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According to Tom G. Christensen on 9/2/2008 9:28 AM:
>> So, with my typo fixed, can you once again try those debugging steps, to
>> see if the breakpoint in overflow_handler trips?
>>
> It does not.
Which means I think we have isolated the bug to the recurse function.
Gnulib's version must be doing something that actually manages to recurse
with p == 0 in the final stack frame, then segv's dereferencing NULL
rather than triggering stack overflow:
static long
recurse (char *p)
{
char array[500];
array[0] = 1;
return *p + recurse (array);
}
Whereas libsigsegv's version goes to greater lengths to try to force a
pure stack overflow:
volatile int *
recurse_1 (int n, volatile int *p)
{
if (n < INT_MAX)
*recurse_1 (n + 1, p) += n;
return p;
}
int
recurse (volatile int n)
{
return *recurse_1 (n, &n);
}
I wonder if switching to libsigsegv's version will solve it. In the
meantime, I would be curious to see the disassembly of recurse, to see if
anything obvious appears as to why p==0 rather than a valid stack address
before the final stack frame. In gdb, you can get this with 'disas recurse'.
- --
Don't work too hard, make some time for fun as well!
Eric Blake [EMAIL PROTECTED]
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