u-boot-brain/arch/sh/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

71 lines
2.0 KiB
C

/*
* (C) Copyright 2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (c) Copyright 2008 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
* (c) Copyright 2008 Renesas Solutions Corp.
*
* 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
*
*/
#include <common.h>
#include <command.h>
#include <asm/byteorder.h>
#ifdef CONFIG_SYS_DEBUG
static void hexdump(unsigned char *buf, int len)
{
int i;
for (i = 0; i < len; i++) {
if ((i % 16) == 0)
printf("%s%08x: ", i ? "\n" : "",
(unsigned int)&buf[i]);
printf("%02x ", buf[i]);
}
printf("\n");
}
#endif
int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
/* Linux kernel load address */
void (*kernel) (void) = (void (*)(void))images->ep;
/* empty_zero_page */
unsigned char *param
= (unsigned char *)image_get_load(images->legacy_hdr_os);
/* Linux kernel command line */
char *cmdline = (char *)param + 0x100;
/* PAGE_SIZE */
unsigned long size = images->ep - (unsigned long)param;
char *bootargs = getenv("bootargs");
if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
return 1;
/* Setup parameters */
memset(param, 0, size); /* Clear zero page */
strcpy(cmdline, bootargs);
kernel();
/* does not return */
return 1;
}