u-boot/common/cmd_ubifs.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

151 lines
3.1 KiB
C

/*
* (C) Copyright 2008
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
/*
* UBIFS command support
*/
#undef DEBUG
#include <common.h>
#include <config.h>
#include <command.h>
static int ubifs_initialized;
static int ubifs_mounted;
/* Prototypes */
int ubifs_init(void);
int ubifs_mount(char *vol_name);
int ubifs_ls(char *dir_name);
int ubifs_load(char *filename, u32 addr, u32 size);
int do_ubifs_mount(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *vol_name;
int ret;
if (argc != 2) {
cmd_usage(cmdtp);
return 1;
}
vol_name = argv[1];
debug("Using volume %s\n", vol_name);
if (ubifs_initialized == 0) {
ubifs_init();
ubifs_initialized = 1;
}
ret = ubifs_mount(vol_name);
if (ret)
return -1;
ubifs_mounted = 1;
return 0;
}
int do_ubifs_ls(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *filename = "/";
int ret;
if (!ubifs_mounted) {
printf("UBIFS not mounted, use ubifs mount to mount volume first!\n");
return -1;
}
if (argc == 2)
filename = argv[1];
debug("Using filename %s\n", filename);
ret = ubifs_ls(filename);
if (ret)
printf("%s not found!\n", filename);
return ret;
}
int do_ubifs_load(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *filename;
char *endp;
int ret;
u32 addr;
u32 size = 0;
if (!ubifs_mounted) {
printf("UBIFS not mounted, use ubifs mount to mount volume first!\n");
return -1;
}
if (argc < 3) {
cmd_usage(cmdtp);
return -1;
}
addr = simple_strtoul(argv[1], &endp, 16);
if (endp == argv[1]) {
cmd_usage(cmdtp);
return 1;
}
filename = argv[2];
if (argc == 4) {
size = simple_strtoul(argv[3], &endp, 16);
if (endp == argv[3]) {
cmd_usage(cmdtp);
return 1;
}
}
debug("Loading file '%s' to address 0x%08x (size %d)\n", filename, addr, size);
ret = ubifs_load(filename, addr, size);
if (ret)
printf("%s not found!\n", filename);
return ret;
}
U_BOOT_CMD(
ubifsmount, 2, 0, do_ubifs_mount,
"mount UBIFS volume",
"<volume-name>\n"
" - mount 'volume-name' volume"
);
U_BOOT_CMD(ubifsls, 2, 0, do_ubifs_ls,
"list files in a directory",
"[directory]\n"
" - list files in a 'directory' (default '/')"
);
U_BOOT_CMD(ubifsload, 4, 0, do_ubifs_load,
"load file from an UBIFS filesystem",
"<addr> <filename> [bytes]\n"
" - load file 'filename' to address 'addr'"
);