u-boot/arch/i386/lib/bootm.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

94 lines
2.4 KiB
C

/*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* Copyright (C) 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
*
* 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
*
*/
#include <common.h>
#include <command.h>
#include <image.h>
#include <u-boot/zlib.h>
#include <asm/byteorder.h>
#include <asm/zimage.h>
/*cmd_boot.c*/
int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
void *base_ptr;
ulong os_data, os_len;
image_header_t *hdr;
#if defined(CONFIG_FIT)
const void *data;
size_t len;
#endif
if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
return 1;
if (images->legacy_hdr_valid) {
hdr = images->legacy_hdr_os;
if (image_check_type (hdr, IH_TYPE_MULTI)) {
/* if multi-part image, we need to get first subimage */
image_multi_getimg (hdr, 0, &os_data, &os_len);
} else {
/* otherwise get image data */
os_data = image_get_data (hdr);
os_len = image_get_data_size (hdr);
}
#if defined(CONFIG_FIT)
} else if (images->fit_uname_os) {
ret = fit_image_get_data (images->fit_hdr_os,
images->fit_noffset_os, &data, &len);
if (ret) {
puts ("Can't get image data/size!\n");
goto error;
}
os_data = (ulong)data;
os_len = (ulong)len;
#endif
} else {
puts ("Could not find kernel image!\n");
goto error;
}
base_ptr = load_zimage ((void*)os_data, os_len,
images->rd_start, images->rd_end - images->rd_start, 0);
if (NULL == base_ptr) {
printf ("## Kernel loading failed ...\n");
goto error;
}
#ifdef DEBUG
printf ("## Transferring control to Linux (at address %08x) ...\n",
(u32)base_ptr);
#endif
/* we assume that the kernel is in place */
printf("\nStarting kernel ...\n\n");
boot_zimage(base_ptr);
/* does not return */
error:
return 1;
}