Hi Bart,
1st, I hope you live in a different timezone.
at 4:07 we all should be in bed ;)
> so in the end the issue is a stack overflow:
nice find :))
> filenames on the stack
> overflow into a const buffer used by strtok. I had raised it from 2K
> to 4K back in January but that is not enough.
if not exist unistd.c~ ren unistd.c *.c~
needs 4600 bytes (see below)
so far all retested
TESTS KE2041
TESTS JED
TESTS PICOC
work, but require at least 4600 byte stack
> Since Blair Campbell's LFN work in 2006 cmd_rename() which calls
> fillFnam() together use at least 13 ~256-sized fixed sized filename
> buffers, which is already 3.3K right there.
maybe finally found the reason nobody wants to use this code
fixing bugs is not sexy. leaving bugs as an exercise to the reader.
> You can raise the stack for OW in shell/wlinker.bat to at least 6K,
> maybe 8K is better to be more on the safe side.
so far found code that uses 4600 byte
I will take 8k as it doesn't matter much as everything is swapped out anyway.
> Or alternatively
> redesign that code a bit to use less stack space.
> Or also just compile without -s to enable stack checking and see what
> that gives. I'll do some more tests tomorrow.
I added the following to shell\command.c
int process_input(int xflag, char *commandline)
{
...
if(tracethisline)
--tracemode;
}
+ {
+ extern int stack_check(const char *commandline);
+
+ stack_check(parsedline);
+ }
}
while (!canexit || !exitflag);
and later
static void * stack_bottom, * stack_unused;
void stack_check_init()
{
char current_stack_location;
void **barrier;
//
place a barrier at the
//
bottom of the stack
// code
assumes 8 K right now
stack_bottom = ¤t_stack_location - 8*1024 + 50;
stack_unused = (char*)(¤t_stack_location);
for (barrier = stack_bottom; barrier < stack_unused ; barrier++)
{
*barrier = barrier;
}
}
int stack_check(const char *commandline)
{
void **barrier;
for (barrier = stack_bottom; barrier < stack_unused; barrier++)
{
if (*barrier != barrier)
{
break;
}
}
if (barrier < stack_unused)
{
unsigned stack_left = (char*)barrier - (char*)stack_bottom;
if (stack_left < 5000)
{
printf("stack left %u after
<%.60s>\n",stack_left,commandline);
cgetchar();
}
stack_unused = barrier;
}
return 0;
}
int main(void)
{
/*
* * main function
*/
stack_check_init();
....
Tom
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