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/renesas/sh7785lcr/rtl8169_mac.c | 4 ++-- board/renesas/sh7785lcr/selfcheck.c | 2 +- board/renesas/sh7785lcr/sh7785lcr.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'board/renesas') diff --git a/board/renesas/sh7785lcr/rtl8169_mac.c b/board/renesas/sh7785lcr/rtl8169_mac.c index 634efb42a..dae01ec77 100644 --- a/board/renesas/sh7785lcr/rtl8169_mac.c +++ b/board/renesas/sh7785lcr/rtl8169_mac.c @@ -298,7 +298,7 @@ void mac_read(void) data[0], data[1], data[2], data[3], data[4], data[5]); } -int do_set_mac(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_set_mac(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int i; unsigned char mac[6]; @@ -328,7 +328,7 @@ U_BOOT_CMD( "setmac - write MAC address for RTL8110SCL" ); -int do_print_mac(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_print_mac(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { if (argc != 1) { cmd_usage(cmdtp); diff --git a/board/renesas/sh7785lcr/selfcheck.c b/board/renesas/sh7785lcr/selfcheck.c index e803b3c9c..44247c850 100644 --- a/board/renesas/sh7785lcr/selfcheck.c +++ b/board/renesas/sh7785lcr/selfcheck.c @@ -108,7 +108,7 @@ static void test_pci(void) printf("PCI CN2 ID = %08x\n", readl(0xfe040220)); } -int do_hw_test(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_hw_test(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { char *cmd; diff --git a/board/renesas/sh7785lcr/sh7785lcr.c b/board/renesas/sh7785lcr/sh7785lcr.c index 9948d04ea..cad3905ff 100644 --- a/board/renesas/sh7785lcr/sh7785lcr.c +++ b/board/renesas/sh7785lcr/sh7785lcr.c @@ -56,7 +56,7 @@ int board_eth_init(bd_t *bis) } #if defined(CONFIG_SH_32BIT) -int do_pmb(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pmb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { /* clear ITLB */ writel(0x00000004, 0xff000010); -- cgit v1.2.3