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 --- board/mpl/common/common_util.c | 2 +- board/mpl/mip405/cmd_mip405.c | 4 ++-- board/mpl/pati/cmd_pati.c | 4 ++-- board/mpl/pip405/cmd_pip405.c | 4 ++-- board/mpl/vcma9/cmd_vcma9.c | 4 ++-- 5 files changed, 9 insertions(+), 9 deletions(-) (limited to 'board/mpl') diff --git a/board/mpl/common/common_util.c b/board/mpl/common/common_util.c index 32bf244..a3722b2 100644 --- a/board/mpl/common/common_util.c +++ b/board/mpl/common/common_util.c @@ -428,7 +428,7 @@ void check_env(void) #endif /* #if !defined(CONFIG_PATI) */ -int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong size,src,ld_addr; int result; diff --git a/board/mpl/mip405/cmd_mip405.c b/board/mpl/mip405/cmd_mip405.c index cd93a7c..8ddb54d 100644 --- a/board/mpl/mip405/cmd_mip405.c +++ b/board/mpl/mip405/cmd_mip405.c @@ -30,12 +30,12 @@ extern void print_mip405_info(void); -extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); +extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]); /* ------------------------------------------------------------------------- */ -int do_mip405(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mip405(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong led_on; diff --git a/board/mpl/pati/cmd_pati.c b/board/mpl/pati/cmd_pati.c index 740881e..aba11d5 100644 --- a/board/mpl/pati/cmd_pati.c +++ b/board/mpl/pati/cmd_pati.c @@ -31,7 +31,7 @@ #include "pci_eeprom.h" extern void show_pld_regs(void); -extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); +extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]); extern void user_led0(int led_on); extern void user_led1(int led_on); @@ -355,7 +355,7 @@ static void display_pci_regs(void) } -int do_pati(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pati(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { if (strcmp(argv[1], "info") == 0) { diff --git a/board/mpl/pip405/cmd_pip405.c b/board/mpl/pip405/cmd_pip405.c index 6bbae89..554c8d1 100644 --- a/board/mpl/pip405/cmd_pip405.c +++ b/board/mpl/pip405/cmd_pip405.c @@ -30,12 +30,12 @@ extern void print_pip405_info(void); -extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); +extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]); /* ------------------------------------------------------------------------- */ -int do_pip405(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pip405(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong led_on,led_nr; diff --git a/board/mpl/vcma9/cmd_vcma9.c b/board/mpl/vcma9/cmd_vcma9.c index 0ee9595..0d5f46e 100644 --- a/board/mpl/vcma9/cmd_vcma9.c +++ b/board/mpl/vcma9/cmd_vcma9.c @@ -50,11 +50,11 @@ extern int vcma9_nanderase(void); extern int vcma9_nandread(ulong); extern int vcma9_nandwrite(ulong); extern int vcma9_dactest(int); -extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); +extern int do_mplcommon(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]); /* ------------------------------------------------------------------------- */ -int do_vcma9(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_vcma9(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { struct eth_device *dev; char cs8900_name[10]; -- cgit v1.1