hush/modutils/modutils.c
Denys Vlasenko 77c066ea5c modutils: add FEATURE_INSMOD_TRY_MMAP option
function                                             old     new   delta
try_to_mmap_module                                     -     121    +121
bb_init_module_24                                   4514    4578     +64
bb_init_module                                       119     173     +54
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/0 up/down: 239/0)             Total: 239 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-10-25 04:35:22 +01:00

182 lines
4.2 KiB
C

/*
* Common modutils related functions for busybox
*
* Copyright (C) 2008 by Timo Teras <timo.teras@iki.fi>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "modutils.h"
#ifdef __UCLIBC__
extern int init_module(void *module, unsigned long len, const char *options);
extern int delete_module(const char *module, unsigned int flags);
#else
# include <sys/syscall.h>
# define init_module(mod, len, opts) syscall(__NR_init_module, mod, len, opts)
# define delete_module(mod, flags) syscall(__NR_delete_module, mod, flags)
#endif
void FAST_FUNC replace(char *s, char what, char with)
{
while (*s) {
if (what == *s)
*s = with;
++s;
}
}
char* FAST_FUNC replace_underscores(char *s)
{
replace(s, '-', '_');
return s;
}
int FAST_FUNC string_to_llist(char *string, llist_t **llist, const char *delim)
{
char *tok;
int len = 0;
while ((tok = strsep(&string, delim)) != NULL) {
if (tok[0] == '\0')
continue;
llist_add_to_end(llist, xstrdup(tok));
len += strlen(tok);
}
return len;
}
char* FAST_FUNC filename2modname(const char *filename, char *modname)
{
int i;
char *from;
if (filename == NULL)
return NULL;
if (modname == NULL)
modname = xmalloc(MODULE_NAME_LEN);
from = bb_get_last_path_component_nostrip(filename);
for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
modname[i] = (from[i] == '-') ? '_' : from[i];
modname[i] = '\0';
return modname;
}
char* FAST_FUNC parse_cmdline_module_options(char **argv)
{
char *options;
int optlen;
options = xzalloc(1);
optlen = 0;
while (*++argv) {
options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
/* Spaces handled by "" pairs, but no way of escaping quotes */
optlen += sprintf(options + optlen, (strchr(*argv, ' ') ? "\"%s\" " : "%s "), *argv);
}
return options;
}
#if ENABLE_FEATURE_INSMOD_TRY_MMAP
void* FAST_FUNC try_to_mmap_module(const char *filename, size_t *image_size_p)
{
/* We have user reports of failure to load 3MB module
* on a 16MB RAM machine. Apparently even a transient
* memory spike to 6MB during module load
* is too big for that system. */
void *image;
struct stat st;
int fd;
fd = xopen(filename, O_RDONLY);
fstat(fd, &st);
image = NULL;
/* st.st_size is off_t, we can't just pass it to mmap */
if (st.st_size <= *image_size_p) {
size_t image_size = st.st_size;
image = mmap(NULL, image_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (image == MAP_FAILED) {
image = NULL;
} else if (*(uint32_t*)image != SWAP_BE32(0x7f454C46)) {
/* No ELF signature. Compressed module? */
munmap(image, image_size);
image = NULL;
} else {
/* Success. Report the size */
*image_size_p = image_size;
}
}
close(fd);
return image;
}
#endif
/* Return:
* 0 on success,
* -errno on open/read error,
* errno on init_module() error
*/
int FAST_FUNC bb_init_module(const char *filename, const char *options)
{
size_t image_size;
char *image;
int rc;
bool mmaped;
if (!options)
options = "";
//TODO: audit bb_init_module_24 to match error code convention
#if ENABLE_FEATURE_2_4_MODULES
if (get_linux_version_code() < KERNEL_VERSION(2,6,0))
return bb_init_module_24(filename, options);
#endif
image_size = INT_MAX - 4095;
mmaped = 0;
image = try_to_mmap_module(filename, &image_size);
if (image) {
mmaped = 1;
} else {
errno = ENOMEM; /* may be changed by e.g. open errors below */
image = xmalloc_open_zipped_read_close(filename, &image_size);
if (!image)
return -errno;
}
errno = 0;
init_module(image, image_size, options);
rc = errno;
if (mmaped)
munmap(image, image_size);
else
free(image);
return rc;
}
int FAST_FUNC bb_delete_module(const char *module, unsigned int flags)
{
errno = 0;
delete_module(module, flags);
return errno;
}
const char* FAST_FUNC moderror(int err)
{
switch (err) {
case -1: /* btw: it's -EPERM */
return "no such module";
case ENOEXEC:
return "invalid module format";
case ENOENT:
return "unknown symbol in module, or unknown parameter";
case ESRCH:
return "module has wrong symbol version";
case ENOSYS:
return "kernel does not support requested operation";
}
if (err < 0) /* should always be */
err = -err;
return strerror(err);
}