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/i386/cpu/cpu.c b/arch/i386/cpu/cpu.c
index 3010519..bd6aced 100644
--- a/arch/i386/cpu/cpu.c
+++ b/arch/i386/cpu/cpu.c
@@ -56,7 +56,7 @@
return 0;
}
-int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
printf ("resetting ...\n");
udelay(50000); /* wait 50 ms */
diff --git a/arch/i386/lib/board.c b/arch/i386/lib/board.c
index 3f849f6..0adc664 100644
--- a/arch/i386/lib/board.c
+++ b/arch/i386/lib/board.c
@@ -431,7 +431,7 @@
for (;;);
}
-unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char *argv[])
+unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char * const argv[])
{
/*
* x86 does not use a dedicated register to pass the pointer
diff --git a/arch/i386/lib/bootm.c b/arch/i386/lib/bootm.c
index f96d7bd..b36e58d 100644
--- a/arch/i386/lib/bootm.c
+++ b/arch/i386/lib/bootm.c
@@ -29,7 +29,7 @@
#include <asm/zimage.h>
/*cmd_boot.c*/
-int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
+int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
void *base_ptr;
ulong os_data, os_len;
diff --git a/arch/i386/lib/interrupts.c b/arch/i386/lib/interrupts.c
index 51def59..5a28278 100644
--- a/arch/i386/lib/interrupts.c
+++ b/arch/i386/lib/interrupts.c
@@ -136,7 +136,7 @@
}
#if defined(CONFIG_CMD_IRQ)
-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[])
{
int irq;
diff --git a/arch/i386/lib/zimage.c b/arch/i386/lib/zimage.c
index b39615a..89fe015 100644
--- a/arch/i386/lib/zimage.c
+++ b/arch/i386/lib/zimage.c
@@ -245,7 +245,7 @@
enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s);
}
-int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
void *base_ptr;
void *bzImage_addr;