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authorWolfgang Denk <wd@denx.de>2010-06-28 22:00:46 +0200
committerWolfgang Denk <wd@denx.de>2010-07-04 23:55:42 +0200
commit54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch)
tree400f22f0a12ff0ae6c472bed6ac648befc1744a2 /board/amcc/taihu
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
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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 <wd@denx.de> Acked-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'board/amcc/taihu')
-rw-r--r--board/amcc/taihu/lcd.c8
-rw-r--r--board/amcc/taihu/taihu.c4
-rw-r--r--board/amcc/taihu/update.c2
3 files changed, 7 insertions, 7 deletions
diff --git a/board/amcc/taihu/lcd.c b/board/amcc/taihu/lcd.c
index c3dc983..595dee3 100644
--- a/board/amcc/taihu/lcd.c
+++ b/board/amcc/taihu/lcd.c
@@ -129,7 +129,7 @@ int lcd_init(void)
return 0;
}
-static int do_lcd_clear (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+static int do_lcd_clear (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
out_8((u8 *) LCD_CMD_ADDR, 0x01);
udelay(2000);
@@ -137,7 +137,7 @@ static int do_lcd_clear (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return 0;
}
-static int do_lcd_puts (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+static int do_lcd_puts (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
if (argc < 2) {
cmd_usage(cmdtp);
@@ -148,7 +148,7 @@ static int do_lcd_puts (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return 0;
}
-static int do_lcd_putc (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+static int do_lcd_putc (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
if (argc < 2) {
cmd_usage(cmdtp);
@@ -159,7 +159,7 @@ static int do_lcd_putc (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return 0;
}
-static int do_lcd_cur (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+static int do_lcd_cur (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
ulong count;
ulong dir;
diff --git a/board/amcc/taihu/taihu.c b/board/amcc/taihu/taihu.c
index be381d6..1682cf7 100644
--- a/board/amcc/taihu/taihu.c
+++ b/board/amcc/taihu/taihu.c
@@ -78,7 +78,7 @@ int checkboard(void)
return 0;
}
-static int do_sw_stat(cmd_tbl_t* cmd_tp, int flags, int argc, char *argv[])
+static int do_sw_stat(cmd_tbl_t* cmd_tp, int flags, int argc, char * const argv[])
{
char stat;
int i;
@@ -97,7 +97,7 @@ U_BOOT_CMD (
""
);
-static int do_led_ctl(cmd_tbl_t* cmd_tp, int flags, int argc, char *argv[])
+static int do_led_ctl(cmd_tbl_t* cmd_tp, int flags, int argc, char * const argv[])
{
int led_no;
diff --git a/board/amcc/taihu/update.c b/board/amcc/taihu/update.c
index f9c31b3..b87eac4 100644
--- a/board/amcc/taihu/update.c
+++ b/board/amcc/taihu/update.c
@@ -98,7 +98,7 @@ static uchar buf_66[] =
0x00
};
-static int update_boot_eeprom(cmd_tbl_t* cmdtp, int flag, int argc, char *argv[])
+static int update_boot_eeprom(cmd_tbl_t* cmdtp, int flag, int argc, char * const argv[])
{
ulong len = 0x20;
uchar chip = CONFIG_SYS_I2C_EEPROM_ADDR;