Is it possible to have the number of elements in the array larger than the size of the array, which is determined at compile time?

Question

In the linux kernel (version 4.8), "struct pid" is defined as follows (from the file: http://lxr.free-electrons.com/source/include/linux/pid.h ). Here, "numbers [1]" (on line 64) is a static array that can have only one element (due to the size of the array referred to as 1).

 57 struct pid
 58 {
 59         atomic_t count;
 60         unsigned int level;
 61         /* lists of tasks that use this pid */
 62         struct hlist_head tasks[PIDTYPE_MAX];
 63         struct rcu_head rcu;
 64         struct upid numbers[1];
 65 };

But then in the following code on line 319 and 320 (from the file: http://lxr.free-electrons.com/source/kernel/pid.c ), the array of "numbers" is inside the for loop as 'numbers [i]' . How is this even right, because the variable "i" cannot have any value other than zero without a segmentation error? I checked the value of "i" during the cycles to see if it will ever be greater than 1. Yes, but it is still, but I do not see any segmentation error. Did I miss something?

297 struct pid *alloc_pid(struct pid_namespace *ns)
298 {
299         struct pid *pid;
300         enum pid_type type;
301         int i, nr;
302         struct pid_namespace *tmp;
303         struct upid *upid;
304         int retval = -ENOMEM;
305 
306         pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
307         if (!pid)
308                 return ERR_PTR(retval);
309 
310         tmp = ns;
311         pid->level = ns->level;
312         for (i = ns->level; i >= 0; i--) {
313                 nr = alloc_pidmap(tmp);
314                 if (nr < 0) {
315                         retval = nr;
316                         goto out_free;
317                 }
318 
319                 pid->numbers[i].nr = nr;
320                 pid->numbers[i].ns = tmp;
321                 tmp = tmp->parent;
322         }

Answer 1

Is it possible to have the number of elements in an array larger than the size of the array that was determined at compile time?

. undefined , .

, "i" , , ?

; . . . undefined.

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C , seg. . .
C