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/include/bedbug/type.h b/include/bedbug/type.h
index 38ee9de..b7b447b 100644
--- a/include/bedbug/type.h
+++ b/include/bedbug/type.h
@@ -15,7 +15,7 @@
int current_bp;
struct pt_regs *regs;
- void (*do_break) (cmd_tbl_t *, int, int, char *[]);
+ void (*do_break) (cmd_tbl_t *, int, int, char * const []);
void (*break_isr) (struct pt_regs *);
int (*find_empty) (void);
int (*set) (int, unsigned long);
diff --git a/include/command.h b/include/command.h
index 55caa6e..9144d69 100644
--- a/include/command.h
+++ b/include/command.h
@@ -48,14 +48,14 @@
int maxargs; /* maximum number of arguments */
int repeatable; /* autorepeat allowed? */
/* Implementation function */
- int (*cmd)(struct cmd_tbl_s *, int, int, char *[]);
+ int (*cmd)(struct cmd_tbl_s *, int, int, char * const []);
char *usage; /* Usage message (short) */
#ifdef CONFIG_SYS_LONGHELP
char *help; /* Help message (long) */
#endif
#ifdef CONFIG_AUTO_COMPLETE
/* do auto completion on the arguments */
- int (*complete)(int argc, char *argv[], char last_char, int maxv, char *cmdv[]);
+ int (*complete)(int argc, char * const argv[], char last_char, int maxv, char *cmdv[]);
#endif
};
@@ -67,7 +67,7 @@
/* common/command.c */
int _do_help (cmd_tbl_t *cmd_start, int cmd_items, cmd_tbl_t * cmdtp, int
- flag, int argc, char *argv[]);
+ flag, int argc, char * const argv[]);
cmd_tbl_t *find_cmd(const char *cmd);
cmd_tbl_t *find_cmd_tbl (const char *cmd, cmd_tbl_t *table, int table_len);
@@ -83,7 +83,7 @@
*
* All commands use a common argument format:
*
- * void function (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+ * void function (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
*/
typedef void command_t (cmd_tbl_t *, int, int, char *[]);
diff --git a/include/common.h b/include/common.h
index 48f6a1a..eddec22 100644
--- a/include/common.h
+++ b/include/common.h
@@ -718,7 +718,7 @@
int cpu_status(int nr);
int cpu_reset(int nr);
int cpu_disable(int nr);
-int cpu_release(int nr, int argc, char *argv[]);
+int cpu_release(int nr, int argc, char * const argv[]);
#endif
#endif /* __ASSEMBLY__ */
diff --git a/include/exports.h b/include/exports.h
index 9588bc9..1d79a31 100644
--- a/include/exports.h
+++ b/include/exports.h
@@ -35,7 +35,7 @@
#endif
#include <spi.h>
-void app_startup(char **);
+void app_startup(char * const *);
#endif /* ifndef __ASSEMBLY__ */
diff --git a/include/image.h b/include/image.h
index 366b622..bcc08d1 100644
--- a/include/image.h
+++ b/include/image.h
@@ -328,12 +328,12 @@
int genimg_has_config (bootm_headers_t *images);
ulong genimg_get_image (ulong img_addr);
-int boot_get_ramdisk (int argc, char *argv[], bootm_headers_t *images,
+int boot_get_ramdisk (int argc, char * const argv[], bootm_headers_t *images,
uint8_t arch, ulong *rd_start, ulong *rd_end);
#ifdef CONFIG_OF_LIBFDT
-int boot_get_fdt (int flag, int argc, char *argv[], bootm_headers_t *images,
+int boot_get_fdt (int flag, int argc, char * const argv[], bootm_headers_t *images,
char **of_flat_tree, ulong *of_size);
int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base,
char **of_flat_tree, ulong *of_size);
diff --git a/include/kgdb.h b/include/kgdb.h
index f543cd6..b6ba742 100644
--- a/include/kgdb.h
+++ b/include/kgdb.h
@@ -55,7 +55,7 @@
extern void kgdb_putreg(struct pt_regs *, int, char *, int);
extern void kgdb_putregs(struct pt_regs *, char *, int);
extern int kgdb_trap(struct pt_regs *);
-extern void kgdb_breakpoint(int argc, char *argv[]);
+extern void kgdb_breakpoint(int argc, char * const argv[]);
/* these functions are provided by the platform serial driver */
extern void kgdb_serial_init(void);
diff --git a/include/vxworks.h b/include/vxworks.h
index 1633904..917a9ff 100644
--- a/include/vxworks.h
+++ b/include/vxworks.h
@@ -24,7 +24,7 @@
#ifndef _VXWORKS_H_
#define _VXWORKS_H_
-int do_bootvx(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+int do_bootvx(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
/*
* Use bootaddr to find the location in memory that VxWorks