test stack

test.c

-----------------------------------------
; getSP functions
   .text
   .globl getSP
   .type getSP, @function

getSP:
   MOVQ %rsp, %rax
   RET 
------------------------------------------
// test.c
#include <sys/time.h>
#include <sys/resource.h>
#include <stdio.h>
#include <alloca.h>

extern unsigned long long getSP(void);

long long i;
int main(int argc, char** argv) {
	char t;
	char a;
    
	struct rlimit rlim;
	for (;;) {
	getrlimit(RLIMIT_STACK, &rlim);
	printf("soft=%dK, hard=%dK\n",
		(int)rlim.rlim_cur/1024, 
		(int)rlim.rlim_max/1024);
	printf("t address: 0x%08llx\n", &t);
	printf("pid = %d", getpid());
	a = getchar();
	if (a == 'e') break;	
	for (i=0; i< 8192*1024 ; i ++ ) {
		alloca(1024);
		printf("%8lld kb, sp: 0x%08llx\n",i, getSP());
	}
	printf("sucess, i = %lld\n", i);
	}
}
----------------------
 result 
---------------------
 soft=8192K, hard=0K
t address: 0x7ffe30c6308e
pid = 12689
       0 kb, sp: 0x7ffe30c62c58
       1 kb, sp: 0x7ffe30c62848
       2 kb, sp: 0x7ffe30c62438
       3 kb, sp: 0x7ffe30c62028
       4 kb, sp: 0x7ffe30c61c18
       5 kb, sp: 0x7ffe30c61808
       6 kb, sp: 0x7ffe30c613f8