busybox/miscutils/flash_lock_unlock.c
Denys Vlasenko 798b94518e ubi tools: ubiupdatevol supports "-" input and actually respects -s SIZE
Decided to not make any flash applets NOEXEC.
Minor robustifications here and there. Better error messages. Save on strings:

function                                             old     new   delta
ubi_tools_main                                      1235    1288     +53
ubi_get_volid_by_name                                125     133      +8
ubirename_main                                       198     204      +6
get_num_from_file                                     90      94      +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 71/0)               Total: 71 bytes
   text	   data	    bss	    dec	    hex	filename
 915696	    485	   6880	 923061	  e15b5	busybox_old
 915670	    485	   6880	 923035	  e159b	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-07 16:00:25 +02:00

103 lines
3.1 KiB
C

/* vi: set sw=4 ts=4: */
/* Ported to busybox from mtd-utils.
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config FLASH_LOCK
//config: bool "flash_lock (2.1 kb)"
//config: default n # doesn't build on Ubuntu 8.04
//config: help
//config: The flash_lock binary from mtd-utils as of git head 5ec0c10d0. This
//config: utility locks part or all of the flash device.
//config:
//config:config FLASH_UNLOCK
//config: bool "flash_unlock (1.3 kb)"
//config: default n # doesn't build on Ubuntu 8.04
//config: help
//config: The flash_unlock binary from mtd-utils as of git head 5ec0c10d0. This
//config: utility unlocks part or all of the flash device.
// APPLET_ODDNAME:name main location suid_type help
//applet:IF_FLASH_LOCK( APPLET_ODDNAME(flash_lock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_lock))
//applet:IF_FLASH_UNLOCK(APPLET_ODDNAME(flash_unlock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_unlock))
/* not NOEXEC: if flash operation stalls, use less memory in "hung" process */
//kbuild:lib-$(CONFIG_FLASH_LOCK) += flash_lock_unlock.o
//kbuild:lib-$(CONFIG_FLASH_UNLOCK) += flash_lock_unlock.o
//usage:#define flash_lock_trivial_usage
//usage: "MTD_DEVICE OFFSET SECTORS"
//usage:#define flash_lock_full_usage "\n\n"
//usage: "Lock part or all of an MTD device. If SECTORS is -1, then all sectors\n"
//usage: "will be locked, regardless of the value of OFFSET"
//usage:
//usage:#define flash_unlock_trivial_usage
//usage: "MTD_DEVICE"
//usage:#define flash_unlock_full_usage "\n\n"
//usage: "Unlock an MTD device"
#include "libbb.h"
#include <mtd/mtd-user.h>
int flash_lock_unlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int flash_lock_unlock_main(int argc UNUSED_PARAM, char **argv)
{
/* note: fields in these structs are 32-bits.
* apparently we can't win anything by using off_t
* or long long's for offset and/or sectors vars. */
struct mtd_info_user info;
struct erase_info_user lock;
unsigned long offset;
long sectors;
int fd;
#define do_lock (ENABLE_FLASH_LOCK && (!ENABLE_FLASH_UNLOCK || (applet_name[6] == 'l')))
if (!argv[1])
bb_show_usage();
/* parse offset and number of sectors to lock */
offset = 0;
sectors = -1;
if (do_lock) {
if (!argv[2] || !argv[3])
bb_show_usage();
offset = xstrtoul(argv[2], 0);
sectors = xstrtol(argv[3], 0);
}
fd = xopen(argv[1], O_RDWR);
xioctl(fd, MEMGETINFO, &info);
lock.start = 0;
lock.length = info.size;
if (do_lock) {
unsigned long size = info.size - info.erasesize;
if (offset > size) {
bb_error_msg_and_die("%lx is beyond device size %lx\n",
offset, size);
}
if (sectors == -1) {
sectors = info.size / info.erasesize;
} else {
// isn't this useless?
unsigned long num = info.size / info.erasesize;
if (sectors > num) {
bb_error_msg_and_die("%ld are too many "
"sectors, device only has "
"%ld\n", sectors, num);
}
}
lock.start = offset;
lock.length = sectors * info.erasesize;
xioctl(fd, MEMLOCK, &lock);
} else {
xioctl(fd, MEMUNLOCK, &lock);
}
return EXIT_SUCCESS;
}