From 54841ab50c20d6fa6c9cc3eb826989da3a22d934 Mon Sep 17 00:00:00 2001 From: Wolfgang Denk Date: Mon, 28 Jun 2010 22:00:46 +0200 Subject: 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 Acked-by: Mike Frysinger --- include/bedbug/type.h | 2 +- include/command.h | 8 ++++---- include/common.h | 2 +- include/exports.h | 2 +- include/image.h | 4 ++-- include/kgdb.h | 2 +- include/vxworks.h | 2 +- 7 files changed, 11 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/bedbug/type.h b/include/bedbug/type.h index 38ee9ded73..b7b447b1fe 100644 --- a/include/bedbug/type.h +++ b/include/bedbug/type.h @@ -15,7 +15,7 @@ typedef struct { 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 55caa6eaf8..9144d69206 100644 --- a/include/command.h +++ b/include/command.h @@ -48,14 +48,14 @@ struct cmd_tbl_s { 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 @@ extern cmd_tbl_t __u_boot_cmd_end; /* 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 @@ extern int cmd_auto_complete(const char *const prompt, char *buf, int *np, int * * * 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 48f6a1a074..eddec22752 100644 --- a/include/common.h +++ b/include/common.h @@ -718,7 +718,7 @@ void show_boot_progress(int val); 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 9588bc94e4..1d79a3162c 100644 --- a/include/exports.h +++ b/include/exports.h @@ -35,7 +35,7 @@ int i2c_read (uchar, uint, int , uchar* , int); #endif #include -void app_startup(char **); +void app_startup(char * const *); #endif /* ifndef __ASSEMBLY__ */ diff --git a/include/image.h b/include/image.h index 366b622ccf..bcc08d1a73 100644 --- a/include/image.h +++ b/include/image.h @@ -328,12 +328,12 @@ int genimg_get_format (void *img_addr); 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 f543cd6e18..b6ba742ad3 100644 --- a/include/kgdb.h +++ b/include/kgdb.h @@ -55,7 +55,7 @@ extern int kgdb_getregs(struct pt_regs *, char *, int); 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 1633904bd8..917a9ff856 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 -- cgit v1.2.1