u-boot/common/cmd_spibootldr.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

36 lines
773 B
C

/*
* U-boot - spibootldr.c
*
* Copyright (c) 2005-2008 Analog Devices Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <command.h>
#include <asm/blackfin.h>
#include <asm/mach-common/bits/bootrom.h>
int do_spibootldr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
s32 addr;
/* Get the address */
if (argc < 2)
addr = 0;
else
addr = simple_strtoul(argv[1], NULL, 16);
printf("## Booting ldr image at SPI offset 0x%x ...\n", addr);
return bfrom_SpiBoot(addr, BFLAG_PERIPHERAL | 4, 0, NULL);
}
U_BOOT_CMD(spibootldr, 2, 0, do_spibootldr,
"boot ldr image from spi",
"[offset]\n"
" - boot ldr image stored at offset into spi\n");