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/arch/powerpc/cpu/mpc86xx/cpu.c b/arch/powerpc/cpu/mpc86xx/cpu.c
index 1887575..9064e78 100644
--- a/arch/powerpc/cpu/mpc86xx/cpu.c
+++ b/arch/powerpc/cpu/mpc86xx/cpu.c
@@ -124,7 +124,7 @@
void
-do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
volatile immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
volatile ccsr_gur_t *gur = &immap->im_gur;
diff --git a/arch/powerpc/cpu/mpc86xx/interrupts.c b/arch/powerpc/cpu/mpc86xx/interrupts.c
index c78fc72..d8ad6d3 100644
--- a/arch/powerpc/cpu/mpc86xx/interrupts.c
+++ b/arch/powerpc/cpu/mpc86xx/interrupts.c
@@ -101,7 +101,7 @@
/*
* irqinfo - print information about PCI devices,not implemented.
*/
-int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
return 0;
}
diff --git a/arch/powerpc/cpu/mpc86xx/mp.c b/arch/powerpc/cpu/mpc86xx/mp.c
index b4a0faa..24eb30a 100644
--- a/arch/powerpc/cpu/mpc86xx/mp.c
+++ b/arch/powerpc/cpu/mpc86xx/mp.c
@@ -66,7 +66,7 @@
return 0;
}
-int cpu_release(int nr, int argc, char *argv[])
+int cpu_release(int nr, int argc, char * const argv[])
{
/* dummy function so common/cmd_mp.c will build
* should be implemented in the future */