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>

7 files changed, 7 insertions, 7 deletions

diff --git a/arch/sparc/cpu/leon2/cpu.c b/arch/sparc/cpu/leon2/cpu.c
index d6e23b129c4..46512c761f8 100644
--- a/arch/sparc/cpu/leon2/cpu.c
+++ b/arch/sparc/cpu/leon2/cpu.c
@@ -49,7 +49,7 @@ void cpu_reset(void)
 	_reset_reloc();
 }
 
-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[])
 {
 	cpu_reset();
 
diff --git a/arch/sparc/cpu/leon2/interrupts.c b/arch/sparc/cpu/leon2/interrupts.c
index 9b0da963af2..5149550e8f7 100644
--- a/arch/sparc/cpu/leon2/interrupts.c
+++ b/arch/sparc/cpu/leon2/interrupts.c
@@ -195,7 +195,7 @@ void irq_free_handler(int irq)
 /****************************************************************************/
 
 #if defined(CONFIG_CMD_IRQ)
-void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
 {
 	int irq;
 	unsigned int pil = get_pil();
diff --git a/arch/sparc/cpu/leon3/cpu.c b/arch/sparc/cpu/leon3/cpu.c
index 976f3113480..a1646e22f5d 100644
--- a/arch/sparc/cpu/leon3/cpu.c
+++ b/arch/sparc/cpu/leon3/cpu.c
@@ -52,7 +52,7 @@ void cpu_reset(void)
 	_reset_reloc();
 }
 
-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[])
 {
 	cpu_reset();
 
diff --git a/arch/sparc/cpu/leon3/interrupts.c b/arch/sparc/cpu/leon3/interrupts.c
index ac6aca5d187..4138f9b673d 100644
--- a/arch/sparc/cpu/leon3/interrupts.c
+++ b/arch/sparc/cpu/leon3/interrupts.c
@@ -197,7 +197,7 @@ void irq_free_handler(int irq)
 /****************************************************************************/
 
 #if defined(CONFIG_CMD_IRQ)
-void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
 {
 	int irq;
 	unsigned int pil = get_pil();
diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
index d55cc863da2..12901bcef85 100644
--- a/arch/sparc/include/asm/prom.h
+++ b/arch/sparc/include/asm/prom.h
@@ -79,7 +79,7 @@ struct linux_mem_v0 {
 
 /* Arguments sent to the kernel from the boot prompt. */
 struct linux_arguments_v0 {
-	char *argv[8];
+	char * const argv[8];
 	char args[100];
 	char boot_dev[2];
 	int boot_dev_ctrl;
diff --git a/arch/sparc/lib/board.c b/arch/sparc/lib/board.c
index 11eea603c11..b776c21d603 100644
--- a/arch/sparc/lib/board.c
+++ b/arch/sparc/lib/board.c
@@ -63,7 +63,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 extern void timer_interrupt_init(void);
 extern void malloc_bin_reloc(void);
-extern int do_ambapp_print(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]);
+extern int do_ambapp_print(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]);
 extern int prom_init(void);
 
 #if defined(CONFIG__CMD_DOC)
diff --git a/arch/sparc/lib/bootm.c b/arch/sparc/lib/bootm.c
index c62cf57d80b..4c226a3a752 100644
--- a/arch/sparc/lib/bootm.c
+++ b/arch/sparc/lib/bootm.c
@@ -92,7 +92,7 @@ void arch_lmb_reserve(struct lmb *lmb)
 }
 
 /* boot the linux kernel */
-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)
 {
 	char *bootargs;
 	ulong initrd_start, initrd_end;