diff options
author | Wolfgang Denk <wd@denx.de> | 2010-06-28 22:00:46 +0200 |
---|---|---|
committer | Wolfgang Denk <wd@denx.de> | 2010-07-04 23:55:42 +0200 |
commit | 54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch) | |
tree | 400f22f0a12ff0ae6c472bed6ac648befc1744a2 /board/tqc/tqm5200/cmd_stk52xx.c | |
parent | b218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff) | |
download | u-boot-imx-54841ab50c20d6fa6c9cc3eb826989da3a22d934.zip u-boot-imx-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.gz u-boot-imx-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.bz2 |
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>
Diffstat (limited to 'board/tqc/tqm5200/cmd_stk52xx.c')
-rw-r--r-- | board/tqc/tqm5200/cmd_stk52xx.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/board/tqc/tqm5200/cmd_stk52xx.c b/board/tqc/tqm5200/cmd_stk52xx.c index e309beb..0db7050 100644 --- a/board/tqc/tqm5200/cmd_stk52xx.c +++ b/board/tqc/tqm5200/cmd_stk52xx.c @@ -301,7 +301,7 @@ static int i2s_squarewave(unsigned long duration, unsigned int freq, return 0; } -static int cmd_sound(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int cmd_sound(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned long reg, val, duration; char *tmp; @@ -419,7 +419,7 @@ static int cmd_sound(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return 1; } -static int cmd_wav(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int cmd_wav(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned long length, addr; unsigned char volume; @@ -484,7 +484,7 @@ static int cmd_wav(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return rcode; } -static int cmd_beep(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int cmd_beep(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned char volume; unsigned int channel; @@ -581,7 +581,7 @@ void led_init(void) * return 1 if led number unknown * return 0 else */ -int do_led(char *argv[]) +int do_led(char * const argv[]) { struct mpc5xxx_gpio *gpio = (struct mpc5xxx_gpio *)MPC5XXX_GPIO; struct mpc5xxx_gpt_0_7 *gpt = (struct mpc5xxx_gpt_0_7 *)MPC5XXX_GPT; @@ -892,7 +892,7 @@ int can_init(void) * return 1 on CAN failure * return 0 if no failure */ -int do_can(char *argv[]) +int do_can(char * const argv[]) { int i; struct mpc5xxx_mscan *can1 = @@ -994,7 +994,7 @@ int do_can(char *argv[]) * return 3 on rts/cts failure * return 0 if no failure */ -int do_rs232(char *argv[]) +int do_rs232(char * const argv[]) { int error_status = 0; struct mpc5xxx_gpio *gpio = (struct mpc5xxx_gpio *)MPC5XXX_GPIO; @@ -1123,7 +1123,7 @@ static void sm501_backlight (unsigned int state) } #endif /* !CONFIG_FO300 & !CONFIG_TQM5200S */ -int cmd_fkt(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int cmd_fkt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int rcode; |