diff options
author | Wolfgang Denk <wd@denx.de> | 2010-06-28 20:00:46 (GMT) |
---|---|---|
committer | Wolfgang Denk <wd@denx.de> | 2010-07-04 21:55:42 (GMT) |
commit | 54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch) | |
tree | 400f22f0a12ff0ae6c472bed6ac648befc1744a2 /board/netstar | |
parent | b218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff) | |
download | u-boot-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.xz |
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/netstar')
-rw-r--r-- | board/netstar/crcit.c | 2 | ||||
-rw-r--r-- | board/netstar/eeprom.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/board/netstar/crcit.c b/board/netstar/crcit.c index 0eef41a..a162649 100644 --- a/board/netstar/crcit.c +++ b/board/netstar/crcit.c @@ -71,7 +71,7 @@ static int do_crc(char *path, unsigned version) return EXIT_SUCCESS; } -int main(int argc, char **argv) +int main(int argc, char * const *argv) { if (argc == 2) { return do_crc(argv[1], 0); diff --git a/board/netstar/eeprom.c b/board/netstar/eeprom.c index aca4458..aa375a4 100644 --- a/board/netstar/eeprom.c +++ b/board/netstar/eeprom.c @@ -149,7 +149,7 @@ static int parse_element(char *s, unsigned char *buf, int len) return cnt; } -int eeprom(int argc, char *argv[]) +int eeprom(int argc, char * const argv[]) { int i, len, ret; unsigned char buf[58], *p; |