u-boot/board/w7o
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
..
cmd_vpd.c Make sure that argv[] argument pointers are not modified. 2010-07-04 23:55:42 +02:00
config.mk * Code cleanup: 2003-06-27 21:31:46 +00:00
errors.h * Code cleanup: 2003-06-27 21:31:46 +00:00
flash.c rename CFG_ macros to CONFIG_SYS 2008-10-18 21:54:03 +02:00
fpga.c Cleanup for GCC-4.x 2005-10-13 16:45:02 +02:00
fsboot.c * Code cleanup: 2003-06-27 21:31:46 +00:00
init.S ppc4xx: Convert PPC4xx SDRAM defines from lower case to upper case 2009-09-28 10:45:54 +02:00
Makefile Cleanup out-or-tree building for some boards (.depend) 2008-07-02 23:49:18 +02:00
post1.S Big white-space cleanup. 2008-05-21 00:14:08 +02:00
post2.c rename CFG_ macros to CONFIG_SYS 2008-10-18 21:54:03 +02:00
u-boot.lds.debug Move arch/ppc to arch/powerpc 2010-04-21 23:42:38 +02:00
vpd.c rename CFG_ macros to CONFIG_SYS 2008-10-18 21:54:03 +02:00
vpd.h * Code cleanup: 2003-06-27 21:31:46 +00:00
w7o.c Move arch/ppc to arch/powerpc 2010-04-21 23:42:38 +02:00
w7o.h W7OLMC/W7OLMG: fix build problems (redundant #define) 2008-03-04 17:38:50 +01:00
watchdog.c rename CFG_ macros to CONFIG_SYS 2008-10-18 21:54:03 +02:00