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/esd/pmc440/cmd_pmc440.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'board/esd/pmc440') diff --git a/board/esd/pmc440/cmd_pmc440.c b/board/esd/pmc440/cmd_pmc440.c index 476e940962..200d7ee30d 100644 --- a/board/esd/pmc440/cmd_pmc440.c +++ b/board/esd/pmc440/cmd_pmc440.c @@ -67,7 +67,7 @@ int fpga_interrupt(u32 arg) return rc; } -int do_waithci(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_waithci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { pmc440_fpga_t *fpga = (pmc440_fpga_t *)FPGA_BA; @@ -118,7 +118,7 @@ void dump_fifo(pmc440_fpga_t *fpga, int f, int *n) } } -int do_fifo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_fifo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { pmc440_fpga_t *fpga = (pmc440_fpga_t *)FPGA_BA; int i; @@ -269,7 +269,7 @@ U_BOOT_CMD( "'fifo' or 'address'" ); -int do_setup_bootstrap_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_setup_bootstrap_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong sdsdp[5]; ulong delay; @@ -344,7 +344,7 @@ U_BOOT_CMD( #include extern env_t *env_ptr; -int do_painit(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_painit(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { u32 pram, nextbase, base; char *v; @@ -404,7 +404,7 @@ U_BOOT_CMD( ); #endif /* CONFIG_PRAM */ -int do_selfreset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_selfreset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { in_be32((void*)CONFIG_SYS_RESET_BASE); return 0; @@ -415,7 +415,7 @@ U_BOOT_CMD( "" ); -int do_resetout(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_resetout(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { pmc440_fpga_t *fpga = (pmc440_fpga_t *)FPGA_BA; @@ -452,7 +452,7 @@ U_BOOT_CMD( "" ); -int do_inta(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_inta(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { if (is_monarch()) { printf("This command is only supported in non-monarch mode\n"); @@ -485,7 +485,7 @@ U_BOOT_CMD( ); /* test-only */ -int do_pmm(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_pmm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong pciaddr; @@ -518,7 +518,7 @@ U_BOOT_CMD( ); #if defined(CONFIG_SYS_EEPROM_WREN) -int do_eep_wren(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_eep_wren(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int query = argc == 1; int state = 0; -- cgit v1.2.1