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/trab/trab_fkt.c | 58 +++++++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 29 deletions(-) (limited to 'board/trab/trab_fkt.c') diff --git a/board/trab/trab_fkt.c b/board/trab/trab_fkt.c index 2df9a04407..268162e53a 100644 --- a/board/trab/trab_fkt.c +++ b/board/trab/trab_fkt.c @@ -115,21 +115,21 @@ int do_rotary_switch (void); int do_pressure (void); int do_v_bat (void); int do_vfd_id (void); -int do_buzzer (char **); -int do_led (char **); -int do_full_bridge (char **); -int do_dac (char **); +int do_buzzer (char * const *); +int do_led (char * const *); +int do_full_bridge (char * const *); +int do_dac (char * const *); int do_motor_contact (void); -int do_motor (char **); -int do_pwm (char **); -int do_thermo (char **); -int do_touch (char **); -int do_rs485 (char **); -int do_serial_number (char **); +int do_motor (char * const *); +int do_pwm (char * const *); +int do_thermo (char * const *); +int do_touch (char * const *); +int do_rs485 (char * const *); +int do_serial_number (char * const *); int do_crc16 (void); int do_power_switch (void); -int do_gain (char **); -int do_eeprom (char **); +int do_gain (char * const *); +int do_eeprom (char * const *); /* helper functions */ static void adc_init (void); @@ -150,8 +150,8 @@ static unsigned short updcrc(unsigned short icrc, unsigned char *icp, unsigned int icnt); #if defined(CONFIG_CMD_I2C) -static int trab_eeprom_read (char **argv); -static int trab_eeprom_write (char **argv); +static int trab_eeprom_read (char * const *argv); +static int trab_eeprom_write (char * const *argv); int i2c_write_multiple (uchar chip, uint addr, int alen, uchar *buffer, int len); int i2c_read_multiple ( uchar chip, uint addr, int alen, uchar *buffer, @@ -163,7 +163,7 @@ int i2c_read_multiple ( uchar chip, uint addr, int alen, uchar *buffer, * test. */ -int trab_fkt (int argc, char *argv[]) +int trab_fkt (int argc, char * const argv[]) { int i; @@ -585,7 +585,7 @@ int do_vfd_id (void) return 0; } -int do_buzzer (char **argv) +int do_buzzer (char * const *argv) { int counter; @@ -635,7 +635,7 @@ int do_buzzer (char **argv) } -int do_led (char **argv) +int do_led (char * const *argv) { struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio(); @@ -690,7 +690,7 @@ int do_led (char **argv) } -int do_full_bridge (char **argv) +int do_full_bridge (char * const *argv) { struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio(); @@ -724,7 +724,7 @@ static inline unsigned long tsc2000_to_uv (u16 val) } -int do_dac (char **argv) +int do_dac (char * const *argv) { int brightness; @@ -799,7 +799,7 @@ int do_motor_contact (void) return 0; } -int do_motor (char **argv) +int do_motor (char * const *argv) { struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio(); @@ -824,7 +824,7 @@ static void print_identifier (void) printf ("## FKT: "); } -int do_pwm (char **argv) +int do_pwm (char * const *argv) { int counter; struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio(); @@ -869,7 +869,7 @@ int do_pwm (char **argv) } -int do_thermo (char **argv) +int do_thermo (char * const *argv) { int channel, res; @@ -892,7 +892,7 @@ int do_thermo (char **argv) } -int do_touch (char **argv) +int do_touch (char * const *argv) { int x, y; @@ -1045,7 +1045,7 @@ static void touch_read_x_y (int *px, int *py) } -int do_rs485 (char **argv) +int do_rs485 (char * const *argv) { int timeout; char data[RS485_MAX_RECEIVE_BUF_LEN]; @@ -1110,7 +1110,7 @@ static int rs485_receive_chars (char *data, int timeout) } -int do_serial_number (char **argv) +int do_serial_number (char * const *argv) { #if defined(CONFIG_CMD_I2C) unsigned int serial_number; @@ -1249,7 +1249,7 @@ static unsigned short updcrc(unsigned short icrc, unsigned char *icp, } -int do_gain (char **argv) +int do_gain (char * const *argv) { int range; @@ -1265,7 +1265,7 @@ int do_gain (char **argv) } -int do_eeprom (char **argv) +int do_eeprom (char * const *argv) { #if defined(CONFIG_CMD_I2C) if (strcmp (argv[2], "read") == 0) { @@ -1286,7 +1286,7 @@ int do_eeprom (char **argv) } #if defined(CONFIG_CMD_I2C) -static int trab_eeprom_read (char **argv) +static int trab_eeprom_read (char * const *argv) { int i; int len; @@ -1331,7 +1331,7 @@ static int trab_eeprom_read (char **argv) return (0); } -static int trab_eeprom_write (char **argv) +static int trab_eeprom_write (char * const *argv) { int i; int len; -- cgit v1.2.1