segmentation fault with big array size

Asked Sep 22 '16 at 14:37

Active Sep 22 '16 at 14:37

Viewed 33 times

The following piece of code compiles and runs without any problems:

#include <stdbool.h>
#define N 1000000

int main( void ){

  bool num[N];
  bool *p;
  for( p = num; p < &num[N]; )
    *p++ = true;
}

If, however, the value of N gets 10 times bigger (extra 0 -- ten million instead of one million),

#include <stdbool.h>
#define N 10000000

int main( void ){

  bool num[N];
  bool *p;
  for( p = num; p < &num[N]; )
    *p++ = true;
}

I get a segmentation fault on the line beginning with for. What is going on here? I don't see anything special about going from 1000000 to 10000000 (million to ten million).

asked Sep 22 '16 at 14:37

dmitry

Which OS ? And what's your stack size limitation ? (`ulimit -a` under linux) – Pierre Sep 22 '16 at 14:38
@dasblinkenlight Thanks, I now see that the problem is that the stack size has been exceeded. – dmitry Sep 22 '16 at 14:43
@Pierre Thanks -- I see that the problem is with the stack size limit. Thanks for your help! – dmitry Sep 22 '16 at 14:44
@dmitry Yes - that's it! Stack errors are notoriously hard to catch in C, especially when the allocation is done statically. – Sergey Kalinichenko Sep 22 '16 at 14:45

segmentation fault with big array size

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