mirror of
https://github.com/brain-hackers/u-boot-brain
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54841ab50c
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>
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|---|---|---|
| .. | ||
| xilinx_jtag | ||
| auto_update.c | ||
| auto_update.h | ||
| cmd_loadpci.c | ||
| esd405ep_nand.c | ||
| flash.c | ||
| fpga.c | ||
| lcd.c | ||
| lcd.h | ||
| misc.c | ||
| pci.c | ||
| s1d13505_640_480_16bpp.h | ||
| s1d13704_320_240_4bpp.h | ||
| s1d13705_320_240_8bpp.h | ||
| s1d13806_320_240_4bpp.h | ||
| s1d13806_640_480_8bpp.h | ||
| s1d13806_640_480_16bpp.h | ||
| s1d13806_1024_768_8bpp.h | ||