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Make sure that argv[] argument pointers are not modified.

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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>
This commit is contained in:
Wolfgang Denk 2010-06-28 22:00:46 +02:00
parent b218ccb543
commit 54841ab50c
295 changed files with 671 additions and 670 deletions
Download patch file Download diff file Expand all files Collapse all files

30
common/cmd_i2c.c
View file

@ -178,7 +178,7 @@ static uint get_alen(char *arg)
* i2c read {i2c_chip} {devaddr}{.0, .1, .2} {len} {memaddr}
*/
static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u_char chip;
uint devaddr, alen, length;
@ -226,7 +226,7 @@ static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* Syntax:
* i2c md {i2c_chip} {addr}{.0, .1, .2} {len}
*/
static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u_char chip;
uint addr, alen, length;
@ -324,7 +324,7 @@ static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* Syntax:
* i2c mw {i2c_chip} {addr}{.0, .1, .2} {data} [{count}]
*/
static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
uchar chip;
ulong addr;
@ -388,7 +388,7 @@ static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* Syntax:
* i2c crc32 {i2c_chip} {addr}{.0, .1, .2} {count}
*/
static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
uchar chip;
ulong addr;
@ -452,7 +452,7 @@ static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
*/
static int
mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[])
mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char * const argv[])
{
uchar chip;
ulong addr;
@ -575,7 +575,7 @@ mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[])
* Syntax:
* i2c probe {addr}{.0, .1, .2}
*/
static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int j;
#if defined(CONFIG_SYS_I2C_NOPROBES)
@ -619,7 +619,7 @@ static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* {length} - Number of bytes to read
* {delay} - A DECIMAL number and defaults to 1000 uSec
*/
static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u_char chip;
ulong alen;
@ -731,7 +731,7 @@ static void decode_bits (u_char const b, char const *str[], int const do_once)
* Syntax:
* i2c sdram {i2c_chip}
*/
static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
enum { unknown, EDO, SDRAM, DDR2 } type;
@ -1208,7 +1208,7 @@ static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
#endif
#if defined(CONFIG_I2C_MUX)
static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
int ret=0;
@ -1239,7 +1239,7 @@ static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
#endif /* CONFIG_I2C_MUX */
#if defined(CONFIG_I2C_MULTI_BUS)
static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
int bus_idx, ret=0;
@ -1257,7 +1257,7 @@ static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
}
#endif /* CONFIG_I2C_MULTI_BUS */
static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
int speed, ret=0;
@ -1274,17 +1274,17 @@ static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return ret;
}
static int do_i2c_mm(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_mm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
return mod_i2c_mem (cmdtp, 1, flag, argc, argv);
}
static int do_i2c_nm(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_nm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
return mod_i2c_mem (cmdtp, 0, flag, argc, argv);
}
static int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
@ -1312,7 +1312,7 @@ static cmd_tbl_t cmd_i2c_sub[] = {
U_BOOT_CMD_MKENT(speed, 1, 1, do_i2c_bus_speed, "", ""),
};
static int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
static int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
cmd_tbl_t *c;