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>
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index e8273ee..d1065f4 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -150,7 +150,7 @@
#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 f2510a3..5b33c1f 100644
--- a/drivers/misc/ds4510.c
+++ b/drivers/misc/ds4510.c
@@ -273,7 +273,7 @@
#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 87f0aede..274327f 100644
--- a/drivers/misc/fsl_pmic.c
+++ b/drivers/misc/fsl_pmic.c
@@ -156,7 +156,7 @@
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 8882c4f..63cc68e 100644
--- a/drivers/qe/qe.c
+++ b/drivers/qe/qe.c
@@ -436,7 +436,7 @@
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;