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 --- common/cmd_i2c.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'common/cmd_i2c.c') diff --git a/common/cmd_i2c.c b/common/cmd_i2c.c index 8b9c2c9490e..fb9d3b038fa 100644 --- a/common/cmd_i2c.c +++ b/common/cmd_i2c.c @@ -178,7 +178,7 @@ static uint get_alen(char *arg) * i2c read {i2c_chip} {devaddr}{.0, .1, .2} {len} {memaddr} */ -static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { u_char chip; uint devaddr, alen, length; @@ -226,7 +226,7 @@ static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * Syntax: * i2c md {i2c_chip} {addr}{.0, .1, .2} {len} */ -static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { u_char chip; uint addr, alen, length; @@ -324,7 +324,7 @@ static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * Syntax: * i2c mw {i2c_chip} {addr}{.0, .1, .2} {data} [{count}] */ -static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { uchar chip; ulong addr; @@ -388,7 +388,7 @@ static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * Syntax: * i2c crc32 {i2c_chip} {addr}{.0, .1, .2} {count} */ -static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { uchar chip; ulong addr; @@ -452,7 +452,7 @@ static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) */ static int -mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]) +mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char * const argv[]) { uchar chip; ulong addr; @@ -575,7 +575,7 @@ mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]) * Syntax: * i2c probe {addr}{.0, .1, .2} */ -static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int j; #if defined(CONFIG_SYS_I2C_NOPROBES) @@ -619,7 +619,7 @@ static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * {length} - Number of bytes to read * {delay} - A DECIMAL number and defaults to 1000 uSec */ -static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { u_char chip; ulong alen; @@ -731,7 +731,7 @@ static void decode_bits (u_char const b, char const *str[], int const do_once) * Syntax: * i2c sdram {i2c_chip} */ -static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { enum { unknown, EDO, SDRAM, DDR2 } type; @@ -1208,7 +1208,7 @@ static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) #endif #if defined(CONFIG_I2C_MUX) -static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { int ret=0; @@ -1239,7 +1239,7 @@ static int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) #endif /* CONFIG_I2C_MUX */ #if defined(CONFIG_I2C_MULTI_BUS) -static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { int bus_idx, ret=0; @@ -1257,7 +1257,7 @@ static int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) } #endif /* CONFIG_I2C_MULTI_BUS */ -static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { int speed, ret=0; @@ -1274,17 +1274,17 @@ static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret; } -static int do_i2c_mm(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_mm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { return mod_i2c_mem (cmdtp, 1, flag, argc, argv); } -static int do_i2c_nm(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_nm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { return mod_i2c_mem (cmdtp, 0, flag, argc, argv); } -static int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); return 0; @@ -1312,7 +1312,7 @@ static cmd_tbl_t cmd_i2c_sub[] = { U_BOOT_CMD_MKENT(speed, 1, 1, do_i2c_bus_speed, "", ""), }; -static int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { cmd_tbl_t *c; -- cgit v1.2.3