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/common/cmd_bootm.c b/common/cmd_bootm.c
index 74ff205..bf77fb4 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -78,7 +78,7 @@
#if defined(CONFIG_CMD_IMLS)
#include <flash.h>
extern flash_info_t flash_info[]; /* info for FLASH chips */
-static int do_imls (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+static int do_imls (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
#endif
#ifdef CONFIG_SILENT_CONSOLE
@@ -90,9 +90,9 @@
static int fit_check_kernel (const void *fit, int os_noffset, int verify);
#endif
-static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag,int argc, char *argv[],
+static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag,int argc, char * const argv[],
bootm_headers_t *images, ulong *os_data, ulong *os_len);
-extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
/*
* Continue booting an OS image; caller already has:
@@ -102,7 +102,7 @@
* - loaded (first part of) image to header load address,
* - disabled interrupts.
*/
-typedef int boot_os_fn (int flag, int argc, char *argv[],
+typedef int boot_os_fn (int flag, int argc, char * const argv[],
bootm_headers_t *images); /* pointers to os/initrd/fdt */
#ifdef CONFIG_BOOTM_LINUX
@@ -121,8 +121,8 @@
#if defined(CONFIG_CMD_ELF)
static boot_os_fn do_bootm_vxworks;
static boot_os_fn do_bootm_qnxelf;
-int do_bootvx (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
-int do_bootelf (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+int do_bootvx (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+int do_bootelf (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
#endif
#if defined(CONFIG_INTEGRITY)
static boot_os_fn do_bootm_integrity;
@@ -206,7 +206,7 @@
#endif
}
-static int bootm_start(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+static int bootm_start(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
void *os_hdr;
int ret;
@@ -438,10 +438,10 @@
return 0;
}
-static int bootm_start_standalone(ulong iflag, int argc, char *argv[])
+static int bootm_start_standalone(ulong iflag, int argc, char * const argv[])
{
char *s;
- int (*appl)(int, char *[]);
+ int (*appl)(int, char * const []);
/* Don't start if "autostart" is set to "no" */
if (((s = getenv("autostart")) != NULL) && (strcmp(s, "no") == 0)) {
@@ -450,7 +450,7 @@
setenv("filesize", buf);
return 0;
}
- appl = (int (*)(int, char *[]))ntohl(images.ep);
+ appl = (int (*)(int, char * const []))ntohl(images.ep);
(*appl)(argc-1, &argv[1]);
return 0;
@@ -473,7 +473,7 @@
U_BOOT_CMD_MKENT(go, 0, 1, (void *)BOOTM_STATE_OS_GO, "", ""),
};
-int do_bootm_subcommand (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_bootm_subcommand (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int ret = 0;
int state;
@@ -576,7 +576,7 @@
/* bootm - boot application image from image in memory */
/*******************************************************************/
-int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong iflag;
ulong load_end = 0;
@@ -811,7 +811,7 @@
* pointer to image header if valid image was found, plus kernel start
* address and length, otherwise NULL
*/
-static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
+static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
bootm_headers_t *images, ulong *os_data, ulong *os_len)
{
image_header_t *hdr;
@@ -1012,7 +1012,7 @@
/* bootd - boot default image */
/*******************************************************************/
#if defined(CONFIG_CMD_BOOTD)
-int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int rcode = 0;
@@ -1047,7 +1047,7 @@
/* iminfo - print header info for a requested image */
/*******************************************************************/
#if defined(CONFIG_CMD_IMI)
-int do_iminfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_iminfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int arg;
ulong addr;
@@ -1134,7 +1134,7 @@
/* imls - list all images found in flash */
/*******************************************************************/
#if defined(CONFIG_CMD_IMLS)
-int do_imls (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_imls (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
flash_info_t *info;
int i, j;
@@ -1237,7 +1237,7 @@
/*******************************************************************/
#ifdef CONFIG_BOOTM_NETBSD
-static int do_bootm_netbsd (int flag, int argc, char *argv[],
+static int do_bootm_netbsd (int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
void (*loader)(bd_t *, image_header_t *, char *, char *);
@@ -1325,7 +1325,7 @@
#endif /* CONFIG_BOOTM_NETBSD*/
#ifdef CONFIG_LYNXKDI
-static int do_bootm_lynxkdi (int flag, int argc, char *argv[],
+static int do_bootm_lynxkdi (int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
image_header_t *hdr = &images->legacy_hdr_os_copy;
@@ -1347,7 +1347,7 @@
#endif /* CONFIG_LYNXKDI */
#ifdef CONFIG_BOOTM_RTEMS
-static int do_bootm_rtems (int flag, int argc, char *argv[],
+static int do_bootm_rtems (int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
void (*entry_point)(bd_t *);
@@ -1380,7 +1380,7 @@
#endif /* CONFIG_BOOTM_RTEMS */
#if defined(CONFIG_CMD_ELF)
-static int do_bootm_vxworks (int flag, int argc, char *argv[],
+static int do_bootm_vxworks (int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
char str[80];
@@ -1402,7 +1402,7 @@
return 1;
}
-static int do_bootm_qnxelf(int flag, int argc, char *argv[],
+static int do_bootm_qnxelf(int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
char *local_args[2];
@@ -1428,7 +1428,7 @@
#endif
#ifdef CONFIG_INTEGRITY
-static int do_bootm_integrity (int flag, int argc, char *argv[],
+static int do_bootm_integrity (int flag, int argc, char * const argv[],
bootm_headers_t *images)
{
void (*entry_point)(void);