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>
Many of the help messages were not really helpful; for example, many
commands that take no arguments would not print a correct synopsis
line, but "No additional help available." which is not exactly wrong,
but not helpful either.
Commit ``Make "usage" messages more helpful.'' changed this
partially. But it also became clear that lots of "Usage" and "Help"
messages (fields "usage" and "help" in struct cmd_tbl_s respective)
were actually redundant.
This patch cleans this up - for example:
Before:
=> help dtt
dtt - Digital Thermometer and Thermostat
Usage:
dtt - Read temperature from digital thermometer and thermostat.
After:
=> help dtt
dtt - Read temperature from Digital Thermometer and Thermostat
Usage:
dtt
Signed-off-by: Wolfgang Denk <wd@denx.de>
Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
This commit gets rid of a huge amount of silly white-space issues.
Especially, all sequences of SPACEs followed by TAB characters get
removed (unless they appear in print statements).
Also remove all embedded "vim:" and "vi:" statements which hide
indentation problems.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Fixed some broken instances of "#ifdef CMD_CFG_IDE" too.
Those always evaluated TRUE, and thus were always compiled
even when IDE really wasn't defined/wanted.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
This is a compatibility step that allows both the older form
and the new form to co-exist for a while until the older can
be removed entirely.
All transformations are of the form:
Before:
#if (CONFIG_COMMANDS & CFG_CMD_AUTOSCRIPT)
After:
#if (CONFIG_COMMANDS & CFG_CMD_AUTOSCRIPT) || defined(CONFIG_CMD_AUTOSCRIPT)
Signed-off-by: Jon Loeliger <jdl@freescale.com>
