u-boot/arch/mips/lib/bootm_qemu_mips.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

76 lines
2.1 KiB
C

/*
* (C) Copyright 2008
* Jean-Christophe PLAGNIOL-VILLARD <jcplagniol@jcrosoft.com>
*
* 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 <image.h>
#include <asm/byteorder.h>
#include <asm/addrspace.h>
DECLARE_GLOBAL_DATA_PTR;
int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
void (*theKernel) (int, char **, char **, int *);
char *bootargs = getenv ("bootargs");
char *start;
uint len;
/* find kernel entry point */
theKernel = (void (*)(int, char **, char **, int *))images->ep;
show_boot_progress (15);
debug ("## Transferring control to Linux (at address %08lx) ...\n",
(ulong) theKernel);
gd->bd->bi_boot_params = gd->bd->bi_memstart + (16 << 20) - 256;
debug ("%-12s= 0x%08lX\n", "boot_params", (ulong)gd->bd->bi_boot_params);
/* set Magic */
*(int32_t *)(gd->bd->bi_boot_params - 4) = 0x12345678;
/* set ram_size */
*(int32_t *)(gd->bd->bi_boot_params - 8) = gd->ram_size;
start = (char*)gd->bd->bi_boot_params;
len = strlen(bootargs);
strncpy(start, bootargs, len + 1);
start += len;
len = images->rd_end - images->rd_start;
if (len > 0) {
start += sprintf(start," rd_start=0x%08X rd_size=0x%0X",
(uint) UNCACHED_SDRAM (images->rd_start),
(uint) len);
}
/* we assume that the kernel is in place */
printf ("\nStarting kernel ...\n\n");
theKernel (0, NULL, NULL, 0);
/* does not return */
return 1;
}