busybox/modutils/depmod.c

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/* vi: set sw=4 ts=4: */
/*
* depmod - generate modules.dep
* Copyright (c) 2008 Bernhard Fischer
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#undef _GNU_SOURCE
#define _GNU_SOURCE
#include <libbb.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
*/
struct globals {
llist_t *lst;
unsigned moddir_base_len;
};
#define G (*(struct globals*)&bb_common_bufsiz1)
/* We have to zero it out because of NOEXEC */
#define INIT_G() memset(&G, 0, sizeof(G))
static int fill_lst(const char *modulename, struct stat ATTRIBUTE_UNUSED *sb,
void ATTRIBUTE_UNUSED *data, int ATTRIBUTE_UNUSED depth)
{
if (last_char_is(modulename, 'o') != NULL) /* it is a module, remember it */
llist_add_to(&G.lst, xstrdup(modulename + G.moddir_base_len));
return TRUE;
}
static int fileAction(const char *fname, struct stat *sb,
void *data, int ATTRIBUTE_UNUSED depth)
{
size_t len = sb->st_size;
void *the_module, *ptr;
int fd;
char *depends, *deps;
/*XXX: FIXME: does not handle compressed modules!
* There should be a function that looks at the extension and sets up
* open_transformer for us.
*/
if (last_char_is(fname, 'o') == NULL) /* not a module */
goto skip;
fd = xopen(fname, O_RDONLY);
the_module = mmap(NULL, len, PROT_READ, MAP_SHARED
#if defined MAP_POPULATE
|MAP_POPULATE
#endif
, fd, 0);
close(fd);
if (the_module == MAP_FAILED)
bb_perror_msg_and_die("mmap");
ptr = the_module;
fprintf((FILE*)data, "%s:", fname + G.moddir_base_len);
//bb_info_msg("fname='%s'", fname + G.moddir_base_len);
do {
/* search for a 'd' */
ptr = memchr(ptr, 'd', len - (ptr - the_module));
if (ptr == NULL) /* no d left, done */
goto done;
if (memcmp(ptr, "depends=", sizeof("depends=")-1) == 0)
break;
++ptr;
} while (1);
deps = depends = xstrdup (ptr + sizeof("depends=")-1);
//bb_info_msg(" depends='%s'", depends);
while (*deps) {
llist_t * _lst = G.lst;
char *buf1;
ptr = strchr(deps, ',');
if (ptr != NULL)
*(char*)ptr = '\0';
/* remember the length of the current dependency plus eventual 0 byte */
len = strlen(deps) + (ptr != NULL);
buf1 = xasprintf("/%s.", deps); /* match the correct file */
while (_lst) {
ptr = strstr(_lst->data, buf1);
if (ptr != NULL)
break; /* found it */
_lst = _lst->link;
}
free(buf1);
if (_lst /*&& _lst->data*/) {
//bb_info_msg("[%s] -> '%s'", deps, _lst->data);
fprintf((FILE*)data, " %s", _lst->data);
deps += len;
}
}
free(depends);
fprintf((FILE*)data, "\n");
done:
munmap(the_module, sb->st_size);
skip:
return TRUE;
}
int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int depmod_main(int ATTRIBUTE_UNUSED argc, char **argv)
{
int ret;
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char *moddir_base = NULL, *moddir, *system_map, *chp;
FILE *filedes = stdout;
enum {
ARG_a = (1<<0), /* All modules, ignore mods in argv */
ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
ARG_b = (1<<2), /* not /lib/modules/$(uname -r)/ but this base-dir */
ARG_e = (1<<3), /* with -F, print unresolved symbols */
ARG_F = (1<<4), /* System.map that contains the symbols */
ARG_n = (1<<5) /* dry-run, print to stdout only */
};
getopt32(argv, "aAb:eF:n", &moddir_base, &system_map);
argv += optind;
/* got a version to use? */
if (*argv && (sscanf(*argv, "%u.%u.%u", &ret, &ret, &ret) == 3)) {
moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, *argv++);
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} else {
struct utsname uts;
if (uname(&uts) < 0)
bb_simple_perror_msg_and_die("uname");
moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, uts.release);
}
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/* if no modules are given on the command-line, -a is on per default */
option_mask32 |= *argv == NULL;
if (option_mask32 & ARG_b) {
G.moddir_base_len = strlen(moddir_base);
if (ENABLE_FEATURE_CLEAN_UP) {
chp = moddir;
moddir = concat_path_file(moddir_base, moddir);
free (chp);
} else
moddir = concat_path_file(moddir_base, moddir);
}
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if (!(option_mask32 & ARG_n)) { /* --dry-run */
chp = concat_path_file(moddir, CONFIG_DEFAULT_DEPMOD_FILE);
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filedes = xfopen(chp, "w");
if (ENABLE_FEATURE_CLEAN_UP)
free(chp);
}
ret = EXIT_SUCCESS;
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/* have to do a full walk to collect all needed data */
if (!recursive_action(moddir,
ACTION_RECURSE, /* flags */
fill_lst, /* file action */
NULL, /* dir action */
NULL, /* user data */
0)) {
ret = EXIT_FAILURE;
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} else
do {
chp = option_mask32 & ARG_a ? moddir : *argv++;
if (!recursive_action(chp,
ACTION_RECURSE, /* flags */
fileAction, /* file action */
NULL, /* dir action */
(void*)filedes, /* user data */
0)) { /* depth */
ret = EXIT_FAILURE;
}
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} while (!(option_mask32 & ARG_a) && *argv);
if (ENABLE_FEATURE_CLEAN_UP) {
fclose_if_not_stdin(filedes);
llist_free(G.lst, free);
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free(moddir);
}
return ret;
}