)
if (*u == '-')
*u = '_';
ptr += string_to_llist(ptr, &info->dependencies, ",");
} else if (ENABLE_FEATURE_MODUTILS_ALIAS
&& strncmp(ptr, "alias=", 6) == 0
) {
llist_add_to(&info->aliases, xstrdup(ptr + 6));
ptr += strlen(ptr);
} else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
&& strncmp(ptr, "__ksymtab_", 10) == 0
) {
ptr += 10;
if (strncmp(ptr, "gpl", 3) == 0
|| strcmp(ptr, "strings") == 0
) {
continue;
}
llist_add_to(&info->symbols, xstrdup(ptr));
ptr += strlen(ptr);
}
}
free(image);
return TRUE;
}
static module_info *find_module(module_info *modules, const char *modname)
{
module_info *m;
for (m = modules; m != NULL; m = m->next)
if (strcmp(m->modname, modname) == 0)
return m;
return NULL;
}
static void order_dep_list(module_info *modules, module_info *start,
llist_t *add)
{
module_info *m;
llist_t *n;
for (n = add; n != NULL; n = n->link) {
m = find_module(modules, n->data);
if (m == NULL)
continue;
/* unlink current entry */
m->dnext->dprev = m->dprev;
m->dprev->dnext = m->dnext;
/* and add it to tail */
m->dnext = start;
m->dprev = start->dprev;
start->dprev->dnext = m;
start->dprev = m;
/* recurse */
order_dep_list(modules, start, m->dependencies);
}
}
static void xfreopen_write(const char *file, FILE *f)
{
if (freopen(file, "w", f) == NULL)
bb_perror_msg_and_die("can't open '%s'", file);
}
//usage:#if !ENABLE_MODPROBE_SMALL
//usage:#define depmod_trivial_usage "[-n] [-b BASE] [VERSION] [MODFILES]..."
//usage:#define depmod_full_usage "\n\n"
//usage: "Generate modules.dep, alias, and symbols files"
//usage: "\n"
//usage: "\n -b BASE Use BASE/lib/modules/VERSION"
//usage: "\n -n Dry run: print files to stdout"
//usage:#endif
/* Upstream usage:
* [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
* -a --all
* Probe all modules. Default if no MODFILES.
* -A --quick
* Check modules.dep's mtime against module files' mtimes.
* -b --basedir BASE
* Use $BASE/lib/modules/VERSION
* -C --config FILE or DIR
* Path to /etc/depmod.conf or /etc/depmod.d/
* -e --errsyms
* When combined with the -F option, this reports any symbols
* which are not supplied by other modules or kernel.
* -F --filesyms System.map
* -n --dry-run
* Print modules.dep etc to standard output
* -v --verbose
* Print to stdout all the symbols each module depends on
* and the module's file name which provides that symbol.
* -r No-op
* -u No-op
* -q No-op
*
* So far we only support: [-n] [-b BASE] [VERSION] [MODFILES]...
* Accepted but ignored:
* -aAe
* -F System.map
* -C FILE/DIR
*
* Not accepted: -v
*/
enum {
//OPT_a = (1 << 0), /* All modules, ignore mods in argv */
//OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
OPT_b = (1 << 2), /* base directory when modules are in staging area */
//OPT_e = (1 << 3), /* with -F, print unresolved symbols */
//OPT_F = (1 << 4), /* System.map that contains the symbols */
OPT_n = (1 << 5), /* dry-run, print to stdout only */
OPT_r = (1 << 6), /* Compat dummy. Linux Makefile uses it */
OPT_u = (1 << 7), /* -u,--unresolved-error: ignored */
OPT_q = (1 << 8), /* -q,--quiet: ignored */
OPT_C = (1 << 9), /* -C,--config etc_modules_conf: ignored */
};
int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int depmod_main(int argc UNUSED_PARAM, char **argv)
{
module_info *modules, *m, *dep;
const char *moddir_base = "/";
char *moddir, *version;
struct utsname uts;
int tmp;
getopt32(argv, "aAb:eF:nruqC:", &moddir_base, NULL, NULL);
argv += optind;
/* goto modules location */
xchdir(moddir_base);
/* If a version is provided, then that kernel version's module directory
* is used, rather than the current kernel version (as returned by
* "uname -r"). */
if (*argv && sscanf(*argv, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
version = *argv++;
} else {
uname(&uts);
version = uts.release;
}
moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
xchdir(moddir);
if (ENABLE_FEATURE_CLEAN_UP)
free(moddir);
/* Scan modules */
modules = NULL;
if (*argv) {
do {
parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
} while (*++argv);
} else {
recursive_action(".", ACTION_RECURSE,
parse_module, NULL, &modules, 0);
}
/* Generate dependency and alias files */
if (!(option_mask32 & OPT_n))
xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);
for (m = modules; m != NULL; m = m->next) {
printf("%s:", m->name);
order_dep_list(modules, m, m->dependencies);
while (m->dnext != m) {
dep = m->dnext;
printf(" %s", dep->name);
/* unlink current entry */
dep->dnext->dprev = dep->dprev;
dep->dprev->dnext = dep->dnext;
dep->dnext = dep->dprev = dep;
}
bb_putchar('\n');
}
#if ENABLE_FEATURE_MODUTILS_ALIAS
if (!(option_mask32 & OPT_n))
xfreopen_write("modules.alias", stdout);
for (m = modules; m != NULL; m = m->next) {
char modname[MODULE_NAME_LEN];
const char *fname = bb_basename(m->name);
filename2modname(fname, modname);
while (m->aliases) {
/*
* Last word used to be a basename
* (filename with path and .ko.* stripped)
* at the time of module-init-tools 3.4.
* kmod v.12 uses module name, i.e., s/-/_/g.
*/
printf("alias %s %s\n",
(char*)llist_pop(&m->aliases),
modname);
}
}
#endif
#if ENABLE_FEATURE_MODUTILS_SYMBOLS
if (!(option_mask32 & OPT_n))
xfreopen_write("modules.symbols", stdout);
for (m = modules; m != NULL; m = m->next) {
char modname[MODULE_NAME_LEN];
const char *fname = bb_basename(m->name);
filename2modname(fname, modname);
while (m->symbols) {
printf("alias symbol:%s %s\n",
(char*)llist_pop(&m->symbols),
modname);
}
}
#endif
if (ENABLE_FEATURE_CLEAN_UP) {
while (modules) {
module_info *old = modules;
modules = modules->next;
free(old->name);
free(old->modname);
free(old);
}
}
return EXIT_SUCCESS;
}