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 /drivers | |
parent | b218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff) |
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 'drivers')
-rw-r--r-- | drivers/gpio/pca953x.c | 2 | ||||
-rw-r--r-- | drivers/misc/ds4510.c | 2 | ||||
-rw-r--r-- | drivers/misc/fsl_pmic.c | 2 | ||||
-rw-r--r-- | drivers/qe/qe.c | 2 |
4 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c index e8273ee363..d1065f4f8e 100644 --- a/drivers/gpio/pca953x.c +++ b/drivers/gpio/pca953x.c @@ -150,7 +150,7 @@ cmd_tbl_t cmd_pca953x[] = { #endif }; -int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR; int val; diff --git a/drivers/misc/ds4510.c b/drivers/misc/ds4510.c index f2510a38fd..5b33c1ffce 100644 --- a/drivers/misc/ds4510.c +++ b/drivers/misc/ds4510.c @@ -273,7 +273,7 @@ cmd_tbl_t cmd_ds4510[] = { #endif }; -int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { static uint8_t chip = CONFIG_SYS_I2C_DS4510_ADDR; cmd_tbl_t *c; diff --git a/drivers/misc/fsl_pmic.c b/drivers/misc/fsl_pmic.c index 87f0aedeb6..274327f470 100644 --- a/drivers/misc/fsl_pmic.c +++ b/drivers/misc/fsl_pmic.c @@ -156,7 +156,7 @@ static void pmic_dump(int numregs) puts("\n"); } -int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { char *cmd; int nregs; diff --git a/drivers/qe/qe.c b/drivers/qe/qe.c index 8882c4f627..63cc68e307 100644 --- a/drivers/qe/qe.c +++ b/drivers/qe/qe.c @@ -436,7 +436,7 @@ struct qe_firmware_info *qe_get_firmware_info(void) return qe_firmware_uploaded ? &qe_firmware_info : NULL; } -static int qe_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int qe_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr; |